Table 1

Patient characteristics based on the presence of CADM or anti-MDA-5 antibodies

CADM

α-MDA-5-positive


Years of sera collection

Total number of DM patients (M:F)

Mean age at onset (range)

Number (%) of patients (M:F)

P value*

Mean age at onset (range)

Number (%) of patients (M:F)

P value**

Mean age at onset (range)


T1 (1994 to 1995)

32 (12:20)

47.5 (4 to 80)

6 (18.8%) (2:4)

P for difference = 0.012

45.5 (4 to 73)

2 (6.3%) (1:1%)

P for difference = 0.003

53 (43 to 63)

T2 (1996 to 2003)

30 (6:24)

50.1 (15 to 79)

12 (40.0%) (1:11)

P for trend = 0.003

50.7 (20 to 73)

10 (33.3%) (0:10)

P for trend = 0.001

48.9 (20 to 66)

T3 (2004 to 2011)

33 (10:23)

43.6 (1 to 73)

18 (54.5%) (5:13)

40.8 (1 to 69)

14 (42.4%) (4:10)

44.4 (11 to 58)


CADM, clinically amyopathic dermatomyositis; DM, dermatomyositis; M:F, male:female; MDA-5, melanoma differentiation-associated gene 5. *Prevalence of CADM in total DM. **Prevalence of anti-MDA-5 in total DM.

Muro et al. Arthritis Research & Therapy 2011 13:R214   doi:10.1186/ar3547

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