RESUMO
BACKGROUND: This is an evaluation of the treatment of 63 patients with chronic immune thrombocytopenic purpura (54 splenectomized and nine nonsplenectomized) with weekly doses of anti-D (IgG)-coated red blood cells (RBCs). METHODS: All patients were given one 5-15 microg/kg/dose of intravenous (i.v.) anti-D (IgG)-coated RBCs per week (average of 300 microg/dose/week) for a median 3-month period (3-6 months). Treatment modality was evaluated on a weekly basis by platelet counts, measuring of hemoglobin levels, and performance of Coombs tests. RESULTS: All patients presented a clinical response. Fifty-two patients (82.5%) increased their platelet count (PC) and 45 (69.8%) increased their PC >50 x 10(9)/L. In 34 cases, response was sustained. Six of nine nonsplenectomized patients (67%) increased PC, thus avoiding splenectomy; four patients attained a stable complete response (CR). Similar platelet responses were observed in homozygous and heterozygous Rh (D)-positive patients (Rh/Hr phenotypes). Currently, after >10 years, 43 patients present a now permanent complete response with platelet count >50 x 10(9)/L. Ten patients subsequently decreased their platelet count, although they were able to attain CR after receiving six doses of anti-D (IgG)-coated RBCs. CONCLUSIONS: Based on our study of Fc receptor blockade treatment with anti-D (IgG)-coated RBCs with the most difficult cases of ITP, which resulted in a 69.8% successful response rate, we concluded that weekly prescription of anti-D (IgG)-coated RBCs is an effective approach to treating chronic refractory ITP.
Assuntos
Transfusão de Eritrócitos , Eritrócitos/imunologia , Imunoglobulina G/imunologia , Púrpura Trombocitopênica/imunologia , Púrpura Trombocitopênica/terapia , Receptores Fc/imunologia , Imunoglobulina rho(D)/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Imunoglobulina G/química , Masculino , Pessoa de Meia-Idade , Púrpura Trombocitopênica/sangue , Imunoglobulina rho(D)/química , Baço/fisiologia , Fatores de TempoRESUMO
Se presenta el resultado del estudio serológico de un paciente masculino de 48 años, mestizo, con diagnóstico de carcinoma de colon a quien despues de tres transfusiones en el lapso de 10 días se le encontró un anticuerpo contra el antígeno Ge2 (Gerbich 2). El paciente fue grupo A1 Rho (D) positivo; la prueba de la antiglobulina humana directa realizada con diferentes marcas de suero de Coombs mostró grados diferentes de reacción. Las enzimas bromelina y ficina suprimieron, in vitro, la reacción antígeno-anticuerpo. Al experimentar con 116 diferentes muestras de sangre sólo se encontraron tres compatibles. Se descartaron otras especificidades de aloanticuerpos contra sistemas MNSsU, Kidd, Duffy, Lewis, Lutheran, Diego, etc,tera. Los resultados serológicos iniciales sugirieron que el antígeno causal estaba relacionado con las glucoforinas. Investigaciones subsecuentes demostraron la especificidad Ge2. Se trata del primer caso que se informa en México de un anticuerpo específico contra el antígeno Ge2.