Plasma interleukin-7 (IL-7) and IL-8 concentrations in acute rheumatic fever and chronic rheumatic heart disease.

Interleukin-7 (IL-7) and IL-8 productions in 25 children with acute rheumatic fever (ARF) and in 15 children with chronic rheumatic heart disease (CRHD) and in 15 children with streptococcal pharyngitis (SP), were investigated in order to determine whether they have a role in the pathogenesis of rheumatic fever. Significantly higher IL-8 levels were found in ARF patients in the clinically active period. IL-7 concentrations remained unchanged during different stages of rheumatic fever. The decrease of elevated IL-8 concentrations within 3 months and normal IL-8 concentrations in patients with CRHD and SP indicate an excessive production of IL-8, probably by cellular infiltrates in the joint throughout the active period of rheumatic disease.