Mariana C. Castells, M.D.

Specialty: Allergy and Immunology

Brigham and Women’s Hospital

850 Boylston Street
Suite 540
Chestnut Hill, MA 02467


The following is a list of recent publications for which this Partners Asthma Center physician has been cited as an author in PubMed databases. Study abstracts have been provided for your convenience.

Abonia, J. P. and M. C. Castells (2002). "Common variable immunodeficiency." Allergy Asthma Proc 23(1): 53-7.

We present a case report and review of the literature that illustrates many key features of patients with common variable immunodeficiency (CVID). These patients frequently present with repeated infections with a variety of different microorganisms. Recurrent sinopulmonary infections can lead to serious chronic complications such as bronchiectasis, and gastrointestinal infections can result in malabsorption. In addition to serious infection, CVID is associated with a number of comorbid disorders including a variety of autoimmune diseases and neoplasms. Here, we provide an illustrative case report and discuss the primary features and therapy for patients with CVID.

Castells, M. (1997). "Update on mast cells and mast cell precursors and hypersensitivity responses." Allergy Asthma Proc 18(5): 287-92.

Mast cells are important effector cells providing granule and membrane mediators as well as cytokines in allergic and inflammatory diseases. The study of surface molecules such as immunoglobulin receptors and adhesion molecules has greatly expanded the functional implications of mast cells. An active role for mast cells in antigen presentation to T cells has recently been shown, and direct interaction between mast cells and B cells providing signals for specific IgE production has been demonstrated. Functional receptors other than the high affinity IgE (Fc epsilon RI) have been implicated in the anaphylactic response of IgE-deficient mice, suggesting that IgG receptors present in mast cells may be involved in immediate hypersensitivity reactions. Although metachromatic mast cells are easily recognized in peripheral tissues, little is known about the phenotype of mast cell precursors, their fate from the bone marrow to the tissues, migration and homing processes, and factors and adhesion molecules that affect those processes. This review will describe the most recent studies in mouse and human mast cell biology and ontogeny.

Castells, M. and K. F. Austen (2002). "Mastocytosis: mediator-related signs and symptoms." Int Arch Allergy Immunol 127(2): 147-52.

Patients with systemic mastocytosis present symptoms related to the tissue response to the release of mediators from mast cells and to the local mast cell burden. Such patients often have a history of chronic and acute mediator-related symptoms. Most patients have indolent disease with a good prognosis and a normal life span. Symptoms can include pruritus, flushing, syncope, gastric distress, nausea and vomiting, diarrhea, bone pain and neuropsychiatric symptoms, most of which are controlled by medication. Because there is no current cure for mastocytosis, successful therapeutic interventions rely on the recognition of mediator-related symptoms and their treatment, and established intervention approaches for the relatively uncommon leukemic concomitants. Efforts to link a particular mast cell-derived mediator to some aspect of the symptom complex depend on the known actions of the mediator and the efficacy of target-based interventions.

Castells, M. and J. Boyce (1998). "Transfer of peanut allergy by a liver allograft." N Engl J Med 338(3): 202-3.

Castells, M. and L. B. Schwartz (1988). "Tryptase levels in nasal-lavage fluid as an indicator of the immediate allergic response." J Allergy Clin Immunol 82(3 Pt 1): 348-55.

To examine mast cell involvement in allergic rhinitis, levels of tryptase, a specific marker for mast cell activation, and histamine, a marker of mast cell and basophil activation, were measured in nasal-lavage fluid after nasal-allergen challenge. Twelve atopic subjects with allergic rhinitis and five nonatopic subjects were challenged with timothy grass or ragweed pollen at increasing doses of allergen. Tryptase and histamine levels were determined by an ELISA and radioenzyme assay, respectively; clinical responses were measured by assessment of sneezing, rhinorrhea, nasal congestion, and ocular tearing or itching. A positive clinical response was observed in seven of the atopic subjects and in none of the nonatopic subjects. Tryptase levels increased at least sevenfold higher than baseline levels in 100% of the atopic clinical responders and reached a maximum at the same dose of allergen where clinical symptoms were maximal. In contrast, histamine levels were only threefold or greater elevated in five of seven atopic clinical responders at this dose of allergen. (Histamine levels were lower in one subject and were only 50% higher in another subject than the corresponding baseline value.) Histamine levels and symptom scores were maximal at the same dose of allergen in only four of seven clinical responders. Overlap of peak mediator levels in subjects without a clinical response with those of the clinical responders occurred only in the case of histamine. Tryptase levels in nasal-lavage fluid appear promising as a useful indicator of allergic reactions and indicate that mast cell activation is the major factor in the immediate nasal-allergic response.

Castells, M. C. (1994). "Surface makers for mast cell subtypes: low affinity IgG receptors and gp49 family." Allerg Immunol (Paris) 26(4): 127-31.

