The ability of three global plasma assays to recognize thrombophilia.
Three global assays, the Calibrated Automated Thrombogram (CAT), the ProC Global (PCG), and the Coagulation Inhibitor Potential (CIP) were performed in frozen plasma samples from 24 normal controls and 24 patients with inherited thrombophilia. Six patients had inherited antithrombin (AT) deficiency; 18 patients had abnormalities in the protein C/S anticoagulant system (protein C deficiency (n=3), protein S deficiency (n=10), homozygous FV Leiden mutation (n=5)). Nine of these twenty four patients carried additionally the heterozygous FV Leiden mutation. All three assays separated the thrombophilia group and the control group (P=0.083 for CAT, P<0.0001 for the other two assays) but there was considerable overlap, particularly in the CAT assay. The CAT assay separated all plasma samples with AT deficiency but was less sensitive to abnormalities in the protein C/S system. In contrast, ProC Global was more sensitive to abnormalities in the protein C system than to AT deficiency. The CIP assay was approximately equally sensitive to defects in both systems. Receiver operator characteristic (ROC) curves confirmed that the ProC Global and the CIP assays performed better than the CAT assay (P=0.0179 and P=0.0003, respectively). With the CIP assay ROC analysis showed that with a sensitivity of 100% the specificity was 87.5%. With the PCG assay, optimal threshold resulted in both a sensitivity and a specificity of 79.2%. Although our material is relatively small, the data suggest that at a cut-off value with a specificity of >80%, the CIP assay should be evaluated as a screening test for severe thrombophilia.
Andresen
Marianne S
MS
Haematological Research Laboratory, Aker University Hospital, Trondheimsveien 235, N-0514 Oslo, Norway.
Abildgaard
Ulrich
U
Liestøl
Sigurd
S
Sandset
Per Morten
PM
Mowinckel
Marie-Christine
MC
Ødegaard
Ole Rasmus
OR
Larsen
Mette Lie
ML
Diep
Lien My
LM
D000328:Adult; D000368:Aged; D001780:Blood Coagulation Tests / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods*; D012680:Sensitivity and Specificity; D019851:Thrombophilia / Q000097:blood* / Q000175:diagnosis*