Summary. We recently observed an increase in factor‐VIII clot promoting activity as measured by a one‐stage assay (VIII AHF1) in a haemophiliac with hepatitis. However, VIII AHF as measured by a two‐stage assay (VIII AHF2) was 0.013 u/ml at a time when VIII AHF1 measured 0.38 u/ml. We then studied seven non‐haemophiliacs with liver disease, and attempted to correlate the levels of VIII AHF1 and VIII AHF2 with factor VIII‐like antigen (VIII AGN) as measured by quantitative immunoelectrophoresis. In four of the seven patients, disproportionate elevations of VIII AHF2 compared to VIII AHF1 were found. Furthermore, VIII AHF2 values correlated well with VIII AGN values. No such discrepancy was apparent in four normal control subjects. These findings emphasize the necessity for performing two‐stage assays in haemophiliacs as well as non‐haemophiliacs with liver disease to assess factor‐VIII levels. In addition, they suggest that confirmation of the diagnosis of haemophilia may not be possible in the haemophiliac with hepatitis unless VIII AHF2 determinations are performed. The reason for the disparity between VIII AHF1 and VIII AHF2 levels is not apparent. However, the correlation of VIII AGN and VIII AHF2 levels in the non‐haemophiliacs with liver disease provides further support for the concept that VIII AGN and VIII AHF are closely related or identical molecular entities.
|Original language||English (US)|
|Number of pages||7|
|Journal||British Journal of Haematology|
|State||Published - Dec 1976|
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