Revista Brasileira de Hematologia e Hemoterapia (Mar 2004)
Estudo da refratariedade plaquetária do dia 0 ao 50, em pacientes submetidos a transplante de medula óssea Study of the platelet refractoriness in patients submitted to bone marrow transplant from day 0 to day 50
Abstract
Entre outubro de 1997 e julho de 1999 pesquisou-se a refratariedade plaquetária em 15 pacientes na fase precoce do TMO alogênico e autoplástico, com idade variando de 1 a 66 anos no Hospital São Camilo. Para esta avaliação, foram utilizados os seguintes parâmetros: evolução clínica, cálculo corrigido do incremento plaquetário (CCI), teste de microlinfocitotoxicidade dependente de complemento (CDC) e ensaios plaquetários por aderência de células vermelhas em fase sólida (SPRCA). A refratariedade plaquetária foi definida como falha de resposta a uma transfusão de dois concentrados de plaquetas ABO compatíveis, quando o cálculo corrigido do incremento plaquetário (CCI) de uma hora pós-transfusional era inferior a 7,5 ou de 24 horas From October 1997 to July 1999, platelet refractoriness was studied in 15 patients, aged from 1 to 66 years old, in the early stage of allogeneic and autologous BMT, carried out at the São Camilo Hospital. The following parameters were used for this analysis: daily clinical progress, 1- and 24 hour-post-transfusion platelet corrected count increment (CCI),complement-dependent microlymphocytotoxicity test (CDC) sensitized by human antiglobulin (AGH) and solid phase red blood cell adherence (SPRCA) platelet analysis. Platelet concentrated products were obtained from automated cell separator machines, filtered through retention filters of pre-storage leukocyte reduction and, subsequently, stored at room temperature for a maximum of 96 hours. Each platelet unit featured on average 0.51 x 10(4) leukocytes, with platelet cell counts of 3.58 x 10(11). The mean pH of each thrombocytapherese concentrate was 6.34 and was storage for 32 hours and 21 minutes. Platelets concentrates were transfused on a prophylactic basis, when the platelet counts were below 20 x 10(9) /L or above these values in cases of therapeutic intervention or bleeding. The platelet refractory potential was defined as the lack of response to a transfusion of two compatible ABO platelet concentrate products confirmed by the reduction in platelet CCI 1 hour after transfusion was less than 7.5 or 24 hours after transfusion was less than 4.5. Only the 24-hour CCI analysis showed statistically significance with the platelets refractoriness occurring in 80.0% of the cases, as a consequence of non-immune factors, such as, amphotericin 66.66%, veno-occlusive disease 53.33 %, undetermined fever 40.0%, splenomegaly, slight nose bleeds, fever, severe melene, severe hematemesis and bacterial infection, 20.0%. Slight melene, severe enterorrhagia and moderate and severe nose bleeds 13.33%, whereas CIVD, moderate and severe enterorrhagia were 6.66%. The presence of immune factors was detected by GVHD and CMV infections that were identified in 33.33% and 13.33% of the cases, respectively, although the detection of autoantibodies was negative. The conclusion is that the 24-hour post-transfusion CCI analysis has proven to be a predictor of platelet refractoriness and a useful test in refractory thrombocytopenic patients, mainly those undergoing BMT.
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