Increased incidence of autoimmune hepatitis is associated with wider use of biological drugs

Abstract

Background & aims Population‐based studies on the epidemiology of autoimmune hepatitis (AIH) are scarce. Drug‐induced AIH (DIAIH) is increasingly recognized in association with immunomodulatory therapy. We aimed to determine the incidence, prevalence and natural history of AIH in a population‐based setting. Methods We collected data of new diagnosis of AIH in Iceland from 2006 to 2015. Cases were identified through search of diagnostic codes and text search for AIH within electronical medical records of all hospitals in Iceland and through records of smooth muscle antibodies (SMA) test results by the only laboratory in the country analyzing SMA. Patients were included in the final analysis if they received the clinical diagnosis of AIH or were started on immunosuppressive therapy. Results The mean annual incidence of AIH in Iceland was 2.2 cases per 100 000 inhabitants. Point prevalence on 31 December 2015 was 27/100 000. The median age at diagnosis was 56 years and 86% of patients were of female gender. DIAIH was suspected in 13 of 71 patients (18%) of which eight cases were related to infliximab. Immunosuppressive treatment was started in all but two patients. At the end of follow‐up (median 4.8 years) 66 of 71 (93%) patients were alive. Conclusion The incidence and prevalence rates of AIH in Iceland are the highest reported so far in a population‐based setting. Higher incidence can partly be explained by the increasing use of biological drugs. Immunosuppressive therapy was very effective in achieving remission and prognosis was favorable.

Incidence, prevalence and mortality of autoimmune hepatitis in England 1997‐2015. A population‐based cohort study

“…Our incidence and prevalence estimates are in accordance with other studies using registry diagnoses for AIH patient identification 7,14 as well as in accordance with studies using medical notes, biochemistry, and histology for patient identification. 3,5,6,[8][9][10][11][12][13] This indicates that our case ascertainment is likely to be reasonably complete.…”

“…1,2 The incidence rate of AIH from various regions of the world ranges from 0.4 to 3.0 per 100,000 population per year. [3][4][5][6][7] Some authors have reported a stable incidence over time, 5,[8][9][10] others an increasing incidence. 3,6,7,[11][12][13][14] Apart from sex, age, and calendar time, socioeconomic status and region of residence may affect the likelihood of being diagnosed with AIH.…”

“…[3][4][5][6][7] Some authors have reported a stable incidence over time, 5,[8][9][10] others an increasing incidence. 3,6,7,[11][12][13][14] Apart from sex, age, and calendar time, socioeconomic status and region of residence may affect the likelihood of being diagnosed with AIH. 15,16 Evaluation of the variation in AIH incidence over time and place may provide novel insight into the risk factors for AIH.…”

Belimumab is a promising third-line treatment option for refractory autoimmune hepatitis

“… 17 Under this context, it has already reported that TNF-α inhibition can sometimes result in exactly the opposite outcome. [17] , [18] , [19] , [20] , [21] Indeed, in a recent large international pharmacovigilance database including 389 patients with anti-TNF-α inhibitor-associated AIH, it was shown that infliximab was the most frequently involved drug, followed by adalimumab and etanercept. 17 This ‘therapeutic paradox’ is mainly attributed to the disruption of the regulatory role of TNF-α signalling in the immune system.…”

The Asian Pacific Association for the Study of the Liver clinical practice guidance: the diagnosis and management of patients with autoimmune hepatitis

“…First, genetic factors may play an important role and this can partly explain the higher prevalence rate of AIH in New Zealand than other Asia–Pacific countries, as 83% of the population is of European descent [ 7 ]. Second, environmental factors may also play a role in the development of AIH, as supported by a recent study showing biological use was associated with increased incidence of AIH in Iceland [ 8 ]. Third, health care system difference and relatively low awareness/recognition of AIH in Asia [ 4 ].…”