Members of the Immunoglobulin Superfamily (Ig) present in the surface of rodent mast cells include the high affinity IgE receptor (Fc epsilon RI), the low affinity receptors for the Fc portion of IgG, the Fc gamma RII family and Fc gamma RIII as well as the recently cloned gp49 family that includes three members gp49A, gp49B1 and gp49B2. Fc epsilon RI and Fc gamma RIII are members of the multi-chain immune recognition receptor (MIRR) family since they possess a multimeric structure in which the signal transducing chains (gamma chains) contain six acids that conform the Antigen Homology Receptor 1 Motif (ARH1M), also present in the T cell receptor (TCR) transducing chains. gp49B1, gp49B2 and the FC gamma R family are monomeric chains that also contain the partial of full AHR1M motif in their cytoplasmic domain indicating the capability for signal transduction through tyrosine phosphorylation and the possibility of cell activation with mediator (s) or cytokine (s) release. Distribution of the Fc gamma R receptors and gp49 family members varies in the different stages of mast cell differentiation and maturation.

Castells, M. C. (2004). "Mastocytosis: classification, diagnosis, and clinical presentation." Allergy Asthma Proc 25(1): 33-6.

Mastocytosis comprises several diseases characterized by an abnormal increase in tissue mast cells. Cutaneous mastocytosis (CM) is the most common form of mastocytosis, affects predominantly children, and presents as a mast cell hyperplasia limited to the skin. Systemic mastocytosis (SM) comprises multiple distinct entities in which mast cells in filtrate the skin and/or other organs. The diagnosis of SM is based on the presence of one major criterion and one minor criterion or three minor criteria. Major criteria include the presence of multifocal dense infiltrates of > 15 mast cells in bone marrow and/or other extracutaneous organs. Four minor criteria include the presence of elevated serum alpha-tryptase levels > 20 ng/mL, the expression of CD2 and CD25 surface markers in c-kit-positive mast cells from bone marrow or other organs, the presence of a c-kit mutations on bone marrow and/or other tissues mast cells, and the presence of > 25% abnormal spindle-shaped mast cells in bone marrow and/or tissues. Symptoms of CM include pruritus, flushing urticaria, and dermatographism. Symptoms of SM include cutaneous symptoms in association with syncope, gastric distress, nausea and vomiting, diarrhea, bone pain, and neuropsychiatric symptoms. Activating and nonactivating mutations of c-kit (Asp816Val) are seen in adult SM and in some pediatric CM (Gly839Lys), indicating a clonal dysregulation. There is no cure for mastocytosis but the majority of pediatric CM regress at puberty. Women with mastocytosis are fertile and pregnancy and delivery have been successful by blocking mast cell-mediated symptoms. Symptomatic treatment aimed at reducing the effect of mediators is effective with antihistamines and mast cell-stabilizing agents such as sodium cromolyn. To reduce mast cell burden, interferon alpha, steroids, and purine analogs have been used with varying results. Future directions include tyrosine kinase inhibitors and bone marrow transplant.

Castells, M. C., D. S. Friend, et al. (1996). "The presence of membrane-bound stem cell factor on highly immature nonmetachromatic mast cells in the peripheral blood of a patient with aggressive systemic mastocytosis." J Allergy Clin Immunol 98(4): 831-40.

BACKGROUND: Systemic mastocytosis is characterized by mast cell infiltration of bone marrow and tissues in the absence of identified circulating bone marrow-derived progenitors. A 58-year-old man was first seen with aggressive systemic mastocytosis manifested by urticaria pigmentosa, hepatosplenomegaly, generalized bone lesions, anemia, thrombocytopenia, monoclonal gammopathy, and increased urine histamine levels.

OBJECTIVES AND METHODS: A rapidly progressive anemia and thrombocytopenia dictated a splenectomy. We sought to identify the mast cell progenitors in the peripheral blood and to provide evidence of their maturation in tissues with immunohistochemical and ultrastructural analyses.

RESULTS: The peripheral blood contained 1% to 3% nonmetachromatic mononuclear cells with eccentric nuclei that expressed the mast cell proteases, tryptase and carboxypeptidase A, along with c-kit, stem cell factor (SCF), and high-affinity IgE receptor (Fc epsilon RI), but not chymase. Similar mononuclear cells colocalized in the spleen and lymph nodes with mature, metachromatic mast cells that expressed tryptase, chymase, carboxypeptidase A, c-kit, SCF, and Fc epsilon RI. Electron microscopy disclosed, at each site, a mature mast cell population with electron-dense, scroll-poor granules.

CONCLUSIONS: The peripheral blood of a patient with aggressive systemic mastocytosis contained immature mononuclear cells of the mast cell lineage that express c-kit, SCF, tryptase, carboxypeptidase A, and Fc epsilon RI. These cells were also found in the skin, spleen, and lymph nodes where they presumably expand, differentiate, and mature, assuming the mast cell phenotype for those tissues characterized by metachromasia, expression of a full range of mast cell-related secretory granule proteases, and ultrastructural appearance. The presence of SCF on the surface membrane of the circulating, highly immature mast cells suggests an autocrine regulation of the c-kit-SCF interaction.

