OBJECTIVE: To analyze the results of activated partial thromboplastin time (APTT) mixing test in coagulation factor Ⅷ inhibitor-positive hemophilia patients, so as to increase the value of APTT mixing test in the screen of factor Ⅷ inhibitor. METHODS: Eighty plasmas samples with different titers of coagulation factor Ⅷ inhibitors had been collected and diluted for routine immediate APTT mixing test and at 37 ℃ 2 hours incubation APTT mixing test. Fifteen samples were selected for immediate and normal temperature incubation for 15 min, 30min, 1 hour, 2 hours and 37 ℃ for 30 min, 1 hour, 2 hours APTT mixing test. RESULTS: The results of APTT mixing test were significantly correlated with the titers of coagulation factor Ⅷ inhibitors. The ROC curve result showed that the best diagnostic cut-off value for 2 hours incubation APTT mixing test at 37 ℃ to determine the presence or absence of coagulation factor Ⅷ inhibitors was 43.8 s (sensitivity and specificity was 85.90% and 100%, respectively), while the best diagnostic cut-off value for distinguishing high-titer and low-titer Ⅷ inhibitors was 52.4 s (sensitivity and specificity was 98.18% and 95.65%, respectively). The critical coagulation factor Ⅷ inhibitor titer that could not be corrected by immediate APTT was 5.14 BU/ml, while that could not be corrected by 37 ℃ 2 hours incubation APTT was 1.31 BU/ml. Paired samples t -test was performed on the APTT mixing test results at different times and temperatures, and the differences were statistically significant (P < 0.05). CONCLUSIONS The APTT mixing test can be used as a screening index for coagulation factor Ⅷ inhibitors. APTT mixing test result shows a significant time-temperature dependence with lower titers of coagulation factor Ⅷ inhibitor. Patients with hemophilia who cannot be corrected by immediate APTT mixing test should be alert to the possibility of high titer of coagulation factor Ⅷ.
Humans ; Factor VIII ; Hemophilia A/diagnosis* ; Blood Coagulation Tests/methods* ; Partial Thromboplastin Time ; Blood Coagulation Factors

Adolescent ; Adult ; Child ; Factor VIII ; genetics ; metabolism ; Hemophilia A ; blood ; diagnosis ; Humans ; Male ; Young Adult

In order to analyze the clinical features and laboratory findings in patients with acquired hemophilia A, one case of acquired hemophilia A was studied, the medical history, clinical features, ultrasonography and laboratory examination including activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT) and FVIII:C, FIX:C, FXI:C, FXII:C ratio, as well as medical treatment were analyzed. The results showed 99.3 sec of APTT, 13 sec of PT, and 13.5 sec of TT, 2% of FVIII:C, 7% of FIX:C, 9% of FXI:C and 21% of FXII:C. The prolongation of APTT could not be completely corrected by mixing the patient plasma with an equal volume of normal fresh plasma; the APTT increased with prolongation of incubation time, when patient plasma was mixed with an equal volume of normal fresh plasma and incubated at 37 degrees C. The plasma FVIII:C, FIX:C, FXI:C and FXII:C levels in patient were 6%, 75%, 95% and 123% respectively, when patient's plasma was diluted by tenfold and mixed with an equal volume of non-diluted normal plasma. FVIII inhibitor in the patient's serum was at a level >32.0 Bethesda units/ml after acquired hemophilia was diagnosed, the patient was admitted to hospital and given orally prednisone and azathioprine therapy. One month later, clinical status of the patient were improved with 33.3 seconds of APTT, 128% of FVIII level and elimination of FVIII inhibitor. In conclusion, inquiring case history, analyzing imaging results, detecting level of APTT, performing dilution test and assaying titer of FVIII inhibitor can reduce misdiagnosis and wrong therapy for patients with acquired hemophilia A. The FVIII inhibitor can be eliminated and function of clotting can be recovered by using immunosuppressive therapy.
Factor VIII ; analysis ; antagonists & inhibitors ; Female ; Hemophilia A ; blood ; diagnosis ; Humans ; Middle Aged

Acquired hemophilia A (AHA) is a rare disease where typically coagulation factor VIII is inhibited by autoantibodies. It occurs in patients with no personal or familial history of bleeding. In this case study a 61-year-old male presented with a huge psoas hematoma. He had no history of bleeding disorders. He was initially diagnosed with delayed traumatic hematoma. Despite conservative and surgical treatments, coagulopathy was not resolved and postoperative bleeding continued. Consequently, coagulation factor tests were performed and showed reduced activity of factor VIII (2.7%). In addition, factor VIII inhibitor was detected. The patient was diagnosed with AHA and administered recombinant factor VIII for 3 days which resulted in the cessation of bleeding. AHA can lead to a life-threatening hemorrhage, and needs to be considered in differential diagnoses in any patients presenting with unexplained and repeated bleeding, where there is no personal or familial history of bleeding disorders.
Autoantibodies ; Blood Coagulation Disorders ; Blood Coagulation Factors ; Diagnosis, Differential ; Factor VIII ; Hematoma ; Hemophilia A ; Hemorrhage ; Humans ; Male ; Middle Aged ; Rare Diseases

OBJECTIVETo determine the cut-off value for coagulation factor Ⅷ activity (FⅧ:C) to von Willebrand factor antigen (vWFAg) ratio which can classify obligatory carriers of hemophilia A and normal females, and assess its feasibility to diagnose suspected carriers in affected families through comparison with the method of gene diagnosis.

