José Antonio Cornejo-García

Cytokine and chemokine expression in the skin from patients with maculopapular exanthema to drugs

Background:  Maculopapular exanthema (MPE) is the most frequent clinical manifestation of nonimmediate allergic reactions to drugs and T helper 1 (Th1) cytokines and CD4+ T cells have been shown to play an important role in its pathogenesis. We assessed the role of cytokines and chemokines and their receptors in the pathogenesis of MPE.

Monitoring non-immediate allergic reactions to iodine contrast media

Non‐immediate reactions to iodine contrast media (ICM) affect 2–5% of patients receiving these agents. We studied the immunological mechanisms involved in patients with a confirmed non‐immediate reaction, maculopapular exanthema, after administration of ICM. The diagnosis was carried out by skin testing or drug provocation test. The immunological study was performed in sequential peripheral blood mononuclear cells taken from the onset of the reaction by flow cytometry and in skin biopsy by immunohistochemistry, with specific recognition by the lymphocyte transformation test (LTT) with different ICM. Flow cytometry showed an increase in the different activation markers [CD69, CD25 and human leucocyte antigen D‐related (HLA‐DR)] and the skin homing receptor [cutaneous lymphocyte‐associated antigen (CLA)] in CD4 lymphocytes, whereas perforin was higher in the CD8 lymphocytes. The skin biopsy showed a perivascular mononuclear infiltrate composed of CD4 lymphocytes, expressing CD25, HLA‐DR and CLA, with eosinophils. Intradermal skin tests and the LTT were positive to several ICM, including the culprit agent in four and three patients, respectively, with negative results in all 10 tolerant controls. We showed that a specific immunological mechanism was implicated in patients with non‐immediate reactions to ICM. Moreover, the positive results in skin tests and lymphocyte proliferation tests indicated that an important cross‐reactivity exists.

Hypersensitivity Reactions to Non-Steroidal Anti-Inflammatory Drugs

NSAIDs are the most important group of drugs involved in hypersensitivity drug reactions, and include heterogeneous compounds with very different chemical structures. These reactions can be IgE dependent (immediate reactions), T cell-mediated (non-immediate), or induced by a non-specific immunological mechanism related with the blocking of the COX-1 enzyme and the shunting to the lipooxygenase pathway (cross-intolerant reactions). Cutaneous symptoms are the most frequent, with ibuprofen, naproxen and diclofenac being common culprit drugs worldwide, although others can be involved because patterns of consumption and exposure rates vary between countries. A very important proportion of immunological reactions are immediate, with urticaria and anaphylaxis being the typical clinical manifestations. Non-immediate reactions comprise a number of heterogeneous entities ranging from mild exanthema to severe TEN or DRESS syndrome, as well as organ-specific reactions such as hepatitis or pneumonitis. Cross-intolerant reactions appear to non-chemically related drugs, and involve respiratory airways, skin or both. In vivo diagnostic tests are based on the capacity of the skin to respond to the culprit drug, but their sensitivity is in many instances rather low. The approach for in vitro testing consists of either detecting specific IgE antibodies or studying the proliferation of T lymphocytes toward the eliciting drug. No appropriate tests are yet available for the in vitro validation of cross-intolerance reactions, although techniques based on the stimulation of basophils have been proposed. Based on these findings, the diagnostic approach is often based on the controlled administration of the drug to assess tolerance. In this work we review current knowledge on hypersensitivity reactions to NSAIDs, including diagnostic approach and genetic studies.

HLA-DRA variants predict penicillin allergy in genome-wide fine-mapping genotyping

