[Erythropoietin assay. Comparison of a biological test system with an haemagglutination inhibition test (author's transl)].

The results from a biological test for erythropoietin (using the rate of iron absorption in polycythemic mice) and a commercially-available immunological test (haemagglutination-inhibition test) were compared. Of 19 batches of the immunological test which were investigated, 7 batches were completely inactive and a further 3 batches reacted only with the test serum supplied with the test. There was a poor correlation between the results from the biological and the immunological measurements, both on patients with high and those with low serum erythropoietin levels. The difficulty of the immunological erythropoietin test is that pure erythropoietin is not sufficiently available. The immunological test investigated here does not use pure erythropoietin. Aside from this, pathophysiological considerations would lead one to expect basic differences between the results from immunological and biological tests.