Renal hypoplasia can be the cause of membranous nephropathy-like lesions
CLINICAL AND EXPERIMENTAL NEPHROLOGY
Authors: Takizawa, Keiichi; Miura, Kenichiro; Kaneko, Naoto; Yabuuchi, Tomoo; Ishizuka, Kiyonobu; Kanda, Shoichiro; Harita, Yutaka; Akioka, Yuko; Horita, Shigeru; Taneda, Sekiko; Honda, Kazuho; Hattori, Motoshi
Abstract
Background Renal hypoplasia (RH) is the most common cause of chronic kidney disease in children. In cases of RH, proteinuria is often induced by glomerular hypertrophy and hyperfiltration that is commonly associated with focal segmental glomerulosclerosis. This study reports the first case series of a possible association between RH and membranous nephropathy (MN). Methods Of the 168 children with RH who visited our department between 1999 and 2017, five with overt proteinuria (>= 1 g/gCr) underwent renal biopsy. We retrospectively reviewed the medical charts and analyzed biopsy specimens using light microscopy (LM), immunofluorescence (IF), and electron microscopy. Results The five children (four boys and one girl) had a median age of 5.5 years at the time of renal biopsy. The median proteinuria was 4.23 g/gCr (range 1.46-14.25), median serum albumin, 2.9 g/dL (range 2.3-3.7), and median estimated glomerular filtration rate, 59.7 mL/min/1.73 m(2) (range 36.7-103.6). LM showed segmental spike formation and mesangial hypercellularity and IF study showed segmental granular immunoglobulin G (IgG) staining (IgG1 and IgG3 dominant) along the capillary loops in all five patients. Electron-dense deposits were observed in the subepithelial and mesangial areas. Thus, the pathological studies showed MN-like lesions in all patients. Conclusion Our study suggests that RH can be the cause of MN-like lesions.
Immunoglobulin G subclass 3 in ISN/RPL lupus nephritis classification
CLINICAL NEPHROLOGY
Authors: Yabuuchi, Junko; Hoshino, Junichi; Mizuno, Hiroki; Ozawa, Yuko; Sekine, Akinari; Kawada, Masahiro; Sumida, Keiichi; Hiramatsu, Rikako; Hayami, Noriko; Yamanouchi, Masayuki; Hasegawa, Eiko; Suwabe, Tatsuya; Sawa, Naoki; Fujii, Takeshi; Ohashi, Kenichi; Takaichi, Kenmei; Ubara, Yoshifumi
Abstract
Objectives: In lupus nephritis. the immune complex plays a very important role in kidney disease progression, and immunoglobulin G subclass 3 (IgG3) may play an important role in endothelial damage as lupus nephropathy progresses. We evaluated the association between IgG3 positivity and lupus nephritis activity. Materials and methods: We identified 71 biopsies taken from 57 patients who had lupus nephritis with enough tissue to allow light and immunofluorescence microscopy. We compared the intensity of IgG subclass staining (on a scale of 0 - 3+) with IgG subclass dominance among lupus nephritis classes as defined by the ISN/RPS 2003 classification. Results; The proportion of IgG3-positive patients with capillary loop lesion was significantly higher in the class IV group compared with other groups (p < 0.01). Interestingly, in most patients IgG1 was the strongest subclass; in class IV groups, IgG3 was the strongest in 21% of the biopsies. IgG3 deposition in capillary loops was significantly associated with C1q deposition in those loops. According to Kaplan-Meier analysis, renal survival rates in the patients with IgG3 deposition was lower (82.2%) than in patients without IgG3 deposition (93.3%), but the difference was not significant. Conclusion: Our results suggest that capillary loop deposition of IgG3 is associated with disease activity in lupus nephritis.