Proliferative glomerulonephritis with monoclonal immunoglobulin G3κ deposits in association with parvovirus B19 infection.
ABSTRACT Proliferative glomerulonephritis with monoclonal immunoglobulin G deposits is a recently described disease entity, characterized by nonorganized electron-dense deposits in glomeruli and immunofluorescence findings indicating monoclonal immunoglobulin G deposits. The pathogenesis of many cases of proliferative glomerulonephritis with monoclonal immunoglobulin G deposits remains unknown. We herein report 2 patients with parvovirus B19 infection who developed acute nephritic syndrome with hypocomplementemia (patient 1) or persistent proteinuria and congestive heart failure (patient 2); however, neither patient had detectable levels of serum monoclonal immunoglobulin G. Renal biopsy in both patients showed diffuse endocapillary proliferative glomerulonephritis with monoclonal immunoglobulin G3κ deposits, and electron microscopy showed nonorganized electron-dense deposits mainly in the subendothelial and mesangial areas. Clinical symptoms, abnormal laboratory findings, and urinary abnormalities recovered spontaneously in both cases within 4 weeks. Our 2 cases may be the first reported patients with proliferative glomerulonephritis with monoclonal immunoglobulin G deposits possibly associated with parvovirus B19 infection. Virus infection-associated immune disorders could be implicated in the pathogenesis of proliferative glomerulonephritis with monoclonal immunoglobulin G deposits.
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ABSTRACT: A novel form of glomerular injury with monoclonal immunoglobulin (Ig) IgG deposition, termed “proliferative glomerulonephritis (GN) with monoclonal IgG deposits” (PGNMID), is a recently described entity. PGNMID presents with various histological patterns, such as membranoproliferative GN, endocapillary proliferative GN and membranous nephropathy (MN). The deposits are composed of monoclonal immunoglobulin, most commonly IgG3 and occasionally IgG2. At present, the clinical significance of each IgG subclass and the morphological patterns of glomerular injury have not been fully investigated due to the limited number of PGNMID cases reported. The patient was a 27-year-old woman presenting with a mild degree of proteinuria and no other physical or serological abnormalities. Monoclonal Ig could not be identified in her serum or urine. Renal biopsy found features of MN with deposition of monoclonal IgG2κ. Electron microscopy examination revealed non-organised electron-dense deposits predominantly in subepithelial locations. Based on a diagnosis of PGNMID, she was treated with prednisolone and proteinuria significantly decreased in less than 4 weeks. Although the clinical outcomes of PGNMID remain to be defined, MN features may possibly be a sign of favourable prognosis—a hypothesis supported by recent reports. The absence of advanced chronic damage in the kidney, such as glomerulosclerosis or tubulointerstitial fibrosis, may also have contributed to the favourable outcome in the present case. Further studies on additional PGNMID cases that allow the correlation of morphological features and IgG subclasses with clinical outcomes are needed in order to confirm our findings and further solidify the clinical aspects of this new disease entity.11/2013; 2(2). DOI:10.1007/s13730-013-0064-3
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ABSTRACT: Proliferative glomerulonephritis with monoclonal immunoglobulin G (IgG) deposits (PGNMID) is a recently described disease entity. In the kidney transplantation literature, only 6 recurrent and 2 de novo PGNMID cases, including 7 of the IgG3 subclass (6 with κ light chain and 1 with λ light chain) and 1 of the IgG1 subclass (λ light chain), have been described to date. We describe a 52-year-old man with end-stage renal disease whose primary glomerular disease had been suggested to be membranoproliferative glomerulonephritis. The patient underwent living related donor kidney transplantation and presented with proteinuria, hematuria, and decreased kidney function at 4 months posttransplantation. Biopsy of the transplanted kidney showed diffuse endocapillary proliferative glomerulonephritis. Immunofluorescence microscopy showed prominent granular glomerular staining for IgG, C3, and λ light chain, with IgM, IgA, and κ light chain undetectable. Immunofluorescence staining for IgG subclass showed signal for IgG2 only. Retrospective analysis of the native kidney biopsy specimen also showed the same monoclonal glomerular staining for the IgG2λ subtype. These findings led us to the diagnosis of PGNMID of the IgG2λ subtype as both the primary glomerular disease and recurrent disease in the transplanted kidney. Recurrence was treated with high-dose prednisolone, which decreased proteinuria, hematuria, and serum creatinine level. The case demonstrates that PGNMID of the IgG2λ subtype also can recur in the transplanted kidney.American Journal of Kidney Diseases 03/2013; 62(3). DOI:10.1053/j.ajkd.2013.01.013 · 5.76 Impact Factor
- Human pathology 06/2013; 44(6):1193-1194. DOI:10.1016/j.humpath.2013.02.012 · 2.81 Impact Factor