METHODSFⅧ:C assay was carried out by a one-stage method in both obligatory carriers and normal females. vWF antigen was measured with ELISA assay. The FⅧ:C/vWF ratio was calculated. Statistic analysis was carried out to determine the cut-off value which can classify the two groups. The ratio was then used to diagnose suspected carriers from families affected with hemophilia A. The results were compared with that by long distance polymerase chain reaction, genetic linkage analysis and/or direct sequencing.

RESULTSThe FⅧ:C/vWFAg value for 90.6% of obligatory carriers was under 0.82. Should 0.82 be selected as the cut-off value to diagnose the 42 suspected carriers, most of them can be readily diagnosed. The results were all in agreement with that of genetic analysis.

CONCLUSIONCut-off value of FⅧ:C/vWFAg may be used for initial diagnose of the suspected carriers from families affected with hemophilia A. The method is quite convenient and reliable.

Blood Coagulation Tests ; methods ; Factor VIII ; genetics ; Female ; Genetic Linkage ; Hemophilia A ; diagnosis ; genetics ; Humans ; Male ; von Willebrand Factor ; genetics

Factor VIII inhibitors are produced during or after coagulation factor VIII (FVIII) therapy in hemophilia A patients. These inhibitors are usually detected by a modified Bethesda assay or an enzymelinked immunosorbent assay (ELISA). In this study, we used the Bethesda assay to determine the incidence of FVIII inhibitors in 75 fresh plasma samples obtained from 50 hemophilia A patients, and then used ELISA and the Bethesda assay to determine the titres of these inhibitors after the samples had been frozen and thawed. The samples from the screening Bethesda assay were centrifuged and stored at -70degrees C in accordance with the assay guidelines. Subsequently, these samples were thawed and analyzed using ELISA and the Bethesda assay. The incidence of inhibitors in hemophilia A patients was 20.0%. Among the 35 inhibitor-positive samples identified in the screening Bethesda assay, 16 were positive in ELISA while only 4 were positive in the repeated Bethesda assay. In this study, the ELISA technique showed a higher sensitivity than the Bethesda assay in the detection of FVIII inhibitors in samples that were subjected to freezing and thawing procedures; this was because the Bethesda assay could not identify the FVIII inhibitors that were degraded after freezing and thawing.
Blood Coagulation Factor Inhibitors/*analysis ; *Enzyme-Linked Immunosorbent Assay ; Factor VIII/*antagonists &inhibitors/metabolism ; Hemophilia A/*blood/diagnosis ; Humans ; Immunologic Tests ; Male

PURPOSE: Molecular genetic analysis is the main approach used for prenatal diagnosis of hemophilia A and B. However, in certain cases, such analysis is uninformative. In such situations, direct measurement of fetal coagulation factor levels is still the best option, and it may be the only option in some cases. This study was conducted to determine the normal ranges of midtrimester cord blood factor VIII (FVIII) and IX (FIX) in a Korean population. MATERIALS AND METHODS: Twenty-six FVIII samples and 29 FIX samples were assayed in fetal cord blood acquired by ultrasound-guided cordocentesis. Sampling was conducted during gestational ages of 19-24 weeks. RESULTS: The mean and standard deviations for FVIII and FIX activity were 45.5±30.5% and 19.9±12.2%, respectively. Ranges for FVIII and FIX were 1.5-125.0% and 6.0-52.0%, respectively. CONCLUSION: Our study revealed the normal ranges and lowest level of factor VIII and factor IX in non-affected normal fetus by fetal cord blood sampling during the mid-trimester in a Korea population. The factor assay of the fetal cord blood is invasive but feasible and provides important basic data related to hemophilia.
Blood Coagulation Factors ; Cordocentesis ; Factor IX ; Factor VIII* ; Female ; Fetal Blood* ; Fetus* ; Gestational Age ; Hemophilia A* ; Humans ; Korea ; Molecular Biology ; Pregnancy ; Pregnancy Trimester, Second ; Prenatal Diagnosis ; Reference Values

