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.