[Role of toxoplasma and viruses in polydermatomyositis]

The causes of polymyositis are imperfectly known. The role of Toxoplasma, the myotropism of which is significant in acute myositis, may be suspected on the ground of secondary serological data, but it has not yet been confirmed. On the other hand, the role of coxsackie virus, which until recently had been established only on morphological or serological data, has now been ascertained by molecular biology techniques. The best example of experimental viral polymyositis is the disease induced by inoculation of retrovirus to the monkey. This has led to the identification in man of polymyositis revealing an acquired immunodeficiency syndrome.