Lymphokines in systemic lupus erythematosus: A study of interleukin-1B, interleukin-2 and tumour necrosis factor-A

Lymphokines are potent immunoregulatory factors that may be directly involved in the disordered immunoregulation found in systemic lupus erythematosus (SLE). The present study was directed to an examination of interleukin 1b (IL-1b), interleukin 2 (IL-2) and tumour necrosis factor-a (TNF-a) in SLE. A total of 61 patients affected by SLE and 16 healthy volunteers, matched for age and sex, were studied. 26 of the patients were newly diagnosed and not receiving treatment or were treated with nonsteroidal antiinflammatory drugs. The remaining 35 patients were being treated with 6-methyl-prednisolone in doses ranging from 4 to 40 mg daily. The SLE patients showed a statistically significant increase of IL-1b levels and a statistically significant decrease of IL-2 levels as compared to controls. A tendency to higher TNF-a levels was observed in the SLE patients. Statistically significant inverse correlations were found between IL-2 and anti-dsDNA antibody levels (p < 0.05) and between IL-2 and IgG and IgA concentrations (p < 0.01). Our results are in agreement with previous observations of reduced IL-2 in SLE. Decreased IL-2 seems to be inversely correlated with disease activity in SLE, as demonstrated by the inverse relationship with anti-dsDNA antibodies and immunoglobulins. The result of increased IL-1b does not confirm previous findings of reduced IL-1b in SLE. Furthermore TNF-a, a cytokine capable of inducing synthesis of IL-1b, appears to be elevated in SLE.