[Evaluation of the allergenicity of ß-casein in Japanese children with cow milk allergy by using the basophil activation test].

BACKGROUND: Among the casein components, αs-casein (αs-CAS) is considered the major allergen in Japan, and there are very few reports on the allergenicity of ß-casein (ß-CAS). In this study, we compared the allergenicity of ß-CAS with that of αs-CAS in Japanese children with cow milk allergy (CMA). METHOD: The allergenicity of αs-CAS and ß-CAS in 29 CMA patients and 11 control subjects was assessed using the basophil activation test (BAT). The accuracy of the BAT to distinguish the patients with CMA from the control subjects was estimated using a receiver operating characteristic (ROC) analysis and was expressed as the area under the curve (AUC). RESULTS: BAT results for CM were positive in 93.1% of the CMA patients. The results of the ß-CAS-BAT and αs-CAS-BAT were found to be positive in 86.2% and 69.0% of the CMA patients, respectively, however, the difference was not significant. The AUC for the ß-CAS-BAT was 0.893, which was not significantly different from that for the αs-CAS-BAT (0.859). CONCLUSIONS: These results suggest that the allergenicities of ß-CAS and αs-CAS are similar in Japanese patients with CMA.

Importance of C-reactive protein level in predicting non-response to additional intravenous immunoglobulin treatment in children with Kawasaki disease: a retrospective study.

BACKGROUND: Intravenous immunoglobulin (IVIG) therapy in the acute stage of Kawasaki disease (KD; mucocutaneous lymph node syndrome) is the treatment of first choice for preventing the development of coronary artery lesions (CALs). Failure of initial treatment with IVIG remains the most consistent risk factor for CALs. However, there are few reports on nonresponders to additional IVIG therapy in KD. OBJECTIVE: The goal of the present study was to predict non-responders to additional IVIG therapy in children with KD. METHODS: This was a retrospective study aimed at predicting non-responders to additional IVIG therapy for KD in a cohort of 446 patients. The IVIG response group ('responders') was defined as those patients who were afebrile 48 hours after administration of initial IVIG. The IVIG non-response group ('non-responders') was defined as those patients who remained febrile 48 hours after administration of initial IVIG and was divided into two subgroups: (i) those patients who remained febrile 48 hours after administration of additional IVIG (non-responders 1), and (ii) those patients who were afebrile 48 hours after additional IVIG (non-responders 2). RESULTS: Ninety-one patients received additional IVIG; of these, 25 patients (non-responders 1) received additional rescue therapy because no improvement was observed and 66 patients (non-responders 2) were afebrile. Mean ­ SD C-reactive protein (CRP) levels were higher in non-responders 1 than in non-responders 2 (12.05 ­ 5.14 vs 7.67 ­ 4.99 mg/dL; p = 0.002). The optimal cutoff point of sensitivity and specificity for predicted non-responders was ≥8 mg/dL. The sensitivity and specificity for prediction of IVIG response was 76.0% and 63.6%, respectively. Forty-three patients had a CRP level of ≥8 mg/dL after initial IVIG, 18 of whom developed CALs (eight persistent lesions and ten transient lesions). Forty-eight patients had a CRP level of <8 mg/dL after initial IVIG, of whom only eight developed CALs (all transient). CONCLUSION: We have discovered a biomarker able to identify KD patients at high risk of complications who require additional IVIG treatment, thus avoiding overtreatment of low-risk individuals. We suggest that patients who have a CRP level of ≥8mg/dL after initial IVIG are likely to fail additional IVIG and may require further IVIG plus rescue therapy.