A chromogenic assay for coagulation factor VII: analytical performance characteristics and application in several diseases

A chromogenic assay for coagulation factor VII has been adapted for use on a Cobas Bio centrifugal analyzer. The interassay coefficients of variation ranged from 4.1% to 14%. There was no effect on the factor VII amidolytic activity after freezing and thawing of the samples. The test was linear up to 200% factor VII. The correlation with a chronometric method for prothrombin time was acceptable (r = 0.97, y = 1.05 x + 5.5). The reference ranges for males (54%-138%) and females (56%-200%) were significantly different. The factor VII amidolytic activities were significantly elevated in males with non-insulin-dependent diabetes mellitus and in male hypertensives. No statistically significant increase was observed for female patients rather a decrease in females with insulin-dependent diabetes mellitus. Only in the male hypertensive patients and in the male patients with non-insulin-dependent diabetes mellitus were noticeable proportions of increased values seen (39.4% and 12.0%). Nevertheless, the availability of a precise, rapid and easy to perform test for the determination of factor VII might be useful in the study of the role of this factor in the development of cardiovascular disease.