Table 1 Clinical characteristics of patients with AAV and coexisting RA

Female

9 (60.0%)

24 (75.0%)

33 (70.2%)

Age at diagnosis of AAV (ys)

54 ± 17

50 ± 15

51 ± 15

 P-ANCA or myeloperoxidase -ANCA

14 (93.3%)

24 (75%)

38 (80.9%)

 C-ANCA or proteinase 3-ANCA

2 (13.3%)

6 (18.8%)

8 (17.0%)

 negative

0 (0.0%)

2 (6.3%)

2 (4.3%)

 Microscopic Polyangiitis

15 (100.0%)

22 (68.8%)

37 (78.7%)

 Granulomatosis with polyangiitis

0 (0.0%)

10 (31.3%)

10 (21.3%)

 Rheumatoid arthritis first

13 (86.7%)

26 (81.3%)

39 (83.0%)

 ANCA associated vasculitis first

0 (0.0%)

4 (12.5%)

4 (8.5%)

 Contemporaneous

2 (13.3%)

2 (6.3%)

4 (8.5%)

Interval between diagnosis of RA and AAV (ys)

5.0 (2.0–20.0)

6.5 (1.6–12.0)

5.0 (2.0–12.0)

 Kidney

13 (86.7%)

22 (68.8%)

35(74.5%)

 Lung

8 (53.3%)

16 (50.0%)

24(51.1%)

 Skin

1 (6.7%)

3 (9.4%)

4(8.5%)

 Nose

0 (0.0%)

2 (6.3%)

2(4.3%)

 Nervous system

1 (6.7%)

0 (0.0%)

1 (2.1%)

n = 15

n = 19

n = 34

 Serum creatinine (umol/L)

164 (106–471)

292 (148–352)

282(132–379)

n = 15

n = 17

n = 32

 24-h urine protein(g/d)

1.56(0.38–4.79)

0.94 (0.50–3.10)

1.25(0.50–3.40)

n = 15

n = 32

n = 47

 Rapidly progressive glomerulonephritis

2(13.3%)

4(12.5%)

6(12.8%)

Therapy for RA

n = 12

n = 29

n = 41

 Gold compounds

1 (8.3%)

5 (17.2%)

6(15.6%)

 Methotrexate

1 (8.3%)

10(34.5%)

11(26.8%)

 Leflunomide

4 (33.3%)

2(6.9%)

6(14.6%)

Therapy for AAV

n = 15

n = 31

n = 46

 Glucocorticoid

1 (6.7%)

4 (12.9%)

5(10.9%)

 Glucocorticoid plus cyclophosphamide

13 (86.7%)

16 (51.6%)

29(63.0%)

 Glucocorticoid plus other immunosuppressants

1 (6.7%)

9 (29.0%)

10(21.7%)

 None

0 (0.0%)

2 (6.5%)

2(4.3%)

Prognosis

n = 14

N = 31

n = 45

 Improved

8 (57.1%)

22 (71.0%)

30(66.7%)

 End Stage Renal Failure

4 (28.6%)

7 (22.6%)

11(24.4%)

 Death

2 (14.3%)

2 (6.5%)

4(8.9%)