[Determination of autoimmune antibodies using Western blot technique in the routine laboratory. Problems with determining and comparing three test kits].

For routine testing Western blot technique is a suitable method for the detection of autoimmune antibodies. Advantages of this procedure are the fast performance even for single samples, the detection of many different antibodies in one assay, and the possibility to save the strips for later reevaluation. There are several commercial test kits available. The spectrum of antibodies to be detected and the exact molecular weight of the antigens determine the choice of the test kit. Test kits from the companies AID (A), Viramed (V), and Biolab (B) were compared using serum samples from selected patients. Kits A and V were sensitive especially for the detection of SSA(Ro) and SSB(La) antibodies. The results using these two test kits corresponded well with the respective clinical diagnoses. Test kit A detected the highest number of different antibodies. The question of differentiating between U1-snRNP and Sm antibodies by immunoblotting is discussed.