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THU0335 Anti C1-Q Antibodies and Urinary Monocyte Chemoattractant Protein-1 Levels as Biomarkers for Renal Involvement in Patients with Systemic Lupus Erythematosus
  1. J.A. Gόmez-Puerta1,
  2. B.L. Ortiz Reyes1,
  3. C. Perez Koller2,
  4. T. Urrego1,
  5. A.L. Vanegas3,4,
  6. C.H. Muñoz3,4,
  7. M. Restrepo Escobar3,
  8. L.A. González3,
  9. G.M. Vasquez1
  1. 1Grupo de Inmunología Celular e Inmunogenética, Universidad de Antioquia, Medellín
  2. 2Inova Diagnostics, Werfen, Bogotá
  3. 3Secciόn de Reumatología, Universidad de Antioquia
  4. 4Hospital Universitario de San Vicente Fundaciόn, Medellín, Colombia

Abstract

Background Some previous studies in Caucasian, Asian, and African-american patients have shown that the anti-C1q antibodies and urine levels of MCP-1 (uMCP-1) were significantly greater in patients with LN. However, information in Mestizo and Afro-Latin American patients is very limited.

Objectives Our aim was to evaluate diagnostic value of Anti-C1q and uMCP-1 as a potential markers for the diagnosis of LN in Colombian SLE patients

Methods We examined serum levels of anti-C1q and uMCP-1 in 67 consecutive SLE patients (ACR criteria 1997) from Hospital San Vicente Fundaciόn, at Medellín, Colombia. A fresh urine sample from each patient was collected in a sterile container. Serum Anti-C1q antibodies and uMCP-1 were measured by ELISA techniques (Inova, San Diego, and R&D system, Minneapolis, EEUU, respectively). Several clinical and serological features were analyzed as well as disease activity (SLEDAI). Descriptive statistics were used to describe data. Mann-Whitney tests were used to compare data and Spearman'srho for correlations. Additionally, ROC curves relating the specificity and sensitivity profiles of the 2 biomarkers were done

Results 67 SLE patients were recruited (89% female) with median age of 33.5± 12.0 yrs and median disease duration of 6.76 ± 6.80 years. Mestizo (71%) and Afro-latin American (26%) were majority. Hematologic disease (89%), arthritis (86%), cutaneous involvement (80%), and renal disease (66%) were among most common manifestations. Sixty-three percent of patients were positive for anti-C1q and 56% had elevated levels of uMCP-1 (mean levels 1678 ±3722 pg/ml). Mean SLEDAI score was 10.0 ± 9.0. We found significant association between anti C1q antibodies and several clinical features including serositis, proteinuria, renal and hematological involvement and with several serological markers including anti-dsDNA, low complement and higher SLEDAI score. Patients with LN had higher levels of anti-C1q antibodies than patients without LN (mean levels of 91.3 ± 85.4 vs 31.7 ± 38.7, p value=0.002). uMCP-1 levels were significantly higher in patients with LN than in patients without LN (2399 ± 4566 vs 472 ± 596 pg/ml, p value=0.017) and in patients with proteinuria (2537 ± 4731 vs 553 ± 688, p value=0.025). There was no correlation between anti-C1q levels and uMCP-1. An ROC curve constructed for anti-C1q and uMCP-1 and renal in all SLE patients showed that uNGAL had a good level of sensitivity and specificity with an AUC of 0.74 for anti-C1q and 0.82for uMCP1 (see figure).

ROC curve on Anti-C1q and uMCP-1. Solid line for Anti-C1q, dotted line for MCP-1.

Conclusions Although further confirmatory testing is underway, LN patients had almost 3 times and 5 times higher levels of Anti-C1q and uMCP-1, respectively than patients without LN. Anti-C1q antibodies and uMCP-1 may be a good biomarkers for LN in Mestizo and Afro-Latin american SLE patients, and can be a useful marker to identify patients with higher risk of renal involvement

Acknowledgement JA Gόmez-Puerta was supported by Colciencias (conv. 656 de 2014). Anti-C1q antibodies were provided by Inova, Werfen, Colombia

Disclosure of Interest None declared

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