Spontaneously acquired factor IX inhibitor in a nonhemophiliac child

Hemophilia B: A Pain in the Back

This case report describes an unusual manifestation of hemophilia B, in the form of a lateral chest wall hematoma. A 27-year-old hemophiliac male was found to have a lateral chest wall hematoma after presenting with back pain associated with localized chest wall swelling. Even more unusual than the location of his hematoma was the absence of any preceding triggers such as a fall or trauma to the area. To our knowledge, this is the first reported case of its kind in a patient with inherited hemophilia B. We believe the reporting of such rare presentations increases awareness of these possibilities and thus aids in the prompt diagnosis and treatment of other similar cases when they are encountered.

Concurrent acquired inhibitors to factor VIII and IX, a laboratory artifact: a case report

Acquired inhibitors to coagulation factors other than factor VIII are extremely rare. We describe a case of a 59-year-old woman with abnormal bleeding, diagnosed with concurrent inhibitor antibodies to factor VIII and IX by Bethesda testing. We demonstrate that anti-FVIII antibodies of a very high titre are capable of disturbing the aPTT-based Bethesda assay, resulting in falsely-positive antibodies to factor IX. The case also illustrates the usefulness of the immunological assay (ELISA) in complementing the inhibitor diagnosis.

Familial antiphospholipid antibodies and acquired circulating anticoagulants

Familial clustering of elevated antiphospholipid antibody levels has been described, but the reports are heterogeneous with regard to the characterization of the antiphospholipid syndrome (APS), coexisting autoimmune diseases and clinical implications. We report a familial occurrence of APS in two patients, in the presence of SLE in the mother and absence of autoimmune diseases in the daughter along with acquired circulating inhibitors in both cases: platelet inhibitor and factor IX inhibitor, respectively.

Acquired hemophilia in pediatrics: a systematic review

Acquired hemophilia A is a rare but potentially life-threatening hemorrhagic disorder caused by the development of autoantibodies directed mostly against coagulation factor VIII. Acquired hemophilia is frequently associated with several underlying conditions such as malignancy, autoimmune disorders, drug reactions, and pregnancy, although the pathogenesis remains undetermined (idiopathic) in up to 50% of reported cases. The disorder occurs most commonly in the elderly and only rarely affects pediatric patients, who might however experience severe, and sometimes life-threatening, hemorrhage. The maternal transplacental transfer of the autoantibody to the neonate occurs very rarely and also in this circumstance it may be associated with clinically significant bleeding. The management of acute bleeding and the inhibitor eradication are the mainstay of the treatment. The outcome in pediatric patients seems more favorable than in adults because the inhibitors usually resolve more quickly and in a higher rate of patients. The epidemiology, diagnosis, clinical course, and management of this hemorrhagic disorder in children will be addressed in this systematic review.

Acquired anti-FVIII inhibitors in children

Acquired inhibitors to FVIII (anti-FVIII) are uncommon in children. An acquired anti-FVIII developed in a previously healthy 4-year-old boy treated with penicillin for streptococcal pharyngitis. Aspirin prophylaxis begun for suspected rheumatic fever led to compartment syndromes of all four extremities, which resolved with high-dose FVIII and surgical decompression. Anti-FVIII in this patient, and the five additional cases identified in a survey of 160 haemophilia treatment centres, occurred at a median age of 8 years, with median initial and peak titres of 4.6 and 6.9 Bethesda Units (BU), respectively. All six presented with bleeding, including haematomas (three intramuscular, one intracranial), and ecchymoses in three. The median baseline FVIII was 0.05 U mL(-1), and the median baseline activated partial thromboplastin time (APTT) was 79.8 s. The inhibitor resolved completely in five patients (83%) within a median 5 months, after treatment with FVIII concentrate, steroids, cytoxan, methotrexate, and no treatment. The inhibitor persisted in the patient with Goodpasture's disease, despite steroids, cytoxan, cyclosporin, and intravenous gamma globulin. Aspirin therapy, in two, worsened ongoing bleeding. The association of penicillin-like drugs in this and three other cases in the literature suggest that to avoid potential catastrophic bleeding, it is prudent to obtain an APTT prior to initiating aspirin for suspected rheumatic fever. In conclusion, acquired anti-FVIII inhibitors in children may cause severe bleeding, and remit in the majority after FVIII and/or immunosuppressive therapy.

