Temporal prescribing trends in AIH: exploring the influence of early thiopurine use on corticosteroid dependency and biochemical response

Objective Patients with autoimmune hepatitis (AIH) receive variable corticosteroid and thiopurine regimens. Our aim was to undertake a cohort study to determine whether earlier introduction of azathioprine allowed reduction in cumulative corticosteroid burden. We also determined temporal trends in treatment choices and outcomes. Method 226 adults with AIH treated from 1970 to 2020 at Kings College Hospital were divided into two groups: patients who received azathioprine therapy within 8 weeks of initiation of corticosteroid therapy (early group, n=106) and patients who had received azathioprine more than 8 weeks after corticosteroid initiation (late group, n=120). Results Cumulative exposure to corticosteroid was not significantly different between each group. 80% of patients achieved normalisation of aspartate aminotransferase within 6 months of corticosteroid induction compared with 64.5% in the late group (p=0.013). When evaluated by decade, the cumulative corticosteroid exposure and dose declined over time (p<0.001). Azathioprine initiation fell from a mean of 80 weeks from corticosteroid induction in the 1970s to 10 weeks in the 2010s (p=0.026). Biochemical remission occurred at a faster rate in more recent cohorts (p=0.001). Conclusion Earlier introduction of azathioprine after corticosteroid therapy resulted in a higher rate of transaminase normalisation at 6 months but did not significantly reduce the cumulative prednisolone exposure over 5 years. Temporal effects in the management of AIH are evident, whereby earlier introduction of thiopurines in recent decades facilitated more rapid reduction in corticosteroid dose while achieving a higher rate of biochemical response.