Diagnostic Value of a Novel but an Old Non-invasive Marker in Early Detection of Lupus Nephritis
Journal of Pan-Arab League of Dermatologists
Vol. 19, No. 3, October 2008 Page 31- 38
Diagnostic Value of a Novel but an Old Non-invasive Marker in EarlyDetection of Lupus Nephritis
Nassar A, Khamis S*, Abdel-Halim A** and Al-Sawy A***
Department of Dermatology, Andrology & STDs, Tanta University, Department of Internal Medicine*, Menoufia
University, Medical Biochemistry**, Assiut Faculty of Medicine, and Department of Microbiology***,
Al-Azhar University, Egypt
Abstract
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. This study was designed to evaluate the clinical significance of anti-GBM antibodies in sera of SLE patients as a potential non- nvasive predictor of LN.
This study was carried out on 42 patients with SLE (17 without and 25 with proteinuria) and 22 healthy subjects as a control group. All participants were subjected to full clinical assessment and laboratory investigations that included 24h urinary protein excretion, serum creatinine, serum complement (C3 and C4) levels, antinuclear (ANA), anti- ouble stranded DNA (anti-dsDNA), anti-Smith (anti-Sm), and serum anti-GBM antibodies.
Results showed that 59.5% of the studied patients were proteinuric. Serum creatinine increased insignificantly in nonproteinuric 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 nonproteinuric (P<0.05) and proteinuric patients (P<0.001) than the control group. ANA were detected in 4.5% of the control group, 82% of the nonproteinuric patients, and 96% of the proteinuric patients. Anti-dsDNA antibody was negative in the control group and positive in 65% of the nonproteinuric group and 84% of the proteinuric one. Anti-Sm antibody was also negative in the control group and positive in 41% of the nonproteinuric group and 56% of the proteinuric one. Anti-GBM antibodies increased significantly (P<0.01) and highly significantly (P< 0.001) in nonproteinuric and proteinuric patients, respectively.
It could be concluded that monitoring of serum level of anti-GBM antibodies after the diagnosis of SLE might be helpful and represents a non invasive predictive marker, along with the other routine autoantibodies, for early detection and ultimately proper management of LN in SLE patients.Hopefully, in the future, this may negate the need for renal biopsy, which remains an invasive test with a measurable, although low, inherent risk
Journal of Pan-Arab League of Dermatologists
Vol. 19, No. 3, October 2008 Page 31- 38
Diagnostic Value of a Novel but an Old Non-invasive Marker in EarlyDetection of Lupus Nephritis
Nassar A, Khamis S*, Abdel-Halim A** and Al-Sawy A***
Department of Dermatology, Andrology & STDs, Tanta University, Department of Internal Medicine*, Menoufia
University, Medical Biochemistry**, Assiut Faculty of Medicine, and Department of Microbiology***,
Al-Azhar University, Egypt
Abstract
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. This study was designed to evaluate the clinical significance of anti-GBM antibodies in sera of SLE patients as a potential non- nvasive predictor of LN.
This study was carried out on 42 patients with SLE (17 without and 25 with proteinuria) and 22 healthy subjects as a control group. All participants were subjected to full clinical assessment and laboratory investigations that included 24h urinary protein excretion, serum creatinine, serum complement (C3 and C4) levels, antinuclear (ANA), anti- ouble stranded DNA (anti-dsDNA), anti-Smith (anti-Sm), and serum anti-GBM antibodies.
Results showed that 59.5% of the studied patients were proteinuric. Serum creatinine increased insignificantly in nonproteinuric 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 nonproteinuric (P<0.05) and proteinuric patients (P<0.001) than the control group. ANA were detected in 4.5% of the control group, 82% of the nonproteinuric patients, and 96% of the proteinuric patients. Anti-dsDNA antibody was negative in the control group and positive in 65% of the nonproteinuric group and 84% of the proteinuric one. Anti-Sm antibody was also negative in the control group and positive in 41% of the nonproteinuric group and 56% of the proteinuric one. Anti-GBM antibodies increased significantly (P<0.01) and highly significantly (P< 0.001) in nonproteinuric and proteinuric patients, respectively.
It could be concluded that monitoring of serum level of anti-GBM antibodies after the diagnosis of SLE might be helpful and represents a non invasive predictive marker, along with the other routine autoantibodies, for early detection and ultimately proper management of LN in SLE patients.Hopefully, in the future, this may negate the need for renal biopsy, which remains an invasive test with a measurable, although low, inherent risk