speculated that this pathological features of IgA nephropathy may not be observed because the number of glomeruli free from destruction is very limited [10]. diagnosis was IgA nephropathy. Eight months later, the patients serum creatinine suddenly rose to 4.53?mg/dL and urinalysis showed 100 red blood cells per high power field with nephrotic range proteinuria (12.3?g/gCr). The serological assessments revealed the presence of anti-GBM antibody at the titer of 116?IU/mL. Treatments were begun after admission, consisting of hemodialysis, plasma exchange, and intravenous methylprednisolone pulse therapy. At 4 weeks after admission, the second renal biopsy was performed. Light microscopy revealed crescents in 18 of 25 glomeruli, excluding six global sclerotic glomeruli. IF showed linear IgG deposition along the GBM in addition to granular IgA and C3 deposition. Based on these findings, the diagnosis of anti-GBM glomerulonephritis and IgA nephropathy was confirmed. Renal function was not restored despite treatment, but alveolar hemorrhage was prevented. Conclusions We report a patient with a diagnosis of anti-GBM RYBP disease during the course of IgA nephropathy. This case strongly suggests that the presence of autoantibodies should be checked to rule out overlapping autoimmune conditions even in patient who have previously been diagnosed with chronic glomerulonephritis, such as IgA nephropathy, who present an unusually rapid clinical course. white blood cells, red blood cells, hemoglobin, platelets, high-power field, total protein, albumin, aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, blood urea nitrogen, creatinine, sodium, potassium, chloride, calcium, phosphate, C-reactive protein, anti-nuclear antibody, glomerular basement membrane, anti-neutrophil cytoplasmic antibody, proteinase 3, myeloperoxidase After admission, treatments with hemodialysis, plasma exchange, and intravenous methylprednisolone pulse therapy followed by oral prednisolone at the dose of 50?mg/day were initiated. The second renal biopsy was performed at 4 weeks after admission in order to assess the probability of renal recovery and to make the final diagnosis. It revealed cellular to fibrocellular crescents in 18 of 25 glomeruli, excluding six global sclerotic glomeruli by light microscopy. By immunofluorescence study, linear IgG deposition along the glomerular capillary walls and mesangial staining for IgA were observed. On the other hand, C3 deposition was observed in the mesangium as well as in the glomerular capillary walls (Fig.?2b). Electron-dense deposits were observed in mesangial areas, as in the first biopsy likewise, by electron microscopy (Fig.?4). Predicated on the aforementioned results, the analysis of anti-GBM glomerulonephritis and IgA nephropathy was verified. Plasmapheresis was performed eight instances, anti-GBM antibody decreased, and alveolar hemorrhage was avoided. Nevertheless, her renal function cannot become restored and she underwent maintenance hemodialysis (Fig.?5). Open up in another windowpane Fig. 4 Electron microscopic picture of the next renal biopsy, displaying the electron-dense debris in mesangial areas Open up in another windowpane Fig. 5 Clinical program after entrance. Cre: serum creatinine level, Anti-GBM antibody: anti-glomerular basement membrane antibody, PEX: plasma exchange, mPSL: methylprednisolone, PSL: prednisolone, HD: hemodialysis, RBX: renal biopsy Extra immunosuppressant had not been given as the patient didn’t show any indication of pulmonary participation and as the renal recovery was quite improbable from medical (constant oliguria and hemodialysis dependence) aswell as histological (crescent development generally in most of non-sclerotic glomeruli) perspective. Clinical and histological presentations from IgA nephropathy (during 1st renal biopsy) and from anti-GBM disease (during second renal biopsy) had been summarized in the Desk?2. Desk 2 Clinical and histological demonstration at the proper period of 1st and second renal biopsy chronic glomerulonephritis, progressive glomerulonephritis rapidly, glomerular basement membrane, glomerulonephritis, mesangium Dialogue and conclusions IgA nephropathy can be an immune system complex-mediated glomerulonephritis described immunohistologically by the current presence of glomerular mesangial IgA debris along with a selection of histopathologic lesions, including mesangial proliferation [7]. Anti-GBM disease is definitely due to antibodies reactive towards the Mutant EGFR inhibitor alveolar and glomerular basement membrane. The causal relationship of anti-GBM IgA and glomerulonephritis nephropathy is unclear. There is one hypothesis how the IgA-related immune system complicated may promote immunologic and inflammatory occasions, leading to conformational exposure and shifts from the GBM antigens resulting in advancement of anti-GBM antibody [4]. However, it really is challenging to demonstrate whether anti-GBM disease with this individual created as an incidental problem or was supplementary to IgA nephropathy since there is still no founded marker to tell apart primary Mutant EGFR inhibitor from supplementary anti-GBM disease. In this respect, we performed immunofluorescence staining for IgG subclasses on the next Mutant EGFR inhibitor renal biopsy, and discovered that IgG4 was the primary subclass of IgG destined to GBM with this individual (Fig.?6). The primary subclass of pathogenic IgG in anti-GBM disease was reported to become generally IgG1 [8]. Whether predominance of IgG4 relates with anti-GBM disease created supplementary to IgA nephropathy deserves potential study. Open up in another windowpane Fig. 6 Immunofluorescence staining for IgG subclasses on the next renal biopsy (Size pubs?=?20.0?m). The primary subclass of.