Castells, M. C., R. F. Horan, et al. (1999). "Exercise-induced anaphylaxis (EIA)." Clin Rev Allergy Immunol 17(4): 413-24.

EIA is a unique physical allergy with increasing incidence as the exercising population increases. Clinical features are indistinguishable from IgE-mediated anaphylaxis in which the offending allergens are known (food or insect stings). Recognition of the association with exercise is crucial. A wide variety of exercises can induce the symptoms, including brisk walking. Symptoms may not be always reproduced by the same amount and type of exercise in a given patient suggesting that associated factors are also needed. Food is an associated factor recognized with increasing frequency, and in the last 5 yr, wheat has been the most frequently associated. Avoidance of the known associated factors, such as food or nonsteroidals, induces a long-lasting remission of EIA. Treatment does not differ from that of anaphylaxis of any other cause. General recommendations for patients with EIA include avoidance of exercise 4-6 h after eating, avoidance of aspirin and nonsteroidals before exercise, and avoidance of all associated conditions known to trigger attacks in each particular patient. Discontinuation of exercise at the earliest warning symptom is critical.

Castells, M. C., R. F. Horan, et al. (2003). "Exercise-induced Anaphylaxis." Curr Allergy Asthma Rep 3(1): 15-21.

Exercise-induced anaphylaxis has been recognized with increasing frequency since its original description in 1980. Recent studies suggest food-induced reactions may occur frequently in this syndrome, which is a mast cell-dependent phenomenon. In this article, the clinical manifestations of exercise-induced anaphylaxis are reviewed, and food-related factors contributing to the disorder are considered.

Castells, M. C., A. M. Irani, et al. (1987). "Evaluation of human peripheral blood leukocytes for mast cell tryptase." J Immunol 138(7): 2184-9.

Murine monoclonal and goat polyclonal antibodies against tryptase, the dominant neutral protease and protein component in secretory granules of human mast cells, were used to assess the presence of tryptase in peripheral leukocytes. Carnoy's fluid-fixed cytocentrifuge preparations of enriched populations of lymphocytes, monocytes, eosinophils, and neutrophils showed no reactivity with anti-tryptase antibodies by a sensitive indirect immunoperoxidase procedure. Dispersed human lung mast cells showed strong granular cytoplasmic staining with both antibodies, whereas only approximately 50% of the peripheral blood basophils detectable with Wright's stain were detected with anti-tryptase antibodies, and these showed a staining pattern that was faint, granular, and cytoplasmic at high concentrations of antibody. At lower antibody concentrations mast cell staining was still intense, whereas basophils were not stained. Extracts of neutrophils and lymphocytes of up to 90% purity had undetectable amounts of tryptase by an ELISA sandwich immunoassay, as well as undetectable enzymatic activity with tosyl-L-gly-pro-lys-p-nitroanilide (a sensitive substrate for tryptase) in the presence of soybean trypsin inhibitor. Extracts of basophil-enriched (6 to 50% purity) preparations contained 0.046 +/- 0.013 pg of tryptase per basophil by the immunoassay along with 2 X 10(-9) +/- 0.8 X 10(-9) U of tryptase-like enzyme activity per basophil, compared with corresponding values of 12 pg, 480 X 10(-9) U of tryptase per human lung mast cell. Thus very small amounts of tryptase are present in human basophils (approximately 0.4% of that found in mast cells), but not in other peripheral leukocytes.

Castells, M. C., L. B. Klickstein, et al. (2001). "gp49B1-alpha(v)beta3 interaction inhibits antigen-induced mast cell activation." Nat Immunol 2(5): 436-42.

We have identified the integrin alpha(v)beta3 as a ligand for mouse gp49B1, thus identifying a new class of ligand for a member of the family of inhibitory immunoreceptors that bear C2-type immunoglobulin-like domains. The specific interaction was shown by both cell-protein and cell-cell binding assays. In addition, we found that the interaction of alpha(v)beta3 with gp49B1 on bone marrow-derived mouse mast cells inhibited antigen-induced immunoglobulin E-mediated cell activation. Because neither gp49B1 nor alpha(v)beta3 exhibit substantive allelic variation, their newly appreciated interaction may reflect an innate pathway for down-regulating the activity of mast cells.

Castells, M. C., C. Pascual, et al. (1986). "Allergy to white potato." J Allergy Clin Immunol 78(6): 1110-4.

