Year : 2013 | Volume
: 40 | Issue : 3 | Page : 141--146
Anti-C1q antibodies in systemic lupus erythematosus patients and their significance in lupus nephritis
Ali M El-Sayed Yousef1, Sherry K Abd El-Rahman2, Hatem Mezayen3, Fathy EL Taweel4, Walaa Elsayed5
1 Department of Internal Medicine, Benha Teaching Hospital, Benha, Egypt
2 Department of Rheumatology and Rehabilitation, Benha Teaching Hospital, Benha, Egypt
3 Department of Chemistry, Biochemistry Division, Faculty of Science, Helwan University, Helwan, Egypt
4 Department of Chemistry, Organic Chemistry Division, Faculty of Science, Damietta University, Damietta, Egypt
5 Department of Chemistry, Biochemistry Division, Faculty of Science, Damietta University, Damietta, Egypt
Systemic lupus erythematosus (SLE) is a prototype of systemic autoimmune diseases characterized by overproduction of various autoantibodies. It was reported that over 150 autoantibodies had been identified in sera from patients with SLE. Earlier investigations suggested that anti-C1q antibodies (anti-C1q Abs) are found in SLE patients, particularly in patients with renal involvement.
The aim of this study was to evaluate the prevalence of anti-C1q Abs in the serum of patients with SLE and to investigate their association with systemic lupus erythematosus disease activity index (SLEDAI), lupus nephritis (LN) as well as other clinical and laboratory parameters.
Patients and methods
We studied 70 SLE patients (68 women and two men) defined by the Systemic Lupus International Collaborating Clinics (SLICC) criteria. Patients«SQ» mean age was 30.5 9.8 years. They were classified into two groups: group I included 40 SLE patients with LN diagnosed according to the renal parameters of the American Collage of Rheumatology for the classification of SLE. LN activity was determined by the renal SLEDAI (rSLEDAI). Group II included 30 SLE patients without LN. Thirty age-matched and sex-matched healthy individuals were included in the study as a control group.
Anti-C1q Abs occurred in about 73% of SLE patients and 100% of patients with LN. The mean anti-C1q Abs titers were significantly elevated (Po0.0001) in SLE patients compared with the controls (41.5 vs. 3U/ml), as well as in patients with LN (Po0.0001) than in those without LN (67.4 vs. 15.5U/ml); also, they were elevated in active SLE patients (without LN) compared with inactive SLE patients (without LN) (24 vs. 6.6U/ml) and also in active LN patients compared with LN patients, in whom they were inactive (89.8. vs. 29.4U/ml). Significant positive correlations were found between anti-C1q Abs titers with erythrocyte sedimentation rate (r=0.575, P<0.0001), creatinine (r=0.809, P<0.0001), antinuclear antibodies titers (r=0.747, P<0.0001), anti-dsDNA titers (r=0.585, P<0.0001), proteinuria (r=0.860, P<0.0001), SLEDAI-2000 (r=0.736, P<0.0001), and rSLEDAI (r=0.843, P<0.0001), whereas they had significant negative correlations with hemoglobin percentage (r= - 0.640, P<0.0001), C3 (r= - 0.666, P<0.0001), and C4 (r= - 0.655, P<0.0001) levels.
In SLE, the prevalence of anti-C1q Abs is about 73%. Higher titers of these autoantibodies can be considered as surrogate markers for an active disease, an active LN, and an increased inflammatory burden. In LN, the positive predictive value of anti-C1q Abs titers was 65%, whereas their negative predictive value was 100%.
Sherry K Abd El-Rahman
MD, Department of Rheumatology and Rehabilitation, Benha Teaching Hospital, Benha
|How to cite this article:|
El-Sayed Yousef AM, Abd El-Rahman SK, Mezayen H, Taweel FE, Elsayed W. Anti-C1q antibodies in systemic lupus erythematosus patients and their significance in lupus nephritis.Egypt Rheumatol Rehabil 2013;40:141-146
|How to cite this URL:|
El-Sayed Yousef AM, Abd El-Rahman SK, Mezayen H, Taweel FE, Elsayed W. Anti-C1q antibodies in systemic lupus erythematosus patients and their significance in lupus nephritis. Egypt Rheumatol Rehabil [serial online] 2013 [cited 2020 Feb 18 ];40:141-146
Available from: http://www.err.eg.net/article.asp?issn=1110-161X;year=2013;volume=40;issue=3;spage=141;epage=146;aulast=El-Sayed;type=0