Spontaneous factor VIII inhibitor occurring in association with chronic graft-versus-host disease

Acquired hemophilia a: diagnosis, aetiology, clinical spectrum and treatment options

Acquired hemophilia A (AHA) is a rare disorder with an incidence of approximately 1 per million/year with a high mortality rate of more than 20%. The disease occurs due to autoantibodies against coagulation factor VIII (FVIII) which neutralize its procoagulant function and result in severe, often life-threatening bleeding. The antibodies arise in individuals with no prior history of hemophilia A. AHA may be associated with pregnancy, autoimmune diseases, malignancy, infections or medication and occurs most commonly in the elderly. Approximately 50% of the patients remain idiopathic with no known underlying pathological condition. Clinical manifestations include spontaneous hemorrhages into the skin, muscles or soft tissues or excessive bleeding during surgery. Hemarthrosis which is the hallmark of congenital severe hemophilia A seldom occurs in AHA. The diagnosis of AHA is based on the isolated prolongation of activated partial thromboplastin time (APTT) which does not normalize after the addition of normal plasma along with reduced FVIII levels. The treatment involves two aspects-eradication of antibodies and maintaining effective hemostasis during a bleeding episode. The protocols for eradication of antibodies include immunoadsorption, immunosuppression or immune tolerance induction (ITI). The treatment of acute bleeding episodes involves use of different bypassing agents like recombinant activated factor VIIa (rFVIIa, NovoSeven®) and activated prothrombin complex concentrate (aPCC, (FEIBA®) in case of patients with high titer inhibitors or with antifibrinolytics,1-deamino-8-D-arginine vasopressin (DDAVP) or FVIII concentrates in low titer inhibitor patients. The anti CD20 monoclonal antibody, rituximab, has shown very good results either singly or in combination with immunosuppressive regimens in patients who do not respond to standard immunosuppressors. The present review summarizes the diagnostic, aetiological, clinical and treatment aspects of AHA focusing on the recent advances in this area.

Thrombocytopenia and hemostatic disorders in chronic graft versus host disease

Chronic graft versus host disease (cGVHD) is a major and frequent late complication in allogeneic stem cell transplantation recipients. Although thrombocytopenia in cGVHD patients is among the most consistent and strongest predictors of poor survival across many cGVHD studies, such correlation is still neither clearly explained nor well understood. Low platelet counts in the setting of cGVHD are associated with an increase in complications and treatment-related mortality, but usually not with higher relapse rate or engraftment failure rate. Bleeding might be occasionally increased along with, paradoxically, thrombosis. Hemostatic disorders in the context of cGVHD are significant complications with multifactorial etiology, including tissue injury with releasing microparticles, cytokine release, macrophage/monocyte clearance, CMV infection, production of transforming growth factor-beta, and low levels of thrombopoietin. Future clinical trials with agents that stimulate megakaryocytopoiesis or influence underlying impaired hemostasis mechanisms should investigate whether such interventions may improve outcomes in patients with cGVHD.

Acquired hemophilia A: a concise review

Acquired hemophilia A is a rare but severe autoimmune bleeding disorder. It is more frequent in the elderly and results from the presence of autoantibodies directed against clotting factor VIII. In this review, we briefly report on the present state of knowledge regarding acquired hemophilia A, analyzing its epidemiology, pathogenesis, diagnostic, and clinical features. We also describe the main characteristics of this disorder according to its association with different conditions and the most important advances in the treatment of bleeding episodes and the eradication of the autoantibody.

Chronic graft-versus-host disease

Chronic graft versus host disease (GVHD) remains today one of the most vexing late complications of allogeneic stem cell transplantation. Occurring a minimum of 100 days following stem cell transplantation, approximately 50% of patients will experience some degree of chronic GVHD. Host-reactive lymphocytes of donor origin are the cells responsible for the "alloimmune" attack. The increased use of hematopoietic stem cells collected from the peripheral blood instead of bone marrow and the increasing age of stem cell transplant recipients has led to a higher incidence of chronic GVHD. Chronic GVHD most commonly affects the skin, liver, eyes or the mouth, however multiple other sites may also be affected. Chronic GVHD and the medications used to treat it result in a profoundly immunocompromised state. Death due to severe chronic GVHD is usually a consequence of infectious complications. Standard treatment for severe chronic GVHD is a combination of cyclosporine and prednisone. An alternating day regimen of these two agents prolongs survival and reduces drug-related adverse events. Topical therapy to affected areas is preferred for patients with mild disease. The 10-year survival of patients with mild chronic GVHD is approximately 80%, but is less than 5% for patients affected by severe chronic GVHD.

Chronic graft-versus-host disease: clinical manifestation and therapy

Chronic graft-versus-host disease (GVHD) is a major cause of morbidity and mortality in long-term survivors of allogeneic stem cell transplantation. The immunopathogenesis of chronic GVHD is, in part, TH-2 mediated, resulting in a syndrome of immunodeficiency and an autoimmune disorder. The most important risk factor for chronic GVHD is prior history of acute GVHD and strategies that prevent acute GVHD also decrease the risk of chronic GVHD. Other important risk factors are the use of a non-T cell-depleted graft, and older age of donor and recipient. Whether recipients of peripheral blood stem cells are at increased risk of chronic GVHD remains unsettled. There are no known pharmacologic agents which can specifically prevent development of chronic GVHD. Agents which have efficacy in the treatment of autoimmune disorders have been utilized as therapy for established chronic GVHD and are associated with response rates of 20% to 80%. Most responses are confined to skin, soft tissue, oral mucosa and occasionally liver. Bronchiolitis obliterans responds infrequently to therapy and is associated with a dismal prognosis. Newer, promising therapeutic strategies under investigation include thalidomide, photopheresis therapy, anti-tumor necrosis factor and B cell depletion with anti-CD20 monoclonal antibody.

Development of spontaneous factor VIII inhibitor in association with acute graft-versus-host disease

A 57-year-old female with recurrent AML underwent a T cell-depleted (TCD) bone marrow (BM) plus TCD and CD34-selected peripheral blood stem cell (PBSC) transplant. Eleven weeks post transplantation, the patient developed acute graft-versus-host disease (GVHD) manifested by rash and elevated liver enzymes. Concurrently, the patient presented with a bleeding diathesis and a left forearm hematoma due to the development of a spontaneous factor VIII inhibitor. She was treated with human recombinant factor VIII and intravenous methylprednisolone. Subsequently she was managed with a prednisone taper leading to resolution of the GVHD, as well as the spontaneous factor VIII inhibitor. Bone marrow transplant-related spontaneous factor VIII inhibitor has previously been reported in association with one patient with chronic GVHD. To our knowledge this is the first report of spontaneous factor VIII inhibitor associated with acute GVHD.

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.