Cryoimmunoglobulinemia in Felty's syndrome.

Seven of 9 patients with Felty's syndrome exhibited cryoglobulins in greater amounts than found in uncomplicated RA but similar to amounts found in RA with vasculitis. Antinuclear antibodies were found in high titer in the sera and cryoglobulins of Felty's patients; when compared to SLE patients, whose sera and cryoglobulins also contained antinuclear factors, an antinuclear antibody reacting with nuclei of polymorphonuclear granulocytes appeared to be selectively concentrated in the cryoglobulins of some Felty's patients.