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BACKGROUND: Fms-like tyrosine kinase 3 (FLT3) expression and mutation have been considered a poor prognostic factor in acute myeloid leukemia (AML). FLT3-ITD mutation is present in 30% of adult patients with AML and 2-5% in childhood acute lymphoblastic leukemia (ALL). The impact of these mutations on the prognosis of ALL patients, has not yet been established. Moreover, a limited number of publications regarding the level of expression of the FLT3 receptor (CD135) in both leukemias exist. This study aimed to analyze the clinical outcomes associated to the presence of FLT3-ITD mutation and the expression of CD135. METHODS: 82 adult patients with newly diagnosed acute leukemia (39 with AML and 43 with ALL) were included. Flow cytometry and RT-PCR were done to analyze the expression of CD135 and the presence of FLT3 ITD mutation, respectively. RESULTS: FLT3-ITD was present in 14 (36%) of AML and 15 (35%) of ALL patients. Disease free survival (DFS) and overall survival (OS) were lower in ALL patients having a CD135 expression >3000 cells/µL. There was a trend for poor OS in AML patients expressing FLT3 ITD. OS was worse in AML patients with high expression of CD135. CONCLUSION: A higher (35%) frequency of FLT3-ITD was found in adult ALL patients. The presence of FLT3-ITD was associated with a trend of poor OS in AML cases, and overexpression of CD135 was correlated with poor DFS in ALL cases and poor OS in both acute leukemias.

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Hereditary hemophilias are X-linked inherited bleeding disorders defined as deficiencies of the coagulation factors VIII or IX. They are characterized by easy to provoke or spontaneous bleeding. HIV infection in hemophilic patients is a risk factor for the reduction of CD4+ T cells. There is no information regarding the cellular immune function in HIV-negative patients with hemophilia. To evaluate the number of lymphocyte subsets in adult patients with hemophilia A or B as compared with healthy donors. 39 Adult hemophilics and 27 healthy donors were included. Lymphocyte subsets [CD4 and CD8 T cells, natural killer cells, natural killer T (NKT) cells, invariant NKT (iNKT) cells, gamma-delta T (γδT) cells, type 1 and 2 dendritic cells, CD14 monocytes, CD4 and CD8 regulatory T cells (Tregs), and B cells], were analyzed by flow cytometry. A significant decrease of CD4+ T lymphocytes, γδT cells, iNKT cells, CD4+ and CD8+ Tregs was observed in patients with hemophilia. Those patients having factor VIII inhibitor had the lowest CD4+ Treg and CD8+ Treg counts. CD14 monocytes were increased, as well as iNKT and type 2 dendritic cells in obese-overweight hemophilics. CD4+ lymphocytes, iNKT, γδT cells, and Tregs (CD4+ and CD8+), are significantly decreased in patients with hemophilia. Depletion of Tregs is more important in patients with factor VIII inhibitor. Physicians caring for hemophilia patients should realize that, even when they are not suffering infections frequently, may have early evidence of cellular immunodeficiency.

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Of a group of 149 patients who underwent allogeneic stem cell transplantation using the "Mexican approach", a nonablative preparative regimen, 49 individuals developed bone marrow relapse, and 8 patients developed extramedullary relapse (EMR). All EMR cases presented in patients who received allografts for myeloid malignancies. In contrast, bone marrow relapses presented in patients with myeloid or lymphoid malignancies. EMR presented 60 to 1010 days after the allograft and appeared in 3 cases as subcutaneous nodules in different parts of the body, in the vertebrae in 3 cases, and in the kidney and the breast in 1 case each. One patient had both subcutaneous nodules and epididymis EMR. When EMR was noted, acute graft-versus-host disease (GVHD) had presented in 4 patients, and limited forms of chronic GVHD were present in 3 patients. All but 1 of the patients were full chimeras when the EMR ensued, and the EMR preceded an overt hematologic relapse in all but 1 of the patients. Patients who experienced an overt hematologic relapse died 20 to 180 days (median, 40 days) after the EMR. The only individual alive 240 days after relapse shows no evidence of a full-blown hematologic relapse. An EMR after allogeneic hematopoietic stem cell transplantation usually has a bad prognosis and presents mainly in individuals with high-risk malignancies.

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Multiple myeloma (MM) is the second most common hematologic malignancy, affecting approximately 14,000 new patients per year in the United States. For over four decades, the standard treatment for MM has been a regimen of melphalan combined with prednisone. Using this treatment modality, complete responses are rare, and 50% of patients have had disease that was resistant to chemotherapy. Attempts have been made to improve the outcome of MM by administering combinations of I. V. polichemotherapy, but these treatments are equivalent in terms of overall survival. High-dose therapy with peripheral blood stem cell support can be applied safely in these patients and achieves significantly higher complete remission rates as well as better event-free survival and overall survival. However, neither tumor-cell purging, positive selection, intensification of conditioning with additional chemotherapeutic agents, nor total body irradiation have been shown to improve outcome. The role of tandem transplantation with high-dose melphalan seems to be a good selection of treatment in hospitals having all resources. Future research will include the combination of the best remission-induction regimen with tandem transplants and maintenance treatments (thalidomide, idiotype or dendritic cell vaccination) that will sustain complete remission. Development of non-myeloablative allogeneic transplantation in order to exploit the graft-versus myeloma effect provides an alternative for patients who have a compatible donor. Combining all of these modalities with the new drugs developed few years ago (thalidomide, bortezomib, revlimid), we hope that MM will become a manageable chronic disease and perhaps a curable disease at least for 30% to 40% of the patients.

El mieloma múltiple (MM) es la segunda patología oncohematológica más frecuente. En Estados Unidos son diagnosticados anualmente 14,000 casos nuevos. En las últimas cuatro décadas el tratamiento estándar ha sido la combinación de melfalán y prednisona. Con este régimen raramente se logran remisiones completas y 50% de los pacientes no responden a esta terapia. Se han hecho intentos de mejorar los resultados combinando poliquimioterapia, pero la sobrevida global ha sido la misma. Al aplicar quimioterapia a dosis altas y rescate con trasplante de células hematopoyéticas se logra un mayor porcentaje de remisiones completas, asimismo, una mayor sobrevida libre de enfermedad y sobrevida global. La purga de células hematopoyéticas, selección positiva, intensificación del régimen de acondicionamiento con otras drogas o irradiación corporal total, no han demostrado utilidad en términos de sobrevida global. El doble trasplante autólogo de células hematopoyéticas parece ser una opción útil para hospitales que cuentan con la infraestructura y los recursos necesarios para realizarlo. En un futuro, la investigación deberá incluir el uso del mejor régimen de inducción a la remisión más doble trasplante autólogo y terapia de mantenimiento (talidomida o vacunas con células dendríticas), con la finalidad de al menos prolongar la remisión completa. El uso del trasplante alogénico no mieloablativo para provocar el efecto injerto contra mieloma parece una buena alternativa para los pacientes que tengan donador. Al combinar todas estas modalidades de tratamiento con las nuevas drogas desarrolladas en los últimos años (talidomida, bortezomid, revlimid), se espera que en un futuro el MM se convierta en una enfermedad crónica y curable en al menos 30 a 40% de los enfermos.

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