Background: Systemic lupus erythematosus (SLE) is a complex disease which has posed a continuing challenge to scientists and clinicians of diverse areas of specialization. Renal involvement is evident in 25-50% of SLE patients. Antiglomerular basement membrane (anti-GBM) antibodies were found to be associated with lupus nephritis (LN) on direct immunofluorescence. Accordingly, this study was designed to evaluate the clinical significance of anti-GBM antibodies in sera of SLE patients as a potential non-invasive predictor of LN.
Methods: This study was carried out on 36 patients with SLE (15 without and 21 with proteinuria) attending the Rheumatology and Rehabilitation Center, Nephrology Outpatient Clinic, and the Dermatology and Venereology Unit, Al-Noor Specialist Hospital, the Holy Makkah, Kingdom of Saudi Arabia, and 20 healthy subjects as a control group. All participants were subjected to full clinical assessment. Additionally, laboratory investigations that included 24h urinary protein excretion, serum creatinine, serum complement (C3 and C4) levels, antinuclear (ANA), anti-double stranded DNA (anti-dsDNA), anti-Smith (anti-Sm), and serum anti-GBM antibodies were checked for all participants.
Results: 61% of our studied SLE patients had proteinuria. Serum creatinine increased insignificantly in non-proteinuric patients (p > 0.05) and significantly in proteinuric patients (p < 0.05) when compared to the control group. Serum levels of C3 and C4 showed significant decrease in non-proteinuric (p < 0.05) and proteinuric patients (p < 0.001) than control the control group. ANA were detected in 3.5% of the control group, 83% of the non-proteinuric patients, and 94% of the proteinuric patients. Anti-dsDNA antibody was negative in the control group and positive in 50% of the non-proteinuric group and 75% of the proteinuric one. An |