Effect of Penicillin Treatment on Serum Complement Levels in Acute Rheumatic Fever

Abstract

Serum complement levels were studied in a longitudinal fashion throughout the hospitalization of 40 patients with acute rheumatic fever. In a group of 19 patients who had normal serum complement values on admission, the levels remained normal throughout the course of observation in 14 and fell to below normal in 2. In a group of 21 patients with raised serum complement values on admission all returned to normal in less than 16 days. A secondary rise in serum complement levels above the initial values was observed in 12 patients after starting treatment with antibiotics. This rebound phenomenon may be regarded as suggestive of increased complement consumption in acute rheumatic fever. Correlation of clinical and serological data suggests that treatment with penicillin (or erythromycin or sulphadiazine) resulted in all raised complement values returning to normal within 16 days. Treatment with salicylates had no significant influence on complement levels. These data support the impression that the rise in serum complement which occurs in acute rheumatic fever is caused predominantly by the infection with hemolytic streptococci.