ABSTRACT
lupus nephritis is a fatal complication of systemic lupus erythematosus [SLE], the serological hallmark of SLE is the presence of circulating autoantibodies directed against a wide variety of nuclear, cytoplasmic and plasma membrane antigens among which are anticardiolipin [ACL],anti B2 glycoprotein and anti-C1q antibodies, together with the consumption of complement component [C3 andC4] by immune complex mediated reaction. To shed light on the relations among these autoantibodies and with complement component in lupus nephritis patients. The study was conducted on 25 patients with lupus nephritis, attended the renal clinic in specialized surgical hospital! medical city /Baghdad, 25 lupus patients without nephritia and 25 healthy controls. Enzyme linked immunsorbant assay was used for detection for ACL, anti-B20P, anti-C1q, while single radial immundiffusion plates used for the estimation of C3and C4. Anticardiolipin antibodies correlated significantly with anti-B20P IgG and IgM [P<0.05], anti-C1q antibodies [P<0.01] respectively, also anti-C1q correlated with C3, C4 complement respectively