Prolonged activated partial thromboplastin time in pregnancy: a brief report

BACKGROUND: Limited data are available regarding causes of prolonged activated partial thromboplastin time (aPTT) in otherwise normal pregnancies. We retrospectively evaluated clinical data of pregnant women in whom an elevated aPTT was noted on routine prenatal testing. Our intent was to identify various causes of prolonged aPTT and to evaluate whether the pregnancies were adversely affected. METHODS: A retrospective review of medical records of 36 pregnant patients with a prolonged aPTT as the sole abnormal coagulation test seen in the outpatient department of a tertiary care hospital over a period of 4 years. RESULTS: Patients' median age was 26 (range, 19-41) years and median duration of gestation period was 19 (range, 8-38) weeks. Fifteen patients were primigravida. Of 36 patients, repeated aPTT values were normal in 24 (67%) patients, whereas 12 (33%) patients had persistently elevated aPTT values. Factor XI deficiency was found in 5 patients, lupus anticoagulant in 3 patients, elevated anticardiolipin antibody in 2 patients, and low von Willebrand Factor level in 1 patient. Overall, 23 patients delivered. No patients experienced excessive bleeding or thromboembolism. CONCLUSION: Factor XI deficiency and antiphospholipid antibody were 2 major abnormalities identified in patients with prolonged aPTT. These coagulopathies were not associated with excessive bleeding or thromboembolism. Repeat normal aPTT in approximately 2 thirds of patients suggests that proper sample collection and processing are important for coagulation assays to avoid erroneous clotting times.     

Congenital combined deficiency of coagulation factors VII and X – different genetic mechanisms

Combined coagulation factor VII (FVII) and factor X (FX) deficiency (combined FVII/FX deficiency) belongs to the group of bleeding disorders in which both factors show reduced plasma activity. It may arise from coincidental inheritance of separate coagulation factor deficiencies or a common cause as large deletions comprising both gene loci. The F7 and F10 genes are located on the long arm of chromosome 13. Here, we describe 10 cases with combined FVII/FX deficiency representing both genetic mechanisms of occurrence. Genetic analyses included direct sequencing of the F7 and F10 genes and MLPA (multiplex ligation‐dependent probe amplification) for detection of heterozygous large deletions. In four patients, the combined deficiency was due to a large deletion within the terminal end of chromosome 13. In the remaining six cases the deficiency resulted from coincidental inheritance of different genetic alterations affecting both genes independently. In most cases, the genetic defects were heterozygous, presenting with prolonged PT, normal aPTT and mild or no bleeding symptoms. Only in one case compound heterozygous mutations were detected in the F10, resulting in prolonged aPTT and a more severe bleeding phenotype. To avoid a misdiagnosis of combined FVII/FX deficiency, analyses of single factor activities have to be performed in all cases with prolonged PT even if aPTT is normal. Genetic analyses are substantial for correct prediction of an inheritance pattern and a proper genetic counselling.     

Bedeutung von Quick,partieller Thromboplastinzeit und Co.

The Quick test and activated partial thromboplastin time (aPTT) are so-called global assays used to characterize different steps in plasmatic hemostasis. They reflect hemostasis in its classical differentiation into extrinsic and intrinsic pathways. However, they do not cover physiological aspects of cell-based hemostasis. Results are not necessarily congruent with a specific clinical situation and do not replace a complete medical history. Patients suffering from hemophilia A or B, for example, have normal Quick test results. Severe factor XII deficiency reveals an extreme aPTT prolongation without a significant bleeding tendency. In Lupus patients, aPTT is also prolonged with clinically a rather increased thrombotic risk. Fibrinogen as a substrate of coagulation discloses pathological results in both global tests in case of considerable reduction. In case of positive bleeding history and a normal global assay, disorders in platelets, von Willebrand factor and factor XIII must be considered. Reduced Quick test results may be expected in factor VII, II, V, or X deficiency. Disorders of liver synthesis of coagulation factors as well as vitamin K deficiency will be indicated by the Quick test rather than by aPTT. The most frequent hereditary reasons for a prolonged aPTT are hemophilia A and B as well as von Willebrand disease. In case of an acquired bleeding tendency, the diagnostic strategy must include autoantibodies. The sensitivity of the aPTT reagent varies widely. Low-molecular weight heparin and pentasaccharides do not influence the test. Oral direct inhibitors may reveal pathological results in a reagent-dependent manner.     

