Positive classic antineutrophil cytoplasmic antibody (C-ANCA) titer at switch to azathioprine therapy associated with relapse in proteinase 3-related vasculitis
✍ Scribed by Slot, Marjan C. ;Tervaert, Jan Willem Cohen ;Boomsma, Maarten M. ;Stegeman, Coen A.
- Publisher
- John Wiley and Sons
- Year
- 2004
- Tongue
- English
- Weight
- 78 KB
- Volume
- 51
- Category
- Article
- ISSN
- 0004-3591
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✦ Synopsis
Objective:
To analyze disease-free survival in patients with antineutrophil cytoplasmic antibody (anca)-associated small-vessel vasculitis (aav) treated with cyclophosphamide only or switched to azathioprine after 3 months of full remission while taking cyclophosphamide.
Methods:
We analyzed disease-free survival in all consecutive patients diagnosed with aav between 1990 and 2000 at our center. patients were treated with cyclophosphamide only (1990-1996) or switched to azathioprine after 3 months of remission while taking cyclophosphamide (1997-2000). all patients received at least 12 months of followup.
Results:
Of the total 128 patients, 53 (41%) relapsed. forty-four of the 128 patients (34%) had been switched to azathioprine therapy. disease-free survival at 2 and 4 years was 76% and 65% in the cyclophosphamide group compared with 76% and 51% in the azathioprine group. in patients with proteinase 3 (pr3) classic anca (c-anca)-associated vasculitis who were switched to azathioprine (n = 33), a positive c-anca titer at the moment of treatment switch (n = 13) was significantly associated with relapse (rr 2.6, 95% confidence interval 1.1-8.0; p = 0.04). in patients with a negative anca titer at the time of switch to azathioprine, disease-free survival at 2 and 4 years was 80% and 62%, which was identical to that for patients treated with cyclophosphamide only. in patients who were anca-positive at the time of treatment switch, disease-free survival at 2 and 4 years was only 58% and 17%.
Conclusion:
Switching cyclophosphamide to azathioprine after induction of remission in patients with pr3-anca-associated vasculitis who are still anca-positive at the time of treatment switch is associated with a high risk of relapse.