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OBJECTIVE: This study was to investigate the variables in bone marrow harvesting procedure and individual donor factors which can potentially affect the yield of mesenchymal stromal cells (MSC). METHODS: WE DETERMINED THE YIELD OF MSC FROM BONE MARROW UNDER DIFFERENT CLINICAL CONDITIONS BY COMPARING THE MSC COLONY NUMBERS FROM: (1) donors of different ages; (2) healthy donors and patients with leukemia; (3) bone marrow aspirated at different time points during marrow harvesting; (4) bone marrow harvested by different needles. RESULTS: During the process of harvesting, the number of MSC significantly decreased with increase number of aspiration, from 675/ml at the initial decreased to 60/ml after 100 ml bone marrow aspirated, and 50/ml after 200 ml bone marrow aspirated. The number of MSC retrieved from leukemia patients (99/ml bone marrow) was significantly lower than that of healthy donors (708/ml bone marrow). However, there was no significant difference in growth rate. There was no significant age-related difference of MSC yielded from donors <55 years. And there was no significant difference in MSC number between the samples from single end-holed needle and those from multiple-side-hole needle. CONCLUSION: The optimal bone marrow samples for MSC collection should be obtained earlier in the process of harvesting procedure. Bone marrow from donors <55 years was equally good as MSC sources. The autologous MSC from leukemia patients can be utilized for in-vitro MSC expansion.
RESUMO
BACKGROUND: Essential thrombocythemia (ET) is a clonal myeloproliferative disease associated with thrombohemorrhagic complications and myeloid transformation to diseases such as myelofibrosis and acute myeloid leukemia. METHODS: A multicenter study was conducted among 231 consecutive Chinese patients with ET. The literature about leukemogenic risk associated with the use of hydroxyurea therapy was reviewed. RESULTS: The median patient age was 65 years. Thrombosis rates at and after diagnosis of ET were comparable to those of white patients, but bleeding rates at and after diagnosis were much lower. The projected 10-year thrombosis-free, bleeding-free, and overall survival rates were 66%, 83%, and 80%, respectively. There were no deaths among patients 60 years or younger during a maximum follow-up of 15 years, and splenomegaly at diagnosis of ET appeared to protect against thrombosis. In multivariate analysis, advanced age predicted inferior 10-year thrombosis-free and overall survival, and male sex predicted inferior bleeding-free survival. Half the deaths were related to ET. The probability of myelofibrosis transformation was 9.7% at 10 years. Prior myelofibrosis (P = .008) and the use of melphalan treatment (P = .002) were risk factors for acute myeloid leukemia evolution. CONCLUSIONS: Essential thrombocythemia is a benign disease of older persons. Chinese patients have a low risk of bleeding, and prior myelofibrosis is a major risk factor for evolution to acute myeloid leukemia. Leukemic transformation with hydroxyurea therapy alone is rare and warrants further prospective studies.