Allergy to potato is uncommon, and even more uncommon is allergy to potato pollen. The occurrence of both phenomena in the same patient made it possible to study cross-reactivity patterns of potato antigens. An 11-year-old girl, exclusively breast-fed for her first 4 months, developed anaphylactic symptoms after ingestion of potato at 5 months of age when she was fed potato for the first time. Subsequently, she developed urticaria, angioedema, and respiratory and systemic symptoms on contact with potatoes, ingestion of potatoes, and exposure to cooking potatoes or potato pollen. Three allergenic extracts from potato pulp, peel, and pollen were prepared. Polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate and isoelectrofocusing of the three extracts were performed. IgE-mediated allergy to these extracts was demonstrated by means of immediate skin test reactivity, positive passive transfer, RAST, RAST inhibition, and leukocyte histamine release. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the pulp extract followed by electroblotting and autoradiography demonstrated specific IgE antibodies directed against several proteins ranging from 14,000 to 40,000 daltons.

Castells, M. C., X. Wu, et al. (1994). "Cloning of the gp49B gene of the immunoglobulin superfamily and demonstration that one of its two products is an early-expressed mast cell surface protein originally described as gp49." J Biol Chem 269(11): 8393-401.

gp49 was originally defined as a 49-kDa surface glycoprotein preferentially expressed on mouse interleukin-3-dependent, bone marrow-derived mast cells, which are immature progenitor cells. A previously cloned cDNA (gp49A) indicated that gp49 was a member of the immunoglobulin (Ig) superfamily, and genomic DNA analysis indicated that two genes might encode a gp49 family. We have now characterized a 5.6-kilobase pair gene, gp49B, that encodes two novel gp49 cDNAs, gp49B1 and gp49B2. The two cDNAs are identical except that gp49B2 is missing exon 6, which encodes a predicted transmembrane domain. In contrast to gp49A, gp49B1 and gp49B2 have 32 additional amino acids at their C termini containing 4 of the 6 consensus amino acids of the antigen receptor homology 1 motif found on several signal-transducing members of the Ig superfamily. When COS-7 cells were transfected with either the gp49B1 or gp49B2 cDNA, only the gp49B1 transfectants bound the B23.1 monoclonal antibody that originally defined gp49. Reverse transcriptase-polymerase chain reaction analysis of the transfectants established that both transcripts were expressed, suggesting that the product of the gp49B2 transcript was not inserted in the plasma membrane. Thus, cloning of the gp49B gene has established the organization of one of the gp49 genes and provided evidence of alternate splicing of transcripts from that gene.

Escribano, L., C. Akin, et al. (2002). "Mastocytosis: current concepts in diagnosis and treatment." Ann Hematol 81(12): 677-90.

Mastocytosis consists of a group of disorders characterized by a pathologic increase in mast cells in tissues including skin, bone marrow, liver, spleen, and lymph nodes. Mastocytosis is a rare disease. Because of this, general practitioners have limited exposure to its clinical manifestations, diagnosis, classification, and management. Diagnosis of mastocytosis is suspected on clinical grounds and is established by histopathologic examination of involved tissues such as skin and bone marrow. The most common clinical sign of mastocytosis is the presence of typical skin lesions of urticaria pigmentosa. Most patients experience symptoms related to mast cell mediator release, and prevention of the effects of these mediators on tissues constitutes the major therapeutic goal in the management of mastocytosis. Despite recent advances in knowledge about the pathophysiology, diagnosis, and classification of mastocytosis, a curative treatment for mastocytosis does not now exist. Management of patients within all categories of mastocytosis includes: (1) a careful counseling of patients (parents in pediatric cases) and care providers, (2) avoidance of factors triggering acute mediator release, (3) treatment of acute mast cell mediator release, (4) treatment of chronic mast cell mediator release, and if indicated (5) an attempt to treat organ infiltration by mast cells. The goal of this manuscript is to provide an overview of the mediators produced and released by mast cells, the diagnostic criteria for the different variants of mastocytosis, and the treatment options currently available.

Feldweg, A. M., C. W. Lee, et al. (2005). "Rapid desensitization for hypersensitivity reactions to paclitaxel and docetaxel: a new standard protocol used in 77 successful treatments." Gynecol Oncol 96(3): 824-9.

OBJECTIVE: Administration of paclitaxel is associated with hypersensitivity reactions (HSRs) in up to 9% of patients despite premedication. The purpose of this study was to evaluate the effectiveness of a standardized desensitization protocol in patients with HSRs to taxanes, based on our experience with carboplatin desensitization.

METHODS: We analyzed seventeen consecutive patients with documented HSRs to taxanes who required continued treatment with a taxane agent. The patients were treated with either paclitaxel or docetaxel using the 6- to 7-h standard desensitization protocol.

