Table 1.
Ethnicity and prevalence of dermatomyositis with anti-MDA5 antibodies.
| Country | DM cases* (n) | Anti-MDA5+ | Detection technique | CADM among anti-MDA5+ | CADM cases (n) | Anti-MDA5+ among CADM | Prevalence of women anti-MDA5+ | ILD among anti-MDA5+ | RP-ILD among anti-MDA5+ | Ref | Publication year |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Japan | 42 | 19% | IP/IB/IIF | 100% | 15 | 53% | 75% | 88% | 50% | (4) | 2005 |
| Japan | 30 | 27% | IP | 75% | 13 | 46% | 88% | 100% | 100% | (5) | 2009 |
| Japan | 65 | 22% | IP/ELISA | 57% | 15 | 53% | 79% | 100% | 71% | (6) | 2010 |
| Japan | 37 | 35% | IP/IB | 85% | 15 | 73% | 69% | 92% | 54% | (7) | 2010 |
| Japan | 55 | 11% | IP | 17% | ND | ND | 50% | 83% | 50% | (8) | 2011 |
| Japan | 376 | 11% | IP/IB/ELISA | 77% | 51 | 65% | 79% | 93% | 65% | (9) | 2011 |
| Japan | 79 | 22% | IP/ELISA | 82% | 21 | 67% | 88% | 94% | 71% | (10) | 2012 |
| China | 84 | 23% | ELISA | 26% | 8 | 63% | 58% | ND | 79% | (11) | 2012 |
| China | 64 | 23% | ELISA | 80% | 32 | 38% | 60% | 100% | 60% | (12) | 2012 |
| China | 43 | 60% | ELISA | 35% | 9 | 100% | 39% | 100% | 39% | (13) | 2013 |
| China | 213 | 21% | ID | 77% | 81 | 42% | 71% | 82% | 64% | (14) | 2020 |
| North America | 77 | 13% | IP | 50% | ND | ND | 88% | 67% | 20% | (15) | 2011 |
| North America | 160 | 7% | IP | 46% | ND | ND | 73% | 73% | ND | (16) | 2013 |
| Spain | 117 | 12% | ELISA/IB/IIF | 57% | 15 | 53% | 64% | 64% | 57% | (17) | 2014 |
| Italy | 34 | 15% | IP-WB/ELISA/IIF | 100% | ND | ND | 60% | 60% | 20% | (18) | 2014 |
| Brazil | 131 | 16% | ELISA | 24% | 22 | 23% | 71% | 38% | ND | (19) | 2018 |
| France | 54 | 9% | IIF/ID | ND | ND | ND | ND | ND | ND | (1) | 2018 |
*Selection of cohorts with at least 30 patients (cohorts with JDM patients excluded).
DM, dermatomyositis; CADM, clinically amyopathic dermatomyositis; JDM, juvenile dermatomyositis; ILD, interstitial lung disease; RP-ILD, rapidly progressive interstitial lung disease; IP, immunoprecipitation; IB, immunoblot; IIF, indirect immunofluorescence; ELISA, enzyme-linked immunosorbent assay; WB, western blot; ID, immunodot assay; ND, not done.