RESUMEN
Aim of the work: To evaluate the role of IL-34 in the pathogenesis of SLE and RA and to assess its role as a biomarker of disease activity. Subjects and methods: This study was carried out on 29 patients with SLE, 29 patients with RA, and 29 healthy control subjects. SLE disease activity was measured by systemic lupus erythematosus disease activity index (SLEDAI). RA disease activity was measured by 28-joint disease activity score (DAS-28). Serum IL-34 was measured by enzyme-linked immunosorbent assay (ELISA) . Results: There was highly significant elevation in IL-34 level in SLE and RA when compared to control group (p<0.001). IL34 level did not differ significantly between SLE and RA groups (pË 0.05). There was a significant positive correlation between IL-34 level and SLEDAI in SLE patients as well DAS 28 score in RA patients. The highest level was detected in patients with high disease activity. There was statistically significant correlation between IL-34 levels and ESR, CRP, and anti-ds DNA antibodies but inversely correlated with C3 in SLE patients. There was also statistically significant correlation between IL-34 levels and ESR, CRP RF, and anti CCP antibodies in RA patients. Conclusion: IL-34 could be useful marker for disease activity in SLE and RA