title: Antibodies against monomeric C-reactive protein - a promising biomarker of lupus nephritis?
abstract: OBJECTIVE
  A significant incidence of systemic lupus erythematosus (SLE), the severity of lupus nephritis and varying responses to treatment rationalize the search for novel biomarkers of disease activity. The aim of the study was to assess whether antibodies against monomeric C reactive protein (anti-mCRP) are associated with the presence of lupus nephritis, correlate with disease activity, and whether they can serve to evaluate a response to treatment.
  
  
  METHODS
  The study involved 74 patients with lupus nephritis, 29 patients with systemic lupus without renal involvement and 31 patients with primary glomerulonephritis; the control group included 31 healthy volunteers. Interleukin-6 and tumor necrosis factor alpha were measured using commercially available ELISA tests. The presence of anti-mCRP in the serum was tested with the use of in-house ELISA.
  
  
  RESULTS
  The highest prevalence and concentrations of antibodies against monomeric C-reactive protein were observed among patients with lupus nephritis, as compared to other groups. The elevated level of anti-mCRP was associated with standard clinical and laboratory indicators of SLE activity. Moreover, the highest concentrations of both Il-6 and TNF-α were observed for patients with the most severe nephropathy. A significant decrease in anti-mCRP and cytokines' levels in the course of treatment was observed.
  
  
  CONCLUSIONS
  The study gives further evidence that antibodies against monomeric C-reactive protein may be considered an indicator of renal involvement in patients with SLE. Assessment of anti-mCRP supports monitoring of disease activity and can be used in evaluating the treatment effectiveness.
authors.affiliation: Department of Nephrology and Transplantation Medicine, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw, Poland. Electronic address: kasia.jakuszko@wp.pl.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Jakuszko
authors.affiliation: Department of Nephrology and Transplantation Medicine, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw, Poland. Electronic address: magdalena.krajewska@umed.wroc.pl.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Krajewska
authors.affiliation: Department of Nephrology and Transplantation Medicine, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw, Poland. Electronic address: katarzynakoscielska@interia.pl.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Kościelska-Kasprzak
authors.affiliation: Department of Nephrology and Transplantation Medicine, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw, Poland.
authors.forename: Marta
authors.initials: M
authors.lastname: Myszka
authors.affiliation: Department of Rheumatology and Internal Medicine, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw, Poland. Electronic address: agatasebastian@vp.pl.
authors.forename: Agata
authors.initials: A
authors.lastname: Sebastian
authors.affiliation: Department of Nephrology and Transplantation Medicine, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Gniewek
authors.affiliation: Department of Rheumatology and Internal Medicine, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw, Poland.
authors.forename: Piotr
authors.initials: P
authors.lastname: Wiland
authors.affiliation: Department of Nephrology and Transplantation Medicine, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw, Poland. Electronic address: klinger@wp.pl.
authors.forename: Marian
authors.initials: M
authors.lastname: Klinger
mesh_terms: D000328:Adult; D001323:Autoantibodies / Q000032:analysis*; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000037:antagonists & inhibitors*; D015536:Down-Regulation; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005500:Follow-Up Studies; D005921:Glomerulonephritis / Q000097:blood / Q000276:immunology / Q000503:physiopathology; D006801:Humans; D015850:Interleukin-6 / Q000097:blood*; D008181:Lupus Nephritis / Q000097:blood* / Q000276:immunology / Q000503:physiopathology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D011044:Poland; D012720:Severity of Illness Index; D014409:Tumor Necrosis Factor-alpha / Q000097:blood*; D015854:Up-Regulation
chemical_list: D001323:Autoantibodies; D015415:Biomarkers; C508600:IL6 protein, human; D015850:Interleukin-6; C439524:TNF protein, human; D014409:Tumor Necrosis Factor-alpha; D002097:C-Reactive Protein
keywords: Autoantibodies; C-reactive protein; Cytokines; Lupus nephritis; Systemic lupus erythematosus