RESULTS: Seventeen patients who previously had severe taxane HSRs successfully completed 77 planned cycles of desensitization to paclitaxel or docetaxel, 72 of which were without reactions. Four patients developed HSRs during the desensitization protocol that were much less severe than their original HSRs and tolerated the re-administration of infusions without further reactions. Of these four patients, the first had palmar erythema 8 h after her 1st desensitization. The second patient had mild abdominal pain during her 1st cycle, and the third patient developed mild chest burning during her 2nd and 4th cycles. These three patients also completed subsequent desensitization cycles without reactions. The fourth patient developed a delayed urticaria reaction and gastrointestinal symptoms 6 h after completing her 1st desensitization. She elected to be treated with an alternative chemotherapy and did not receive additional courses of desensitization.

CONCLUSION: The rapid standard desensitization protocol provides a safe and effective strategy for the re-administration of paclitaxel or docetaxel even after severe HSRs.

Hepner, D. L. and M. C. Castells (2003). "Anaphylaxis during the perioperative period." Anesth Analg 97(5): 1381-95.

Anesthesiologists use a myriad of drugs during the provision of an anesthetic. Many of these drugs have side effects that are dose related, and some lead to severe immune-mediated adverse reactions. Anaphylaxis is the most severe immune-mediated reaction; it generally occurs on reexposure to a specific antigen and requires the release of proinflammatory mediators. Anaphylactoid reactions occur through a direct non-immunoglobulin E-mediated release of mediators from mast cells or from complement activation. Muscle relaxants and latex account for most cases of anaphylaxis during the perioperative period. Symptoms may include all organ systems and present with bronchospasm and cardiovascular collapse in the most severe cases. Management of anaphylaxis includes discontinuation of the presumptive drug (or latex) and anesthetic, aggressive pulmonary and cardiovascular support, and epinephrine. Although a serum tryptase confirms the diagnosis of an anaphylactic reaction, the offending drug can be identified by skin-prick, intradermal testing, or serologic testing. Prevention of recurrences is critical to avoid mortality and morbidity.

Hepner, D. L. and M. C. Castells (2003). "Latex allergy: an update." Anesth Analg 96(4): 1219-29.

Hepner, D. L., M. C. Castells, et al. (2003). "Should local anesthetic allergy testing be routinely performed during pregnancy?" Anesth Analg 97(6): 1853-4; author reply 1854.

Katz, H. R., E. Vivier, et al. (1996). "Mouse mast cell gp49B1 contains two immunoreceptor tyrosine-based inhibition motifs and suppresses mast cell activation when coligated with the high-affinity Fc receptor for IgE." Proc Natl Acad Sci U S A 93(20): 10809-14.

Mouse mast cells express gp49B1, a cell-surface member of the Ig superfamily encoded by the gp49B gene. We now report that by ALIGN comparison of the amino acid sequence of gp49B1 with numerous receptors of the Ig superfamily, a newly recognized family has been established that includes gp49B1, the human myeloid cell Fc receptor for IgA, the bovine myeloid cell Fc receptor for IgG2, and the human killer cell inhibitory receptors expressed on natural killer cells and T lymphocyte subsets. Furthermore, the cytoplasmic domain of gp49B1 contains two immunoreceptor tyrosine-based inhibition motifs that are also present in killer cell inhibitory receptors; these motifs downregulate natural killer cell and T-cell activation signals that lead to cytotoxic activity. As assessed by flow cytometry with transfectants that express either gp49B1 or gp49A, which are 89% identical in the amino acid sequences of their extracellular domains, mAb B23.1 was shown to recognize only gp49B1. Coligation of mAb B23.1 bound to gp49B1 and IgE fixed to the high-affinity Fc receptor for IgE on the surface of mouse bone marrow-derived mast cells inhibited exocytosis in a dose-related manner, as defined by the release of the secretory granule constituent beta-hexosaminidase, as well as the generation of the membrane-derived lipid mediator, leukotriene C4. Thus, gp49B1 is an immunoreceptor tyrosine-based inhibition motif-containing integral cell-surface protein that downregulates the high-affinity Fc receptor for IgE-mediated release of proinflammatory mediators from mast cells. Our findings establish a novel counterregulatory transmembrane pathway by which mast cell activation can be inhibited.

Kaye, R. E., D. A. Fruman, et al. (1992). "Effects of cyclosporin A and FK506 on Fc epsilon receptor type I-initiated increases in cytokine mRNA in mouse bone marrow-derived progenitor mast cells: resistance to FK506 is associated with a deficiency in FK506-binding protein FKBP12." Proc Natl Acad Sci U S A 89(18): 8542-6.

