Rapid enzyme immunoassay of anti-streptokinase antibodies in human plasma.

A simple enzyme immunoassay for determination of anti-streptokinase antibodies (aSKa) in plasma is described. Commercially available reagents have been used for the assay, which is calibrated with a reference preparation of aSKa containing 100 AU/ml. The assay is specific and reproducible with a variation coefficient of 4.8%. In healthy individuals a broad range of values between 4 and 291 AU/ml was observed with a large difference between the mean and median value (55 AU/ml and 27 AU/ml, respectively). Data from a study on 21 patients with myocardial infarction treated with the streptokinase derivative antistreplase suggest that a high titre of aSKa before treatment is associated with failure of thrombolytic therapy. The assay procedure can be shortened to 0.5 h to screen patients for a high aSKa level. This assay allows a more routine assessment of aSKa in the clinic.