Gabriel Gastaminza

Allergic reactions to betalactams : studies in a group of patients allergic to penicillin and evaluation of cross-reactivity with cephalosporin

A group of 34 penicillin‐allergic patients was studied to determine skin test reactivity to the different penicillins involved in inducing the allergic reaction and the cross‐reactivity with side‐chain‐related and side‐chain‐unrelated cephalosporins. All the subjects selected for the study had to be skin test positive to at least one of the following determinants: benzyl‐penicilloyl‐polylysine (BPO‐PLL), minor‐determinant mixture (MDM), amoxicillin (AX), or ampicillin (AMP), or to possess in vitro IgE to the following conjugates: benzyl‐penicilloyl‐human‐serum albumin (BPO‐HSA), ampicilloyl‐human‐serum albumin (AMP‐HSA), and amoxicilloyl‐human‐serum albumin (AX‐HSA). Cephalexin (CE) and ceftazidime (CEF) were used to assess cross‐reactivity. If skin tests to any of these compounds were positive, the patient was considered to be allergic; if negative, a challenge test was performed. Sixteen patients (47%) were skin test positive to BPO and/or MDM, and nine (26%) exclusively to AX and/or AMP. In three cases (8%), the RAST was positive although the skin test was negative; one to BPO‐HSA and two to AX‐HSA and AMP‐HSA. Six patients (17%) needed to be challenged with the penicillin involved to establish the diagnosis. In five patients (14%), the skin tests were positive to CE and in none to CEF. In all the others, the skin tests were negative to both cephalosporins, and the patients tolerated the drugs when challenged. These results indicate the relevance of side‐chain‐specific minor determinants in betalactams allergy and provide support for the role of this chemical structure in the evaluation of cross‐reactivity between penicillins and cephalosporins.

Systemic reactions to immunotherapy: influence of composition and manufacturer.

Background Although immunotherapy clearly demonstrated the benefit of reducing allergic symptoms, it has the drawback of adverse events, mainly systemic reactions that could be very inconvenient for patients and even life‐threatening.

An unusual case of baboon syndrome due to mercury present in a homeopathic medicine

Keywords: systemic contact dermatitis; baboon syndrome; mercury; homeopathy; children; thimerosal

Can component‐based microarray replace fluorescent enzimoimmunoassay in the diagnosis of grass and cypress pollen allergy?

Background Few data on the diagnostic accuracy in pollinosis of the microarray ISAC of allergens are available.

Comparable actions of omalizumab on mast cells and basophils

Omalizumab (OmAb) has recently been approved for the treatment of diseases other than allergic asthma, including chronic urticaria. The exploration of the use of OmAb in chronic urticaria was based on the presence of IgE autoantibodies against autoantigens such as anti‐IgE, anti‐FcεRI, and IgE antibodies against thyroid peroxidase in certain patients with chronic urticaria. OmAb recognizes and sequesters free IgE to prevent its interaction with FcεRI. However, OmAb is equally and rapidly effective against autoimmune and non‐autoimmune urticaria, suggesting the possible involvement of additional mechanisms of IgE.

Positive patch test in vancomycin allergy

Case Report A 39-year-old man, with no personal history of allergy and on haemodialysis for a year, contracted a staphylococcal infection of the arteriovenous fistula, and therapy with i.v. vancomycin was begun. After 3 weeks of treatment, the patient developed a high fever and a cutaneous eruption, which responded to corticosteroids and antihistamines. 4 days later, the fever and rash reappeared, with pruritus and hypotension, such that cefotaxim, gentamicin and, later, rifampicin were added, but the fever persisted and blood cultures remained negative. A drug reaction was suspected and daily haemodialysis was therefore carried out to filter out vancomycin, thus resolving the symptoms. Physical examination showed a fever of 39.5 æC, a pruriginous macular exanthem on the trunk and lower extremities, and palpebral and lip oedema. There was a leucocytosis, with a normal neutrophil count. Skin tests (prick and intradermal) with vancomycin and teicoplanin (TargocidA) were negative at immediate and delayed readings. However, patch tests with both drugs were positive: vancomycin 0.005% aq. π at D2 and ππ at D4; teicoplanin 4% aq. a at D2 and π at D4. 20 controls were tested, with negative results.

The usefulness of plasma histamine and different tryptase cut‐off points in the diagnosis of peranaesthetic hypersensitivity reactions

Anaesthetic hypersensitivity reactions can be IgE‐ or not IgE‐mediated and are a challenge to find the causal agent. Histamine and tryptase determination are classically considered useful in the diagnosis of these reactions. The aim of our study was to assess the diagnostic usefulness of plasma histamine and different cut‐off points of serum tryptase.

Nanoparticle based-immunotherapy against allergy

Allergic diseases are one of the most prevalent diseases, reaching epidemic proportions in developed countries. An allergic reaction occurs after contact with an environmental protein, such as inhalants allergens (pollen, animal dander, house dust mites), or food proteins. This response is known as part of the type 2 immunity that is counterbalanced by Type 1 immunity and Tregs. Widely used allergen-specific immunotherapy (IT) is a long term treatment to induce such switch from Th2 to Th1 response. However, conventional IT requires multiple allergen injections over a long period of time and is not free of risk of producing allergic reactions. As a consequence, new safer and faster immunotherapeutic methods are required. This review deals with allergen IT using nanoparticles as allergen delivery system that will allow a different way of administration, reduce dose and diminish allergen exposure to IgE bound to mast cells or basophils.

Immunogenicity of Peanut Proteins Containing Poly(Anhydride) Nanoparticles

ABSTRACT In the last decade, peanut allergy has increased substantially. Significant differences in the prevalence among different countries are attributed to the type of thermal processing. In spite of the high prevalence and the severe reaction induced by peanuts, there is no immunotherapy available. The aim of this work was to evaluate the potential application of poly(anhydride) nanoparticles (NPs) as immunoadjuvants for peanut oral immunotherapy. NPs loaded with raw or roasted peanut proteins were prepared by a solvent displacement method and dried by either lyophilization or spray-drying. After physicochemical characterization, their adjuvant capacity was evaluated after oral immunization of C57BL/6 mice. All nanoparticle formulations induced a balanced TH1 and TH2 antibody response, accompanied by low specific IgE induction. In addition, oral immunization with spray-dried NPs loaded with peanut proteins was associated with a significant decrease in splenic TH2 cytokines (interleukin 4 [IL-4], IL-5, and IL-6) and enhancement of both TH1 (gamma interferon [IFN-γ]) and regulatory (IL-10) cytokines. In conclusion, oral immunization with poly(anhydride) NPs, particularly spray-dried formulations, led to a pro-TH1 immune response.

Early skin testing is effective for diagnosis of hypersensitivity reactions occurring during anesthesia.

Allergic skin tests have to be performed 4–6 weeks after an allergic anesthetic reaction. Patients with allergic reactions during anesthesia were prospectively included (n = 44). Skin tests were performed in two stages: (i) Stage 1 (S1), 0–4 days after the reaction; and (ii) Stage 2 (S2), 4–8 weeks after. Five (11.5%) surgical procedures were suspended due to the reaction. Positive skin tests were obtained in 25/44 patients (57%). Allergic diagnosis was carried out at S1 in 15/25 (60%) and at S2 in 10/25 (40%). Three patients resulted positive only in S1. Overall agreement among S1 and S2 skin tests was 70.45%. The kappa statistic was 0.41 (P‐value = 0.002). Odds ratio of obtaining a false negative in S1 (compared with S2) was 3.33. Early allergological study is useful, could minimize false negatives, but should be considered as a complement to late skin tests.