The inhibitory effects of cyclosporin A (CsA) and FK506 on Fc epsilon receptor type I-initiated increases in cytokine mRNA and the expression of their intracellular binding proteins were studied in interleukin 3 (IL-3)-dependent, mouse bone marrow-derived mast cells (BMMCs). In BMMCs sensitized with IgE anti-trinitrophenyl, CsA inhibited trinitrophenylated bovine serum albumin-induced increases in mRNA for IL-1 beta, tumor necrosis factor alpha (TNF-alpha), and IL-6 in a dose-related manner (IC50 values of 4, 65, and 130 nM, respectively). FK506 did not inhibit hapten-specific increases of mRNA for TNF-alpha or IL-6, and for IL-1 beta the IC50 was greater than 50-fold higher than that of CsA. Neither agent inhibited exocytosis of the endogenous secretory granule mediators beta-hexosaminidase and histamine at the IC50 values for inhibition of increases in cytokine mRNA. BMMCs expressed cyclophilin, and CsA inhibited the phosphatase activity of cellular calcineurin with an IC50 of approximately 8 nM. That CsA inhibited IL-1 beta mRNA accumulation in IgE-activated BMMCs with an IC50 similar to that for inhibition of calcineurin activity, whereas the IC50 values were approximately 20-fold higher for the inhibition of TNF-alpha and IL-6 mRNA, suggests that the induction of TNF-alpha and IL-6 is less dependent upon calcineurin activity than is the induction of IL-1 beta. BMMCs were deficient in the 12-kDa FK506-binding protein FKBP12, but not FKBP13, as assessed by RNA and protein blot analyses. FK506 did not inhibit calcineurin phosphatase activity in BMMCs, even at drug concentrations of 1000 nM. The resistance of BMMCs to inhibition of Fc epsilon receptor type I-mediated increases in cytokine mRNA by FK506 is most likely due to their deficiency of FKBP12 and the related inability to inhibit the activity of calcineurin.

Lee, C. W. and M. C. Castells (2004). "Perioperative anaphylaxis to cefazolin." Allergy Asthma Proc 25(1): 23-6.

The incidence of generalized reactions during anesthesia has been reported to range from 1 in 5000 to 1 in 25,000 cases with a mortality rate of up to 6%. The most common causes are neuromuscular blocking agents, latex, and antibiotics. Identification of the offending agent may be difficult because multiple medications are administered over a short period. Furthermore, up to 40% of all generalized reactions during anesthesia are non-immunoglobulin E mediated and therefore can not be evaluated by skin testing. We report a case of perioperative anaphylaxis to cefazolin. Sensitization to cefazolin was determined through skin testing, and the patient underwent successful surgery subsequently with the avoidance of cefazolin.

Lee, C. W., U. A. Matulonis, et al. (2004). "Carboplatin hypersensitivity: a 6-h 12-step protocol effective in 35 desensitizations in patients with gynecological malignancies and mast cell/IgE-mediated reactions." Gynecol Oncol 95(2): 370-6.

OBJECTIVES: The incidence of hypersensitivity reactions (HR) is increased in patients treated with multiple courses of carboplatin. The purposes of this investigation were to evaluate the effectiveness of a 12-step desensitization protocol and to characterize the immune mechanism of carboplatin HR.

METHODS: We analyzed 10 consecutive patients who had documented HR to carboplatin and in whom continued treatment with carboplatin was considered advantageous. The patients were treated with carboplatin using a 6-h, 12-step desensitization protocol with a 30-min premedication regimen. Skin tests were performed on five patients.

RESULTS: Ten patients successfully completed 35 planned courses of desensitizations to carboplatin, 31 of which were without reactions. Four patients had symptoms during their first (n = 3) and third (n = 1) desensitizations but tolerated the re-administration of infusions without further reactions. For subsequent courses, the protocol was modified for two patients who had extracutaneous symptoms during desensitization and was unchanged for the patient who had mild urticaria. These three patients tolerated subsequent courses of desensitizations without reactions. The fourth patient with symptoms during desensitization no longer required carboplatin due to progressive disease. Of the five patients who were skin tested to carboplatin, four had positive wheal and flare reactions. In one patient, the skin test response to carboplatin became negative after desensitization.

CONCLUSION: The 6-h, 12-step desensitization protocol is safe and effective for treating patients with carboplatin HR. Positive skin tests to carboplatin suggest a mast cell/IgE-mediated mechanism. Conversion of the positive skin test to a negative response after desensitization supports antigen-specific mast cell desensitization.

Lee, C. W., U. A. Matulonis, et al. (2005). "Rapid inpatient/outpatient desensitization for chemotherapy hypersensitivity: Standard protocol effective in 57 patients for 255 courses." Gynecol Oncol 99(2): 393-9.

OBJECTIVES.: Hypersensitivity reactions (HR) to chemotherapy often prompt permanent discontinuation and deprive the patient of the most active regimen. We investigated the safety and effectiveness of a rapid desensitization protocol used in inpatient and outpatient settings for patients with HR to various chemotherapy and related agents.

