Anti-C1q autoantibodies do not correlate with the occurrence or severity of experimental lupus nephritis.
BACKGROUND
In systemic lupus erythematosus patients, a strong association between the occurrence of antibodies against complement C1q (anti-C1q) and lupus nephritis can be observed. However, the predictive value of anti-C1q titres for a renal flare remains to be determined. Increasing titres of anti-C1q before the occurrence of clinical apparent nephritis might not only serve as a clinical parameter but also indicate a direct pathogenic mechanism of anti-C1q.


METHODS
The aim of this study was to analyse the occurrence of anti-C1q before the onset of experimental lupus nephritis in MRL/MpJ +/+ mice and to correlate anti-C1q titres with the type and severity of glomerulonephritis (GN) developing at advanced age.


RESULTS
As judged by a number of morphological and immunological analyses, GN in MRL/MpJ +/+ mice resembled human lupus nephritis and occurred in variable degrees of severity. We also observed an abundant and early presence of anti-C1q. However, anti-C1q neither correlated with overall survival nor with any histological marker of severity of GN.


CONCLUSIONS
The absence of a correlation between the presence of anti-C1q and the occurrence of experimental lupus nephritis contradicts the hypothesis that anti-C1q are pathogenic. However, different pathogenic mechanisms of experimental lupus nephritis and human proliferative lupus nephritis cannot be excluded.
Bigler
Cornelia
C
Clinical Immunology, Department of Biomedicine, University Hospital Basel, Switzerland.
Hopfer
Helmut
H
Danner
Doris
D
Schaller
Monica
M
Mihatsch
Michael J
MJ
Trendelenburg
Marten
M
D000818:Animals; D000974:Antibodies, Antinuclear / Q000097:blood; D001323:Autoantibodies / Q000097:blood*; D015415:Biomarkers / Q000097:blood*; D015922:Complement C1q / Q000276:immunology*; D005260:Female; D005455:Fluorescent Antibody Technique; D005921:Glomerulonephritis / Q000097:blood / Q000175:diagnosis / Q000276:immunology*; D006801:Humans; D007124:Immunoenzyme Techniques; D008181:Lupus Nephritis / Q000097:blood / Q000175:diagnosis / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D015996:Survival Rate
D000974:Antibodies, Antinuclear; D001323:Autoantibodies; D015415:Biomarkers; D015922:Complement C1q