Transforming growth factor beta 1 in children with systemic lupus erythematosus: a possible relation with clinical presentation of lupus nephritis

Plasma and urinary (latent and active) TGF-beta 1 levels were assessed in 32 children with active lupus and compared to 15 healthy controls of matched age and sex. Plasma latent and active TGF-beta 1 levels in children with active disease were significantly lower than controls (P = 0.004 and 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 disease were significantly higher than controls (P < 0.001 and P = 0.003 respectively). Urinary active TGF-beta 1 levels correlated positively with Anti-ds DNA titre (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 urinary active TGF-beta 1 levels in comparison to those with silent nephritis (P = 0.008). From this data we conclude that lowered plasma TGF-beta 1 levels may be a feature of systemic immune dysfunction in children with active lupus while increased renal production of active TGF-beta 1 seems to have a role in the clinical presentation of lupus nephritis.