Multiple antinuclear antibodies in mixed connective tissue disease: report of a patient with an unusual antibody profile.

A patient with antibodies to RNP, n-DNA, Sm and PM-I is described. The first clinical manifestations of connective tissue disease appeared at age 10. A cystic pulmonary lesion, pericardial effusion and nephropathy appeared after 7 years of disease limited to skin and joints. Pulmonary, pericardial and renal disease all appeared to respond to corticosteroid therapy.