Immunoradiometric assay of inhibitors of antihaemophilic factor A

Research output: Contribution to journalArticle


An immunoradiometric assay (IRMA) for determination of antibodies against f. VIII:C in haemophilia A was developed. The assay was based on competitive binding of radiolabelled anti-VIII:C and antibodies in the test material to immobilized VIII:C. Fifteen haemophiliacs with known inhibitors were investigated with the new method and with a conventional neutralization test. In 3 cases the inhibitors were detected only with the IRMA and in the other 12 there was good agreement between the inhibitor levels found with the two methods. It was also possible to demonstrate the antibodies in three non-haemophilic patients with acquired inhibitors. The IRMA, which can detect the antibodies down to a concentration of 0.02 inhibitor units per ml, is more sensitive than conventional neutralization tests and is thus of practical importance in the investigation of patients with low inhibitor titres.


Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Hematology


  • blood clotting factor 8, radioisotope, blood and hemopoietic system, case report, congenital disorder, diagnosis, hemophilia A, radioimmunoassay
Original languageEnglish
Pages (from-to)1019-1023
Number of pages5
JournalActa Paediatrica Scandinavica
Issue number6
Publication statusPublished - 1982 Oct 26
Publication categoryResearch