Clinical experience of factor XI deficiency: the role of fresh frozen plasma and factor XI concentrate

Summary. Factor XI deficiency is a rare autosomally transmitted coagulopathy that is associated with a variable bleeding tendency. Recently there have been reports of thrombotic events following the administration of a virally inactivated factor XI concentrate (BPL) to factor XI deficient patients. We have therefore reviewed a single centre's experience of the use of factor XI concentrate over a 6-year period and compared this to our previous experience of either no treatment or treatment with fresh frozen plasma (FFP) in 103 patients.
There were 156 procedures performed without haemo- static cover. The incidence of bleeding was greatest following tonsillectomy (71%) and dental extraction (Sl'h). There was a trend for bleeding complications to be associated with lower levels of factor XI but patients with all levels of factor XI suffered bleeding complica- tions. There were 38 procedures carried out under FFP cover, with only one patient suffering excessive bleeding and no serious complications.
Factor XI concentrate was given to 25 patients to cover 45 episodes. There were no bleeding complications. Three patients suffered serious complications. One patient, with a previous history of cardiovascular disease, died of a myocardial infarction and a second had an ischaemic episode resulting in a %day hospital admission. These episodes both occurred on the same day as the factor XI infusion. A third patient suffered bilateral pulmonary emboli 7 weeks after a prolonged course of factor XI concentrate.
These finding suggest that factor XI concentrate should be contraindicated in patients with a history of cardiovascular disease, when FFP should be used. Guide- lines for the use of factor XI concentrates should be revised, and work performed to establish the mechanism of these thrombotic events.     

Life-threatening bleeding and acquired factor V deficiency associated with primary systemic amyloidosis.

Acquired factor X deficiency has been described in patients with amyloidosis but acquired factor V deficiency is quite rare. We report here a case of life-threatening bleeding and acquired factor V deficiency associated with primary amyloidosis. A 50-year-old man who had no previous hemorrhagic diathesis was referred to our hospital because of recurrent epistaxis, gingival bleeding and hemospermia. The laboratory examination revealed that both the prothrombin time (PT) and the activated partial thromboplastin time (aPTT) were significantly prolonged, and factor V activities were markedly decreased to 14-39% of the normal value. Other coagulation factors such as fibrinogen, prothrombin, factor VII, factor VIII, factor IX and factor X were subnormal and normal. Transaminases were slightly elevated but serological tests of hepatitis B and hepatitis C were negative. Mild hepatosplenomegaly was noted without sign of liver cirrhosis. The PT and aPTT obtained 8 years ago when he received a cholecystectomy due to cholecystitis were both normal. Specific assays for the detection of factor V inhibitor were repeatedly performed but no factor V inhibitor was found. Furthermore, a significant recovery of the infused factor V was noted shortly after an intravenous administration of 5-10 U fresh frozen plasma, but it did not last more than 6 h. Melena, bleedings into the left shoulder and buttock, and finally mortal retroperitoneal hemorrhage developed despite repeated infusions of large amounts of fresh frozen plasma. Acquired factor V deficiency associated with primary amyloidosis was suspected but histological diagnosis was not obtained because of the severe bleeding tendency. Autopsy revealed hepatosplenomegaly and massive deposits of AL amyloid in the liver, spleen, heart and other parenchymal organs. Perivascular amyloid deposition and factor V deficiency are both thought to be the cause of the severe hemorrhagic tendency seen in this patient.     

Factor XI activity and factor XI antigen in homozygous and heterozygous factor XI deficiency

A relatively potent antiserum against highly purified, unactivated human factor XI antigen was raised in a rabbit. This antiserum, after concentration, neutralized 50% of the factor XI clotting activity of a standard normal plasma at an antiserum dilution of 1/900. The antiserum was used in a neutralization-inhibition assay to study the relation between factor XI clotting activity and factor XI antigen in plasma from ten unrelated patients with homozygous factor XI deficiency and from 12 heterozygous family members of these patients. No evidence of factor XI antigen significantly in excess of factor XI activity was found in either group. All data to date have been consistent with the hypothesis that hereditary factor XI deficiency represents a genetic disorder resulting from the absence of factor XI molecule. Severity of bleeding in factor XI deficiency could not be correlated with the level of factor XI activity or factor XI antigen.     

