Relationship of Systemic Lupus Erythematosus to Rheumatoid Arthritis, Discoid Lupus Erythematosus, and Sjoegren's Syndrome: a Clinical Study.

Because of the frequent presence of polyarthritis and the rheumatoid factor in cases of systemic lupus erythematosus (S.L.E.) and that of the L.E.-cell phenomenon and visceral lesions in cases of rheumatoid arthritis, it was thought that it would be profitable to study the correlation between the two diseases. The disseniination of discoid lupus erythematosus, especially after exposure to strong sunlight, and its accompanying visceral manifestations have been known for a long time (Kaposi, 1872). There are also some data on the relationship between Sjogren's syndrome and S.L.E. in the recent literature (Heaton, 1959). However, the correlation of rheumatoid arthritis, discoid lupus erythematosus, Sjogren's syndrome, and S.L.E. has not been satisfactorily demonstrated, and we have therefore carried out more intensive systemic clinical, and laboratory investigations of the four conditions in 274 cases (Table).