BACKGROUND Immediate reactions to β-lactams are the most common causes of anaphylactic reactions and can be life-threatening. The few known genetic factors influencing these reactions suggest a link with atopy and inflammation. OBJECTIVE We performed a fine-mapping genome-wide association study of the genetic predictors of β-lactam allergy to better understand the underlying mechanisms. METHODS We studied 387 patients with immediate allergic reactions to β-lactams and 1124 paired control subjects from Spain. We replicated the results in 299 patients and 362 paired control subjects from Italy. RESULTS We found significant associations with the single nucleotide polymorphisms rs4958427 of ZNF300 (c.64-471G>A, P = 9.9 × 10(-9)), rs17612 of C5 (c.4311A>C [p.Glu1437Asp], P = 7.5 × 10(-7)), rs7754768 and rs9268832 of the HLA-DRA | HLA-DRB5 interregion (P = 1.6 × 10(-6) and 4.9 × 10(-6)), and rs7192 of HLA-DRA (c.724T>G [p.Leu242Val], P = 7.4 × 10(-6)) in an allelic model, with similar results in an additive model. Single nucleotide polymorphisms of HLA-DRA and ZNF300 predicted skin test positivity to amoxicillin and other penicillins but not to cephalosporins. A haplotype block in HLA-DRA and the HLA-DRA | HLA-DRB5 interregion encompassed a motif involved in balanced expression of the α- and β-chains of MHC class II, whereas rs7192 was predicted to influence α-chain conformation. HLA-DRA rs7192 and rs8084 were significantly associated with allergy to penicillins and amoxicillin (P = 6.0 × 10(-4) and P = 4.0 × 10(-4), respectively) but not to cephalosporins in the replication study. CONCLUSIONS Gene variants of HLA-DRA and the HLA-DRA | HLA-DRB5 interregion were significant predictors of allergy to penicillins but not to cephalosporins. These data suggest complex gene-environment interactions in which genetic susceptibility of HLA type 2 antigen presentation plays a central role.

The Diamine Oxidase Gene Is Associated with Hypersensitivity Response to Non-Steroidal Anti-Inflammatory Drugs

Non-steroidal anti-inflammatory drugs (NSAIDs) are the drugs most frequently involved in hypersensitivity drug reactions. Histamine is released in the allergic response to NSAIDs and is responsible for some of the clinical symptoms. The aim of this study is to analyze clinical association of functional polymorphisms in the genes coding for enzymes involved in histamine homeostasis with hypersensitivity response to NSAIDs. We studied a cohort of 442 unrelated Caucasian patients with hypersensitivity to NSAIDs. Patients who experienced three or more episodes with two or more different NSAIDs were included. If this requirement was not met diagnosis was established by challenge. A total of 414 healthy unrelated controls ethnically matched with patients and from the same geographic area were recruited. Analyses of the SNPs rs17740607, rs2073440, rs1801105, rs2052129, rs10156191, rs1049742 and rs1049793 in the HDC, HNMT and DAO genes were carried out by means of TaqMan assays. The detrimental DAO 16 Met allele (rs10156191), which causes decreased metabolic capacity, is overrepresented among patients with crossed-hypersensitivity to NSAIDs with an OR  = 1.7 (95% CI  = 1.3–2.1; Pc  = 0.0003) with a gene-dose effect (P = 0.0001). The association was replicated in two populations from different geographic areas (Pc  = 0.008 and Pc  = 0.004, respectively). Conclusions and implications The DAO polymorphism rs10156191 which causes impaired metabolism of circulating histamine is associated with the clinical response in crossed-hypersensitivity to NSAIDs and could be used as a biomarker of response.

Genome-wide association study in NSAID-induced acute urticaria/angioedema in Spanish and Han Chinese populations

AIM Acute urticaria/angioedema (AUA) induced by cross-intolerance to NSAIDs is the most frequent clinical entity in hypersensitivity reactions to drugs. In this work, we conducted a genome-wide association study in Spanish and Han Chinese patients suffering from NSAID-induced AUA. MATERIALS & METHODS A whole-genome scan was performed on a total of 232 cases (112 Spanish and 120 Han Chinese) with NSAID-induced AUA and 225 unrelated controls (124 Spanish and 101 Han Chinese). RESULTS Although no polymorphism reached genome-wide significance, we obtained suggestive associations for three clusters in the Spanish group (RIMS1, BICC1 and RAD51L 1) and one region in the Han Chinese population (ABI3BP). Five regions showed suggestive associations after meta-analysis: HLF, RAD51L1, COL24A1, GalNAc-T13 and FBXL7. A majority of these genes are related to Ca(2+), cAMP and/or P53 signaling pathways. CONCLUSION The associations described were different from those related to the metabolism of arachidonic acid and could provide new mechanisms underlying NSAID-induced AUA.

Immediate allergy to tetanus toxoid vaccine: determination of immunoglobulin E and immunoglobulin G antibodies to allergenic proteins.