The investigation of a prolonged APTT with specific clotting factor assays is unnecessary if an APTT with Actin FS is normal

Introduction: An isolated prolongation to the activated partial thromboplastin time (APTT) can be caused by the presence of the lupus anticoagulant or an intrinsic or contact factor deficiency, of which only deficiencies of factors VIII, IX or XI are associated with bleeding. Our local protocol states that further investigation of a prolonged APTT by specific assays of FVIII, FIX and FXI should only be undertaken where the APTT with one reagent (Synthasil) is more than 3 s prolonged, and further investigation by an APTT with a second reagent (Actin FS) is also prolonged, unless there is a history of bleeding in the patient, in which case assays are indicated irrespective of the APTT. Methods: We retrospectively reviewed the results of all APTTs performed over a 36 ‐month period to evaluate whether strictly applying our protocol would reduce the number of unnecessary clotting factor assays performed, without leaving patients with potentially significant bleeding disorders undiagnosed. Results: Of a total number of 587 samples tested for coagulation factors VIII, IX and XI, only 117 samples yielded an abnormal result. Thus, 80% of all the assays requested in the 3 ‐year period audited gave a result within the reference range for factors VIII, FIX and XI. Three quarters of the abnormal results revealed mild FXI deficiency. Conclusion: This review has demonstrated that no significant coagulation factor deficiency would be left undiagnosed if the protocol was followed. This would have considerably reduced the cost and time spent performing these assays.     

Factor XI deficiency caused by a mutation of Gly400Val

The patient described herein is a 69-year-old Japanese woman with a history of excessive bleeding after left heminephrectomy for a malignant renal tumor at 31 years of age. Her parents, who do not have abnormal bleeding, are first cousins. Her factor XI activity was less than 1% of normal with an prolonged activated partial thromboplastin time (APTT) of 74.3 seconds. Analysis of the patient's factor XI genes revealed homozygosity for a valine substituting for the wild-type glycine at amino acid 400 (Gly400Val). The patient has two children, neither of whom has abnormal bleeding and whose factor XI activities are 62% and 57% of normal, with APTT levels within normal limits in both cases. We herein report on a Japanese family with factor XI deficiency caused by Gly400Val mutation.     

Surreptitious bleeding in surgery: a major challenge in coagulation

Apart from inadequate surgical haemostasis, postoperative bleeding can be related to acquired disorders of platelet number, platelet function or coagulation proteins (e.g. Vitamin K deficiency, DIC or liver injury). We highlight our experience with three patients who suffered life-threatening bleeding in the postoperative setting. The three patients - a 47-year-old man and 70- and 74-year-old women -- all had negative histories for excessive bleeding with prior surgeries, and all had normal preoperative PT and aPTT tests. Surgeries were resection of ischaemic bowel, cholecystectomy and coronary artery bypass grafting. All patients experienced unexpected bleeding within the first few postoperative days requiring multiple red cell transfusions and surgical re-explorations. Evaluations within the first 4--7 days after surgery revealed that these three patients had developed prolonged aPTT due to demonstrable factor VIII antibodies initially at low titre. One patient was treated with high doses human factor VIII, corticosteroids, intravenous gammaglobulin and plasma exchanges. The inhibitor was no longer demonstrable after 6 weeks of such therapy, and he has remained in remission without therapy. The second patient was initially treated with high-dose human factor VIII infusions. Five months later, prednisone and 6-mercaptopurine were begun for worsening inhibitor titre and diffuse purpura and subcutaneous haematomas. The factor inhibitor remitted, but the patient died from liver failure related to post-transfusion hepatitis. The third patient was initially managed with high-dose human factor VIII. Two months later, worsening inhibitor titre and tongue haematoma was treated with activated prothrombin complex, corticosteroids and cyclophosphamide. Eight years later, she is on no therapy, demonstrates a mild bleeding tendency and has a stable low-titre inhibitor. There have been a few case reports of inhibitors to coagulation factors including factor VIII becoming manifest in the postoperative setting but surgery has not been widely recognized as an underlying cause for acquired haemophilia. This paper speculates on pathogenesis and reviews treatment options. This syndrome is remarkable for its abrupt onset in the first few postoperative days and for its substantial morbidity. The problem is potentially reversible with immunosuppressive therapy. Clinicians should be aware of this syndrome, considering acquired haemophilia in patients with unexpected postoperative bleeding.     

