Immediate Hypersensitivity to Contrast Agents: The French 5-year CIRTACI Study.

BACKGROUND: Iodinated and gadolinium-based contrast media (ICM; GBCM) induce immediate hypersensitivity (IH) reactions. Differentiating allergic from non-allergic IH is crucial; allergy contraindicates the culprit agent for life. We studied frequency of allergic IH among ICM or GBCM reactors. METHODS: Patients were recruited in 31 hospitals between 2005 and 2009. Clinical symptoms, plasma histamine and tryptase concentrations and skin tests were recorded. Allergic IH was diagnosed by intradermal tests (IDT) with the culprit CM diluted 1:10, "potentially allergic" IH by positive IDT with pure CM, and non-allergic IH by negative IDT. FINDINGS: Among 245 skin-tested patients (ICM = 209; GBCM = 36), allergic IH to ICM was identified in 41 (19.6%) and to GBCM in 10 (27.8%). Skin cross-reactivity was observed in 11 patients with ICM (26.8%) and 5 with GBCM (50%). Allergy frequency increased with clinical severity and histamine and tryptase concentrations (p < 0.0001). Cardiovascular signs were strongly associated with allergy. Non-allergic IH was observed in 152 patients (62%) (ICM:134; GBCM:18). Severity grade was lower (p < 0.0001) and reaction delay longer (11.6 vs 5.6 min; p < 0.001). Potentially allergic IH was diagnosed in 42 patients (17.1%) (ICM:34; GBCM:8). The delay, severity grade, and mediator release were intermediate between the two other groups. INTERPRETATION: Allergic IH accounted for < 10% of cutaneous reactions, and > 50% of life-threatening ones. GBCM and ICM triggered comparable IH reactions in frequency and severity. Cross-reactivity was frequent, especially for GBCM. We propose considering skin testing with pure contrast agent, as it is more sensitive than the usual 1:10 dilution criteria.

Reversible ileitis secondary to high dose intravenous immunoglobulin in adult kidney transplant patient treated for acute humoral rejection.

Use of high dose intravenous immunoglobulin (IVIg) has been associated with necrotizing enterocolitis in late-preterm and term infants treated for severe isoimmune hemolytic jaundice. We present the first adult case of reversible ileitis related to high dose IVIg that occurred during the treatment of acute humoral rejection in a kidney transplant recipient (original nephropathy: lupus). At the third of the 5 days of a 0.4 g/kg/day IVIg infusion, he had periumbilical pain and nausea. Non-iodine injected abdominal computed tomography (CT) demonstrated a major proximal ileitis that was absent 1 month earlier on a previous CT. After the fourth injection, IVIg therapy was discontinued. Clinical and radiological signs disappeared, respectively, 5 and 7 days after IVIg discontinuation. No other causes of ileitis were diagnosed (especially infectious, vascular, or lupus-related bowel disease causes). Usual abdominal pain and nausea during IVIg therapy may be related to sub-clinical ileitis and/or enteritis. As in newborn, such complication has to be diagnosed and IVIg infusion discontinued because of potential evolution to intestinal necrosis.