Correlations between inflammatory response and percentage of lymphocyte or CD19+ B cell count in Kawasaki disease children of different ages undergoing intravenous immunoglobulin: a retrospective study

Abstract

Background: Intravenous immunoglobulin (IVIG) is the most common therapy in Kawasaki Disease (KD), but during this course, the inflammatory response remains unclear. We evaluated the relationship between inflammatory response and lymphocyte count in KD children with different ages undergoing IVIG, to identify the clues in lab parameters of therapeutic effect of IVIG on KD. Methods: We retrospectively reviewed the medical records of 60 KD children and divided the patients into five groups depending on different ages. We investigated the percentage of neutrophil reduced and that of lymphocyte increased after IVIG in all groups and explored the absolute cell count of CD19+ cells before therapy and the level of interleukin-10 (IL-10) in patients aged 4 years and older after IVIG with linear regression and correlation analysis. Results: During the acute phase of KD and after IVIG, patients’ percentage of reduced neutrophil correlated positively with the percentage of increased lymphocyte. With children grew older, the correlation coefficients valued higher which were respectively 0.91 (group of less than 1 year), 0.87 (1 year), 0.91 (2 years), 0.97 (3 years), 0.99 (4 years and older) with p value less than 0.01 in all of groups. Means of age in five groups correlated positively with the value of correlation coefficient (r = 0.88, P < 0.05). In the patients aged 4 years and older, abnormal higher CD19+ cell absolute count before the administration of IVIG correlated positively with the reduced IL-10 after the IVIG (r = 0.71, P < 0.05). Conclusions: During the acute phase of KD, the older the children’s age, the better the regulatory effect of IVIG on the immune response and the following recovery of immune equilibrium. In KD patient aged 4 years and older the abnormal proliferating CD19+ B cell played dominant role in the humoral immune and may be involved in the secretion of IL-10 to balance the overactive humoral immune. Combined assessment of CD19+ B cell absolute count with the expression of decreased IL-10 after IVIG may be potential to evaluate the effect of IVIG on inflammatory immune response in KD children with older age.