Are anti-proteinase-3 ANCA a useful marker of granulomatosis with polyangiitis (Wegener's) relapses? Results of a retrospective study on 126 patients.
OBJECTIVE
Predicting granulomatosis with polyangiitis (Wegener's) (GPA) relapses based on ANCA titers remains a source of debate. Our objective was to evaluate the relevance of monitoring PR3-ANCA titers for GPA management.


METHODS
This retrospective study included 126 patients fulfilling the 1990 ACR criteria for GPA and PR3-ANCA-positive at the time of diagnosis. Disease activity was assessed with BVAS/WG and Disease Extent Index. For each patient, a median of 12 serum samples was analyzed, i.e., one every 5.5months.


RESULTS
Induction therapy obtained remission in 88% of the patients. ANCA became negative by IF for 70/115 (60.9%) patients and by ELISA for 90/115 (78.3%). After median follow-up of 70months, 85/126 (67.5%) patients had 154 clinical relapses associated with cANCA and PR3-ANCA-positivity for 122 (79.2%) and 102 (66.2%) of them, respectively. Relapse-free survival was significantly longer for patients who remained PR3-ANCA-negative (HR 0.60 [95% CI 0.39-0.92], P=0.02). Individual ANCA-profile analysis revealed that, for 60% of GPA patients, clinical outcomes and ANCA-titer changes were closely associated, i.e., ANCA were always positive during relapses and negative during remission. The 35 patients with fluctuating ANCA-positivity during remission were in partial remission or had developed grumbling GPA.


CONCLUSIONS
Although ANCA were positive during most systemic relapses or residual disease, no strict clinical-immunological correspondence was observed for 25% of the patients. Thus, GPA management cannot be based on ANCA levels alone.
Department of Internal Medicine, French Vasculitis Study Group (FVSG), Referral Center for Rare Autoimmune and Systemic Diseases, Hôpital Cochin, AP-HP, Université Paris Descartes, Paris, France.
Lan-Huong
LH
Thai
Department of Internal Medicine, French Vasculitis Study Group (FVSG), Referral Center for Rare Autoimmune and Systemic Diseases, Hôpital Cochin, AP-HP, Université Paris Descartes, Paris, France.
Pierre
P
Charles
Département de Biostatistique et Informatique Médicale, Hopital Saint-Louis, Université Paris Diderot, Paris, France.
Matthieu
M
Resche-Rigon
Département de Biostatistique et Informatique Médicale, Hopital Saint-Louis, Université Paris Diderot, Paris, France.
Kristell
K
Desseaux
Department of Internal Medicine, French Vasculitis Study Group (FVSG), Referral Center for Rare Autoimmune and Systemic Diseases, Hôpital Cochin, AP-HP, Université Paris Descartes, Paris, France. Electronic address: loic.guillevin@cch.aphp.fr.
Loïc
L
Guillevin
D019268:Antibodies, Antineutrophil Cytoplasmic / Q000097:blood* / Q000276:immunology; D015415:Biomarkers / Q000097:blood; D014890:Granulomatosis with Polyangiitis / Q000097:blood / Q000175:diagnosis* / Q000276:immunology; D006801:Humans; D053146:Myeloblastin / Q000276:immunology*; D012008:Recurrence; D012189:Retrospective Studies
D019268:Antibodies, Antineutrophil Cytoplasmic; D015415:Biomarkers; D053146:Myeloblastin
ANCA; Disease activity; Granulomatosis with polyangiitis (Wegener's); Monitoring; Proteinase 3; Relapse