Increase trend in the prevalence and male‐to‐female ratio of primary biliary cholangitis, autoimmune hepatitis, and primary sclerosing cholangitis in Japan

Abstract

Aim Autoimmune liver diseases (AILD) including autoimmune hepatitis (AIH), primary biliary cholangitis (PBC), and primary sclerosing cholangitis (PSC) impose a significant burden on public health, and it is important to estimate their prevalence. We carried out a nationwide, hospital‐based, epidemiological survey of AIH, PBC, and PSC, and compared the results with those from previous surveys. Method We randomly selected health‐care facilities used in the survey from a list of all facilities in Japan. The selection rate was determined according to a stratification based on the facility characteristics and scale. We sent questionnaires to the selected facilities enquiring about the number and sex of patients with AILD who visited the facility in 2016. An identical survey was undertaken for AIH/PBC in 2004 and for PSC in 2007; we carried out a comparative analysis of these data. Results We selected 1793 departments from health centers all over Japan. Of them, 1078 (60.1%) responded to the questionnaires. The number of reported patients with AIH, PBC, and PSC was 8505, 10 847, and 906, respectively, and point prevalence was 23.9 (95% confidence interval, 23.3–24.5) for AIH (8.7 in 2004), 33.8 (33.0–34.6) for PBC (11.6 in 2004), and 1.80 (1.75–1.85) for PSC (0.95 in 2007) per 100 000 population. Male‐to‐female patient ratio of AILD was 1:4.3 for AIH (1:6.9 in 2004), 1:3.9 for PBC (1:7.1 in 2004), and 1:0.88 for PSC (1:1.4 in 2007). Conclusion The current study indicates an increasing trend of prevalence as well as male‐to‐female patient ratio of AILD in Japan.

Systematic review and meta‐analysis on the incidence and prevalence of autoimmune hepatitis in Asian, European, and American population

“…Among the 11 studies with moderate quality, seven studies were attributed to insufficient case‐finding strategies, such as including only a single hospital data or only outpatients, or only children, while the other four studies were due to the imperfect case‐ascertainment process performed by other diagnostic criteria . Three studies were regarded as poor quality because the case‐ascertainment process was not reported …”

“…[26][27][28] Sixteen studies reporting AIH prevalence rates were included, with nine from Europe, 6,7,9,11,12,20,21,23,24 two from America, 4,29 and five from Asia. 3,5,8,10,30 The characteristics of these studies are summarized in Table 2. In addition, five eligible studies were available to calculate the genderspecific incidence 5,11,23,26,27 and 10 for gender-specific prevalence.…”

“…The reported AIH prevalence rate of Japan is 23.4 per 100 000 persons, which is almost equal to that in European and American countries, and higher than that reported from other Asian countries. Although the reasons for this difference are unclear, one possible explanation might be environmental factors and lifestyles differences and changes . Another explanation is the establishment of a special network on liver diseases and associated increase in awareness and diagnostic ability in Japan (2010) …”

“…[4][5][6][7][8][9] This may be partly due to the wide spectrum of clinical presentation and lack of specific biomarkers and simple diagnostic criteria. Recently, several researches demonstrated that the incidence and prevalence of AIH were increasing, [9][10][11][12] not only in Europe and Northern America 9,11,12 but also in some Asian countries. 10,13 A systematic review on the incidence of AIH published in 2015 described AIH occurrence all over the world but did not conduct a meta-analysis.…”

“…Recently, several researches demonstrated that the incidence and prevalence of AIH were increasing, [9][10][11][12] not only in Europe and Northern America 9,11,12 but also in some Asian countries. 10,13 A systematic review on the incidence of AIH published in 2015 described AIH occurrence all over the world but did not conduct a meta-analysis. 14 Therefore, in this study, we conducted a systematic review and meta-analysis with the aim to pool the global incidence and prevalence rate of AIH and characterize the population difference.…”