Table 3

Main baseline characteristics of patients who developed severe infections in comparison with those who did not

Severe infection

n = 37

No severe infection

n = 307

Bilateral P value


Females

32 (86%)

238 (77%)

0.289

Mean age (years)

49.14 ± 2.77

41.97 ± 0.86

0.008*

Autoimmune diseases

- Systemic lupus erythematosus

11 (30%)

129 (42%)

- Systemic vasculitis

8 (22%)

42 (14%)

- Inflammatory myopathies

6 (16%)

32 (16%)

0.459

- Behçet disease

2 (5%)

29 (9%)

- Primary Sjögren's syndrome

2 (5%)

21 (7%)

- Other diseases

8 (22%)

54 (18%)

Previous therapies (ever exposed)

- Oral corticosteroids

35 (95%)

297 (97%)

0.377

- Methylprednisolone pulses

4 (11%)

82 (27%)

0.043

- Cyclophosphamide

23 (62%)

149 (48%)

0.163

- Mycophenolate

12 (32%)

86 (28%)

0.567

- Azathioprine

6 (16%)

91 (30%)

0.120

- Methotrexate

12 (32%)

97 (32%)

1.000

- Intravenous immunoglobulins

6 (16%)

83 (27%)

0.171

Cumulated dose/length of previous therapies

- Mean length of prednisone therapy (years)

9.50 ± 2.89

7.93 ± 0.67

0.540

- Cumulated dose of cyclophosphamide (gr)

9.00

7.00 ± 1.20

0.629

- Mean length of mycophenolate (years)

0.96 ± 0.79

2.39 ± 0.44

0.236

- Mean length of azathioprine (years)

0.38 ± 0.28

1.56 ± 0.39

0.324

- Number of previous immunosuppressants

> = 3

5 (13%)

68 (22%)

0.289

> = 4

2 (5%)

23 (7%)

1.000

Biological agent

- Rituximab

29 (78%)

235 (76%)

- Infliximab

4 (11%)

33 (11%)

- Etanercept

2 (5%)

19 (6%)

0.982

- Adalimumab

2 (5%)

17 (5%)

- Other

0 (0%)

3 (1%)

Therapies administered concomitantly

- Corticosteroids

35 (95%)

277 (90%)

0.554

- Cyclophosphamide

8 (22%)

95 (31%)

0.342

- Mycophenolate

5 (13%)

17 (5%)

0.073

- Azathioprine

0 (0%)

16 (5%)

0.235

- Methotrexate

5 (13%)

36 (12%)

0.788

- Cyclosporin A/Tacrolimus

5 (13%)

14 (5%)

0.041

- Intravenous immunoglobulins

2 (5%)

12 (4%)

0.653

Time of exposure to biological (person-years)

- Total time

17.59 ± 2.16

17.23 ± 0.75

0.873

- Exposure to rituximab

15.13 ± 1.63

14.07 ± 0.47

0.471

- Exposure to infliximab

26.25 ± 15.4

15.27 ± 1.74

0.124

- Exposure to etanercept

12.50 ± 8.50

29.35 ± 3.84

0.246

- Exposure to adalimumab

26.00 ± 9.00

13.95 ± 2.52

0.183


*Statistically significant in the Cox regression multivariate model (hazard ratio 1.026, 95% confidence interval 1.005 to 1.047, P = 0.014).

Díaz-Lagares et al. Arthritis Research & Therapy 2011 13:R112   doi:10.1186/ar3397

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