SAT0673 ANTI-C1Q ANTIBODIES HAVE HIGHER CORRELATION WITH LUPUS NEPHRITIS DISEASE ACTIVITY
Authors: Xue Wu, Lijun Wu, Cai Nan Luo
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background:</h3> Systemic lupus erythematosus (SLE) is the prototype of autoimmune disease and is characterized by the production of a variety of autoantibodies. and lupus nephritis continues to be a principal cause of morbidity and mortality.The focus is to finding biomarkers that can monitor renal activity and predict prognosis for early diagnosis and treatment. Complement C1q is the starter molecule of the classical pathway of complement activation and plays an important role in the clearance of immune complexes and apoptotic cell debris. Hereditary homozygous deficiency of C1q has been described to be the strongest risk factor for developing SLE.There are some cross-sectional studies on anti-C1q in which the antibody was found to have a significant association with renal involvement but the association of anti-C1q antibodies (antiC1q) with lupus nephritis (LN) still a matter of debate. <h3>Objectives:</h3> We assessed the association between lupus nephritis disease activity and anti-C1q antibodies <h3>Methods:</h3> We retrospectively analyzed the medical records of 88 patients with lupus nephritis, aged 35.7±10.8 years on the average, with SLE of average duration 12 (3, 57) years.In all examines the levels of anti-dsDNA and anti-C1q antibodies were measured using the ELISA, C3, C4, 24-hour urinary protein performed in parallel were reviewed. The Clinical manifestations of SLE was also collected.Lupus nephritis disease activity was measured by The SLICC Renal Activity Score of 2004,All biopsied tissues were scored based on the to ISN/RPS2003 lupus nephritis pathological typing standards,Acute Index,Chronic Index Score were used to evaluated the activities of lupus, All the analyses were performed by SPSS 20.0 software. <h3>Results:</h3> Patients with active lupus nephritis had a higher levels of anti-C1q antibodies than inactive lupus nephritis (68.9(34.1, 140.1)vs. 11.6(5.5, 44.1); p&lt;0.001)(Figure 1). Anti-C1q antibody levels were positively correlated with levels of 24-hour urinary protein(r=0.605; <i> P=</i><i>0.000),</i>AI score<i>(</i>r=0.337; <i>P=</i><i>0.001),</i>and negatively correlated with serum C3(r=-0.573; <i>P=</i><i>0.000)</i> and C4 (r=-0.509; <i>P=</i><i>0.000).</i>(Figure2). Figure 2 A: Anti-C1q antibody levels were positively correlated with AI score Figure 2 B: Anti-C1q antibody levels were positively correlated with levels of 24-hour urinary protein Figure2-C:Anti-C1q antibody levels were positively correlated with C3 Figure2-D:Anti-C1q antibody levels were positively correlated with C4 <h3>Conclusion:</h3> Anti-C1q antibodies are more closely correlated with renal disease activity. <h3>References</h3> [1] Clarke AE, Panopalis P, Petri M, Manzi S, Isenberg DA, Gordon C, et al. SLE patients with renal damage incur higher health care costs[J]. Rheumatology (Oxford, England). 2008;47(3):329-33. [2] Walport MJ. Complement. First of two parts[J]. N Engl J Med. 2001;344(14):1058. [3] Walport MJ. Complement. Second of two parts[J]. N Engl J Med. 2001;344(15):1140. [4] Truedsson L, Bengtsson AA, Sturfelt G. Complement deficiencies and systemic lupus erythematosus[J]. Autoimmunity. 2007;40(8):560-6. [5] Akhter E,., Burlingame RW, Seaman AL, Magder L,., Petri M,. Anti-C1q antibodies have higher correlation with flares of lupus nephritis than other serum markers[J]. Lupus. 2011;20(12):1267-74. <h3>Disclosure of Interests:</h3> None declared