Bleeding disorders

The primary objective of this chapter is to deal with the most important bleeding disorders from a dental point of view. An understanding of the disorders discussed in this section hinges upon a basic knowledge of the various physiological processes involved in normal haemostasis (AU)

Factor VIII:C activity in cryoprecipitate prepared at the Blood Bank, University Hospital of the West Indies, Jamaica - abstract

Cryoprecipitate is the blood product rich in factor VIII: C activity used in the treatment of haemophhlia A. The University Hospital Blood Bank makes most of this product used in Jamaica. Commercially prepared factor VIII concentrates are expensive. We examined the effect of donor variables and techniques of preparation on the potency of cryoprecipitates in order to determine the most efficient production method. Factor VIII: C activity of cryoprecipitate was measured using the activated partial thromboplastin time with a normal plasma pool being used as reference plasma. Donor age and method of freezing the plasma had no effect on potency. Blood group B had a higher yield of factor VIII: C than groups A and O. Potency was decreased by prolonged storage of blood prior to processing (p = 0.015) but was increased by increasing volumes of cryprecipitate (p<0.01). The mean potency of the factor VIII: C was 184 i.u., surprisingly higher than the usually assumed 70 i.u. used for calculating the requirements of our haemophiliacs. We recommend that plasma from fresh tested blood, frozen in - 40§C be used for preparing cryoprecipitate and that a higher value than 70 i.u. of factor VIII: C be used for each bag of cryoprecipitate (AU)

Seroepidemiologic studies of human T-cell leukemia/lymphoma virus type 1 in Jamaica

The prevalence of HTLV-1 antibodies was evaluated in Jamaica among persons with various malignant, infectious, autoimmune and hematologic disorders and in clinically normal persons. Results document that: (1) the prevalence of HTLV-I antibodies in this population increases with age; (2) overall, there is no significant difference in the antibody prevalence between females and males: (3) antibody-positive individuals are born in all major regions of the island and geographical variance in antibody prevalence by place of birth was not prominent; (4) there is further confirmation of the high prevalence of HTLV-I antibody-positive lymphomas in Jamaica; and (5) the prevalence of HTLV-I antibodies in hemophiliacs, patients with chronic lymphocytic leukemia (CLL0, myelogenous leukemias, and patients with breast cancer is higher than in age-matched populations without malignancies, although none of these differences were statistically significant. The increased prevelence in hemophiliacs is most likely related to their frequent transfusion with blood products, but it has not yet been determined whether the prevalence in patients with other diseases is related to their disease or other as yet undefined factors in common. (Au)

Problems in the hematological diagnosis of unusual coagulation disorders

Thirteen cases of severe coagulation disorders occuring during the past 5 years and investigated at the Government Pathological Laboratory, Jamaica are discussed. Nine of these were hemophilias, one had Christmas disease and three further cases which presented complicated aberrations are discussed in detail. Of this latter group one had multiple congenital deficiency of prothrombin complex (i.e. prothrombin factor VII and factor X) and the other two, who were siblings, had multiple anomalies (anti-hemophilic globulin deficiency, a circulating anti-coagulant acting as a thrombo-plastin inhibitor as well as a plasma thromboplastin antecedent deficiency) (AU)

Haemophilia in Jamaica

Comment is made of the few cases of haemophilia reported among mixed and coloured populations, and the literature relevant to this is briefly surveyed. A brief account is given of the history of haemophilia and its recent separation from other coagulation defects. The main theories of blood coagulation are briefly presented. Three cases of haemophilia occurring in Jamaicans of predominantly Negro ancestry are presented with clinical and haematological data. Investigations with the thromboblastin generation test leave no doubt that these are bona fide haemophiliacs. Certain points in connection with the diagnosis, prognosis and treatment of haemophilia are discussed. Despite the few case4s of haemophilia described in coloured populations, it is felt that the incidence of the disease in these racial groups is much higher than had been thought. Once medical facilities become more widely available in underdeveloped territories the incidence of haemophilia will probably be found to be equal or nearly equal to that found among the Teutonic races of Europe and America. (AU)