Because activated T cells target the intrahepatic bile ducts in PBC and pre-clinical models suggested that blocking CD80/CD86 with CTLA-4 Ig might have therapeutic benefit in PBC, we performed an open-label trial to determine if CTLA-4 Ig (abatacept) is safe and potentially efficacious in PBC patients with an incomplete response to UDCA.
Although no significant differences in clinical or biochemical characteristics between patients with PBC and PBC-AITD were seen (all P>0.05), liver function tests and metabolic traits in PBC patients were significantly (all P<0.05) affected by the CTLA4 (rs3087243), MMEL1 (rs2843403), PTPN22 (rs2476601) and RNASET2 (rs9355610) variants.
The connection between gene polymorphisms of cytotoxic T-lymphocyte-associated protein 4 (<i>CTLA4</i>) and primary biliary cholangitis (PBC) is still vague and blurred.
Our pooled analysis revealed that G allele of CTLA-4 gene +49A/G polymorphism may confer an increased risk of PBC in overall (p = 0.001, OR = 1.29; 95% CI = 1.13-1.47) and Caucasians (p = 0.001, OR = 1.32; 95% CI = 1.21-1.44).
Our results provide evidence for RA and PBC association with the CTLA4/ICOS locus and suggest that the risk allele(s) within this region may be common to both diseases.
Single nucleotide polymorphisms of the CTLA4 gene have been implicated in autoimmune diseases, including autoimmune hepatitis and primary biliary cirrhosis.
Recently, polymorphisms in the tumor necrosis factor alpha (TNFA) gene promoter at position -308 and in exon 1 of the cytotoxic T lymphocyte antigen-4 (CTLA-4) gene at position 49 have been associated with susceptibility to PBC in Caucasians.