Keiju Hiromura1, Hidekazu Ikeuchi1, Ken Kayakabe1, Hitoshi Sugiyama2, Michio Nagata3, Hiroshi Sato4, Hitoshi Yokoyama5, Yoshihisa Nojima1. 1. Department of Medicine and Clinical Science, Gunma University Graduate School of Medicine, Maebashi, Japan. 2. Department of Medicine and Clinical Science, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan. 3. Department of Kidney and Vascular Pathology, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan. 4. Clinical Pharmacology and Therapeutics, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan. 5. Division of Nephrology, Kanazawa Medical University School of Medicine, Uchinada, Japan.
Abstract
AIM: The clinical and histological features of lupus nephritis (LN) are highly variable, depending on race and ethnicity. The Japan Renal Biopsy Registry (J-RBR) is a nationwide registry of renal biopsies. Here, we report a cross-sectional analysis of Japanese LN using the J-RBR database. METHODS: Out of 18 463 patients registered in the J-RBR, 331 LN patients, who received renal biopsy for the first time, were extracted and their clinical features were analyzed according to the ISN/RPS 2003 classification. RESULTS: The median age of the 331 LN patients was 37 years (women, 81.3%). The frequencies of each of the ISN/RPS Classes were as follows: I, 1.2%; II, 7.9%; III (±V), 25.1%; IV-S (±V), 13.0%; IV-G (±V), 31.1%; V, 20.8%; and VI, 0.9%. The level of proteinuria and the prevalence of nephrotic syndrome were highest for Class IV-G (±V). When Classes I, II, and VI were excluded from the analysis, Class IV-G (±V) was significantly associated with a lower eGFR and severer haematuria than the other classes. CONCLUSION: This nationwide study revealed that Class IV-G (±V) was the most prevalent form of LN in Japan and was associated with a severe clinical renal presentation.
AIM: The clinical and histological features of lupus nephritis (LN) are highly variable, depending on race and ethnicity. The Japan Renal Biopsy Registry (J-RBR) is a nationwide registry of renal biopsies. Here, we report a cross-sectional analysis of Japanese LN using the J-RBR database. METHODS: Out of 18 463 patients registered in the J-RBR, 331 LN patients, who received renal biopsy for the first time, were extracted and their clinical features were analyzed according to the ISN/RPS 2003 classification. RESULTS: The median age of the 331 LN patients was 37 years (women, 81.3%). The frequencies of each of the ISN/RPS Classes were as follows: I, 1.2%; II, 7.9%; III (±V), 25.1%; IV-S (±V), 13.0%; IV-G (±V), 31.1%; V, 20.8%; and VI, 0.9%. The level of proteinuria and the prevalence of nephrotic syndrome were highest for Class IV-G (±V). When Classes I, II, and VI were excluded from the analysis, Class IV-G (±V) was significantly associated with a lower eGFR and severer haematuria than the other classes. CONCLUSION: This nationwide study revealed that Class IV-G (±V) was the most prevalent form of LN in Japan and was associated with a severe clinical renal presentation.