RESUMO
Inherited macrothrombocytopenia is a rare illness that is often misdiagnosed as idiopathic thrombocytopenia (ITP), a more widespread acquired disease. Automated blood cell counters in routine clinical use usually miss giant platelets and underestimate mean platelet volume (MPV). Incorrect diagnoses might expose patients to a risk of unnecessary treatment. The ADVIA 120 hematology counter efficiently detects large platelets based on two-dimensional laser light scatter. The present study measures and re-evaluates MPV using the ADVIA 120 in 112 patients who had initially been diagnosed with ITP. We identified 11 unrelated patients as having probable macrothrombocytopenia (average MPV of 19.2+/-3.8 fL; normal range 7.8-10.2). Functional, phenotypical and DNA analyses confirmed that three of these patients had Bernard-Soulier syndrome and one had MYH9-related disease, both of which are the most common forms of inherited macrothrombocytopenia. We stress that a conventional automated hematology analyzer had overlooked giant platelets in these patients, and that all of them had received high-dose steroid therapy and/or splenectomy before this study according to a diagnosis of ITP. Thus, checking MPV using the ADVIA 120 in thrombocytopenic patients is a useful method of correctly diagnosing inherited macrothrombocytopenia, and thus avoiding patient exposure to unnecessary and sometimes toxic treatment.
Assuntos
Contagem de Células Sanguíneas/métodos , Plaquetas/patologia , Contagem de Plaquetas , Trombocitopenia/diagnóstico , Trombocitopenia/genética , Adulto , Idoso , Síndrome de Bernard-Soulier/diagnóstico , Contagem de Células Sanguíneas/normas , Tamanho Celular , Diagnóstico Diferencial , Feminino , Humanos , Lasers , Masculino , Pessoa de Meia-Idade , Proteínas Motores Moleculares/genética , Cadeias Pesadas de Miosina/genética , Espalhamento de Radiação , Trombocitopenia/sangue , Trombocitopenia/etiologiaAssuntos
Transtornos da Coagulação Sanguínea/diagnóstico , Testes de Coagulação Sanguínea/métodos , Caulim , Biomarcadores/sangue , Transtornos da Coagulação Sanguínea/sangue , Humanos , Inibidor de Coagulação do Lúpus/sangue , Tempo de Tromboplastina Parcial , Valores de Referência , Manejo de Espécimes , Tempo de Coagulação do Sangue TotalRESUMO
Chronic immune thrombocytopenic purpura (ITP) is an autoimmune disorder characterized by increased platelet clearance because of antiplatelet antibodies. It was recently reported that the balance of T helper 1 (Th1) and T helper 2 (Th2) subsets has been implicated in the regulation of many immune responses. In this study, the intracellular interleukin-4 and interferon-gamma production in CD4+ T-lymphocytes activated by phorbol 12-myristate 13-acetate and ionomycin was assessed via flow cytometry in order to determine the clinical significance of the Th1/Th2 ratio in 42 patients with ITP. The study cohort included 28 untreated patients, seven postprednisolone therapy patients and seven postsplenectomy patients. The mean level of the Th1/Th2 ratio in the untreated group was 36.9 (95% CI 25.8-47.9), and significantly higher than in the control group (mean 12.8, 95% CI 9.5-16.1). The mean levels of the Th1/Th2 ratio in the postprednisolone therapy and postsplenectomy groups were 20.5 (95% CI 8.4-32.6) and 16.4 (95% CI 3.1-29.7), respectively, but were no significant differences as compared with control subjects. When untreated patients were divided into two subgroups by Th1/Th2 ratio, the mean level of platelet associated IgG in the high Th1/Th2 subgroup (higher than upper limit of control group) tended to be higher than in the normal Th1/Th2 subgroup. In conclusion, the high Th1/Th2 ratio was closely related to the etiology and disease status of chronic ITP.
