Hematopoietic progenitor cell count as a potential quantitative marker in apheresis products during allogeneic stem cell transplantation.

BACKGROUND: The quality and quantity of hematopoietic stem cells in apheresis products are essential to the success of peripheral blood hematopoietic stem cell transplantation (PB-HSCT). While the flow cytometry measurement of CD34+ cells as a golden standard for stem cell count is labor and cost-intensive, hematopoietic progenitor cell number evaluated by XN Sysmex series automated hematology analyzers (XN-HPC) is suggested as a surrogate marker. MATERIALS AND METHODS: We evaluated the correlation and consistency of XN-HPC and CD34+ cell count in apheresis samples from both allogeneic donors and autologous patients during PB-HSCT. RESULTS: Good correlation and consistency were observed between XN-HPC and CD34+ cell counts in harvests collected from healthy donors (R = .852) rather than autologous patients (R = .375). Subgroup analysis showed that the correlation was especially poor when autologous patients used plerixafor as an additional mobilizer or were diagnosed with multiple myeloma (MM). In the setting of allogeneic transplantation, the correlation coefficients were even better in samples from non-first-round apheresis (R = .951), with high white blood cell (WBC) counts (R = .941), or having successful engraftment within 2 weeks (R = .895). ROC analysis suggested that an optimal XN-HPC count of 1127 × 106 /L best predicted a sufficient yield of CD34+ stem cells, with diagnostic sensitivity and specificity being 92% and 72%, respectively (AUC = 0.852). CONCLUSIONS: XN-HPC is a sufficient quantitative marker for stem cell assessment of harvest yield in allogeneic but not autologous HSCT.

[Expression of cMPO in 502 cases of acute myeloid leukemia (AML) and its diagnosis significance in AML subtypes].

OBJECTIVE: To investigate the myeloperoxidase (cMPO) expression pattern by flow cytometry (FCM) in patients with acute myeloid leukemia (AML) and its role in classifying AML. METHODS: Eight- color multiparametric FCM with CD45/SSC gating was used to determine the cMPO expression in 502 AML patients. RESULTS: The positive rate of cMPO in all patients was 58.0%, in which the proportion of normal positivity, dim positivity and partial positivity was 21.5%, 34.1% and 2.4%, respectively. The remaining case (42.0%) were all negative. In AML with t (15;17）(q22;q12)/PMLRARα, the positive rate was the highest (100%) and the intensity was similar to that of the normal granular leukocytes, followed by AML with t (8;21（q22;q22/RUNX1-RUNX1T1, the positive rate was 91.4% and the intensity was mostly dim. AML with minimal differentiation and acute megakaryoblastic leukemia were all cMPO negative. The positive rates of cMPO in the remaining subtypes were between 22.7% and 76.2%. CONCLUSION: The positive rate and intensity of cMPO were significantly different among different subtypes of AML.

[Clinical and laboratory features of acute monocytic leukemia with B lymphoproliferative disorders].

OBJECTIVE: To identify the clinical and pathological features of acute myeloid leukemia with B lymphoproliferative disorders. METHODS: The characteristics of 3 cases of acute monocytic leukemia with untreated chronic lymphocytic leukemia/monoclonal B-cell lymphocytosis were reported with literatures review. RESULTS: The patients presented with a history of anemia, bleeding and/or fever. Acute monocytic leukemia was diagnosed by bone marrow morphology, cytochemistry and pathology studies. Immunophenotyping by flow cytometry analysis showed a significant population of absolute B-lymphocyte count of > 5×10(9)/L in a patients, similar to that of chronic lymphocytic leukemia. CONCLUSIONS: The association of acute monocytic leukemia and untreated chronic lymphocytic leukemia/monoclonal B-cell lymphocytosis was a rare event. The abnormal B lymphocytes was likely to be misdiagnosis. Thus, it was important to combine several kinds of laboratory studies, especially flow cytometry to identify this rare disorder.