C3 and systemic lupus erythematosus: Between all the above blood factors, the level of C3, C4, CRP, ESR1h, ESR2h and hemoglobin were significantly correlated to the occurrence of disease which only the level of complement component (C3 and C4) and hemoglobin, like our new proposed marker (SLR) showed a significant negative correlation with the occurrence of systemic lupus erythematosus.