REFERENCE VALUES OF PROTEIN-C ACTIVITY IN HEALTHY ADULT SUBJECTS IN MEXICO

Protein C (pC) is a natural-occurring anticoagulant and its acquired o r hereditary deficiency has been associated with thrombosis. For its s creening, technics that appraise both its plasmatic concentration and biological activity are used. The quantitative deficiency is important , but some characteristics of pC activity (pCA) suggest an essential r ole of the functional deficiency. Because reference levels have not be en previously described in Mexico, we report here the results of a pCA assessed by a chromogenic assay in 88 adult healthy mexican people be tween 15 and 69 years of age. The pCA values at the 2.5 and 97.5% perc entils in our population were 75 and 137% in normal plasma. Functional disorders of this protein have been described in the presence of norm al pC quantitative levels and, therefore, there are individuals with l ow pC concentrations and a normal pCA without thrombosis. These data s uggest that the pCA could be a more important screening test than the quantitative determination as the first step in the study of a possibl e deficiency state of protein C.