Predictive value of C-reactive protein to albumin ratio as a biomarker for initial and repeated intravenous immunoglobulin resistance in a large cohort of Kawasaki disease patients: a prospective cohort study

BACKGROUND: Intravenous immunoglobulin (IVIG) resistance prediction is one pivotal topic of interests in Kawasaki disease (KD). This study aimed to prospectively investigated the value of C-reactive protein-to-albumin (CAR) in predicting both initial and repeated IVIG resistance in patients with KD, and to test the hypothesis that CAR was more valuable or accurate than either C-reactive protein (CRP) or albumin (ALB) alone in IVIG resistance prediction. METHOD: A prospective cohort study involving 550 patients with KD was conducted. The clinical and laboratory data were compared between IVIG-response group and IVIG-resistance group. Multivariate logistic regression analysis was performed to identify the independent risk factors of initial/repeated IVIG resistance. Receiver operating characteristic (ROC) curves analysis was applied to assess the validity of CAR, CRP and ALB in predicting both initial and repeated IVIG resistance. RESULTS: CAR was significantly higher in IVIG non-responders and was identified as independent risk factor for both initial and repeated IVIG resistance in KD. The best cut-off value of CAR for initial and repeated IVIG resistance prediction was 2.07 and 3.34, with a corresponding sensitivity of 0.610 and 0.548, a specificity of 0.552 and 0.813, respectively. The value of CAR was not better than either CRP or ALB alone for both initial and repeated IVIG resistance prediction. CONCLUSION: A higher CAR was an independent risk factor for both initial and repeated IVIG resistance. However, similar with that of CRP or ALB, the predictive value of CAR was not good enough for both initial and repeated IVIG resistance prediction in KD. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12969-021-00517-1.