This study was purposed to investigate the diagnosis, typing and influencing factors of the antibody (inhibitor) to coagulation factors in hemophilia. 500 hemophilia patients were enrolled in this study. The activities of coagulation factor FVIII and FIX were tested by one stage assay. The antibodies of FVIII and FIX were detected by Bethesda assay. All data were analyzed by statistical soft SPSS 10.0. The results indicated that there were 411 cases of hemophilia A, out of which 151 cases (30.2%) showed FVIII antibody positive, the titer was 3.50 ± 2.84 Bu/ml; there were 79 cases of hemophilia B, out of which 18 cases (3.6%) showed FIX antibody positive, the titer was 2.92 ± 2.19 Bu/ml. The other 10 cases were acquired autogeneic hemophilia (2.0%). The antibody was divided into three types: high-response (3 cases), intermediate-response (47 cases), and low-response (119 cases). Among the 169 cases with antibody positive, 157 cases (92.9%) were younger than 30 years old; among 151 (89.35%) cases of hemophilia A; 138 cases (81.66%) were moderate or severe hemophilia; 166 case (98.22%) showed intermediate or low-response antibody. There were 158 cases with allogeneic antibody positive, all of which received blood transfusion. It is concluded that the moderate and low responsive antibodies are the dominant in hemophilia patients, the age of patients and transfusion frequency of blood preparation are the influencing factors. The results of this study provide the basis for the hemophilia diagnosis, antibody typing and evaluation of factors influencing hemophilia, and also suggest that the repeated transfusion of blood preparation may influence the production of antibodies.
Adolescent ; Adult ; Aged ; Autoantibodies ; blood ; Child ; Child, Preschool ; Factor VIII ; immunology ; Female ; Hemophilia A ; blood ; diagnosis ; immunology ; Humans ; Infant ; Male ; Middle Aged ; Young Adult

At present, because of enormous variety of mutations in hemophilia A, carrier detection and prenatal diagnosis by DNA analysis has been relied almost always on indirect detection using linkage analysis of DNA polymorphisms withim or near to the factor VIII gene. However, there is marked ethnic variation in the incidence of heterozygosity for a given DNA polymorphism. So it is very important to find out which DNA polymorphism pattern is useful in Korean families with hemophilia A for carrier detection and prenatal diagnosis. To identify the usefulness of DNA polymorphism in St14 VNTR locus for carrier detection and prenatal diagnosis of hemophilia A in Korean populations, we have analysed the DNA polymorphism in St14 VNTR locus in 80 Korean families with hemophilia A using polymerase chain reaction. We could identify 14 alleles in subjects studied, which ranges from 620 bp to 2830 bp. Expected heterozygosity rate, calculated from the allele frequencies, was 78.7%, and observed heterozygosity rate was 71.3% (57/80). Carrier detection was performed in 43 women from families informative with St14 VNTR : Seventeen women were diagnosed as non-carriers, 11 women as carriers. And 15 women were suspected to be carriers since they were from families of sporadic cases of hemophilia A. And prenatal diagnosis was done in 4 pregnant carrier women : noe fetus proved to be normal males, two fetuses to be normal females, and one to be a carrier. And five pregnant women, suspected to be carrier since they were from families of sporadic cases of hemophilia A, underwent prenatal diagnosis : One fetus was diagnosed as a normal mali, one as a normal female, two as possible carriers, and one as a possible affeted mali, whom the analysis of factor VIII level in fetal blood by cordocentesis revealed to be affected by hemophilia A. These data indicate that PCR-based analysis of St14 VNTR is very useful for the carrier detection and prenatal diagnosis of hemophilia A in Korea.
Alleles ; Cordocentesis ; DNA* ; Factor VIII ; Female ; Fetal Blood ; Fetus ; Gene Frequency ; Hemophilia A* ; Humans ; Incidence ; Korea ; Male ; Mali ; Minisatellite Repeats* ; Polymerase Chain Reaction* ; Pregnant Women ; Prenatal Diagnosis*

Acquired hemophilia A (AHA) is a rare coagulopathy caused by autoantibodies to coagulation factor VIII (FVIII). Most patients with AHA have been previously healthy; however, a variety of morbidities have been associated with the condition including pregnancy. A 40-yr-old woman visited our institution with extensive hematoma on the right hip area. Her medical history revealed no personal or familial history of bleeding diathesis. Her coagulation tests showed markedly prolonged aPTT (117 sec), markedly decreased level of FVIII activity (0.4%) and high-titer FVIII inhibitor (77 BU). Collectively, she was diagnosed as having postpartum AHA and was treated with bypassing agents and corticosteroids. Her aPTT was normalized on the 174th postpartum day and FVIII inhibitor showed negative conversion on the 224th postpartum day. This is the first case of postpartum AHA with high-titer FVIII inhibitor in Korea. Timely diagnosis and management can reduce morbidity and mortality of this potentially life-threatening condition.
Adrenal Cortex Hormones/therapeutic use ; Adult ; Autoantibodies/blood ; Blood Coagulation Factors/therapeutic use ; Factor VIII/immunology ; Factor VIIa/therapeutic use ; Female ; Hematoma/diagnosis ; Hemophilia A/*diagnosis/therapy ; Humans ; Partial Thromboplastin Time ; Postpartum Period ; Pregnancy ; Recombinant Proteins/therapeutic use ; Republic of Korea