Peculiar HLA polymorphisms in Italian patients with primary biliary cirrhosis.

BACKGROUND/AIMS: Primary biliary cirrhosis (PBC) is an autoimmune cholestatic liver disease of unknown etiology with a highly variable progression rate and prevalence among different geographical areas. Data concerning human leukocyte antigen (HLA) polymorphisms in PBC come from a limited number of geographical areas, from which the association with the HLA-DRB1*08 allele has been consistently reported.

METHODS

To investigate whether HLA polymorphisms contribute toward disease susceptibility, we compared 186 well-defined Italian PBC patients with 558 healthy subjects matched by age, gender and geographical area (Northern, Central and Southern Italy). Patients and controls were HLA typed at low resolution by PCR-sequence specific oligonucleotides for the loci A and B; HLA-DRB1 alleles were typed by reverse line blot assay of PCR-amplified DNA.

RESULTS

HLA-DRB111 was associated with a markedly reduced risk of developing PBC (OR: 0.3; 95% CI: 0.2-0.5). No association was found with HLA-DRB108. The B15 (2.5; 1.3-4.6), B41 (12.0; 2.7-72.1), B55 (2.9; 1.1-7.5) and B58 alleles (6.8; 1.1-46.3) were more frequent in PBC. The frequency of HLA polymorphisms was similar in PBC patients with progressive or non-progressive disease, and in those with or without anti-mitochondrial antibodies.

CONCLUSIONS

Our data on a large series of Italian patients suggest that PBC may have a peculiar genetic background in the Mediterranean area.