Investigation of plasmacytoid dendritic cell reconstitution and its relationship with cGVHD and relapse after haploidentical hematopoietic stem cell transplantation / 中国实验血液学杂志

To investigate the characteristics and significance of reconstitution of peripheral blood plasmacytoid dendritic cell (PDC) precursors after allogeneic human leukocyte antigen mismatched/haploidentical hematopoietic stem cell transplantation, and its relationship with chronic graft versus host disease (cGVHD) and relapse, 19 patients with leukemia were enrolled for this study. Peripheral blood dendritic cell (DC) subsets of patients and healthy controls were detected by flow cytometry, and the correlations between reconstitution of DC and cGVHD, relapse were analyzed. The results showed that compared with healthy subjects, patients with leukemia had a significantly decreased proportion and absolute number of myeloid dendritic cell (MDC), MDC1, DC and the ratio of MDC/PDC (P<0.05). There were not statistically different in MDC2 and PDC between patients and healthy subjects. After transplant, all the proportion of WBC and absolute numbers of DC reached to healthy controls levels at 9 months (P>0.05), besides the proportion of PDC which reached to healthy controls levels at 1 year (P=0.494). Compared with levels before relapse, the proportions of MDC1, MDC, DC and the ratio of MDC/PDC were lower, but proportions of MDC2 and PDC were slightly higher after relapse. Patients with a 'high' PDC recovery profile had an improved cumulative incidence of cGVHD in contrast to patients with a 'low' PDC recovery profile on day 120 after transplantation (P=0.007). It is concluded that compared with healthy subjects, de novo leukemia patients have a significantly decreased proportion and absolute number of DC and the ratio of MDC/PDC before haploidentical hematopoietic stem cell transplantation; while ratio of MDC/PDC can be normalized with relative rapidity, the proportions of all DC subsets reached to normal levels on the whole at 9 months after transplantation, and also recovery level of DCs is correlated with occurrence of cGVHD and relapse.

Reconstitution dynamics of plasmacytoid and myeloid dendritic cell precursors after allogeneic HLA mismatched/ haploidentical hematopoietic stem cell transplantation / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore the characteristics and significance of reconstitution of peripheral blood dendritic cells (DCs) after HLA haploidentical hematopoietic stem cell transplantation (HSCT).</p><p><b>METHODS</b>Twenty-one leukemia patients received HLA-haploidentical HSCT. Twelve healthy donors were as normal control. Peripheral blood DC subsets were analyzed by flow cytometry, and correlation between DC reconstitution and acute graft versus host disease (aGVHD) were measured.</p><p><b>RESULTS</b>Compared with healthy subjects, leukemia patients had a significantly decreased proportion and absolute number of DC, myeloid DC (MDC) and MDC1 (0.13% vs 0.76%, 7.89 cells/microl vs 42.66 cells/microl, 0.05% vs 0.65%, 1.52 cells/microl vs 35.56 cells/microl, 0.03% vs 0.44%, 1.33 cells/microl vs 26.70 cells/microl, respectively (P < 0.05). MDC2 and plasmacytoid DC (PDC) were not statistically different between the two groups. The ratio of MDC/PDC was significantly reduced (0.05 vs 4.21) (P = 0.001). After transplantation, the absolute numbers of MDC1, MDC2 and PDC reached to pretransplant levels at day + 14(1.45, 0.32 and 1.60 cells/microl, respectively) (P > 0.05), but remained lower than those of healthy controls up to day + 100. The ratio of MDC/PDC had significantly different between that on + 14 d and pretransplant (1.40 vs 0.50) (P = 0. 024) and reached to healthy controls levels at day +30 (2.00 vs 4.21) (P = 0.602). Patients with higher PDC, DC levels and lower MDC/PDC ratio had lower cumulative incidences of grade II - NV aGVHD as compared with those with lower PDC, DC level and higher MDC/PDC ratio at day + 14(P = 0.006, 0.013 and 0.037, respectively).</p><p><b>CONCLUSION</b>In HLA haploidentical HSCT recipients, DC reconstitution is a slow process, possibly contributing to the cumulative incidences of grade II - IV aGVHD.</p>