Serum and urinary interleukin-6 and serum interleukin-1 receptor antagonist in renal involvement in systemic lupus erythematosus

ABSTRACT

This study included 45 systemic lupus erythematosus [SLE] patients and 15 age and sex matched controls. All patients [3 males and 42 females] met the revised ACR criteria for the diagnosis of SLE, their ages ranged from 11-50 years. Each patient was subjected to complete history, clinical examination and laboratory investigations including complete blood count, complete urine analysis, 24 hours total urinary protein excretion, erythrocyte sedimentation rate [ESR], Coombs test, blood urea, creatinine clearance, anti-nuclear antibodies [ANA], anti- dsDNA IgG antibodies, C-reactive protein [CRP], serum and urinary interleukin-6 [sIL-6 and uIL-6], serum interleukin-1 receptor antagonist [sIL-1 ra], complement [C3 and C4] and renal biopsy. SLE disease activity was measured by systemic lupus activity measure [SLAM]. SLE patients were classified into two groups [renal and non- renal group]; in addition, the renal group was subdivided into two subgroups [active lupus nephritis [ALN] and inactive lupus nephritis [EN]]. The study concluded that urinary IL-6 may reveal the pathological changes more sensitively. Adding the measurement of uIL-6 level to the conventional prognostic indices of lupus nephritis may improve the ability to accurately predict the outcome in patients with lupus nephritis. Low serum concentration of IL-1 ra, low serum level of both CRP and circulating C3 in renal group appear to be markers of kidney involvement