Antibodies to ribosomal P proteins in lupus nephritis: a surrogate marker for a better renal survival?
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.
de Macedo
Patrícia Andrade
PA
Rheumatology Division, School of Medicine, University of São Paulo, São Paulo, Brazil.
Borba
Eduardo Ferreira
EF
Viana
Vilma dos Santos Trindade
Vdos S
Leon
Elaine Pires
EP
Testagrossa
Leonardo de Abreu
Lde A
Barros
Rui Toledo
RT
Nascimento
Ana Patrícia
AP
Bonfá
Eloísa
E
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
D000974:Antibodies, Antinuclear; D015415:Biomarkers; D012269:Ribosomal Proteins