[The PM-Scl (polymyositis-scleroderma) autoantibody and its nucleolar fluorescence pattern]

By indirect immunofluorescence studies of antinuclear antibodies on hamster liver imprints as a substrate performed to determine the nuclear staining pattern of sera from patients with connective tissue diseases 10 sera showed a distinct homogeneous nucleolar staining pattern associated with weaker speckled or homogeneous nucleoplasmic fluorescence. In all 10 cases the antibodies revealed the PM-Scl specificity in immunodiffusion. Clinically 9 patients had an acrosclerosis, in 56% overlapped with symptoms of polymyositis. Only one patient had a diffuse scleroderma. The homogeneous nucleolar immunofluorescence pattern of PM-Scl should be distinguished from mixed nucleolar and diffuse reticular nucleoplasmic pattern of Scl-70.