Acquired inhibitors

Factor VIII auto-antibody inhibitors, though rare, may present significant and often life-threatening haemorrhage. These auto-antibodies, arising predominantly in older individuals, occur in association with autoimmune disorders, lymphoproliferative disorders, solid tumours, medications and the postpartum state. Almost half of the patients develop auto-antibodies spontaneously without an underlying medical condition. Factor VIII auto-antibody inhibitors are characterized as polyclonal IgG immunoglobulins directed against the FVIII procoagulant activity. Laboratory diagnosis is made by performing the aPTT clotting time in conjunction with a mixing study, and subsequently with specific factor assays. Auto-antibodies are quantified most commonly utilizing the Bethesda assay. Acquired inhibitors to other coagulation factors, including factors IX, XI, XIII, vWF protein, and the vitamin K-dependent proteins are extremely rare. The principles of therapy are similar to those which apply to the management of factor VIII auto-antibodies. Treatment of patients with acquired factor VIII auto-antibody inhibitors varies depending upon the underlying medical condition, the titre of the inhibitor, and the clinical presentation. Acutely bleeding patients with high-titre auto-antibodies generally respond well with infusions of porcine factor VIII concentrate, PCCs or rFVIIa. Extracorporeal plasmapheresis with exchange will acutely reduce circulating antibodies and can be used in conjunction with factor infusions and/or IgIV. Haemorrhage in a patient with a low titre auto-antibody will usually respond to high doses of human factor VIII concentrate. DDAVP may also increase factor VIII levels in patients with low-titre inhibitors. Long-term reduction of auto-antibodies can be achieved by immuno-suppressive regimens using steroids and/or cytotoxic agents, IgIV and interferon-alpha. The selection of the appropriate treatment depends upon the associated medical condition, likelihood of spontaneous remission, risk of toxicities of therapy and cost. Determining the efficacy and safety of new treatment modalities for factor VIII auto-antibodies and other coagulation factor inhibitors will require multicentre randomized clinical trials.

Transient hemorrhagic diathesis associated with an inhibitor of prothrombin with lupus anticoagulant in a 1 1/2-year-old girl: report of a case and review of the literature

Acquired inhibitors of coagulation causing bleeding manifestations are rare in children, particularly without an associated underlying disorder such as autoimmune disease. We describe an otherwise healthy 1 1/2-year-old girl who had extensive spontaneous bruising and prolonged bleeding from venipuncture sites. Prothrombin time (PT) and activated partial thromboplastin time (APTT) were prolonged, with evidence of an immediate-acting inhibitor. Thrombin clotting time, fibrinogen, and platelets were normal. Biologic assay of factors II, V, VII, and X were all low, with increasing values at higher dilutions. However, by immunoassay and/or chromogenic assays, only factor II was reduced. An antibody which failed to neutralize prothrombin activity in vitro was detected against radiolabeled prothrombin. Coagulation studies normalized in parallel with clinical recovery and disappearance of the antibody. This case demonstrates acute hypoprothrombinemia-lupus anticoagulant syndrome as a rare presentation of bleeding diathesis in a healthy young child.

Some complications of the therapy of hemorrhagic disorders

The principal mode for treating disorders of hemostasis is correction of the patient's functional defect by transfusions of appropriate fractions of normal plasma or transfusions of platelets. Two major complications of such therapy are the transmission of infectious diseases, particularly hepatitis and the acquired immune deficiency syndrome (AIDS), and the development of antibodies against clotting factors that are deficient in the patient's plasma. Measures that reduce the occurrence of infection include careful selection of donors, fractionation of plasma with the help of monoclonal antibodies, and treatment of plasma or its fractions with heat or with virus-inactivating organic solvents. No technique of preparing or administering blood or its components can prevent the emergence of antibodies against clotting factors. Desensitization by repeated infusions of antigen, for example, antihemophilic factor, however, appears to result in remission in some patients.

