HIGH-LEVELS OF PLASMA IL-10 AND EXPRESSION OF IL-10 BY KERATINOCYTES DURING VISCERAL LEISHMANIASIS PREDICT SUBSEQUENT DEVELOPMENT OF POST-KALA-AZAR DERMAL LEISHMANIASIS

Some patients develop post-kala-azar dermal leishmaniasis (PKDL) after they have been treated for the systemic infection kala-azar (visceral leishmaniasis). It has been an enigma why the parasites cause skin sy mptoms after the patients have been successfully treated for the syste mic disease. We report here that PKDL development can be predicted bef ore treatment of visceral leishmaniasis, and that IL-IO is involved in the pathogenesis. Before treatment of visceral leishmaniasis, Leishma nia parasites were present in skin which appeared normal on all patien ts. However, IL-10 was detected in the keratinocytes and/or sweat glan ds of all patients who later developed PKDL (group 1) and not in any o f the patients who did not develop PKDL (group 2). Furthermore, the le vels of IL-10 in plasma as well as in peripheral blood mononuclear cel l culture supernatants were higher in group 1 than in group 2.