A single apheresis procedure in the donor may be enough to complete an allograft using the "Mexican method" of non-ablative allografting.

BACKGROUND: Since 1999, in Mexico we have been using a regimen to conduct allografts that involves non-myeloablative conditioning and peripheral blood stem cells (PBSC) and have introduced some changes with the main goal of decreasing the cost of the procedure. MATERIALS AND METHODS: We analysed the salient apheresis features of a group of 175 allogeneic peripheral blood stem cell transplants conducted in two institutions in a 7-year period. The grafts were conducted using the "Mexican" non-myelo ablative conditioning regimen employing oral busulphan, i.v. cyclophosphamide and i.v. fludarabine. In all instances, the apheresis machine employed was the Baxter CS3000 Plus and donors were mobilised with filgrastim. The apheresis procedures were performed on days 0, +1 and +2, the end-point of collection being 5,000 mL of blood/m2 in each procedure. Three apheresis sessions were planned but the number was adjusted according to the cell yield. RESULTS: The final number of allografted CD34 cells ranged between 0.5 and 25.4 x 10(6)/Kg of the recipient's body weight (median, 5.2 x 10(6)/Kg). One to three apheresis procedures were needed to obtain a product containing more than 0.5 x 10(6) CD34 cells/Kg of the recipient, the median being two procedures; in 72 cases (41%) a single apheresis procedure was sufficient to obtain the target number of CD34 cells. The volumes of apheresis ranged between 50 and 600 mL (median, 400 mL). CONCLUSIONS: Since the median cost of each apheresis procedure is 900 USD, the fact that two apheresis procedures was spared in 72 cases and one apheresis was spared in another 65 cases, led to a total saving of approximately 188,100 USD. It can be concluded that, in many cases, allogeneic transplants can be completed with a single apheresis session and that there are considerable financial benefits from this practice.

Primary thrombophilia in México VII: the V617F mutation of JAK2 is not a frequent cause of thrombosis.

The study of the V617F JAK2 gene mutation has been used to identify the presence of an underlying myeloproliferative disorder (MPD) as the cause of unexplained thrombosis. In a group of 77 consecutive Mexican patients with a clinical marker of a primary thrombophilic condition, we looked for this JAK2 mutation and did not find any individual displaying it. Given these results, we conclude that an undetected MPD is a very improbable cause of thromboses in Mexican mestizos, a population where the prevalence of these disorders has been found to be lower than that found in Caucasian populations. Accordingly, it seems that the investigation for the V617F mutation of the JAK2 gene is not mandatory in all Mexican mestizo patients with unexplained thrombophilia and that this genetic study should be reserved for special cases, such as patients with thrombosis in uncommon sites or patients with cell counts suggesting the presence of an underlying MPD.

[Primary thrombophilia in México. VI: lack of statistical association among the inherited thrombophilic conditions]. / Trombofilia primaria en México. Parte VI: falta de asociación estadística entre las condiciones trombofílicas heredadas.

OBJECTIVE: Over a 70-month period, 100 consecutive Mexican mestizo individuals with a clinical marker associated with a primary hypercoagulable state were studied. METHODS: We prospectively assessed: the sticky platelet syndrome (SPS), the activated protein C resistance (aPCR) phenotype, coagulation protein C activity and antigen, coagulation protein S, antithrombin III, plasminogen, IgG and IgM isotypes of antiphospholipid antibodies, homocysteine levels, the factor V gene Leiden, Cambridge, Hong Kong, and Liverpool mutations, the 677 C-->T mutation in the 5,10-methylenetetrahydrofolatereductase (MTHFR), and the G20210A polymorphism in the 3'-untranslated region of the prothrombin gene. RESULTS: Of the 100 consecutive patients prospectively accrued in the study, only 29% were males. In only 6 individuals could we not record any abnormality, whereas in most individuals (81%), two to five co-existing abnormalities were identified. In a multivariate analysis of the association of all these assesments, the only significant association was found between the factor V Leiden mutation and the aPCR phenotype (r = .495; p < 0.001). CONCLUSIONS: These results confirm previous observations on thrombophilia in Mexico underlining that it is a multifactorial disease. They also suggest that the abnormalities detected are not associated to each other.

