Determination of rheumatoid factor by means of thin layer immunoassay.

Thin layer immunoassay (TIA), a solid phase immunoassay based on a technically simple visualization method, was adapted for quantitative determination of rheumatoid factor (RF) in blood serum. The influence of various factors of possible significance for accurate quantitation of RF by TIA was studied. Comparison between TIA and the Waaler-Rose test for determination of RF was performed on 335 patient sera. The results obtained by the two methods agreed reasonably well. Preliminary experiments were also performed concerning the use of TIA for differentiation of RF with regard to the immunoglobulin class. It is concluded that, because of its simplicity and screening capacity, TIA could be an attractive method for detection and quantiation of RF.