Abstract
In the treatment of polymyositis and dermatomyositis (PM/DM), the complication of interstitial lung disease (ILD) is an important prognostic factor. It has been reported that autoantibodies against aminoacyl-tRNA synthetases (ARS) are strongly associated with ILD. The aim of this study is to examine the correlation between anti-ARS and the clinical course of ILD. We investigated 41 cases of PM/DM with ILD. The response of ILD to corticosteroids (CS) was determined according to the change in respiratory symptoms, image findings, and pulmonary function between, before and 2 months after the treatment. Anti-ARS (anti-Jo-1, PL-7, PL-12, EJ, OJ and KS) antibodies were screened with the RNA immunoprecipitation assay. In the stratification into ILD-preceding, simultaneous and myopathy-preceding types, anti-ARS antibodies were significantly frequent in the ILD-preceding type (p < 0.05). In the stratification into anti-ARS-positive and negative groups, the response of ILD to CS was significantly better in the positive group (p < 0.05). However, recurrence of ILD was significantly more frequent in the positive group (p < 0.01), and 2 year prognoses of pulmonary function (%VC and %DLCO) were not different between the two groups. In conclusion, screening of anti-ARS may be useful to predict late-onset myopathy in ILD-preceding patients and to predict the clinical course of ILD in PM/DM patients.
Abbreviations | ||
A–aDO2 | = | alveolar–arterial oxygen tension difference |
ADM | = | amyopathic dermatomyositis |
ARS | = | aminoacyl-tRNA synthetases |
CK | = | creatine kinase |
CS | = | corticosteroids |
DLCO | = | diffusing capacity of the lung for carbon monoxide |
DM | = | dermatomyositis |
IBM | = | inclusion body myositis |
IIM | = | idiopathic inflammatory myopathies |
ILD | = | interstitial lung disease |
MAA | = | myositis-associated antibodies |
MSA | = | myositis-specific antibodies |
PM | = | polymyositis |
PSL | = | prednisolone |
SAILD | = | seropositive amyopathic interstitial lung disease |
SRP | = | signal recognition particle |
VC | = | vital capacity |
Abbreviations | ||
A–aDO2 | = | alveolar–arterial oxygen tension difference |
ADM | = | amyopathic dermatomyositis |
ARS | = | aminoacyl-tRNA synthetases |
CK | = | creatine kinase |
CS | = | corticosteroids |
DLCO | = | diffusing capacity of the lung for carbon monoxide |
DM | = | dermatomyositis |
IBM | = | inclusion body myositis |
IIM | = | idiopathic inflammatory myopathies |
ILD | = | interstitial lung disease |
MAA | = | myositis-associated antibodies |
MSA | = | myositis-specific antibodies |
PM | = | polymyositis |
PSL | = | prednisolone |
SAILD | = | seropositive amyopathic interstitial lung disease |
SRP | = | signal recognition particle |
VC | = | vital capacity |
Acknowledgements
This work was supported by a grant for studies on the prophylaxis and treatment of immunologic and allergic diseases from the Ministry of Health, Labour and Welfare of Japan.