Sulfonamide Drug Allergy.

PURPOSE OF REVIEW: We sought to review past and current literature on sulfonamide drug allergy and distill it in a practical manner to assist the clinician, specifically focusing on cross-reactivity and desensitization. RECENT FINDINGS: There do not appear to be consistent genetic markers to reliably predict features of or the presence hypersensitivity reactions. Recent evidence continues to alleviate early concerns cross-reactivity between sulfonamide antibiotics and non-antibiotics. Sulfonamide drug allergy is frequently encountered by the practicing clinician. For sulfonamide antibiotics, delayed rash is the most common clinical manifestation. There is no current evidence to support avoidance of all non-antibiotic sulfonamides in those with a reported allergy to sulfonamide antibiotics, although certain scenarios require caution. Available evidence supports the cautious reintroduction of sulfonamide antibiotics via desensitization, which is usually well tolerated and should be considered in those with strong indications for trimethoprim-sulfamethoxazole and a reported sulfonamide allergy.

Optimal approach to assessing T-cell function in haematopoietic cell transplant recipients.

Standardised approaches to functional immune assessment after haematopoietic cell transplantation (HCT) are lacking. A 12-year-old girl with relapsed acute myelogenous leukaemia, 2 years post-unrelated HCT, underwent immunological evaluation prior to receiving live vaccinations. Assessment of standard immune parameters and T-cell proliferation to phytohaemagglutinin was reassuring. She was given Varicella vaccination based on usual post-transplant protocols but was hospitalised 10 days later with localised Varicella infection (vaccine strain). Following recovery, she underwent further assessment that showed reduced T-cell proliferation to an anti-CD3 stimulation panel (anti-CD3 alone, soluble anti-CD3+ anti-CD28 and soluble anti-CD3+ plus exogenous IL-2). On reassessment, 7 months later, T-cell responses to anti-CD3 stimulation were normal and she was revaccinated without further incident. Measurement of T-cell proliferation to anti-CD3 stimulants likely yields more useful information about global T-cell function and should be strongly considered prior to live vaccine administration post-allogeneic haematopoietic transplant.