Resposta da púrpura trombocitopênica idiopática à esplenectomia tardia.

Autor: Bassitt, Rogerio Pastore
Jazyk: portugalština
Rok vydání: 2002
Předmět:
Druh dokumentu: Dissertação de Mestrado
Popis: A púrpura trombocitopênica idiopática (PTI) é uma patologia adquirida que leva à redução da contagem de plaquetas, mediada por mecanismo imunológico. O tratamento inicial é a corticoterapia e, se caracterizada a falência ou dependência desta, a esplenectomia é a segunda opção. Autores recomendam que a esplenectomia seja realizada antes de se completarem 12 meses do diagnóstico, apesar de estudos sugerirem que a resposta após este período é semelhante. Neste estudo, pesquisaram-se a eficácia da esplenectomia tardia, as complicações da manutenção da terapia imunossupressora e as complicações hemorrágicas na população com esplenectomia tardia. Analisaram-se prontuários de 39 pacientes com idade de 4 a 64 anos (mediana de 27 anos) ao diagnóstico, submetidos à esplenectomia como procedimento terapêutico de PTI. Classificaram-se as respostas à esplenectomia, observadas na última visita, após 6 meses da cirurgia, em resposta completa (RC) (mais de 150.000 plaquetas/ l) parcial (RP) (de 50.000 a 150.000 plaquetas/ l) ou sem resposta (SR) (menos de 50.000 plaquetas/ l ou necessidade de medicação para controle da PTI). No período anterior à esplenectomia, a prednisona causou efeitos colaterais em 18% dos pacientes. Uma paciente que utilizou azatioprina desenvolveu carcinoma ductal de mama. Outros efeitos colaterais da azatioprina, danazol, colchicina, levamisol e vincristina reverteram após a suspensão das drogas. Não houve mortalidade relacionada à PTI nem às esplenectomias, mas houve mais hemorragias graves (21%) no período pré-operatório. As esplenectomias foram realizadas após 1 a 174 meses (mediana 36 meses) do diagnóstico e a última visita ocorreu depois de 9 a 300 meses (mediana 25,5 meses) da cirurgia. As respostas finais à esplenectomia foram: 16 (44%) RC, 10 (28%) RP, 10 (28%) SR. A comparação entre as respostas dos pacientes que realizaram a esplenectomia antes e as dos que a realizaram após 36 meses não mostrou diferença significativa (p=0,687). A esplenectomia tardia tem eficácia, aferida pela soma das RC e RP, comparável à citada pela literatura. As medicações imunossupressoras produziram mais efeitos colaterais e ocorreram mais hemorragias graves do que as relatadas pela literatura.
Idiopathic thrombocytopenic purpura (ITP) is an acquired immunologic disorder associated with reduction of platelet count. The primary treatment is prednisone in the majority of cases, and if it fails or if there is a dependence of it, the splenectomy is performed. The surgery is usually indicated within 12 months after diagnosis because of presumed better results. Nevertheless, clinical studies suggest that splenectomy is effective when performed after this 12 months. In this study the hemorrhagic complications of ITP, the side effects of immunossupressive therapy during preoperative period and the efficacy and safety of the procedure were studied in a population with late splenectomy. Thirty nine patients were included with median age of 27 years (range 4 to 64 years) at the diagnosis of ITP. The response to splenectomy were classified as complete response (CR) (platelets counts above 150.000/ l), partial response (PR) (platelet counts of 50.000 to 150.000/ l), and no response (NR) (less than 50.000/ l or use of drugs to maintain platelet count). In the preoperative period, prednisone caused side effects in 18% of patients. One patient who received azathioprine had breast cancer. Other side effects of azathioprine, danazol, colchicin, levamisole and vincristine remitted after drugs withdrawal. The surgeries were performed after 1 to 174 months of diagnosis (median of 36 months). Of the 39 patients, 36 had assessment of response to splenectomy after 9 to 300 months: 16 patients had CR (44%), 10 PR (28%), and 10 NR (28%). The responses of the patients with period of diagnosis to splenectomy of 36 months or more were not different from the patients with this period of less than 36 months (p=0.687). During the preoperative period, 21% of patients had severe hemorrhagic complications of ITP, but there were no death caused by ITP or splenectomy. Although, the favorable response (sum of CR and PR) of late splenectomy was similar, there were more side effects of immunossupressive therapy and severe hemorrhagic complications than the reported in the literature. Splenectomy is a therapeutic option for immune thrombocytopenic purpura (ITP), usually recommend before 12 months after diagnosis. In this study, 39 patients were splenectomized 1 to 174 months (median of 36 months) after the hemorrages and more side effects of prednisone than reported in the literature, but there were death. The favorable responses of late splectomy were similar to the reported in the literature. the favorable responses of the group with period of ITP diagnosis to splenectomy of the 36 months or more were not different from the group with less than 36 months (p=0.687).
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