Add-on immunosuppressive therapy may benefit selected patients with primary biliary cholangitis and autoimmune phenomena.

Background: Mildly elevated levels of transaminase and/or immunoglobulin G (IgG) are common in patients with primary biliary cholangitis (PBC). It is still unclear whether adding immunosuppressive therapy to ursodeoxycholic acid (UDCA) benefits those patients who are not fulfilling the diagnostic criteria of PBC with autoimmune hepatitis (AIH) features.

Objectives: To assess the efficacy of adding immunosuppressive therapy to UDCA for patients with PBC and autoimmune phenomena but not fulfilling the diagnostic criteria of PBC with AIH features.

Design: This is a retrospective-prospective cohort study in a tertiary medical center.

Methods: Patients with PBC and autoimmune phenomena were defined by the elevation of IgG and/or transaminase but did not fulfill the diagnostic criteria of PBC with AIH features. We grouped these patients based on with and without add-on immunosuppressive therapy and balanced their baseline characteristics using inverse probability treatment weighting (IPTW).

Results: A total of 652 patients with PBC and autoimmune phenomena were included, with a median follow-up of 4.08 years. After IPTW, the pseudo sample size in the add-on therapy and monotherapy groups was 558 and 655, respectively. After 1 year of observation, patients in the add-on therapy group had a higher biochemical response rate (normalization of transaminase and IgG levels) (49% versus 17%, p < 0.001). Furthermore, add-on therapy improved the transplant-free survival in the subgroup of patients with PBC and transaminase ⩾3 × upper limit of normal (ULN) or IgG ⩾1.3 × ULN (p = 0.033).

Conclusion: Add-on immunosuppressive therapy may improve the normalization rates of transaminase and IgG levels in all patients with PBC and mildly elevated transaminase and IgG levels and the long-term outcomes in the subgroup of the patients with transaminase ⩾3 × ULN or IgG ⩾1.3 × ULN.