Trombofilia primaria en México: parte VI: falta de asociación estadística entre las condiciones trombofílicas heredadas / Primary thrombophilia in México: VI: lack of statistical association among the inherited thrombophilic conditions

Objetivo: En un periodo de 70 meses estudiamos de manera prospectiva a 100 pacientes mestizos mexicanos con algún marcador clínico de trombofilia: a) Trombosis antes de los 40 años, b) Historia familiar de trombosis, c) Trombosis recurrente sin la presencia de un factor precipitante aparente, d) Trombosis en sitios anatómicos inusuales, o e) Resistencia a la terapia antitrombótica convencional. Métodos: En estos pacientes, investigamos el síndrome de las plaquetas pegajosas, la mutación 677 C —>T del gen de la 5,10-metilentetrahidrofolato reductasa (MTHFR), el fenotipo de resistencia a la proteína C activada (RPCa), la presencia de anticuerpos antifosfolípidos, las mutaciones Leiden, Cambridge, Liverpool y Hong Kong del gen del factor V, el haplotipo HR2 del mismo gen del factor V, el polimorfismo G20210A de la región 3´-no traducida del gen de la protrombina y las deficiencias de proteínas C y S y de antitrombina III. Resultados: En el 94 % de los casos encontramos por lo menos alguna alteración; de estos casos con alteración, la mayoría (81 %) tuvo dos o más condiciones trombofílicas asociadas. El análisis multivariado de todas estas variables sólo mostró asociación estadística entre la mutación tipo Leiden del gen del factor V y el fenotipo de RPCa (r = .495; p < 0.001). Conclusiones: Se concluye que, realizando este grupo de estudios, es posible identificar alguna alteración trombofílica en la mayoría de los pacientes mestizos mexicanos con algún marcador clínico de trombofilia y que las alteraciones no se asocian entre sí.

OBJECTIVE: Over a 70-month period, 100 consecutive Mexican mestizo individuals with a clinical marker associated with a primary hypercoagulable state were studied. METHODS: We prospectively assessed: the sticky platelet syndrome (SPS), the activated protein C resistance (aPCR) phenotype, coagulation protein C activity and antigen, coagulation protein S, antithrombin III, plasminogen, IgG and IgM isotypes of antiphospholipid antibodies, homocysteine levels, the factor V gene Leiden, Cambridge, Hong Kong, and Liverpool mutations, the 677 C-->T mutation in the 5,10-methylenetetrahydrofolatereductase (MTHFR), and the G20210A polymorphism in the 3'-untranslated region of the prothrombin gene. RESULTS: Of the 100 consecutive patients prospectively accrued in the study, only 29% were males. In only 6 individuals could we not record any abnormality, whereas in most individuals (81%), two to five co-existing abnormalities were identified. In a multivariate analysis of the association of all these assesments, the only significant association was found between the factor V Leiden mutation and the aPCR phenotype (r = .495; p < 0.001). CONCLUSIONS: These results confirm previous observations on thrombophilia in Mexico underlining that it is a multifactorial disease. They also suggest that the abnormalities detected are not associated to each other.

A single-institution, 20-year prospective experience with an affordable Fc-receptor blockade method to treat patients with chronic, refractory autoimmune thrombocytopenic purpura.

In a 20-year period in a single institution, 34 patients with chronic, refractory autoimmune thrombocytopenic purpura were prospectively treated with ex vivo anti-D opsonized autologous red blood cells. All patients had received previous treatment with steroids and/or immunosuppressive agents, and 11 had been splenectomized. Twenty one patients had an increase in the platelet count; in five cases, the increase was more than 50 x 10(9)/L platelets and in 16 the increase was more than 100 x 10(9)/L platelets. Early responses were observed in 20 patients and late responses in seven, whereas seven patients (20%) did not respond at all. Nine of the 20 individuals who achieved an ER had a subsequent drop in the platelet count; however, only three had a drop below 50 x 10(9)/L. When last censored, of the 34 patients, 24 (70%) had a platelet count above 50 x 10(9)/L. The 84-month thrombocytopenia-free (over 50 x 10(9)/L platelets) status of the whole group is 70%, whereas the 84-month complete remission (over 100 x 10(9)/L platelets) status of the whole group is 50%. It is concluded that the use of ex vivo anti-D opsonized red blood cells may represent another, substantially cheaper treatment of patients with chronic, refractory, autoimmune thrombocytopenic purpura.

t(8;21) (q22;q22) acute myelogenous leukemia in Mexico: a single institution experience.

