Extramedullary leukemic relapses following hematopoietic stem cell transplantation with nonmyeloablative conditioning.

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.

Treatment of acute promyelocytic leukemia: a single institution experience.

The results of the treatment of 14 patients with promyelocytic leukemia (PML) treated with all trans-retinoic acid (ATRA), combined chemotherapy (CT) and prophylactic prednisone are reported; the median age was 30 years (range 7 - 49). A complete remission (CR) was obtained in 13 / 14 patients (93%). All patients were given ATRA fully as outpatients; the CR was achieved after the administration of ATRA in five patients, whereas in the remaining eight, CT was required to achieve it. There were no instances of the ATRA syndrome. One patient relapsed with a PML/RAR-a negative PML 575 days after achieving the CR, failed to respond again to ATRA and died. The median overall (OS) and disease free survival (DFS) has not been reached, being above 4,000 days, whereas the 12-month DFS was 93%, the three and five years DFS being 85%. The treatment employed differs from others in: Oral prednisone is used prophylactically, ATRA is given on an outpatient basis and adriamycin is used instead of other anthracyclines. The results are similar to those obtained in other centers worldwide and it is possible that the prophylactic administration of prednisone precluded the development of the full-blown ATRA syndrome in this group of patients.

Treatment of acute promyelocytic leukemia: A single institution experience / Tratamiento de la leucemia promielocítica aguda: Experiencia de una sola institución

The results of the treatment of 14 patients with promyelocytic leukemia (PML) treated with all trans-retinoic acid (ATRA), combined chemotherapy (CT) and prophylactic prednisone are reported; the median age was 30 years (range 7 - 49). A complete remission (CR) was obtained in 13 / 14 patients (93%). All patients were given ATRA fully as outpatients; the CR was achieved after the administration of ATRA in five patients, whereas in the remaining eight, CT was required to achieve it. There were no instances of the ATRA syndrome. One patient relapsed with a PML/RAR-a negative PML 575 days after achieving the CR, failed to respond again to ATRA and died. The median overall (OS) and disease free survival (DFS) has not been reached, being above 4,000 days, whereas the 12-month DFS was 93%, the three and five years DFS being 85%. The treatment employed differs from others in: Oral prednisone is used prophylactically, ATRA is given on an outpatient basis and adriamycin is used instead of other anthracyclines. The results are similar to those obtained in other centers worldwide and it is possible that the prophylactic administration of prednisone precluded the development of the full-blown ATRA syndrome in this group of patients.

Se informan los resultados del tratamiento en una sola institución de 14 pacientes con leucemia aguda promielocítica (LAPM) en quienes se empleó la combinación de ácido holotrans-retinoico (ATRA) quimioterapia combinada y prednisona profiláctica. La mediana de edad fue de 30 años (rango 7-49). Se obtuvo remisión completa (hematológica y molecular) (RC) en 13 pacientes (93%); a todos los pacientes se les administró el ATRA de manera ambulatoria. La RC se obtuvo con el ATRA en cinco pacientes; en los demás la RC se obtuvo después de habérseles administrado la quimioterapia con citarabina/adriamicina. No hubo ningún caso de síndrome de ATRA. Un paciente recayó con una LAPM PML/ RAR-a negativa, 575 días después de haber logrado la RC y falleció. Otro paciente recayó 20 meses después de haber logrado la RC y fue rescatado con el mismo esquema de tratamiento; permanece en segunda remisión molecular por más de seis años. La mediana de supervivencia (SV), tanto global como libre de recaídas de todo el grupo, no se ha alcanzado y es mayor de 4,000 días, en tanto que la SV a 12 meses fue de 93% y a tres y cinco años de 85%. El esquema de tratamiento usado difiere de otros en que se usa prednisona oral, se administra el ATRA de manera ambulatoria y se usa adriamicina y no otras antracidinas; los resultados son similares a los obtenidos con otros esquemas parecidos en otros sitios del mundo; es posible que el uso profiláctico de prednisona haya eliminado la ocurrencia del síndrome de ATRA.