Acquired coagulation inhibitor in association with Rocky Mountain spotted fever. With a review of other acquired coagulation inhibitors

An acutely ill 4-year-old girl with Rocky Mountain spotted fever (RMSF) was found to have a coagulation inhibitor. This child had no serious bleeding manifestations and minimal hemorrhagic skin manifestations despite severe RMSF, concurrent thrombocytopenia, as well as the coagulation inhibitor. Hemostatic abnormalities that occur with RMSF as well as other infectious illnesses associated with coagulation inhibitors are reviewed.

Inhibitors of coagulation in children

Acquired inhibitors of coagulation factor interaction in nonhemophilic children are usually nonspecific, transient, and unassociated with clinical bleeding. They occur with some frequency and are the most common cause for a prolonged APTT found by routine testing. In children, some association with viral infections and treatment with penicillin has been noted, but their interrelationship with the development of antibodies remains unclear. The exact nature of these antibodies, usually directed against coagulant factor phospholipid, is not clear and multiple antibodies both specific as well as nonspecific may occur. No therapy is generally required. Rarely has the acute development of antibodies directed against specific coagulation factors occurred. The laboratory evaluation of the type of inhibitor is, therefore, most important as specific inhibitors may be associated with life-threatening bleeding situations. Their therapy should probably include attempts at eradication of the inhibitor by immunosuppressive agents or other newer modalities. Unfortunately, little information is available regarding the nature and outcome of specific inhibitors in children. Acquired inhibitors in hemophilic patients occur in about 6 to 10% of patients. Newer approaches to their therapy include activated PCC which have generally improved the outlook for such patients. Treatment regimens involve a knowledge of inhibitor response and the concomitant use of plasmapheresis, high-dose or continuous i.v. Factor VIII, and porcine Factor VIII, followed by activated PCC. The role of immunosuppressive agents and other newer modalities appears promising, however, prospective controlled studies are necessary to evaluate their role in the overall management of such patients.

Spontaneously acquired factor VIII inhibitor in a non-haemophiliac child

A three-year-old girl who had for two months suffered bruising after minimal injury was admitted because of diffuse ecchymoses and a large haematoma hindering elbow movement. These symptoms were attributable to the development of antifactor VIII inhibitor. No definite etiology was evident despite repeated immunological investigation. Although the inhibitor still persisted at high levels after two years, no further haemorrhage occurred, excepted haematomas three months after the onset of symptoms, in association with mumps.

Acquired hemophilia, meningioma, and diphenylhydantoin therapy

A patient is reported in whom a meningioma of the lateral one-third of the sphenoid ridge was completely removed and long-term prophylaxis for seizures with diphenylhydantoin was prescribed. One and a half years later, a powerful inhibitor developed that specifically neutralized Factor VIII, the antihemophilic factor, and caused an acquired state of hemophilia. The 4-month hemorrhagic disorder was characterized initially by painless hematuria and later by intracerebral and extradural hematomas at the operative site of the previously excised meningioma. Despite the transfusion of massive quantities of concentrates of clotting factors, and the surgical evacuation of the recurrent hematomas on two occasions, the localized bleeding could not be staunched and the patient died. The types of inhibitors that cause acquired hemophilia and their modes of treatment are examined. Although it is possible that the Factor VIII inhibitor in this patient was induced by the meningioma, most previously reported tumors associated with acquired hemophilia have had an immunological basis. The most probable explanation for the acquired hemophilia in this patient was an inhibitor to Factor VIII from an autoantibody induced by the long-term use of diphenylhydantoin.