METHODS: A 3-solution, 12-step protocol delivered doubling drug doses by step, infusing the target dose over 5.8 h for inpatient and 3.8 h for outpatient administration. RESULTS.: 57 consecutive patients who had moderate to severe HR to chemotherapy were evaluated for desensitization. All 57 patients successfully completed 255 courses of desensitization (127 to carboplatin, 114 to paclitaxel, and 14 to four other agents) where 16 patients received 51 courses in the outpatient setting (34 to carboplatin and 17 to paclitaxel). 225 courses (88.2%) were completed without any HR. 18 patients had breakthrough symptoms (BS) over 30 courses (11.8%) that were less severe than their initial HR. After management of breakthrough symptoms, these patients finished all 30 courses and tolerated subsequent desensitizations on a modified protocol. 21 of 26 patients (81%) with HR to carboplatin had positive skin tests to carboplatin. Cancer response to chemotherapy administered by desensitization was within the expected range after 1-3 years of follow-up.

CONCLUSION.: The rapid desensitization protocol was safe and effective in both the inpatient and outpatient settings and allowed appropriate patients with moderate to severe HR to continue chemotherapy. This study warrants the incorporation of the protocol into standard clinical practice.

Lee, C. W., R. N. Mitchell, et al. (2005). "Cardiogenic shock and peripheral eosinophilia in a young woman." Ann Allergy Asthma Immunol 95(3): 229-33.

McCormick, M. J., M. C. Castells, et al. (1999). "The gp49A gene has extensive sequence conservation with the gp49B gene and provides gp49A protein, a unique member of a large family of activating and inhibitory receptors of the immunoglobulin superfamily." Immunogenetics 50(5-6): 286-94.

Members of the gp49-related family of mouse and human immunoglobulin (Ig) superfamily receptors have significant amino acid sequence homology in their C2-type, Ig-like domains and include the killer cell Ig-like receptors (KIRs) for major histocompatibility complex class I molecules. We now report the cloning, complete sequence, and organization of the mouse gp49A gene that encodes the only member of this newly-appreciated family without either of two mutually exclusive functional motifs, namely, immunoreceptor tyrosine-based inhibitory motifs (ITIMs) or a charged transmembrane amino acid for heterodimerization with activation molecules. The gp49A and gp49B genes are 94% identical over 5.6 kilobases, the 5' flanking regions are 94% identical over 1900 nucleotides, and the 3' flanking regions are 97% identical for 121 nucleotides and then diverge completely; the gp49B gene encodes gp49B1 bearing two ITIMs. As measured by flow cytometry with specific antibody, gp49A is expressed on immature bone-marrow-derived mast cells, mature serosal mast cells, and several mouse mast cell lines. The substantial sequence identity of the introns of the gp49A and gp49B genes is comparable to that of the exons, establishing the gene pair as the most homologous of the gp49-related family and suggesting that the gp49A and gp49B genes arose by duplication with relatively little subsequent mutation. The findings also represent the first demonstration that gp49A is expressed on mast cells in tandem with inhibitory gp49B1, and establish that the gp49A gene is not a pseudogene, but rather encodes a protein product with characteristics different from the other family members.

Morales, A. R., N. Shah, et al. (2005). "Antigen-IgE desensitization in signal transducer and activator of transcription 6-deficient mast cells by suboptimal doses of antigen." Ann Allergy Asthma Immunol 94(5): 575-80.

BACKGROUND: Rapid administration of suboptimal antigen induces transient unresponsiveness in patients with IgE antibodies to beneficial medications, but the molecular mechanisms of desensitization are poorly understood. Mast cells (MCs) have been implicated as the target cells. OBJECTIVE: To establish a physiologic model of IgE-antigen desensitization using mouse bone marrow-derived MCs (mBMMCs) from wild-type and signal transducer and activator of transcription 6 (STAT6)-deficient mice.

METHODS: The mBMMCs were sensitized with dinitrophenyl (DNP) IgE or trinitrophenyl (TNP) IgE and activated with DNP/TNP-human serum albumin. For desensitization, suboptimal doses of DNP/TNP-human serum albumin were administered at fixed intervals.

RESULTS: Desensitized mBMMCs failed to respond to an optimal dose of antigen, indicating successful desensitization. Desensitization was time dependent, with 5 minutes of antigen exposure being optimal. Resensitization with DNP-IgE did not reverse the process. The desensitized cells were responsive to calcium ionophore and phorbol myristate acetate. Thus, the desensitization reaction alters an early event in the high-affinity IgE receptor (FcepsilonRI)-dependent signaling pathway in a nontoxic manner. The mBMMCs from STAT6-null mice could not be desensitized by suboptimal doses of antigen.

CONCLUSIONS: Mast cells can be rendered unresponsive by rapid administration of suboptimal doses of antigen in the presence of calcium, similar to in vivo desensitizations. The STAT6-null mBMMCs cannot be desensitized, providing the first molecular target in this inhibitory process.

Mutinga, M., M. Castells, et al. (2000). "Successful desensitization to 6-mercaptopurine in a patient with Crohn's disease." Am J Gastroenterol 95(5): 1383-4.

