James Fernandez

Dectin-2 mediates Th2 immunity through the generation of cysteinyl leukotrienes

Dectin-2 expression on GM-CSF–cultured bone marrow cells is required for the generation of cysteinyl leukotrienes and Th2 cytokines in response to the house dust mite Dermatophagoides farinae in vivo.

Desensitization regimens for drug allergy: state of the art in the 21st century.

Adverse reactions to drugs are increasingly being recognized as important contributions to disease in their own right as well as impediments to the best treatment of various conditions, including infectious, autoimmune, and neoplastic maladies. Rapid drug desensitization (RDD) is an effective mechanism for safely administering important medications while minimizing or entirely circumventing such adverse reactions in sensitized patients. We reviewed the literature on RDD in the last 10 years, including our experience from the Brigham and Womens Hospital Desensitization Program with hundreds of patients desensitized to a broad variety of drugs. RDD in our programme has been uniformly successful in patients with hypersensitivity reactions to antibiotics, chemotherapeutics, and monoclonal antibodies. Any reactions that occur during desensitization are generally much less severe than the initial hypersensitivity reaction to the drug, and patients have received the full dose of the desired medication 99.9% of the time out of (796) desensitizations. To date, there have been no fatalities. RDD is a safe and highly effective method for treating sensitized patients with the optimal pharmacologic agents. Its use should be expanded, but because patient safety is paramount, protocols must be created, reviewed, and overseen by allergist–immunologists with special training and experience in modern techniques of desensitization.

Safety, Costs, and Efficacy of Rapid Drug Desensitizations to Chemotherapy and Monoclonal Antibodies

BACKGROUND Rapid drug desensitization (RDD) is used to address hypersensitivity reactions to chemotherapeutics and monoclonal antibodies, allowing patients to be treated with optimal pharmacological agents. RDD protocols are tailored to each individual patients reaction and needs, and protect against anaphylaxis, but overall risks, costs, and benefits have not been determined. OBJECTIVE We investigated the safety, efficacy, costs, and life expectancy of patients in a large population undergoing RDD. METHODS We analyzed 2177 RDD procedures performed in 370 patients with cancer, vasculitis, and hematological and connective tissue diseases who presented 402 reactions. A subgroup of carboplatin allergic patients with ovarian cancer treated with RDD was analyzed for costs and life expectancy and compared with a nonallergic control group. RESULTS RDD allowed all patients to receive safely the full dose of the medication to which they were reactive. A gradual increase in the fraction of outpatient desensitizations from 81% to 98% was achieved through risk stratification. Of the 2177 desensitizations, 93% had no or mild reactions whereas 7% had moderate to severe reactions, which did not preclude the completion of the treatment, and there were no deaths. Overall health costs in the carboplatin allergic group were not higher than those in the nonallergic group treated with standard of care. Administration of carboplatin through RDD was as effective as standard administration with a nonsignificant increase in life expectancy in desensitized patients as compared with nonallergic, nondesensitized controls. CONCLUSIONS RDD is cost effective and safe for allergic patients with cancer and chronic disease to remain on first line therapy.

Dectin-2 Regulates the Effector Phase of House Dust Mite-Elicited Pulmonary Inflammation Independently from Its Role in Sensitization

The myeloid C-type lectin receptor Dectin-2 directs the generation of Th2 and Th17 immune responses to the house dust mite Dermatophagoides farinae through the generation of cysteinyl leukotrienes and proinflammatory cytokines, respectively, but a role for Dectin-2 in effector phase responses has not been described. In this study, we demonstrate that administration of the Dectin-2 mAb solely at the time of D. farinae challenge abrogated eosinophilic and neutrophilic inflammation in the bronchoalveolar lavage fluid and Th1, Th2, and Th17 inflammation in the lung of previously sensitized mice. Furthermore, Dectin-2 null mice (Clec4n(-/-)) sensitized with the adoptive transfer of D. farinae-pulsed wild-type (WT) bone marrow-derived dendritic cells (DCs) also had less D. farinae-elicited pulmonary inflammation, supporting an effector function for Dectin-2. The protection from pulmonary inflammation seen with the Dectin-2 mAb or in Clec4n(-/-) mice was associated with little or no reduction in lung-draining lymph node cells or their cytokine production and with no reduction in serum IgE. WT and Clec4n(-/-) mice recipients, sensitized with D. farinae-pulsed WT bone marrow-derived DCs, had comparable levels of D. farinae-elicited IL-6, IL-23, TNF-α, and cysteinyl leukotrienes in the lung. By contrast, D. farinae-elicited CCL4 and CCL8 production from pulmonary CD11c(+)CD11b(+)Ly6C(+) and CD11c(+)CD11b(+)Ly6C(-)CD64(+) monocyte-derived DCs was reduced in Clec4n(-/-) recipients. Addition of CCL8 at the time of D. farinae challenge abrogated the protection from eosinophilic, neutrophilic, and Th2 pulmonary inflammation seen in Clec4n(-/-) recipients. Taken together, these results reveal that Dectin-2 regulates monocyte-derived DC function in the pulmonary microenvironment at D. farinae challenge to promote the local inflammatory response.

