Complete correction of Glanzmann's thrombasthenia by allogeneic bone-marrow transplantation

Allogeneic bone marrow transplantation (BMT) successfully corrected type I thrombasthenia in a 4-year-old boy. The donor was his HLA-A, B and D identical 14-year-old brother who was heterozygous for thrombasthenia. A first transplant after conditioning with cyclophosphamide and thoracoabdominal irradiation was rejected, but a second transplant using CCNU, cyclophosphamide, procarbazine and horse antihuman thymocyte globulin in the preparative regimen was successful. Engraftment was proven by studies of platelet membrane antigens, PLA1 and glycoprotein IIb/IIIa complex and by platelet function studies. Haemorrhagic manifestations completely disappeared; platelet membrane markers and clot retraction returned promptly to normal values, and platelet aggregation tests more slowly. Twenty-four months after bone-marrow transplant, the patient was well with mild chronic hepatic graft versus host disease. BMT therefore appears to be a possible treatment for severe inherited platelet disorders.

Transfusion support in acquired coagulation disorders

Transfusion support for acquired coagulation defects can be life-saving when used correctly. There should be laboratory evidence of such defects combined with clinical evidence of excessive bleeding. The laboratory values alone should not be treated except in preparation for an invasive procedure. Then plasma defects are best treated with fresh frozen plasma immediately before surgery since many of the factors have short half-lives. Platelet infusions are better withheld until the platelet-destroying features of some surgical procedures are completed, as in splenectomy or extracorporeal circulation.

Disorders of platelet function: mechanisms, diagnosis and management

Platelets play an important role in hemostasis, and alterations in platelet function may be the cause of abnormal bleeding in a wide variety of congenital and acquired clinical disorders. Platelet dysfunction may be classified as disorders of (1) substrate connective tissue, (2) adhesion, (3) aggregation and (4) platelet-release reaction. The congenital defects of platelet function, although uncommon, have provided important insights into platelet physiology and pathophysiology and, as a group, are less common, better characterized and more readily classified than the acquired defects. The severity of bleeding resulting from platelet dysfunction varies greatly and is substantially increased when another defect of hemostasis coexists. A disorder of platelet function is suspected on the basis of the history and physical examination and is confirmed by the finding of a prolonged bleeding time in the presence of an adequate number of platelets. A specific diagnosis often requires measurements of the factor VIII and von Willebrand factor complex and other tests of platelet function. Some of these tests may be available only in specialized laboratories. Therapy for bleeding episodes resulting from platelet dysfunction is directed at (1) removing or treating the underlying cause of the platelet disorder; (2) replacing the missing plasma cofactors needed to support normal platelet function (such as by the transfusion of cryoprecipitate in patients with von Willebrand disease, and (3) transfusing functional platelets in the form of platelet concentrates in patients with disorders of intrinsic platelet dysfunction.

The bleeding patient

The author has commented on the more frequently encountered acquired haemostatic defects and briefly outlined the relevant routine laboratory investigations that should be performed and their clinical significance. It is important that any replacement therapy with plasma, coagulation factor preparations and concentrates, and platelet infusions should be given promptly and their effectiveness assessed at regular intervals (Urbaniak and Cash, 1977). One's approach to the bleeding patient should be a combination of clinical assessment and interpretation of laboratory data, thus allowing an effective flexible policy to be followed.

[The treatment of haemorrhagic complications due to disturbance of platelet function after operations with extracorporal circulation (author's transl)]

The preoperative selective blood cell separation followed by the postoperative platelet autoransfusion could prevent the exhaustion of platelet function by operations with extracorporal circulation. The postoperative blood loss could be reduced by about 57%. This method can be recommended specially in cases of increased platelet traumatization after long time perfusion. Partial disturbances of platelet function after operations with ECC can also be favourably influenced by infusion of homologous phospholipid (Fibraccel). The postoperative blood loss could be reduced by about one third. This method is beneficial in open heart surgery with short perfusion times due to its little technical expenses.

Correction of the bleeding time in patients with storage pool deficiency by infusion of cryoprecipitate

Five patients with Hermansky-Pudlak syndrome: storage pool deficiency, albinism and ceroid containing bone marrow macrophages and three patients with uncomplicated storage pool deficiency were treated with cryoprecipitate from 16 donors. Within 2 h of transfusion, bleeding times decreased towards a third of initial values. This effect lasted for at least 4 h but had disappeared after 24 h. Six of these eight patients were also treated with an equal volume of human albumin solution. Infusion of albumin had no effect on the bleeding times. The abnormal platelet function tests and biochemical abnormalities (decreased values of platelet total adenosine diphosphate (ADP), adenosine triphosphate (ATP(I) and serotonin) remained unchanged. On four occasions infusion of cryoprecipitate twice daily protected patients with Hermansky-Pudlak syndrome and storage pool deficiency from bleeding during surgery. The mechanism of action of cryoprecipitate in this clinical situation is obscure.

