SEARCH FOR PICORNAVIRUSES AT ONSET OF INFLAMMATORY MYOPATHY

Picornaviruses may not play a role as persistent agents in the inflamm atory myopathies, but it is still thought likely that they may act as triggers of an autoimmune process. Forty one muscle biopsy specimens, taken from three weeks to six months (mean four months) after onset, w ere examined using three different picornaviral primers and PCR. Moder ate to severe disease activity was evident in all specimens. The resul ts were compared with those of 18 biopsy specimens examined later in t he disease course, and with specimens from 27 patients with noninflamm atory myopathies. All results were negative. Thus, even as early as th ree weeks after clinical disease appears, picornaviruses are not detec table in these disorders.