Transforming growth factor beta 1 in children with systemic lupus erythematosus

ABSTRACT

Systemic lupus erythematosus [SLE] is a disease characterized by loss of immunologic tolerance to self-antigens. About two thirds of children with SLE develop renal involvement during the course of their disease. Transforming growth factor beta 1 [TGF-beta 1] has an inhibitory effect on the immune system and it plays a central role in the pathogenesis of renal diseases. To assess plasma and urinaly TGF beta1 levels in children with active SLE and its possible role in the pathogenesis of the disease. Plasma and urinary [latent and active] TGF-beta 1 levels were assessed-by ELISA-in 32 children with active SLE and compared to 15 healthy controls of matched age and sex. Plasma latent and active TGF-beta 1 levels in children with active SLE were significantly lower than controls [median [IQR]=9.75 [9-27.6] Vs 18.9 [16-30] ng/mI,=0.004 and 0.38 [0.3-0.4] Vs 0.9 [0.8-1] ng/ml, p<0.001; respectively]. Plasma active TGF-beta 1 correlated negatively with Systemic Lupus Erythematosus Disease Activity Index [r=-0.38, P=0.03]. On the contrary; urinary latent and active TGF-beta 1 levels in children with active SLE were significantly higher than controls [median [IQR]=2.1[1.9-6.4] Vs 1.1[0.9-1.9] ng/mg creatinine, p<0.001 and 1.2 [1.07-1.53] Vs 0.7 [05-1] ng/mg creatinine, p=0.003; respectively]. Urinary active TGF-beta 1 levels correlated positively with Anti-ds DNA titer [r=0.42, p=0.015] and negatively with serum C3 levels [r=-0.48, p=0.005]. Patients with symptomatic nephritis had significantly elevated active urinary TGF-beta 1 levels in comparison to children with silent nephritis [P=0,008].In children with active SLE, lowered plasma TGF-beta 1 levels may be a feature of systemic immune dysfunction, which may have a role in the pathogenesis of the disease. On the other hand; increased renal production of TGF-beta 1 plays an important role in the pathogenesis and clinical presentation of lupus nephritis