Clearance of fungal burden during treatment of disseminated histoplasmosiswith liposomal amphotericin B versus itraconazole

Animal studies have shown that fungal burden correlates with survival durin g treatment with new antifungal therapies for histoplasmosis. The purpose o f this report is to compare the clearance of fungal burden in patients,vith histoplasmosis treated with liposomal amphotericin B versus itraconazole, In two separate closed clinical trials that evaluated the efficacy of lipos omal amphotericin B and itraconazole treatment of disseminated histoplasmos is in patients with ALDS, blood was cultured for fungus and blood and urine were tested for Histoplasma: antigen, The clinical response rates were sim ilar; 86% with liposomal amphotericin B (n = 51) versus 85% with itraconazo le (n = 59). Of the patients with positive blood cultures at enrollment, af ter 2 weeks of therapy cultures were negative in over 85% of the liposomal amphotericin B group versus 53% of the itraconazole group (P = 0.0008). Fur thermore, after 2 weeks, median antigen levels in serum fell by 1.6 U in th e liposomal amphotericin B group versus 0.1 U in the itraconazole group (P = 0.02), and those in urine fell by 2.1 U in the liposomal amphotericin B g roup and 0.2 U in the itraconazole group (P = 0.0005). The more rapid clear ance of fungemia supports the use of liposomal amphotericin B rather than i traconazole for initial treatment of moderately severe or severe histoplasm osis.