A new method for factor VII deficient substrate preparation and coagulation studies in malaria.

A simplified technique using DEAE-cellulose chromatography for the preparation of factor VII deficient substrate was developed in order to reduce the high cost of individual factor VII assay in the routine coagulation laboratory. The substrate prepared from cryo-removed human and bovine plasma had a high correlation (r = 0.9929) with two of the most popular imported commercial substrates available (DADE, Ortho). When compared several other imported commercial substrates of equal quality, the prepared substrate was 3,000 to 6,000 times cheaper. Using the prepared factor VII deficient substrate along with other commercial substrates available, two hundred and fifty patients with malaria (fifty cases of P. vivax and two hundred cases of P. falciparum) were studied for coagulation and fibrinolysis abnormalities. Only P. falciparum infections showed prolonged PT and aPTT which correlated with the degree of parasitemia (r = 0.0972). Factors V, VII, and IX were the most sensitive parameters in the expression of coagulation defects and most coagulation abnormalities were due to liver involvement. Plasmin activity was normal in P. vivax patients but it was significantly increased in P. falciparum patients with > 5% parasitemia. Only two of the complicated cases of P. falciparum patients showed the evidence of DIC.