We analyze the prevalence and clinical features of a group of patients with t(8;21) (q22;q22) acute myeloblastic leukemia, identified in a single institution in México over a 10-year period. Fifteen patients presented at the Centro de Hematología y Medicina Interna de Puebla from February 1995 to August 2005; only nine were treated and followed in the institution. Median age was 24 years, (range 7-49); there was only one male. According to the French-American-British (FAB) morphological classification of leukemia, the morphology was M2 in four cases, M4 in three cases, M3 in one case and M0 in one. In addition to the myeloid markers, lymphoid markers were identified in 6 patients. Patients were induced to remission with combined chemotherapy and three subsequently underwent bone marrow transplantation (BMT). The median overall and disease-free survival has not been reached, being above 3390 days, the probability of survival at this time was 73%. In this single-center experience in México, we found that the t(8;21) (q22;q22) variant of leukemia was more frequent than in Caucasian populations, that the co-expression of lymphoid markers in the blast cells is very frequent and that this malignancy is associated with a relatively good prognosis.

The Janus Kinase 2 (JAK2) V617F mutation in hematological malignancies in México / La mutación V617F del gen de la cinasa JAK2 en padecimientos hematológicos malignos en México

A new mutation (V617F) affecting the JAK2 gene has been recently described as acquired in patients with myeloproliferative disorders and other myeloid malignancies. Using an amplification refractory mutation system, we investigated this mutation in 70 Mexican mestizo patients with hematological malignancies: 28 cases of acute lymphoblastic leukemia, 17 cases of Phi-positive chronic myelogenous leukemia, 8 patients with acute myelogenous leukemia, 6 patients with chronic lymphocytic leukemia, 6 patients with polycythemia vera (PV), two patients with essential thrombocythemia (ET), one patient with hypereosinophilic syndrome one patient with primary myelofibrosis (MF) and one patient with chronic myelomonocytic leukemia. The mutation was identified in 4 of 6 patients with PV, in one of 2 patients with ET and in the patient with MF. Our data add to the observation that the JAK2 V617F mutation seems to be rather uncommon in myeloid malignancies other than the classic BCR/ABL negative MPD.

Se ha descrito una nueva mutación (V617F) que afecta al gen de la cinasa JAK2 en pacientes con padecimientos mieloproliferativos y otras neoplasias mieloides. Empleando un sistema de amplificación de mutaciones refractarias y reacción en cadena de la polimerasa, investigamos esta mutación en 70 pacientes mestizos mexicanos con neoplasias hematológicas malignas: 28 casos de leucemia aguda linfoblástica, 17 casos de leucemia granulocítica crónica BCR/ABL (+), ocho casos de leucemia aguda mieloblástica, seis casos de leucemia linfocítica crónica, seis casos de policitemia vera (PV), dos casos de trombocitosis primaria (TP), un caso de síndrome hipereosinofílico primario y un caso de mielofibrosis primaria (MF) y un caso de leucemia mielomonocítica crónica. La mutación se identificó en cuatro de seis pacientes con PV, en uno de dos pacientes con TP y en el paciente con MF. Estos datos confirman que esta mutación es infrecuente en neoplasias hematológicas mieloides diferentes a los síndromes mieloproliferativos malignos negativos al BCR/ABL; es probable que esta mutación se convierta en el marcador molecular de la PV.

The Janus Kinase 2 (JAK2) V617F mutation in hematological malignancies in México.

A new mutation (V617F) affecting the JAK2 gene has been recently described as acquired in patients with myeloproliferative disorders and other myeloid malignancies. Using an amplification refractory mutation system, we investigated this mutation in 70 Mexican mestizo patients with hematological malignancies: 28 cases of acute lymphoblastic leukemia, 17 cases of Ph1-positive chronic myelogenous leukemia, 8 patients with acute myelogenous leukemia, 6 patients with chronic lymphocytic leukemia, 6 patients with polycythemia vera (PV), two patients with essential thrombocythemia (ET), one patient with hypereosinophilic syndrome one patient with primary myelofibrosis (MF) and one patient with chronic myelomonocytic leukemia. The mutation was identified in 4 of 6 patients with PV, in one of 2 patients with ET and in the patient with MF. Our data add to the observation that the JAK2 V617F mutation seems to be rather uncommon in myeloid malignancies other than the classic BCR/ABL negative MPD.