A protein C pathway (PCP) screening test for the detection of APC resistance and protein C or S deficiencies.
A new automated method for screening defects in the Protein C Pathway (PCP) was evaluated. The "PCP test" is based on a phospholipid-rich Russells viper venom reagent, insensitive to heparin and lupus anticoagulants. To minimize interference from other clotting variables, ratios of the clotting time with and without the addition of a protein C activator were usually determined. Plasma samples from healthy volunteers, patients untreated or on oral anticoagulants, patients with factor V Leiden with and without treatment, and patients with protein C and/or S deficiencies were tested. Mixing patient plasmas 1:1 with individual plasmas deficient in factor V, protein C or S was evaluated for identifying the nature of defects by shortening the screening test. The PCP test was found to be sensitive to APC resistance due to factor V Leiden and by mixing with factor V deficient plasma was also useful despite the effects of oral anticoagulants. Results in the group of patients with previous low protein C or S levels suggest that the method has a better sensitivity to protein C than to protein S deficiency. The automated test was simple to use and gave a between-run coefficient of variation below 3% on normal plasmas.
Haas
F J
FJ
St. Antonius Hospital, Nieuwegein, The Netherlands.
van Sterkenburg-Kamp
B M
BM
Scheepers
H A
HA
D020016:Activated Protein C Resistance / Q000175:diagnosis* / Q000503:physiopathology; D000284:Administration, Oral; D000925:Anticoagulants / Q000627:therapeutic use; D016022:Case-Control Studies; D005166:Factor V Deficiency / Q000175:diagnosis; D006493:Heparin / Q000627:therapeutic use; D006801:Humans; D016682:Lupus Coagulation Inhibitor / Q000627:therapeutic use; D008403:Mass Screening / Q000379:methods*; D011486:Protein C / Q000502:physiology*; D020151:Protein C Deficiency / Q000175:diagnosis* / Q000503:physiopathology; D018455:Protein S Deficiency / Q000175:diagnosis* / Q000503:physiopathology; D011517:Prothrombin Time
D000925:Anticoagulants; D016682:Lupus Coagulation Inhibitor; D011486:Protein C; D006493:Heparin