38:
215:
452:(APCR). It involves a modified aPTT test performed in the presence and absence of APC. The ratio of these aPTT values is calculated and is called the APC sensitivity ratio (APCsr) or simply APC ratio (APCr). This ratio is inversely related to the degree of APC resistance. The aPTT-based APC resistance test was developed in 1993.
402:
are performed, in which the patient's plasma is mixed (initially at a 50:50 dilution) with normal plasma. If the abnormality does not disappear, the sample is said to contain an "inhibitor" (either heparin, antiphospholipid antibodies or coagulation factor specific inhibitors), while if it does
324:
and 33 s (depending on laboratory). Longer times of up to 50 s do apply to infants. Shortening of the PTT is considered to have little clinical relevance, but some research indicates that it might increase risk of
790:
Langdell RD, Wagner RH, Brinkhous KM (1953). "Effect of antihemophilic factor on one-stage clotting tests; a presumptive test for hemophilia and a simple one-stage antihemophilic factor assay procedure".
538:
Korte W, Clarke, Susan, Lefkowitz, Jerry B. (January 2000). "Short activated partial thromboplastin times are related to increased thrombin generation and an increased risk for thromboembolism".
329:. Normal PTT requires the presence of the following coagulation factors: I, II, V, VIII, IX, X, XI and XII. Notably, deficiencies in factors VII or XIII will not be detected with the PTT test.
656:
Amiral J, Vissac AM, Seghatchian J (December 2017). "Laboratory assessment of
Activated Protein C Resistance/Factor V-Leiden and performance characteristics of a new quantitative assay".
130:
as materials historically used in the test. Apart from detecting abnormalities in blood clotting, partial thromboplastin time is also used to monitor the treatment effect of
258:
by binding the calcium in a sample. The blood is mixed, then centrifuged to separate blood cells from plasma (as partial thromboplastin time is most commonly measured using
303:) is added, and the time the sample takes to clot is measured optically. Some laboratories use a mechanical measurement, which eliminates interferences from lipemic and
968:
980:
836:
1228:
1233:
1180:
461:
141:
The PTT measures the overall speed at which blood clots form by means of two consecutive series of biochemical reactions known as the
889:
1218:
384:
1114:
829:
1223:
439:
1165:
899:
1202:
1126:
317:
1261:
822:
1028:
449:
191:
The PTT is often used in conjunction with another measure of how quickly blood clotting takes place called the
1155:
913:
1150:
51:
Activated partial thromboplastin time; Activated partial prothrombin time; Activated partial thrombin time
1038:
884:
1160:
1011:
698:"Combined Oral Contraceptives and Venous Thromboembolism: Review and Perspective to Mitigate the Risk"
582:
1121:
918:
511:
350:
998:
127:
56:
1082:
894:
423:(if causing a low factor VIII level) may lead to a prolonged aPTT correcting on mixing studies.
1299:
1016:
908:
879:
373:
231:
518:
1213:
1192:
420:
280:
sample (to reverse the anticoagulant effect of the oxalate enabling the blood to clot again).
265:
A sample of the plasma is extracted from the test tube and placed into a measuring test tube.
227:
1294:
1143:
1109:
930:
856:
284:
223:
196:
142:
493:
8:
1138:
993:
445:
354:
1087:
203:
149:
1033:
942:
937:
772:
724:
697:
633:
563:
157:
1271:
1044:
800:
764:
729:
673:
625:
555:
776:
637:
567:
1170:
1067:
1062:
1005:
988:
756:
719:
709:
665:
617:
547:
192:
669:
955:
326:
62:
551:
1266:
1175:
1104:
925:
874:
473:
230:
on an automated instrument at 37 °C (as a nominal approximation of normal
714:
608:
Hellgren M (April 2003). "Hemostasis during normal pregnancy and puerperium".
218:
Blue Top
Vacutainer tube (sodium citrate vial) used for PT and PTT blood tests
1288:
1094:
1077:
1021:
974:
747:
Clark P (February 2003). "Changes of hemostasis variables during pregnancy".
255:
235:
135:
1256:
1187:
963:
804:
768:
733:
677:
629:
559:
300:
277:
273:
259:
42:
Common notation (Fishbone
Diagram) of coagulation times in medical records
1054:
814:
760:
621:
404:
399:
365:
173:
153:
107:
72:
1251:
1131:
869:
864:
848:
845:
416:
391:
358:
185:
161:
103:
37:
537:
519:"MedlinePlus Medical Encyclopedia: Partial thromboplastin time (PTT)"
427:
412:
408:
369:
243:
181:
123:
341:
177:
169:
165:
1197:
337:
304:
269:
251:
247:
131:
380:
321:
296:
292:
288:
696:
Morimont L, Haguet H, Dogné JM, Gaspard U, Douxfils J (2021).
