Diagnostic Accuracy of Periodic Schiff-Methenamine Silver and Masson’s Trichrome Stains for Immune Complex Deposits in Lupus Nephritis

Context:The Immunofluorescence technique is considered gold standard in the diagnosis of lupus nephritis.Special stains like Periodic Schiff-Methenamine stain (PASM) and Masson's Trichrome (MT), which are more easily accessible, are hypothesized to have an accuracy similar to Immunofluorescence in diagnosing lupus nephritis.Aims: The aim of this study is to assess the diagnostic accuracy of Periodic Schiff-Methenamine stain (PASM) and Masson's Trichrome (MT) stains for immune complex deposits in lupus nephritis.Settings and Design: The study was conducted in a laboratory environment.Renal biopsy samples, which showed full-house deposits on Immunofluorescence were considered.The corresponding biopsy slides were further studied under a light microscope using special stains like PASM and MT.Methods and Material: Fuchsinophilic (red) deposits in the glomeruli were identified as sub-endothelial, sub-epithelial and mesangial deposits under the light microscope and were used to classify lupus nephritis as per the ISN/RPS classification.Statistical analysis used: Diagnostic accuracy study was carried out and the degree of agreement between special stains and Immunofluorescence was expressed as frequencies and percentages.Results: 86.84% of the sample showed agreement between special stains (PASM and MT) and Immunofluorescence.This was most evident in class III and IV lupus nephritis cases with 96.42% agreement.Conclusion: Special stains like PASM and MT were accurate enough to be used in resource limited areas, where Immunofluorescence is not readily available.