Nephrol Dial Transplant (2000) 15: 1600-1603
© 2000 European Renal Association-European Dialysis and Transplant Association
Anti-laminin auto antibodies in ANCA-associated vasculitis
1 Istituto di Clinica Medica e Malattie Cardiovascolari, Cattedra di Nefrologia, Università di Palermo, Palermo, and 2 Dipartimenti di Nefrourologia e di Allergologia e Immunologia Clinica, Azienda Ospedaliera Ospedale San Carlo Borromeo, Milano, Italia
Background. Endothelial cell damage occurs during vasculitic processes in vivo. With the alteration of the endothelium, exposure to basement membrane components may occur with induction of humoral immunity.
Methods. In the present study, we evaluated the prevalence of antibodies against the basement membrane antigen laminin (LMN) in patients with ANCA-associated systemic vasculitis (AASV), pathologic controls (systemic lupus erythematosus, mixed cryoglobulinaemia, HenochSchönlein purpura, primary glomerulonephritis) and normal individuals.
Results. By ELISA, 21.6% of AASV (16/74) and 10% of pathologic controls (3/30), but only one of the normal controls (2.8%) had these antibodies (P=0.02). When AASV patients were divided into two groups according to diagnosis and ANCA antigen specificity, antibodies to LMN were found in 27.5% of MPO-ANCA positive microscopic polyangiitis patients (11/40) vs only 14.7% of PR3-ANCA positive Wegener granulomatosis patients (5/34). There was no correlation between the presence or titre of anti-LMN antibodies and the main clinical and laboratory parameters.
Conclusion. These results indicate that basement membrane antigens may become immunogenic in patients with AASV, especially in those with MPO-ANCA positivity. These antibodies are most likely the result of endothelial damage secondary to the initial inflammatory process but may well perpetuate further vascular damage in some patients.
Keywords: anti-laminin antibodies; antineutrophil cytoplasmic antibodies; vasculitis
Correspondence and offprint requests to: Prof. Maurizio Li Vecchi, Istituto di Clinica Medica e Malattie Cardiovascolari, Cattedra di Nefrologia, Via del Vespro, 129, I-90127 Palermo, Italy.