403:
disappear a factor deficiency is more likely. Deficiencies of
111:
195:(PT). The PT measures the speed of clotting by means of the
214:
22:
695:
460:
The PTT was first described in 1953 by researchers at the
789:
655:
222:
Partial thromboplastin time is typically analyzed by a
234:). The test is termed "partial" due to the absence of
156:. The PTT indirectly measures action of the following
448:(APC) resistance test is used in the diagnosis of
430:but tends to slightly decrease in late pregnancy.
21:"KccT" redirects here. For the radio station, see
433:
1286:
394:against coagulation factors (factor inhibitors)
1229:aPTT-based activated protein C resistance test
691:
689:
687:
651:
649:
647:
357:, which paradoxically increases propensity to
1234:ETP-based activated protein C resistance test
830:
114:. A historical name for this measure is the
740:
684:
644:
601:
531:
462:University of North Carolina at Chapel Hill
844:
837:
823:
136:drug that reduces blood's tendency to clot
36:
890:Mean corpuscular hemoglobin concentration
723:
713:
607:
213:
1219:Ristocetin-induced platelet aggregation
1181:Activated protein C–protein C inhibitor
1287:
540:American Journal of Clinical Pathology
385:disseminated intravascular coagulation
379:coagulation factor consumption (e.g.,
287:of coagulation, an activator (such as
818:
746:
364:coagulation factor deficiency (e.g.,
182:XI (plasma thromboplastin antecedent)
92:activated partial thromboplastin time
1262:Nitro blue tetrazolium chloride test
1224:Activated protein C resistance test
580:
440:Activated protein C resistance test
13:
494:"KCCT - General Practice Notebook"
283:Finally, in order to activate the
14:
1311:
1115:Dilute Russell's viper venom time
900:Red blood cell distribution width
398:To distinguish the above causes,
311:
1127:Calibrated automated thrombogram
344:(or contamination of the sample)
1156:Coagulation activation markers
1029:Erythrocyte sedimentation rate
783:
574:
486:
434:aPTT-based APC resistance test
426:The aPTT is usually normal in
276:suspension) is mixed into the
209:
1:
1166:Thrombin–antithrombin complex
914:White blood cell differential
670:10.1016/j.transci.2017.11.021
479:
332:Prolonged aPTT may indicate:
174:VIII (anti-hemophilic factor)
116:kaolin-cephalin clotting time
16:Test for coagulation of blood
1151:Overall hemostatic potential
254:, molecules which act as an
7:
1073:Partial thromboplastin time
1039:Monocyte distribution width
885:Mean corpuscular hemoglobin
702:Front Endocrinol (Lausanne)
552:10.1309/G98J-ANA9-RMNC-XLYU
467:
238:from the reaction mixture.
84:partial thromboplastin time
31:Partial thromboplastin time
10:
1316:
1012:Hemoglobin electrophoresis
455:
437:
20:
1244:
1161:Prothrombin fragments 1+2
1122:Thrombin generation assay
1053:
953:
919:Absolute neutrophil count
855:
715:10.3389/fendo.2021.769187
351:antiphospholipid antibody
69:
55:
47:
35:
30:
500:. Oxbridge Solutions Ltd
178:X (Stuart–Prower factor)
1083:Activated clotting time
895:Mean corpuscular volume
1017:Sickle solubility test
909:White blood cell count
880:Red blood cell indices
374:von Willebrand disease
242:Blood is drawn into a
232:human body temperature
219:
134:, a widely prescribed
1214:Von Willebrand factor
1193:Euglobulin lysis time
1132:ST Genesia-based test
421:von Willebrand factor
228:laboratory technician
217:
90:), also known as the
1207:-antiplasmin complex
1144:Thrombodynamics test
1110:Ecarin clotting time
999:Kleihauer–Betke test
931:Mean platelet volume
875:Red blood cell count
857:Complete blood count
761:10.1055/s-2003-38329
622:10.1055/s-2003-38897
347:vitamin K deficiency
224:medical technologist
