Kawasaki disease (KD) causes coronary aneurysms in 25% of untreated patients, making it the leading cause of acquired heart disease in children. KD primarily affects those under 5 years of age with a yearly incidence in the United States of roughly 15 cases per 100,000 people. KD classically presents as minimum of 5 days of fever with conjunctivitis, singular lymph node swelling, mucous membrane inflammation, hand and/or feet swelling, and rash. The cause of KD is unclear, however there is evidence supporting a relation to an infectious disease. Unfortunately, there is no reliable diagnostic test for KD.
Due to studies showing infiltrating IgA+ B cells into coronary aneurysms of KD, it’s been theorized that there is an invasive infectious agent within the coronary wall that leads to a specific IgA+ B cell immune response. To date, there have been few published reports on the peripheral blood dynamics during KD. Some reports have shown a paucity of IgA+ cells in the periphery where others have shown no significant changes in B cell subsets. We hypothesized that, if these aneurysm-associated infiltrating IgA+ B cells in published studies are against a specific etiologic agent of KD, we should similarly see an specific elevation of IgA+ B cells in the peripheral blood.
Febrile subjects 9 months to 6 years of age with fever and any symptoms meeting KD criteria undergoing lab evaluation were recruited. Subjects treated for KD were compared to other enrollees with discharge diagnoses other than KD. Peripheral blood mononuclear cells were isolated and evaluated utilizing flow cytometry with specific B cell markers of IgA, IgM, IgG, CD19 and CD20 and plasmablast activation markers CD27 and CD38. Initial power calculations based on IgA+ B cell responses in other systems indicated the need for six subjects in each group.
With non-parametric statistical evaluation, we did not show an increase in IgA+ B cells that correlated with KD. We did show than an increase in a subset of B cell plasmablasts (CD20low, CD27+CD38+) correlated with KD (p=.038).
Peripheral IgA+ cell are not elevated and do not explain IgA+ cell infiltrative findings previously published. Levels of B cell plasmablasts however do show a significant difference and should be further pursued as a potential marker of KD.
H. Qiao, None
H. Sojar, None
M. Hicar, None