Cysteinyl Leukotriene 2 Receptor on Dendritic Cells Negatively Regulates Ligand-Dependent Allergic Pulmonary Inflammation

Cysteinyl leukotrienes (cys-LTs) can mediate Th2 immunity to the house dust mite, Dermatophagoides farinae, via the type 1 receptor CysLT1R on dendritic cells (DCs). However, the role of the homologous type 2 receptor CysLT2R in Th2 immunity is unknown. D. farinae sensitization and challenge of CysLT2R-deficient mice showed a marked augmentation of eosinophilic pulmonary inflammation, serum IgE, and Th2 cytokines. Wild-type (WT) mice sensitized by adoptive transfer of D. farinae-pulsed CysLT2R-deficient bone marrow-derived DCs (BMDCs) also had a marked increase in D. farinae-elicited eosinophilic lung inflammation and Th2 cytokines in restimulated hilar nodes. This response was absent in mice sensitized with D. farinae-pulsed BMDCs lacking leukotriene C4 synthase (LTC4S), CysLT1R, or both CysLT2R/LTC4S, suggesting that CysLT2R negatively regulates LTC4S- and CysLT1R-dependent DC-mediated sensitization. CysLT2R-deficient BMDCs had increased CysLT1R-dependent LTD4-induced ERK phosphorylation, whereas N-methyl LTC4 activation of CysLT2R on WT BMDCs reduced such signaling. Activation of endogenously expressed CysLT1R and CysLT2R occurred over an equimolar range of LTD4 and N-methyl LTC4, respectively. Although the baseline expression of cell surface CysLT1R was not increased on CysLT2R-deficient BMDCs, it was upregulated at 24 h by a pulse of D. farinae, compared with WT or CysLT2R/LTC4S-deficient BMDCs. Importantly, treatment with N-methyl LTC4 reduced D. farinae-induced CysLT1R expression on WT BMDCs. Thus, CysLT2R negatively regulates the development of cys-LT–dependent Th2 pulmonary inflammation by inhibiting both CysLT1R signaling and D. farinae-induced LTC4S-dependent cell surface expression of CysLT1R on DCs. Furthermore, these studies highlight how the biologic activity of cys-LTs can be tightly regulated by competition between these endogenously expressed receptors.

NOD2-associated autoinflammatory disease and immune deficiency

Nucleotide-binding oligomerization domain containing 2eassociated autoinflammatory disease (NAID) is an increasingly recognized emerging disease. This is the first report that NAID may coexist with an underlying immune deficiency, supporting the notion that autoinflammatory disease and immune deficiency may not be mutually exclusive. This study will increase awareness of the new entity in the community of allergy and immunology.

Anaphylaxis after home-made quinoa dinner: hold the mustard

Food is the most common cause of anaphylaxis.1 Very few cases of mustard seed-induced anaphylaxis have been reported. We present a case of mustard seed anaphylaxis. A 29-year-old man presented to our department for evaluation of anaphylaxis. He had an episode of facial flushing and angio-oedema (figure 1), lower extremity urticaria (figure 2), chest tightness and vomiting within 30 min of eating a …

Biologic Therapy in the Treatment of Chronic Skin Disorders

Understanding of the immunologic pathways involved in the pathogenesis of skin-related diseases is constantly advancing. Several biologic agents play important therapeutic roles for management of patients with chronic urticaria, atopic dermatitis, and psoriasis, particularly omalizumab for antihistamine-resistant chronic urticaria, interleukin (IL)-1 inhibitors for cryopyrin-associated periodic syndrome and Schnitzler syndrome, dupilumab for recalcitrant atopic dermatitis, and IL-17 inhibitors for psoriasis. The therapeutic utility of biologic agents for patients with immune-related dermatologic disorders is likely to expand in the future. This article reviews the data regarding biologic agents and their utility in the management of specific skin-related disorders.

PCP: thinking beyond HIV.

A 40-year-old man with a previous AIDS-defining opportunistic infection and five negative HIV tests presented to our outpatient clinic. The laboratory test was relevant for less than 300 total lymphocytes on two separate occasions. He was diagnosed with idiopathic CD4 lymphocytopenia and was started on antibiotic prophylaxis for Pneumocystis carinii pneumonia and Micobacterium avium-intracellulare infection (MAI). This case report summarises the importance of further immunological characterisation in patients presenting with opportunistic infections and decreased cellular immunity.

Other Antibiotic Allergy

Antibiotics are a common cause of adverse drug reactions. Although β-lactam and sulfonamide antibiotics are the most commonly implicated antibiotics in epidemiologic studies, other antibiotics also account for clinically important reactions. It is important for clinicians to also be aware of these reactions.