A "new" congenital haemorrhagic condition due to the presence of an abnormal factor X (factor X Friuli): study of a large kindred

Summary Three related patients are presented who show a congenital coagulation disorder with laboratory features intermediate between classical factor-VII and factor-X deficiencies. A woman and two men had suffered from bleeding since early childhood, with epistaxis, bleeding from the gums, post-traumatic haemarthroses, bleeding after tooth extractions and other surgical procedures. Investigation demonstrated a prolonged prothrombin time, prolonged partial thromboplastin time, abnormal prothrombin consumption and abnormal thromboplastin generation corrected by normal serum. Platelet and vascular tests were normal and no hyperfibrinolysis was found. Factors I, II, V, VII, IX, XI and XII were within normal limits in all three patients. Mutual correction was demonstrated with a known factor-VII-deficient plasma but not with Stuart (X-deficient) plasma. Factor-X assay yielded low (4–9%) levels using tissue whole thromboplastin or tissue partial thromboplastin; but the results were normal with a Stypven-cephalin mixture. In agreement with these results, the Stypven-cephalin clotting time, the Stypven clotting time and the factor II + factor X level using a Stypven-cephalin mixture were normal, ‘correction’ being attributable to the Russell's Viper venom. These results were thought to indicate an abnormal factor X rather than a real deficiency. The presence of abnormal factor X was demonstrated by the antibody neutralization technique and by the immunodiffusion studies. The defect, like classical factor X deficiency, is transmitted as an autosomal incompletely recessive trait. The heterozygote population has factor-X levels varying from 32% to 55% of normal and are usually asymptomatic. The term ‘Factor X Friuli’ is proposed for the abnormality, due to a locally common mutant gene.     

A novel congenital haemostatic defect: combined factor VII and factor XI deficiency.

Isolated deficiencies of factors VII and XI are both rare. Not surprisingly, therefore, combined factor VII and XI deficiency has not been reported previously. We report here a kindred with a combined heterozygous deficiency for both factors VII and XI. The proposita is a 28-year-old woman who had both a prolonged prothrombin time (PT) and a prolonged activated partial prothrombin time (APTT) associated with a mild bleeding tendency. Coagulation studies were performed on the six available members of this kindred. The PT and APTT were normal or mildly abnormal in five of these individuals. Factor VII coagulant activity (VII:C) varied from 0.33 to 0.77 units/ml in affected subjects. In contrast, the concentration of factor VII-related antigen for the six individuals ranged from 0.68 to 2.10 units/ml. Comparable factor VII:C levels were obtained when each subject's plasma was tested with either a rabbit or a human thromboplastin reagent. Factor XI coagulant activity was less than 0.5 units/ml in three of the six subjects and normal (approximately 1.0 units/ml) in the other three. The concentrations of thrombin-antithrombin-III and prothrombin fragment 1.2 were within normal limits for all individuals. In addition to being associated with heterozygous factor XI deficiency, the abnormal factor VII molecule in the plasma of affected individuals in this kindred appears to represent a newly described mutation. This is suggested by the pattern of reactivity with thromboplastin from different species, the normal tissue factor binding and the bleeding tendency in heterozygous individuals in this kindred.     

Inheritance and bleeding in factor XI deficiency

A study of 20 Jewish and four non-Jewish kindreds transmitting factor XI deficiency (164 individuals) confirmed inheritance to be autosomal with severe deficiency in homozygotes (mean factor XI level 3.8 u/dl, SD 2.91) and partial deficiency in heterozygotes (mean factor XI level 57 u/dl, SD 10.42; normal mean factor XI level 96 u/dl, SD 11.6). The probability of an individual being heterozygous can be predicted from the factor XI level using a graph derived from this data. The accuracy is increased by including the prior probability derived from the pedigree. A high frequency of heterozygote to heterozygote mating was observed in the Jewish families consistent with an estimated gene frequency of 13.4% in this racial group. The relationship between factor XI level and bleeding tendency is poor; a third of heterozygotes had bled excessively after surgery, including six with factor XI levels above 50 u/dl, showing this condition to have clear signs of expression in heterozygotes. The lower limit of the normal range (2 SDs from the mean) was found to be 72 u/dl.     