BACKGROUND Adverse reactions to tetanus toxoid (TT) vaccine are mostly mild and limited to the injection site. However, immunoglobulin (Ig)E-mediated reactions may occur, and the incidence of anaphylactic responses to TT immunization is 0.001%. When TT induces an allergic reaction, the potential causative agents can be TT antigens, thimerosal or aluminum phosphate. OBJECTIVE We studied four children who developed immediate urticaria after TT vaccine, soon after the reaction and 5 years later. METHODS Skin tests were performed separately with TT vaccine and two vaccine components, thimerosal and aluminum phosphate, and the diagnosis was confirmed by provocation test. IgE and IgG antibodies to TT and their specificities were determined. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting were performed to characterize the antigenic proteins. RESULTS All four children were immediate skin test-positive to TT, but negative to thimerosal and aluminum phosphate; 3 developed a reaction after intramuscular provocation using increasing doses of TT vaccine; and 1 refused to be tested. All these tests were negative in five controls, all of whom received TT vaccine and developed only local swelling at the site of application 24 hours after vaccine administration. After 5 years the IgG antibodies were still high in all cases and the IgE antibody values fell by 50%. Patients allergic to TT vaccine produced IgE and IgG antibodies, which decreased at different rates but remained for at least 5 years. The pattern of antibody decrease was confirmed by radioallergosorbent test, enzyme-linked immunoadsorbent assay, or immunoblotting assay. IgE and IgG antibodies recognized two proteins derived from TT, of 150 and 50 kDa, corresponding to the intracellular form and to a chain of the extracellular form of the tetanus neurotoxin. CONCLUSIONS In children with immediate allergic reactions to TT vaccine, antibodies may persist for at least 5 years, requiring evaluation by skin and/or in vitro tests before subsequent treatment.

Nonimmediate reactions to betalactams

Purpose of reviewNonimmediate reactions to β-lactams include several clinical entities, from maculopapular rash to severe reactions such as Steven-Johnson syndrome. Toxic epidermal necrolysis and organ-specific reactions may also occur. Recent findingsProgress has been made in understanding the role of the immunological system in nonimmediate reactions to β-lactams. Different T-cell subsets recognize β-lactams after haptenation of serum or cell proteins in the context of major histocompatibility complex. Studies using T-cell lines and clones have shown that a heterogeneous response is generated, with the expression of different cytokine profiles. Betalactams also act on dendritic cells, inducing changes that enable them to interact with naïve lymphocytes, becoming memory T cells. Tissue-activated CD4 and CD8 cells express perforin and other cytotoxic mediators that elicit the lesions. Studies on the clinical course of these entities indicate that cells migrate, establishing a recirculation with homing to the skin and back to the circulation. These cells thus participate not only in skin lesions but probably also in the repair process. SummaryUnderstanding the immunological mechanisms involved in nonimmediate reactions to β-lactams has improved over the last few years, with better definition of the different T-cell subpopulations involved. Experimental studies and monitoring of the response support the implication of different cell subsets.

Unravelling adverse reactions to NSAIDs using systems biology

We introduce the reader to systems biology, using adverse drug reactions (ADRs), specifically hypersensitivity reactions to multiple non-steroidal anti-inflammatory drugs (NSAIDs), as a model. To disentangle the different processes that contribute to these reactions - from drug intake to the appearance of symptoms - it will be necessary to create high-throughput datasets. Just as crucial will be the use of systems biology to integrate and make sense of them. We review previous work using systems biology to study related pathologies such as asthma/allergy, and NSAID metabolism. We show examples of their application to NSAIDs-hypersensitivity using current datasets. We describe breakthroughs in high-throughput technology and speculate on their use to improve our understanding of this and other drug-induced pathologies.

Variability in histamine receptor genes HRH1, HRH2 and HRH4 in patients with hypersensitivity to NSAIDs

AIM Histamine plays an important role in the pathogenesis of allergic diseases. Genetic variations in histamine receptors (HRH) may influence the expression of allergic diseases. This study analyzes the association between HRH variants and NSAID hypersensitivity reactions. PATIENTS & METHODS The authors analyzed copy number variations (CNVs) and common functional SNPs in genes HRH1, HRH2 and HRH4 in 442 unrelated patients with hypersensitivity to NSAIDs and in 414 healthy unrelated controls. RESULTS The authors identified, both in patients and control subjects, individuals carrying CNVs in HRH genes. The most common genotype corresponded to two copies of each gene, but carriers of one or three copies of HRH1 (5% of individuals), HRH2 (1.1%) and HRH4 genes (0.9%) were also identified. CONCLUSION For the first time, we describe CNVs in human HRH genes. Neither common functional SNPs in HRH genes nor CNVs influenced the risk of developing hypersensitivity to NSAIDs.