title: Antibodies to ribosomal P proteins in lupus nephritis: a surrogate marker for a better renal survival?
abstract: OBJECTIVE
  To define if antibodies to ribosomal P proteins disclose a better lupus nephritis long-term survival.
  
  
  METHODS
  Sixty consecutive SLE patients with biopsy-proven nephritis (2004 ISN/RPS) were evaluated for renal survival parameters. Inclusion criteria were at least one serum sample at: renal flares, biopsy, and last follow-up until 2008. Anti-P was detected by ELISA/immunoblot and anti-dsDNA by indirect immunofluorescence/ELISA.
  
  
  RESULTS
  Eleven patients (18%) with anti-P+ (without anti-dsDNA) during renal flare were compared to 49 (82%) persistently negative for anti-P throughout the study. At the final follow-up post-biopsy (6.3±2.5 vs. 6.8±2.4 years, p=0.36), the comparison of anti-P+/anti-dsDNA- with anti-P- group revealed a trend to lower mean creatinine levels (0.9±0.3 vs. 2.3±2.1 mg/dl, p=0.07), lower frequency of dialysis (0% vs. 35%, p=0.025), and higher frequency of normal renal function (91% vs. 53%, p=0.037). The overall renal survival was significantly higher in anti-P+/anti-dsDNA- compared to anti-P- (11.0±4.5 vs. 9.2±4.5 years, p=0.033), anti-dsDNA+/anti-P- (vs. 8.7±4.7 years, p=0.017), and anti-P-/anti-dsDNA- (vs. 9.8±4.3 years, p=0.09) groups.
  
  
  CONCLUSIONS
  Our data supports the notion that anti-P antibody in the absence of anti-dsDNA during nephritis flares is a valuable marker to predict a better long-term renal outcome in lupus patients.
authors.affiliation: Rheumatology Division, School of Medicine, University of São Paulo, São Paulo, Brazil.
authors.forename: Patrícia Andrade
authors.initials: PA
authors.lastname: de Macedo
authors.forename: Eduardo Ferreira
authors.initials: EF
authors.lastname: Borba
authors.forename: Vilma dos Santos Trindade
authors.initials: Vdos S
authors.lastname: Viana
authors.forename: Elaine Pires
authors.initials: EP
authors.lastname: Leon
authors.forename: Leonardo de Abreu
authors.initials: Lde A
authors.lastname: Testagrossa
authors.forename: Rui Toledo
authors.initials: RT
authors.lastname: Barros
authors.forename: Ana Patrícia
authors.initials: AP
authors.lastname: Nascimento
authors.forename: Eloísa
authors.initials: E
authors.lastname: Bonfá
mesh_terms: D000328:Adult; D000974:Antibodies, Antinuclear / Q000097:blood* / Q000276:immunology; D015415:Biomarkers / Q000097:blood; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007668:Kidney / Q000276:immunology / Q000378:metabolism / Q000503:physiopathology; D007677:Kidney Function Tests; D008181:Lupus Nephritis / Q000097:blood / Q000276:immunology* / Q000401:mortality* / Q000503:physiopathology / Q000628:therapy; D008297:Male; D011237:Predictive Value of Tests; D012269:Ribosomal Proteins / Q000276:immunology*; D015996:Survival Rate
chemical_list: D000974:Antibodies, Antinuclear; D015415:Biomarkers; D012269:Ribosomal Proteins