[Rheumatoid arthritis with IgE type rheumatoid factors]

IgE class rheumatoid factors (IgE RF) were sought by indirect immunofluorescence (IFI) in 107 cases of rheumatoid arthritis (RA). They were found at a level of 1/2 in 34 per cent of cases and 1/10 in 16 per cent of cases. From a laboratory standpoint, RA with IgE RF is characterized by the presence in a statistically larger number of cases as well as in larger amounts of agglutinating RF. There is no correlation between IgE RF levels and serum IgE levels. From the clinical standpoint, RA with IgE RF is characterized only by its more advanced state. The presence of abarticular manifestations is far from constant and is no more common than in RA without IgE RF.