CXCR 3 expression on CD4+T cells and in renal tissue of pediatric systemic lupus erythematosus patients

Background: Pediatric systemic lupus erythematosus (pSLE) accounts for about 20% of all cases of Systemic Lupus Erythematosus (SLE), with nephritis occurring in approximately 50% of the patients. Objective: to evaluate the expression of CXCR3 in the kidneys and on CD4+ T cells in pSLE. Methods: This study was conducted on 45 patients with pSLE following up at the Allergy and Immunology Clinic, Children's Hospital, Ain Shams University and 45 age and sex matched healthy children as a control group. Medical history, clinical examination and routine laboratory investigations for assessment of disease activity were done for all patients, the frequency of CXCR3, CD4+ T cells was determined in all patients and controls. Twenty-five Paraffin blocks of patients with lupus nephritis (LN) (available at the time of the study) underwent immunohistochemistry staining for the frequencies of Chemokine C receptor (CXCR3). Results: The absolute level and percentage of serum CD4+CXCR3+ were significantly lower among our patients as compared to healthy controls. A significant direct correlation was found between serum CD4+CXCR3+ and both the lymphocytic count and quantitative Systemic Lupus erythematosus disease activity index (SLEDAI), as well as a significant inverse correlation between it and 24 hours urinary proteins. Variable degrees of CXCR3 expression seemed to have no impact on laboratory tests, British Isles Lupus Assessment Group (BILAG) score and cumulative doses of Immunosuppressives. Conclusion: Serum CD4+CXCR3+ and not renal CXCR3 may be a potential marker of LN activity.