Syndecan-1 (CD138) immunohistochemical expression patterns in lupus nephritis; reflections on different clinicopathological parameters

Syndecan 1 (SCD1) is a lectin expressed at the surface of renal tubular epithelial cells and plasma cells. In epithelial cells, cell surface syndecan1 is cleaved by inflammation-induced proteases (eg, ADAMTS, MMP), since loss of cell surface syndecan1 is associated with higher susceptibility to cell damage.

To explore a potential additional value of SCD1 immunohistochemical expression in lupus nephritis specimens of different ISN/RPS classes and NIH activity and chronicity indices. Patients and

This retrospective study included 50 renal biopsy specimens diagnosed as lupus nephritis at the pathology laboratory, and electron microscopy (EM) laboratory of Ain-Shams University specialized hospitals. Data were collected from records as personal data, medical history and laboratory results including serum creatinine and proteinuria. Immunohistochemical expression of syndecan-1 was evaluated in renal tubular epithelial cells (TECs) followed by correlation with different clinicopathological parameters.

Fifty renal biopsy specimens with lupus nephritis including 14 cases of class II, 4 cases of class III, 20 cases of class IV and 12 cases of class V were re-evaluated. The mean serum creatinine was 1.57 ± 0.67 mg/dL. Nine cases (18%) were negative for proteinuria, while 41 cases (82%) were presented with proteinuria with a mean of 1.5 ± 0.9 g/24 h. There was no statistically significant difference in the percentage of SCD-1 expression with different lupus classes. Serum creatinine and albumin showed a statistically significantly different correlation with semiquantitative score of SCD-1 expression. The highest value of creatinine detected with score 1 of SCD-1 expression (P=0.038) and the highest value of urinary albumin was recorded with score 1 of SCD-1 expression. Accordingly, the lowest mean of urinary albumin recorded in SCD-1 score 3 (P<0.001). There was a weekly negative association between loss of SCD-1 expression and increased NIH activity and chronicity indices.

Loss of syndecan immunohistochemical expression in renal TECs in lupus nephritis is highly associated with proteinuria and elevated serum creatinine and can be used as a predictive marker for disease severity and progression.