HLA AND ALVEOLAR ECHINOCOCCOSIS

Evidence in animal intermediate hosts that susceptibility to larval in fection with Echinococcus multilocularis is restricted to individual h ost factors prompted us to investigate the susceptibility markets: in humans. Because antigens of the extracellular parasite E. multilocular is are possibly presented by MHC molecules in a restricted way we spec ulated thai MHC polymorphism may influence resistance of the host towa rds infection and course ol disease, We studied HLA-A, -B, -DRE1, -DQB 1 and DPB1 polymorphism in 151 patients with alveolar echinococcosis. Patients with an observation period of more than 2 years were grouped according to the clinical follow-up into cured (no recurrence followin g surgery) patients and patients with regressive or progressive forms of disease during benzimidazole chemotherapy. Ey comparing phenotypic frequency between patients with alveolar echinococcosis and healthy co ntrols, HLA-DRB111 was associated with a reduced risk for disease dev elopment (odds ratio=0.55, 95% confidence interval=0.34-0.88;P=0.01). HLA-DQB102 was more frequent in patients with progressive disease whe n compared with patients with regressive disease (54.3% vs 28.3%, P=0. 02). The result suggests that HLA-DRB111 might confer protection agai nst alveolar echinococcosis and that HLA-DQB102 may indicate a risk f or progressive disease development. The findings may facilitate the se arch for immunodominant T-cell epitopes of E. multilocularis.