HLA‐DR Antigens in HBsAg‐Positive Chronic Active Liver Disease with and without Associated Delta Infection

The A, B, C and DR locus specificities of the human leukocyte antigens system (HLA) were determined in 45 delta‐positive and 44 delta‐negative Italian patients, all with HBsAg‐positive chronic active liver disease; controls were 526 healthy Italian blood donors matched for age, sex and geographical origin. HLA‐A, B, C gene frequencies were not significantly changed. In delta‐positive patients, the frequencies of the DR locus specificities were: DR2, 37.8%; DR3, 20%; DR4, 11.1%. In the delta‐negative patients, the frequencies were: DR2, 13.6%; DR3, 36.4%; DR4, 0%. Control frequencies were: DR2, 19.4%; DR3, 17.1%; DR4, 18.5%. The corrected p values of the differences between controls and delta‐positive patients were: DR2, pc = 0.046; DR3, pc = NS (not significant); DR4, pc = NS. The corrected p values of the differences between controls and delta‐negative patients were: DR2, pc = NS; DR3, pc = 0.03; DR4, pc = 0.002. These findings show that: (a) DR3, a genetic marker of autoimmunity, might assist the establishment of chronic HBsAg liver disease in the absence of delta superinfection; (b) DR2 is linked with failure to clear the delta agent, and (c) DR4 may protect from virus B persistence. Identification of adventitious factors such as delta may help uncover a subgroup of HBsAg carriers who are genetically predisposed to develop chronic liver disease. Copyright © 1984 American Association for the Study of Liver Diseases