Design, setting, participants, & measurements: Twenty-three cases of PNCGN superimposed on DGS were identified from the archives of the Renal Pathology Laboratory of Columbia University. The clinical features, pathologic findings, and outcomes are described.

Results: The majority of patients were white, elderly, and had longstanding diabetes. Patients presented with acute renal failure and an active urine sediment. Antinuclear cytoplasmic autoantibody (ANCA) testing was positive by indirect immunofluorescence in 18 of 22 patients. Sixteen patients had a P-ANCA pattern, 9 of whom underwent further testing and were found to be MPO-ANCA positive by enzyme-linked immunosorbent assay. Among the two patients with C-ANCA by indirect immunofluorescence, enzyme-linked immunosorbent assay was performed in one and revealed PR3-ANCA. Eight patients had extrarenal manifestations of vasculitis, including 6 with pulmonary hemorrhage. At the time of presentation and renal biopsy, 11 patients required hemodialysis. The mean percentages of glomeruli with cellular crescents, fibrous crescents, and necrosis were 24.9, 8.4, and 12.9, respectively. Most patients were treated with cyclophosphamide and prednisone. At a mean follow-up of 14.6 mo (available in 21 patients), 8 patients had died and 8 of the remaining 13 patients had reached end-stage renal disease. Correlates of end-stage renal disease were hemodialysis at presentation and the degree of DGS.

Conclusions: PNCGN may occur superimposed on DGS. The prognosis for this dual glomerulopathy is dismal despite aggressive therapy.

Design, setting, participants, & measurements: A skin lesion on a 76-yr-old man with symptoms of nephrogenic systemic fibrosis lasting 5 mo was studied at the ultrastructural level. After confirmation of he diagnosis by histopathologic methods, the presence and distribution of gadolinium, iron, calcium, and magnesium by energy filtering transmission electron microscopy was also examined.

Results: The performed electron spectroscopic imaging and electron energy loss spectroscopic analyses on deparaffinized samples revealed deposition of gadolinium in irregular small aggregates that adhered to cell profiles and collagen fibers of the connective tissue, forming a perivascular "gadolinium-deposit zone" in the skin. Traces of iron signal were demonstrated in singular gadolinium-positive deposits, and iron presence was found in adjacent connective tissue. The ultrastructural cell analysis of the lesion showed among numerous poorly differentiated fibrocytes also higher differentiated cells with myofibroblastic characteristics, including bundles of intermediate filaments and attachment plaques in the cell periphery, indicating an ability of lesional fibroblasts to differentiate into myofibroblastic cells.

Conclusions: These findings support the pivotal role of gadolinium chelates in the development of nephrogenic systemic fibrosis.

Design, setting, participants, & measurements: Ten patients with systemic lupus erythematosus, antineutrophil cytoplasmic antibody positivity, and renal biopsy findings of lupus nephritis and antineutrophil cytoplasmic antibody–associated glomerulonephritis were identified. The clinical features, pathologic findings, and outcomes are described.

Results: The cohort consisted of eight women and two men with a mean age of 48.4 yr. Perinuclear antineutrophil cytoplasmic antibody was detected by indirect immunofluorescence in nine patients. Four of the nine patients and the single remaining patient were found to have myeloperoxidase–antineutrophil cytoplasmic antibodies by enzyme-linked immunosorbent assay. Clinical presentation included proteinuria, hematuria, and acute renal insufficiency, with mean creatinine of 7.1 mg/dl. All biopsies exhibited prominent necrosis and crescents with absent or rare subendothelial deposits and were interpreted as lupus nephritis and antineutrophil cytoplasmic antibody–associated glomerulonephritis. All patients received cyclophosphamide and prednisone. Three patients died of infectious complications. Among the remaining seven patients, five achieved a complete or near-complete remission, one had a remission with subsequent relapse, and one had no response to therapy.

Conclusion: Antineutrophil cytoplasmic antibody–associated necrotizing and crescentic glomerulonephritis may occur superimposed on lupus nephritis. In patients with lupus nephritis and biopsy findings of prominent necrosis and crescent formation in the absence of significant endocapillary proliferation or subendothelial deposits, antineutrophil cytoplasmic antibody testing by enzyme-linked immunosorbent assay is recommended.