Clinical and prognostic role of plasma coagulation factor XIII activity for bleeding disorders and 6-year survival in patients with chronic liver disease.

BACKGROUND/AIMS: Alterations of plasma coagulation factor XIII may contribute to bleeding disorders in patients with liver cirrhosis. As standard clotting tests such as prothrombin time or activated thromboplastin time (aPTT) cannot detect factor XIII deficiency, this may often be overlooked in clinical practice. We aimed to define factor XIII's clinical and prognostic role in chronic liver disease. PATIENTS AND METHODS: Factor XIII activities were assessed among various other parameters in 111 patients with chronic liver diseases during evaluation for liver transplantation in a prospective study. RESULTS: Unlike coagulation factors II, V or VII, factor XIII activity was maintained in the majority of patients with liver cirrhosis. However, although rarely, factor XIII deficiencies (<50%) occurred, especially in Child C cirrhosis. Factor XIII levels correlated with liver's biosynthetic capacity (cholinesterase activity, albumin, total protein) as well as with platelet count, global coagulation tests and other single coagulation factors. Patients reporting a current systemic bleeding tendency at study entry had significantly reduced factor XIII. In a 6-year follow-up, patients with factor XIII<50% had a significantly increased risk of severe upper gastrointestinal bleed, and reduced factor XIII (<50%, 50-75% vs. normal) was associated with increased mortality. CONCLUSIONS: Factor XIII deficiency is rare in patients with liver cirrhosis, but is associated with a clinical bleeding tendency and an unfavorable prognosis for future hemorrhages and survival.     

Aortic valve replacement in a patient with factor XII deficiency: case report

Congenital factor XII deficiency is a rare condition. We report a case of aortic valve replacement (AVR) in a 63-year-old man with factor XII deficiency. On admission, the patient's activated partial thromboplastin time (aPTT) was prolonged (271 s), and activated clotting time was 500 s. His factor XII level was <3%. The Sonoclot signature showed an abnormal pattern. AVR with a prosthetic valve (St. Jude Medical) was performed safely after the normalization of aPTT and the Sonoclot signature by frozen plasma transfusion. The perioperative management in patients with factor XII deficiency is discussed.     

Factor XI deficiency and its management

Factor XI deficiency has a more variable bleeding tendency than haemophilia A or B. Individuals with severe deficiency have only a mild bleeding tendency, which is typically provoked by surgery, but the risk of bleeding is not restricted to individuals with severe deficiency. The bleeding tendency varies between individuals with similar factor XI levels, and sometimes the bleeding tendency of an individual may vary. The reasons for this are not fully understood, although in cases of severe deficiency there is some correlation between phenotype and genotype.
Factor XI is activated by thrombin. The role of factor XI in physiological processes has become clearer since this fact was discovered, and the discovery has contributed to a revised model of blood coagulation. Factor XI deficiency occurs in all racial groups, but is particularly common in Ashkenazi Jews. The factor XI gene is 23 kilobases long. Two mutations are responsible for most factor XI deficiency in the Ashkenazi population, but a number of other mutations have now been reported in other racial groups.
Individuals with factor XI deficiency may need specific therapy for surgery, accidents, and dental extractions. Several therapies are available which include fresh frozen plasma, factor XI concentrates, fibrin glue, antifibrinolytic drugs, and desmopressin. Each has advantages and risks to be considered. Factor XI concentrate may be indicated for procedures with a significant risk of bleeding especially in younger patients with severe deficiency, but its use in older patients has been associated with thrombotic phenomena. If fresh frozen plasma is to be used it is preferable to obtain one of the virally inactivated products. Fibrin glue is a useful treatment which deserves further study.     

