Lymphocyte tubular structures in rheumatoid arthritis.

Two types of lymphocyte tubular structures were studied by electron microscopy in 80 patients with classic or definite rheumatoid arthritis (RA). Fifteen patients with unequivocal systemic lupus erythematosus (SLE) and 10 healthy persons were studied as controls. Lymphocyte tubulo-reticular structures were found in 13 of the 80 patients with RA and in 10 of the 15 patients with SLE. No tubuloreticular structures were found in any of the healthy subjects. In the RA patients antinuclear antibodies, LE cell phenomenon, and chlorambucil treatment were associated significantly with these inclusions but disease activity was not related to their presence. In cases in which tubuloreticular structures were present the number of cells containing inclusions was on average much lower in patients with RA than in those with SLE. Lymphocyte tubular parallel arrays were found in all the patients with RA and SLE and in all the healthy persons. In all three groups the average number of cells containing parallel tubular arrays was similar.