Do extraglomerular microvasculature and mesenchymal interstitial cell proliferation indicate a stable course of lupus nephritis?

BACKGROUND

Lupus Nephritis (LN) is a major and frequent manifestation of Systemic Lupus Erythematosus (SLE), an autoimmune disease. Renal biopsy has a pivotal role in the diagnosis, prognosis, and management of the LN. The aim of this study was to count the mesenchymal interstitial cells utilizing CD34 immunohistochemistry (IHC) and morphometric analysis, correlate them with clinical parameters, class, activity, and chronicity indices and see if it can predict the course of the disease.

METHODS

A total of 32 renal biopsy blocks were analyzed by H&E stain, special stains, and CD34 IHC. Microvasculature density and interstitial stem cells were highlighted by CD34. These were then counted using a previously standardized computerized digital photomicrograph system (Dewinter Optical Inc) and manual count, respectively.

RESULTS

Out of the 32 cases, Lupus class 3 comprised of 11 (34.38%) cases, class 4 comprised of 16 (50%) cases, and mixed class 4 + 5 had 5 (15.62%) cases. It was found that CD34 expression in the microvasculature (for both microvascular density and mean vascular lumen diameter) decreased in patients of Lupus Nephritis with higher disease activity (p < 0.05). Although not statistically significant, the number of interstitial stem cells increased with lower disease activity. A statistical significance was found between serum total protein, serum albumin, and serum creatinine among the three groups of LN.

CONCLUSION

Immunohistochemical staining of renal biopsy with CD34 may be used as a surrogate marker of disease activity in Lupus Nephritis patients.