SERUM-SOLUBLE MARKERS IN THE EVALUATION OF TREATMENT IN HUMAN VISCERAL LEISHMANIASIS

Visceral leishmaniasis (VL) has a fatal course if not properly treated . Recovery from VL is linked to cellular immune response. Unresponsive ness to antimonial therapy reinforces the importance of determining pa rameters for treatment assessment. We analysed the pre- and post-treat ment serum levels of soluble CD4 (sCD4), sCD8, sIL-2R, soluble interce llular adhesion molecule-1 (sICAM-1) and neopterin in groups of VL pat ients either responsive or not to standard antimonial therapy. Pretrea tment serum levels of all markers except for sICAM-1 were significantl y higher in VL patients than in healthy subjects from the same area (P < 0.05). sICAM-1 levels were similar in healthy controls and in VL pa tients refractory to antimonial therapy (P = 0.25), but significantly higher in patients responsive to treatment (P = 0.02). The comparison of pre- and post-treatment concentrations showed that all markers, exc ept sCD4 and sICAM-1, presented a significant fall (P < 0.05) in patie nts responsive to antimonial therapy. However, only neopterin presente d with levels compatible with those of healthy subjects at the end of treatment (P = 0.30). In refractory patients sICAM-1 presented with po st-treatment levels significantly higher than the pretreatment determi nations (P = 0.03), while sCD4 experienced a significant drop (P = 0.0 1). All markers displayed clearly distinct behaviour according to the patient's response to therapy. This makes all soluble molecules studie d suitable for use as indicators of antimonial therapy response. Addit ionally the comparison of pretreatment levels of the markers between r esponders and refractory patients to antimonial therapy showed that se rum concentrations of sIL-2R and sICAM-1 significantly differed among these two groups (P = 0.02 in each case), suggesting that they may be used in future as predictors of antimonial therapy response.