Assessment of plasma and urinary transforming growth factor beta 1 (TGF-β1) in children with lupus nephritis

Abstract

Background: Kidney disease is one of the most serious manifestations of systemic lupus erythematosus (SLE). Despite the improvement in the medical care of SLE in the past two decades, the prognosis of lupus nephritis remains unsatisfactory. Transforming growth factor- β1 (TGF-β1) is an immunosuppressive cytokine, as it inhibits T and B cell proliferation and NK cell cytotoxic activity . Objective: The aim of this study was to assess serum and urinary TGF- β1 levels in children with SLE and their possible role in the renal involvement and activity of the disease. Study design: This cross sectional study was conducted in Nephrology Unit of Pediatric Department, plus Outpatient Clinic of Rheumatology Department, Zagazig University Hospital during the year of 2010. Methods: Twenty-five pediatric patients with SLE were randomly selected and classified according to into 2 groups: Group (Ι): included 13 patients presented with urinary abnormalities and/or disturbed renal function(active nephritis): 5 males, 8 females. Their mean age was 9.7±2.53 years and the mean disease duration was 2.46±1.4 years. Group (ΙΙ): included 12 patients presented by lupus without nephritis : 5 males,7 females. Their mean age was 9.9±2.1 years and the mean disease duration was 2.41±0.9 years. Control group(group ΙΙΙ): Twenty healthy children of matched age and sex served as a control group included 8 males ,12 females. Their mean age was 10.0±2.3 years. Results: There was no significant difference among studied patients groups regarding age, sex , disease duration and lupus therapy (p>0.05). There was a significant difference between both groups regarding urinary albumin and serum creatinine (2.76±0.97 and 1.96±0.84 mg/dl respectively), while there was a high significant difference between them regarding C3 (47.3±12.5 and 76.6±6.6 mg/ml respectively) and anti double stranded DNA (anti-dsDNA) (80.7±32.8 and 26.8±4.5 IU/ml respectively). Plasma TGF- β1 showed significantly lower levels in patients with active nephritis relative to other groups, while urinary TGF- β1 levels were significantly high in SLE patients either with active or silent nephritis when compared with the control group. Plasma TGF- β1 showed a highly significant positive correlation with C3 and a highly significant negative correlation with serum creatinine, urinary albumin, anti dsDNA and SLE disease activity index (SLEDAI) score. While, urinary TGF- β1 had a significant negative correlation with C3 and a high significant positive correlation with anti-dsDNA and SLEDAI score. Conclusion: Low plasma TGF β1 level and increased urinary TGF β1 excretion denotes active renal affection in children with SLE.

Keywords: SLE , nephritis , TGF- β1

Egypt J Pediatr Allergy Immunol 2011;9(1):21-27