Trasplante de células hematopoyéticas alogénicas en niños y adolescentes empleando esquema de acondicionamiento no mieloablativo: Experiencia en una sola institución / Non-myeloablative stem cell transplantation in children and adolescents: a single institucional experience

Introducción. El trasplante de médula ósea es un recurso terapéutico útil en algunos niños. Material y métodos. Se llevaron a cabo 26 trasplantes de células hematopoyéticas alogénicas en 20 pacientes con edades entre 1 y 18 años. Se empleó el esquema "Mexicano" de acondicionamiento no mieloablativo, en una sola institución. Se incluyeron pacientes con enfermedades hematológicas tanto malignas (leucemia linfoblástica aguda, leucemia mieloblástica aguda y leucemia granulocítica crónica) como benignas (anemia aplástica, síndrome de Blackfan-Diamond y talasemia). La mediana de edad de los pacientes fue de 9 años (intervalo 1-18 años). Resultados. La mediana del tiempo de seguimiento post-trasplante fue de 184 días (intervalo 14 a 1 796 días). En 10 de 26 trasplantes (38%) se observó enfermedad aguda de injerto contra huésped, en tanto que en 4 de 19 trasplantes seguidos por más de 100 días (21%) se observó enfermedad de injerto contra huésped crónica. La mortalidad a 100 días post-trasplante fue de 19% y en 12 pacientes hubo recaída post-trasplante de la enfermedad. La supervivencia a 1 796 días fue de 44%. Conclusión. En niños y adolescentes, el trasplante de médula ósea empleando acondicionamiento no mieloablativo es exitoso, tiene mínima toxicidad y costo accesible, por lo que parece una opción terapéutica útil para ser empleada en países en desarrollo. Tal vez sea conveniente considerar la reducción de la toxicidad de los esquemas de acondicionamiento para los trasplantes alogénicos de médula ósea en niños.

Introduction. Bone marrow transplantation is a curative option in some children with diverse underlying diseases. Material and methods. Using the "Mexican" protocol to conduct allogeneic non-myeloablative stem cell transplantation (NST), we have prospectively carried out, in a single institution, 26 allo-grafts in 20 individuals aged 1 to 18 years. Patients with both malignant (acute lymphoblastic leukemia, acute myelogenous leukemia and chronic myelogenous leukemia) and non-malignant (aplastic anemia, Blackfan-Diamond syndrome and homozygous thalassemia) conditions were included. Median age of the patients was 9 years (range 1-18). Results. Median follow-up time is 184 days (range 14-1 796). In 10 of 26 allograft (38%) acute graft versus host disease (GVHD) was observed, whereas chronic GVHD was present in 4 out of 19 (21 %) grafts followed for 100 days or more. The 100-day mortality was 19% and 12 patients experienced a post-transplant relapse of the malignancy. The 1 796 day's overall-survival was 44%. Conclusions. We report our experience with non-myeloablative stem cell transplantation in children and adolescents with both malignant and non-malignant underlying hematologic conditions. Although the experience is limited our results are very promising; moreover, due to the diminished toxicity and reduced cost, this approach seems to be a good alternative to allograft these types of patients in developing countries.

More on geographic hematology: the breakpoint cluster regions of the PML/RARalpha fusion gene in Mexican Mestizo patients with promyelocytic leukemia are different from those in Caucasians.

Acute promyelocytic leukemia is characterized the PML/RARalpha chimeric fusion gene, transcript and protein; the breakpoint cluster regions (bcr) in the PML gene may occur in 3 different sites: Intron 6 (bcr1), exon 6 (bcr2) or intron 3 (bcr3). In a 10-year period in a single institution, we studied prospectively the breakpoint cluster regions of the PML/RARalpha fusion gene in 43 Mexican Mestizo patients with APL, and found that the bcr1 represented 62.7%, the bcr2 9.3% whereas the bcr3 27.9%. The prevalence of the bcr1 subtype is significantly higher than that informed in Caucasians and similar to that in Asians; these data are consonant with those described in other Latin-American patients with APL. Since other Asian genetic markers have been found in the Indian component of the Mexican mestizos, it is possible that the Asian immigration into the Americas through the strait of Behring 12,000 years ago may account for a possible genetic susceptibility to suffer certain forms of APL.