New observations on factor XI deficiency

Summary.  Factor (F) XI is an injury-related bleeding tendency that commonly occurs when trauma involves tissues rich in fibronolytic activators. Severe FXI deficiency is defined when the activity of FXI in plasma is less than 15 U dL⁻¹. The disorder is inherited as an autosomal recessive trait manifesting in homozygotes or compound heterozygotes, and infrequently in heterozygotes. So far 53 mutations in the gene of FXI have been described and four of them were found to be prevalent in Ashkenazi Jews, Iraqi Jews, Basques or the English population. For each of the four mutations a founder effect was discerned. Inhibitors can develop in patients with FXI level < 1U dL⁻¹ who were exposed to plasma which seriously complicates their management during surgery. No correction of a prolonged aPTT by normal plasma is indicative of the presence of an inhibitor. In contrast to patients with haemophilia A, severe FXI deficiency provides no protection against myocardial infarction. In patients with severe FXI deficiency undergoing surgery, fresh frozen plasma is the treatment of choice. FXI concentrates can also be used but cause thrombosis in approximately 10% of patients, particularly those with cardiovascular disease. Recombinant FVIIa has successfully prevented bleeding during or after surgery in patients with FXI inhibitors.     

Prevalence,causes, and characterization of factor XI inhibitors in patients with inherited factor XI deficiency

Factor XI deficiency, an injury-related bleeding disorder, is rare worldwide but common in Jews in whom 2 mutations, Glu117Stop (type II) and Phe283Leu (type III), prevail. Mean factor XI activities in homozygotes for Glu117Stop and for Phe283Leu are 1 and 10 U/dL, respectively. Inhibitors to factor XI in patients with severe factor XI deficiency have been reported in a small number of instances. This study was undertaken to determine the prevalence of acquired inhibitors against factor XI in patients with severe factor XI deficiency, discern whether these inhibitors are related to specific mutations, and characterize their activity. Clinical information was obtained from unrelated patients with severe factor XI deficiency, and blood was analyzed for factor XI activity, inhibitor to factor XI, and causative mutations. Immunoglobulin G purified from patients with an inhibitory activity was tested for binding to factor XI, effects on activation of factor XI by factor XIIa and thrombin, and activation of factor IX by exogenous factor XIa. Of 118 Israeli patients, 7 had an inhibitor; all belonged to a subgroup of 21 homozygotes for Glu117Stop who had a history of plasma replacement therapy. Three additional patients with inhibitors from the United Kingdom and the United States also had this genotype and were exposed to plasma. The inhibitors affected factor XI activation by thrombin or factor XIIa, and activation of factor IX by factor XIa. The results imply that patients with a very low factor XI level are susceptible to development of an inhibitor following plasma replacement.     

Combined dys-form of homozygous factor XI deficiency and heterozygous factor XII deficiency

A 12-year-old girl with lifelong hemorrhagic episodes was found to have both a dys-form of homozygous factor XI deficiency and heterozygous factor XII deficiency. The heredity of the coagulation defects was confirmed by family studies. Severe bleeding after dental surgery occurred in spite of replacement therapy and local measures including fibrin glue. Our findings suggest that the risk of bleeding in patients with homozygous factor XI deficiency must not be underestimated and that the most effective measure is the transfusion of sufficient amounts of fresh frozen plasma until at least the 5th postoperative day.     

An Alu-mediated 31.5-kb deletion as the cause of factor XI deficiency in 2 unrelated patients

Factor XI deficiency (MIM 264900) is an autosomal bleeding disorder of variable severity. Inheritance is not completely recessive as heterozygotes may display a distinct, if mild, bleeding tendency. Recent studies have shown the causative mutations of factor XI deficiency, outside the Ashkenazi Jewish population, to be highly heterogeneous. We studied 39 consecutively referred patients with factor XI deficiency to identify the molecular defect. Conventional mutation screening failed to identify a causative mutation in 4 of the 39 patients. Epstein-Barr virus (EBV)-transformed cells from these 4 patients were converted from a diploid to haploid chromosome complement. Subsequent analysis showed that 2 of the patients had a large deletion, which was masked in the heterozygous state by the presence of a normal allele. We report here the first confirmed whole gene deletion as the causative mutation of factor XI deficiency, the result of unequal homologous recombination between flanking Alu repeat sequences.