Perez-Ramirez, B. and M. Castells (1991). "In vitro biosynthesis of rat sperm outer dense fiber components." Life Sci 49(21): 1549-54.

Conditions were established for in vitro culture of seminiferous tubules of adult rat testis. Tubules fragments were able to incorporate radioactive amino acids for up to 6 hours of incubation at 32 degrees C in a modified Eagle's minimum media, indicating biosynthetic activity. Addition of D-glucose (11 Mm) increased the incorporation of either [3H] Leucine or [35S] Methionine four-fold in the protein components of seminiferous tubules. Polyclonal antibodies against outer dense fibers (ODF) polypeptides, which represent approximately 30% of the total sperm proteins, immunoprecipitated 5% of the total radioactivity from cultures carried out either in the presence or absence of D-glucose. Moreover, antibodies specific for the 27-30 kilodalton polypeptides of ODF immunoprecipitated 2% of the total radioactivity, showing no differences in the presence and absence of D-glucose. This study indicates that ODF polypeptides can be synthesized in vitro at 32 degrees C with and without D-glucose.

Price, K. S. and M. C. Castells (2002). "Taxol reactions." Allergy Asthma Proc 23(3): 205-8.

Paclitaxel (Taxol) a taxane antineoplastic agent causing irreversible microtubule aggregation with activity against breast, ovarian, lung, head and neck, bladder, testicular, esophageal, endometrial and other less common tumors was derived from the bark of the Pacific yew (Taxus brevifolia). Phase I trials conducted in the late 1980s were almost halted because of the high frequency of hypersensitivity-like reactions. Respiratory distress (dyspnea and/or bronchospasm), hypotension, and angioedema were the major manifestations, but flushing, urticaria, chest, abdomen, and extremity pains were described also. Reactions occurred on first exposure in the majority of cases raising etiologic questions. The vehicle for paclitaxel Cremophor EL (polyoxyethylated castor oil in 50% ethanol) was strongly suspect as a direct (non-immunoglobulin E dependent) histamine releaser. Premedication regimens and longer infusion times lowered the incidence of reactivity allowing phase II and III trials to progress through the early 1990s. The mechanism(s) underlying paclitaxel hypersensitivity-like reactions is still unknown, and clinical data on probable complement and mast cell activation are lacking. The original clinical trial protocols for paclitaxel required discontinuation of therapy for patients who experienced hypersensitivity-like reactions. Here, we review the current etiologic knowledge of these reactions and describe our clinical approach to allow completion of chemotherapy with this powerful plant-derived agent.

Schwartz, L. B., A. M. Irani, et al. (1987). "Quantitation of histamine, tryptase, and chymase in dispersed human T and TC mast cells." J Immunol 138(8): 2611-5.

Levels of histamine, chymase, and tryptase were assessed in preparations of dispersed human TC (tryptase+, chymase+) mast cells obtained from foreskin and of dispersed human T (tryptase+, chymase-) mast cells obtained from lung. Consistent with previous immunohistochemical results, extracts of T mast cells, the predominant mast cell type in lung (93% T and 7% TC mast cells), were deficient in human chymase (less than 0.3 microgram and 0.04 U/10(6) mast cells) but not tryptase (10.8 micrograms and 0.3 U/10(6) mast cells) by corresponding immunologic and enzymatic (suc-L-ala-ala-pro-phe-p-nitroanilide in the presence of aprotinin and tosyl-L-gly-pro-lys-p-nitroanilide in the presence of soybean trypsin inhibitor, respectively) assays. The minor presence of chymase activity in lung could be accounted for by the minor presence of lung TC mast cells. Extracts of TC mast cells, the predominant mast cell type (1% T and 99% TC mast cells) in foreskin, contained both proteases. However, TC mast cells from adult foreskin contained eightfold to 10-fold higher levels of chymase (4.5 micrograms and 1.01 U/10(6) mast cells) and twofold to threefold higher levels of tryptase (11.5 micrograms and 0.27 U/10(6) mast cells) than did TC mast cells from newborn foreskin (less than 0.6 microgram and 0.09 U of chymase and 35 micrograms and 0.62 U of tryptase/10(6) mast cells). In contrast, histamine levels were not significantly different in adult foreskin TC (1.9 microgram/10(6) mast cells), newborn foreskin TC (1.6 microgram/10(6) mast cells), and adult lung T (1.5 microgram/10(6) mast cells) mast cells. The relative ratio of each mediator in newborn foreskin mast cells to that in adult foreskin mast cells is highest for histamine, followed by tryptase and then chymase. Tryptase from TC and T mast cells had identical subunit compositions by Western blot analysis and similar apparent specific activities. This study extends the previously reported immunohistochemical distinction between human T and TC mast cells in tissue sections by direct quantitation of chymase and tryptase in dispersed preparations of T and TC mast cells.