INTERLEUKIN-6 DURING ACTIVE VISCERAL LEISHMANIASIS AND AFTER TREATMENT

To determine the utility of the serum concentrations of interleukin 6 (IL-6) as a marker of disease activity and therapeutic efficacy in vis ceral leishmaniasis (VL), IL-6 levels were measured in 19 patients wit h active VL from Sudan before and after treatment. IL-6 levels mere 30 +/- 6 pg/ml during the active phase of the disease, decreased to leve ls around the detection limit of the assay (2 pg/ml) directly after su ccessful antimony therapy, and remained low or undetectable for up to 6 months in persistently cured patients (P < 0.005 versus baseline), I n 2 patients who had a relapse of VL, IL-6 was elevated at the time th e relapse was diagnosed, Two patients with post-kala-azar dermal leish maniasis did not have detectable IL-6 in their circulation. Sequential measurements of serum IL-6 levels maybe useful for monitoring therape utic efficacy in patients with VL. (C) 1995 Academic Press, Inc.