EFFECT OF TISSUE INVASION AND TREATMENT WITH ITRACONAZOLE OR AMPHOTERICIN-B ON GALACTOMANNAN LEVELS IN PLASMA OF GUINEA-PIGS WITH EXPERIMENTAL INVASIVE ASPERGILLOSIS

The guinea-pig model of invasive aspergillosis was used to study the e ffect of the intensity of tissue invasion and of antifungal treatment on galactomannan levels in plasma. In untreated animals, galactomannan titres, determined with Pastorex Aspergillus, steadily increased and reached a maximum shortly before death. There was a significant correl ation (P < 0.05) between this increase and that of the mean colony for ming units of Aspergillus fumigatus in muscle, kidney, brain, peritone um, eye and spleen, but not in skin, liver and lung. Pastorex Aspergil lus detected galactomannan in 19/20 (95%) of the infected untreated an imals. Uninfected guinea-pigs (160 samples) remained negative. In anim als treated with itraconazole or amphotericin B, striking differences in antigenemia were observed between surviving and non-surviving anima ls. Only 5/25 surviving animals had detectable amounts of galactomanna n in plasma, all on day 2 and one also on day 5, suggesting that succe ssful treatment rapidly eradicated A.fumigatus or reduced the fungus t o a level too low to release sufficient amounts of galactomannan. Anti genemia in treated non-surviving guinea-pigs resembled more closely th e results in untreated animals. However, the number of positive animal s (21/29 or 72.5%) was lower, suggesting that unsuccessful antifungal treatment could also affect levels of circulating galactomannan.