Antisynthetase Syndrome

Antisynthetase syndrome — Up to 30 percent of patients with DM or PM have a constellation of clinical findings termed the "antisynthetase syndrome" . These findings include relatively acute disease onset, constitutional symptoms (eg, fever and weight loss), myositis, the Raynaud phenomenon, mechanic's hands, arthritis that is generally nonerosive, and ILD . Affected patients have antibodies to aminoacyl-transfer ribonucleic acid (tRNA) synthetase enzymes; the presence of one of these antibodies is highly specific for DM, PM, or ILD .

This syndrome can be further characterized as follows:

●Not all patients with antisynthetase antibodies or even those classified as having the antisynthetase syndrome have all manifestations of this syndrome. The syndrome is generally considered present in patients with an antisynthetase antibody plus two of the following features, which are elements of the syndrome: ILD, inflammatory myopathy, and inflammatory polyarthritis.

●This group of clinical findings or this general clinical picture is not specific for antisynthetase antibodies. Patients with other types of autoantibodies (eg, anti-PM-Scl or anti-U1 ribonucleoprotein [RNP] antibodies) can also present with these types of features. However, patients with antisynthetase antibodies generally have more prominent or severe myositis and ILD, and they usually lack some of the other clinical features seen in patients with these other autoantibodies.

●Some patients with antisynthetase antibodies have relatively little or no myositis, while ILD or other features are more prominent. The absence of myositis is seen more often with some antisynthetase antibodies than with others.

Bhopalwala. H