186:XII (Hageman factor)
1139:Thromboelastography
610:Semin Thromb Hemost
446:activated protein C
355:lupus anticoagulant
268:Next, an excess of
158:coagulation factors
106:that characterizes
969:Total blood volume
943:Reticulocyte index
938:Reticulocyte count
658:Transfus Apher Sci
220:
1282:
1281:
1272:Immunophenotyping
1045:Osmotic fragility
793:J. Lab. Clin. Med
285:intrinsic pathway
80:
79:
1307:
1171:Fibrinopeptide A
1068:Prothrombin time
1063:Clotting factors
1006:Hemoglobinopathy
989:Fetal hemoglobin
839:
832:
825:
816:
815:
809:
808:
787:
781:
780:
744:
738:
737:
727:
717:
693:
682:
681:
653:
642:
641:
605:
599:
598:
596:
594:
578:
572:
571:
535:
529:
528:
526:
525:
515:
509:
508:
506:
505:
490:
193:prothrombin time
170:V (proaccelerin)
166:II (prothrombin)
73:edit on Wikidata
65:
40:
28:
27:
1315:
1314:
1310:
1309:
1308:
1306:
1305:
1304:
1285:
1284:
1283:
1278:
1257:Blood viscosity
1240:
1206:
1176:Fibrin monomers
1049:
994:Apt–Downey test
981:Red cell volume
956:red blood cells
954:Other tests of
949:
851:
843:
813:
812:
788:
784:
745:
741:
694:
685:
654:
645:
606:
602:
592:
590:
579:
575:
536:
532:
523:
521:
517:
516:
512:
503:
501:
492:
491:
487:
482:
470:
458:
444:The aPTT-based
442:
436:
327:thromboembolism
318:reference range
314:
212:
76:
61:
43:
26:
17:
12:
11:
5:
1313:
1303:
1302:
1297:
1280:
1279:
1277:
1276:
1275:
1274:
1267:Flow cytometry
1264:
1259:
1254:
1248:
1246:
1242:
1241:
1239:
1238:
1237:
1236:
1231:
1221:
1216:
1211:
1210:
1209:
1204:
1200:
1195:
1185:
1184:
1183:
1178:
1173:
1168:
1163:
1153:
1148:
1147:
1146:
1136:
1135:
1134:
1129:
1119:
1118:
1117:
1112:
1107:
1105:Reptilase time
1097:
1092:
1091:
1090:
1085:
1080:
1075:
1070:
1059:
1057:
1051:
1050:
1048:
1047:
1042:
1036:
1031:
1026:
1025:
1024:
1019:
1014:
1003:
1002:
1001:
996:
986:
985:
984:
978:
972:
960:
958:
951:
950:
948:
947:
946:
945:
935:
934:
933:
926:Platelet count
923:
922:
921:
916:
906:
905:
904:
903:
902:
897:
892:
887:
872:
867:
861:
859:
853:
852:
842:
841:
834:
827:
819:
811:
810:
782:
749:Semin Vasc Med
739:
683:
664:(6): 906–913.
643:
600:
573:
530:
510:
484:
483:
481:
478:
477:
476:
474:Thromboplastin
469:
466:
457:
454:
450:APC resistance
435:
432:
396:
395:
388:
377:
362:
348:
345:
320:is between 25
313:
312:Interpretation
310:
309:
308:
281:
266:
263:
211:
208:
204:common pathway
162:I (fibrinogen)
150:common pathway
122:), reflecting
78:
77:
70:
67:
66:
59:
53:
52:
49:
45:
44:
41:
33:
32:
15:
9:
6:
4:
3:
2:
1312:
1301:
1300:Medical signs
1298:
1296:
1293:
1292:
1290:
1273:
1270:
1269:
1268:
1265:
1263:
1260:
1258:
1255:
1253:
1250:
1249:
1247:
1243:
1235:
1232:
1230:
1227:
1226:
1225:
1222:
1220:
1217:
1215:
1212:
1208:
1201:
1199:
1196:
1194:
1191:
1190:
1189:
1186:
1182:
1179:
1177:
1174:
1172:
1169:
1167:
1164:
1162:
1159:
1158:
1157:
1154:
1152:
1149:
1145:
1142:
1141:
1140:
1137:
1133:
1130:
1128:
1125:
1124:
1123:
1120:
1116:
1113:
1111:
1108:
1106:
1103:
1102:
1101:
1100:animal enzyme
1098:
1096:
1095:Bleeding time
1093:
1089:
1086:
1084:
1081:
1079:
1078:Thrombin time
1076:
1074:
1071:
1069:
1066:
1065:
1064:
1061:
1060:
1058:
1056:
1052:
1046:
1043:
1040:
1037:
1035:
1032:
1030:
1027:
1023:
1022:Mentzer index
1020:
1018:
1015:
1013:
1010:
1009:
1007:
1004:
1000:
997:
995:
992:
991:
990:
987:
982:
979:
976:
975:Plasma volume
973:
970:
967:
966:
965:
962:
961:
959:
957:
952:
944:
941:
940:
939:
936:
932:
929:
928:
927:
924:
920:
917:
915:
912:
911:
910:
907:
901:
898:
896:
893:
891:
888:
886:
883:
882:
881:
878:
877:
876:
873:
871:
868:
866:
863:
862:
860:
858:
854:
850:
847:
840:
835:
833:
828:
826:
821:
820:
817:
806:
802:
799:(4): 637–47.
