Evidence map›Paper›PMID 42801414›Full record

ArticleClinical and experimental nephrology2026

The prevalence of IgA nephropathy in Japan: results from a nationwide survey.

Keiichi Matsuzaki, Ryousuke Aoki, Shinya Nakatani, Satoko Ohfuji, Satoru Muto, Wakaba Fukushima, Yoshitaka Isaka, Takashi Yokoo, Yusuke Suzuki

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Article in Clinical and experimental nephrology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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5 · Who and what money

Authors and funding

9 authors.

Keiichi MatsuzakiDepartment of Public Health, Kitasato University School of Medicine, 1-15-1 Kitazato, Minami-Ku, Sagamihara, Kanagawa, 252-0374, Japan. matsuzaki.keiichi@kitasato-u.ac.jp.ORCID http://orcid.org/0000-0002-2113-1574
Ryousuke AokiDepartment of Nephrology, Juntendo University Faculty of Medicine, 2-1-1 Hongo, Bunkyo-Ku, Tokyo, 113-8421, Japan.
Shinya NakataniDepartment of Nephrology, Osaka Metropolitan University Graduate School of Medicine, Osaka, Japan.
Satoko OhfujiDepartment of Public Health, Osaka Metropolitan University Graduate School of Medicine, Osaka, Japan.
Satoru MutoDepartment of Urology, Juntendo University Nerima Hospital, Tokyo, Japan.
Wakaba FukushimaDepartment of Public Health, Osaka Metropolitan University Graduate School of Medicine, Osaka, Japan.
Yoshitaka IsakaDepartment of Nephrology, The University of Osaka Graduate School of Medicine, Suita, Japan.
Takashi YokooDivision of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan.
Yusuke SuzukiDepartment of Nephrology, Juntendo University Faculty of Medicine, 2-1-1 Hongo, Bunkyo-Ku, Tokyo, 113-8421, Japan. yusuke@juntendo.ac.jp.

Funding

Japan Intractable Diseases Research Foundation 23FC1048
6 · The paper itself

Abstract

backgroundPrecise epidemiological statistics regarding IgA nephropathy (IgAN) are essential for healthcare resource allocation and optimal therapeutic management. However, a nationwide epidemiological study has not been conducted in Japan over the past twenty years.

methodsWe conducted a mail-based survey targeting departments at hospitals to estimate the annual numbers of patients with IgAN in 2022. Departments were selected using stratified random sampling based on specialty and hospital size, and a total of 2148 departments (nephrology, pediatrics, and urology) were included in the analysis. The overall and sex-specific annual numbers of patients with IgAN were estimated, along with the number of patients with high disease activity. The corresponding prevalence was calculated using these estimates, divided by the midyear population of Japan in 2022.

resultsA total of 702 departments responded to the survey representing an overall response rate of 32.7%. The estimated numbers of patients with IgAN were 103,800 (95% confidence interval [CI] 83,431-124,170), including 50,160 men (95% CI 40,034-60,287) and 53,640 women (95% CI 42,799-64,481). The annual prevalence of IgAN was 83.1 per 100,000 population (men: 82.6 women: 83.6), with a male-to-female ratio of 0.99. The estimated numbers of IgAN patients with high disease activity were 15,646 (95% CI 12,464-18,828).

conclusionsThis nationwide survey provides updated estimates of the prevalence of IgAN and the number of the IgAN patients with high disease activity in Japan. The prevalence of IgAN has risen substantially over the past twenty years.

Indexed as

EpidemiologyIgA nephropathyJapanNationwide surveyPrevalence

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.