Partial plasma exchange, and adjunct in therapy to complex clinical problems

The use of therapeutic partial plasma exchange (PPE) is reviewed as an adjunct in the treatment of certain complex clinical problems. The procedure is performed with a Model 30 Haemonetics Blood Cell Separator in which the patient's plasma is partially exchanged with fresh frozen plasma, fresh frozen plasma with cryoprecipitate removed or with plasma protein fraction. The present study describes the use of PPE on 12 patients within the last 15 months as a means of altering the plasma proteins to achieve certain therapeutic goals. The study consists of six procoagulant deficient patients (five congentital and one acquired) in which five of the six patients responded by reflecting a satisfactory rise in the plasma procoagulant level following the procedure, resulting in cessation of bleeding. The sixth patient was thought to have had a procoagulant inhibitor, thus the procoagulant level was changed only minimally. The remaining six patients (five with hyperviscosity syndrome and one with platelet antibody) responded only to the degree of the intensiveness of the PPE procedure. More aggressvie, repeated PPE and/or plasmapheresis are needed if the clinical objective is to decrease the plasma viscosity or to lower a humoral antibody within the patient's plasma.

Platelet transfusion therapy

Platelet transfusions are of unquestionably proven benefit for the correction of thrombocytopenia or functional platelet disorders, and they have allowed for more intensive antineoplastic therapy. With the advent of blood component therapy most modern blood banks now have the capabilities for supplying at least limited quantities of platelets. Refinements in procurement methods will inevitably lead to a greater supply of platelets and the establishment of larger transfusion programs. These programs will need to incorporate facilities for platelet storage, recruitment of suitable donors, selection of special donors for refractory patients, and methods for quality control. As antineoplastic therapy becomes more aggressive, such transfusion programs will become an integral part of the operation of cancer treatment centers.

Ischemic therapy in thrombocytopenia from hypersplenism

Percutaneous transfemoral arterial balloon occlusion or gelatin sponge embolization of the splenic artery or both were carried out in three high-risk patients with hepatic cirrhosis to reduce splenic hyperfunction and improve severe thrombocytopenia. Although this maneuver raised peripheral platelet counts in each patient, in one patient left upper quadrant pain with splinting of the lower chest cage led to hypostatic lower lobe pneumonia, while in another septic splentitis with gas-forming organisms necessitated splecectomy. Transfemoral occlusion of the splenic artery, although an effective, noninvasive approach to control splenic hyperfunction, has at the same time potential dangers that should be viewed with extreme caution in therapeutic application.

Congenital release thrombocytopathy: pathophysiology and management

Congenital release thrombocytopathy must be included in the differential diagnosis of bleeding diatheses in women. A review of the coagulation profiles of 7 patients with congenital release thrombocytopathy suggests that more sophisticated platelet aggregation studies must be performed when routine screening procedures fail to determine the cause of a clinically suspected bleeding disorder. Establishing the diagnosis helps to avoid the use of medications which cause an acquired platelet dysfunction, and contributes to adequate prophylaxis against surgical and obstetric hemorrhage.

[Hemostaseopathies in chronic, azotemic renal insufficiency. Pathogenesis, diagnosis, treatment (author's transl)]

A brief survey on the current concepts of diagnosis and pathogenesis of platelet dysfunction in chronic renal insufficiency is given on the basis of clinical hemostaseological investigations. Phenolic compounds, guanidine succinate and fibrin decomposition products are prominent in the discussion of uremia toxins possibly involved in disorders of thrombocytic function. Clinically practicable methods of analysis are briefly presented and the still imperfect status of therapy is emphasized.

Correction of platelet dysfunction and bleeding in cyanotic congenital heart disease by simple red cell volume reduction

Red cell volume reduction corrected the platelet aggregation abnormality and bleeding tendency in four boys, aged 5 to 16 years, with severe cyanotic congenital heart disease and polycythemia. Red cell volume was reduced by replacing 15 to 20 ml/kg body weight of the patient's blood with plasma in 50 ml increments over a 1 to 2 hour period. Within 3 days, platelet aggregation was restored essentially to normal, and previous bleeding symptoms disappeared. Platelet aggregation remained normal during 3 weeks of follow-up study and hematocrit values remained at palliative levels. The procedure was safe and simple, and it had beneficial effects not only on bleeding but also on other symptoms related to polycythemia. These preliminary observations suggest that red cell volume reduction may be useful preoperatively in patients with cyanotic heart disease and defects in platelet function to lessen the risk of serious bleeding during the early postoperative period. Palliation in severely cyanotic children whose condition is inoperable is another possible indication for this procedure.