Relationship between interstitial CD34 positive cells and active phase of lupus nephritis

Lupus nephritis is one of the most serious and common complications of systemic lupus erythematosus. It has an unpredictable course, and the type, severity, and activity of renal lesions cannot be assessed only by clinical and laboratory findings. The aim of the present study was to determine the relationship between the expression of CD34 and the histopathological findings of lupus nephritis.

A total of 73 renal biopsy samples of patients with a diagnosis of lupus nephritis were examined for CD34 expression by immunohistochemistry. Samples without staining were considered as 0, mild staining as 1+, moderate as 2+, and strong staining as 3+. The relationship between CD34 expression and histopathological and clinical data (including activity index, chronicity index, lupus nephritis class, age, sex, blood pressure, complete blood count, renal function tests, and serological findings) was analyzed.

The mean age of the patients was 29.3±11.3 years. CD34 was expressed in all of the cases but with different intensities. There was a significant relationship between the expression of CD34 and the activity index, as a strong expression was seen in lower activity indices (p<0.001). CD34 expression was correlated with patients' white blood cell (WBC) count and systolic blood pressure (SBP). Patients with strong (score 3) CD34 expression had higher SBPs and lower WBC counts (p=0.03 and 0.04, respectively).

A strong interstitial expression of CD34 was observed in lower activity indices. It seems that CD34 expression could play a protective role in lupus nephritis and could reduce renal activity.