Transformation of membranous into anti-GBM nephritis

Concomitant Case of Anti-Glomerular Basement Membrane (GBM) Antibody Disease and Membranous Nephropathy

Anti-glomerular basement membrane (GBM) disease is a form of rapidly progressive glomerulonephritis with acute deterioration of kidney function. Atypical forms of this disease have been described which do not show positive serology for the classical anti-GBM antibody (Ab) but their presence on kidney biopsies. Furthermore, concomitantly any other separate glomerular pathology along with anti-GBM disease has been only rarely seen. A 40-year-old male patient presented with complaints of lower limb swelling and hematuria. Initial blood investigations revealed nephrotic range proteinuria and hypoalbuminemia. The patient underwent a renal biopsy. Initial reports showed the presence of "linear" deposits for immunoglobulin G (IgG) Ab and crescent formation in the majority of glomeruli. Treatment with plasmapheresis was initiated for the same. Electron microscopy, which later revealed subepithelial deposits raised suspicion of concomitant membranous nephropathy (MN). This finding was confirmed with a staining biopsy block with an anti-PLA2R Ab stain. Treatment was initiated to treat both glomerular pathologies, which very rarely present together and do not have standard guidelines for treatment. The patient responded to treatment with a reduction in serum creatinine values and did not require maintenance hemodialysis. There have been only a handful of documented cases, only in the form of a few case series that have described the presence of both anti-GBM disease and MN in the same kidney biopsy.

Anti-glomerular basement membrane vasculitis

Antiglomerular basement membrane disease (anti-GBM) is a rare life-threatening autoimmune vasculitis that involves small vessels and it is characterized by circulating autoantibodies directed against type IV collagen antigens expressed in glomerular and alveolar basement membrane. The typical clinical manifestations are the rapidly progressive glomerulonephritis and the alveolar hemorrhage. The diagnosis is usually confirmed by the detection of anti-GBM circulating antibodies. If not rapidly recognized, anti-GBM disease can lead to end stage kidney disease (ESKD). An early diagnosis and prompt treatment with immunosuppressive therapies and plasmapheresis are crucial to prevent a poor outcome. In this review, we discuss the primary form of anti-GBM (the so called Goodpasture syndrome) but also cases associated with other autoimmune diseases such as antineutrophil-cytoplasmic-antibody (ANCA) vasculitis, membranous nephropathy, IgA nephritis and systemic lupus erythematosus (SLE), as well as the few cases of anti-GBM vasculitis complicating kidney transplantation in the Alport syndrome.

Membranous Nephropathy with Rapid Progression

We report a 49-year-old man with microscopic hematuria, subnephrotic proteinuria, and rapidly progressive renal failure. His biopsy had features of PhosphoLipase A2 Receptor (PLA2R) positive membranous nephropathy with circumferential cellular crescents. Further work-up revealed IgG antiGlomerular Basement Membrane (anti-GBM) antibody titer of 188 U/mL (normal <7 U/mL). A final diagnosis of membranous nephropathy with anti-GBM disease was made. These two distinct pathological entities can occur together resulting in significant morbidity and mortality unless diagnosed early and treatment initiated promptly. Outcomes have been poor, given the nonspecific presentation and delay in diagnosis.

Membranous nephropathy followed by anti-glomerular basement disease: A case report and review of clinical presentation and treatment

Membranous nephropathy is a common cause of nephrotic syndrome in adults and can be primary or secondary through autoimmune disease, medication, infection, or malignancy. Rapidly progressive glomerulonephritis with crescent formation is rare in patients with membranous nephropathy. Thus, in cases with rapid decline in renal function, after excluding complications such as malignant hypertension, acute hypersensitivity interstitial nephritis, and bilateral renal vein thrombosis, the simultaneous occurrence of a superimposed glomerulonephritis should be considered. We report a 55-year-old man suffering from a biopsy-confirmed primary membranous nephropathy, who developed rapidly progressive glomerulonephritis with anti-glomerular basement membrane antibodies after being affected with membranous nephropathy for 8 years. The kidney biopsy revealed a concurrence of membranous nephropathy and anti-glomerular basement membrane disease. Clinical presentation and treatment of membranous nephropathy followed by anti-glomerular basement membrane disease are discussed based on our observation with promising follow-up.