798:
794:
786:
778:
774:
770:
766:
762:
758:
754:
750:
743:
735:
731:
726:
721:
716:
711:
707:
703:
699:
692:
690:
688:
679:
675:
671:
667:
663:
659:
652:
650:
648:
639:
635:
631:
627:
623:
619:
616:(2): 125–30.
615:
611:
604:
588:
584:
577:
569:
565:
561:
557:
553:
549:
545:
541:
534:
520:
514:
499:
495:
489:
485:
475:
472:
471:
465:
463:
453:
451:
447:
441:
431:
429:
424:
422:
418:
414:
410:
406:
401:
393:
389:
386:
382:
378:
375:
371:
367:
363:
360:
356:
352:
349:
346:
343:
339:
335:
334:
333:
330:
328:
323:
319:
306:
302:
298:
294:
290:
286:
282:
279:
275:
271:
267:
264:
261:
257:
256:anticoagulant
253:
249:
245:
241:
240:
239:
237:
236:tissue factor
233:
229:
225:
216:
207:
205:
201:
199:
194:
189:
187:
183:
179:
175:
171:
167:
163:
159:
155:
151:
147:
145:
139:
137:
133:
129:
125:
121:
117:
113:
109:
105:
101:
97:
93:
89:
85:
74:
68:
64:
60:
58:
54:
50:
46:
39:
34:
29:
24:
19:
1188:Fibrinolysis
1099:
1072:
964:Blood volume
796:
792:
785:
755:(1): 13–24.
752:
748:
742:
705:
701:
661:
657:
613:
609:
603:
591:. Retrieved
586:
576:
546:(1): 123–7.
543:
539:
533:
522:. Retrieved
513:
502:. Retrieved
497:
488:
459:
443:
425:
405:factors VIII
400:mixing tests
397:
390:presence of
353:(especially
331:
316:The typical
315:
301:ellagic acid
274:phospholipid
260:blood plasma
221:
197:
190:
143:
140:
119:
115:
99:
95:
91:
87:
83:
81:
18:
1295:Blood tests
1055:Coagulation
1034:Haptoglobin
849:blood tests
589:. WebMD LLC
581:Hammami M.
498:GP Notebook
419:and rarely
366:haemophilia
246:containing
210:Methodology
154:coagulation
108:coagulation
48:Other names
1289:Categories
1252:Blood film
1088:Fibrinogen
870:Hematocrit
865:Hemoglobin
846:Hematology
708:: 769187.
524:2009-01-01
504:2010-06-08
480:References
438:See also:
392:antibodies
359:thrombosis
104:blood test
1203:Plasmin-α
428:pregnancy
370:cirrhosis
244:test tube
198:extrinsic
144:intrinsic
1008:testing
805:13045017
777:36952311
769:15199489
734:34956081
678:29162399
638:22082884
630:12709915
587:Medscape
568:37642249
560:10631865
468:See also
342:warfarin
307:samples.
128:cephalin
102:), is a
1198:D-Dimer
725:8697849
593:25 July
456:History
338:heparin
336:use of
322:seconds
305:icteric
270:calcium
252:citrate
248:oxalate
200:pathway
146:pathway
132:heparin
110:of the
63:D010314
803:
775:
767:
732:
722:
676:
636:
628:
566:
558:
381:sepsis
297:kaolin
293:celite
289:silica
278:plasma
272:(in a
184:, and
124:kaolin
1245:Other
1041:(MDW)
983:(RCV)
971:(TBV)
773:S2CID
634:S2CID
564:S2CID
226:or a
112:blood
71:[
977:(PV)
801:PMID
765:PMID
730:PMID
674:PMID
626:PMID
595:2024
583:"MD"
556:PMID
415:and
202:and
148:and
126:and
120:KCCT
100:APTT
96:aPTT
82:The
57:MeSH
23:KCCT
757:doi
720:PMC
710:doi
666:doi
618:doi
548:doi
544:113
417:XII
340:or
250:or
152:of
98:or
88:PTT
1291::
797:41
795:.
771:.
763:.
751:.
728:.
718:.
706:12
704:.
700:.
686:^
672:.
662:56
660:.
646:^
632:.
624:.
614:29
612:.
585:.
562:.
554:.
542:.
496:.
464:.
413:XI
411:,
409:IX
407:,
383:,
372:,
368:,
299:,
295:,
291:,
262:).
206:.
188:.
180:,
176:,
172:,
168:,
164:,
160::
138:.
1205:2
838:e
831:t
824:v
807:.
779:.
759::
753:3
736:.
712::
680:.
668::
640:.
620::
597:.
570:.
550::
527:.
507:.
387:)
376:)
361:)
118:(
94:(
86:(
75:]
25:.
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
