Pathologic differentiation between lupus and nonlupus membranous glomerulopathy

Abstract

The following clinical and pathologic features were evaluated in 170 patients with electron microscopically documented membranous glomerulopathy: age, sex, race, American Rheumatism Association lupus criteria, serum ANA, serum complement, glomerular hypercellularity, stage of subepithelial dense deposits, endothelial tubuloreticular inclusions, tubular basement membrane deposits, tissue ANA, glomerular deposition of IgG, IgM, IgA, C3, C4, and Clq. At the time of biopsy 148 patients had no clinical evidence for lupus, and 22 had a clinical diagnosis of lupus. Six additional patients eventually developed overt lupus after an average of 12 months. Incidences of serologic and pathologic features in lupus as compared with nonlupus membranous glomerulopathy were determined. These data were used to calculate sensitivity, specificity, positive and negative predictive values, and overall efficiency of each parameter in differentiating between lupus and nonlupus membranous glomerulopathy. In general, serologic, morphologic and immunohistopathologic features are more accurate at ruling out lupus than making the diagnosis of lupus. However, a number of features are significantly more frequent in lupus membranous glomerulopathy. Therefore, identification of these features, especially more than one, warrants a high suspicion of lupus rather than nonlupus membranous glomerulopathy even in patients without clinically overt systemic lupus erythematosus. The positive/negative predictive values of some of the pathologic features studied are as follows: mesangial dense deposits 63/99, subendothelial dense deposits 77/93, tubuloreticular inclusions 61/96, intense C1q deposition 47/95, tubular basement membrane deposits 100/87, and glomerular hypercelularity 26/86.

Determination of primary versus secondary membranous glomerulopathy utilizing phospholipase A2 receptor staining in renal biopsies

“…2,4 Morphological findings commonly associated with secondary membranous glomerulopathy include the presence of mesangial deposits, segmental involvement of glomeruli by deposits, and a 'full-house' staining pattern on immunofluorescence. 9,[16][17][18] The most common of these findings in our series was that of mesangial immune complex deposition. Approximately 29% of cases with mesangial deposits showed positive staining by PLA2R1.…”

“…For this report, the term 'mesangial deposits' refers to deep mesangial deposits within the mesangial matrix and internal to an identifiable paramesangial basement membrane. 9 …”

Membranous Glomerulonephritis Development with Th2-Type Immune Deviations in MRL/lpr Mice Deficient for IL-27 Receptor (WSX-1)

“…Mesangial and subepithelial IC deposition, mesangial cell proliferation, and the presence of tubuloreticular structures in glomerular endothelial cells are characteristic of lupus nephritis (25,26). Notably, the Ig subclass predominantly deposited in lupus and idiopathic MGN is IgG4 (murine IgG1), an isotype typically up-regulated in Th2 responses (27,28).…”

Glomerular Diseases

“…Strong capillary wall deposits of C1q, C3, IgG, IgM, and IgA can also be seen in cases of MN associated with lupus (11), whereas leukocyte infiltration may occur in cases of cancer (12). Extensive C1q deposition is rarely seen in idiopathic MN (11).…”