The frequency and clinical significance of antibodies to soluble liver antigen/liver pancreas in autoimmune hepatitis: a prospective single-center study.

Background and aims: Soluble liver antigen/liver pancreas antibodies (anti-SLA/LP) are specific markers for autoimmune hepatitis (AIH) that have been associated with a distinct clinical phenotype and a more aggressive form of AIH. We prospectively evaluated the frequency and clinical significance of anti-SLA/LP in Turkish patients with AIH.

Material and methods: We prospectively included patients diagnosed with AIH between January 2018 and May 2023. Autoantibodies were detected using by immunofluorescence and immunoblot.

Results: We included 61 (80%, female) AIH patients with a median age of 31 years (15-78) at the time of diagnosis. Anti-SLA/LP was detected in 20% ( n  = 12) of the patients. Baseline characteristics, treatment responses and outcomes were similar among anti-SLA/LP-positive and anti-SLA/LP-negative AIH patients. Anti-SLA/LP-positive patients had significantly higher biochemical response rates after 4 weeks (100 vs. 67%, P  = 0.027), 3 months (100 vs. 39%, P  < 0.001), 6 months (100 vs. 69%, P  = 0.041) of therapy but not after 12 months (100 vs. 76%, P  = 0.103) and at the end of follow-up (100 vs. 91%, P  = 0.328). Relapse rates following treatment response were similar in patients with and without anti-SLA/LP (22 vs. 23%, P  = 0.956). Second-line therapies (tacrolimus and mycophenolate mofetil) were given to seven (11%) patients, all were anti-SLA/LP-negative. Two of these progressed into end-stage liver disease and both underwent liver transplantation.

Conclusion: Our study results suggest that anti-SLA/LP positivity does not entail clinically distinct or severe features in AIH. In our cohort, anti-SLA/LP-positive patients showed a quicker response to immunosuppressive therapy.