title: Laboratory evaluation of patients with undiagnosed bleeding disorders.
abstract: The evaluation of patients with a bleeding tendency represents a challenge as the routinely available tests for evaluating bleeding disorders are limited, complicating the laboratory determination of the clinically observed bleeding tendency. As a result, some bleeding disorders remain undiagnosed. The aim of the study was to evaluate whether global coagulation tests would contribute to the laboratory analysis of patients with undiagnosed bleeding disorders. Patients were evaluated for coagulation and fibrinolysis activities by thrombin generation test and euglobulin lysis time. In addition, plasma activity of factor XIII, plasminogen, α-2 antiplasmin, plasminogen activator inhibitor-1, and thrombin-activatable fibrinolysis inhibitor was also obtained. Forty-five patients were included. Eight per cent presented a mild bleeding disorder and 20% a moderate bleeding disorder. The thrombin generation test results were similar between patients and controls. Euglobulin lysis time results, however, were lower in patients than in controls, both before (median 175 vs. 250 min, respectively; P = 0.003) and after (median 145 vs. 115 min, respectively; P ≤ 0.001) arm constriction, suggesting that they were experiencing hyperfibrinolysis. Interestingly, patients' median thrombin-activatable fibrinolysis inhibitor activity was higher than in controls (21.2 vs. 19.46 μg/ml; P = 0.016). However, plasminogen, α-2 antiplasmin, plasminogen activator inhibitor-1, and factor XIII activities did not differ between the groups. Global coagulation and fibrinolysis tests proved to be limited in detecting the hemostatic disorders in some patients with a relevant bleeding tendency and may not be adequate to address their bleeding risk. Bleeding scores are currently the available medical approach for the evaluation of these patients.
authors.affiliation: aHematology andHemotherapy Center-Universityof Campinas/Hemocentro-Unicamp, Instituto Nacional de Ciência e Tecnologia do Sangue bClinical Pathology Department, UNICAMP, Campinas, São Paulo, Brazil.
authors.forename: Graziela Silveira Araújo
authors.initials: GS
authors.lastname: Alves
authors.forename: Fernanda Andrade
authors.initials: FA
authors.lastname: Orsi
authors.forename: Fernanda Dutra
authors.initials: FD
authors.lastname: Santiago-Bassora
authors.forename: Susan Kelly Picoli
authors.initials: SK
authors.lastname: Quaino
authors.forename: Silmara Aparecida Lima
authors.initials: SA
authors.lastname: Montalvão
authors.forename: Erich Vinicius de
authors.initials: EV
authors.lastname: Paula
authors.forename: Joyce M
authors.initials: JM
authors.lastname: Annichino-Bizzacchi
mesh_terms: D000293:Adolescent; D000328:Adult; D001777:Blood Coagulation; D016022:Case-Control Studies; D005176:Factor XIII / Q000378:metabolism; D005260:Female; D063285:Fibrin Clot Lysis Time; D006474:Hemorrhagic Disorders / Q000097:blood / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010958:Plasminogen / Q000378:metabolism; D017395:Plasminogen Activator Inhibitor 1 / Q000097:blood; D012107:Research Design; D013917:Thrombin / Q000378:metabolism; D010959:Tissue Plasminogen Activator / Q000097:blood; D000979:alpha-2-Antiplasmin / Q000378:metabolism
chemical_list: D017395:Plasminogen Activator Inhibitor 1; D000979:alpha-2-Antiplasmin; D010958:Plasminogen; D005176:Factor XIII; D013917:Thrombin; D010959:Tissue Plasminogen Activator