Donor NKG2C homozygosity contributes to CMV clearance after haploidentical transplantation.

CMV infection remains an important cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Several investigators have reported that adaptive NKG2C+ NK cells persistently expand during CMV reactivation. In our study, 2 cohorts were enrolled to explore the relationships among the NKG2C genotype, NKG2C+ NK cell reconstitution, and CMV infection. Multivariate analysis showed that donor NKG2C gene deletion was an independent prognostic factor for CMV reactivation and refractory CMV reactivation. Furthermore, adaptive NKG2C+ NK cells' quantitative and qualitative reconstitution, along with their anti-CMV function after transplantation, was significantly lower in patients grafted with NKG2Cwt/del donor cells than in those grafted with NKG2Cwt/wt donor cells. At day 30 after transplantation, quantitative reconstitution of NKG2C+ NK cells was significantly lower in patients with treatment-refractory CMV reactivation than in patients without CMV reactivation and those with nonrefractory CMV reactivation. In humanized CMV-infected mice, we found that, compared with those from NKG2Cwt/del donors, adaptive NKG2C+ NK cells from NKG2Cwt/wt donors induced earlier and stronger expansion of NKG2C+ NK cells as well as earlier and stronger CMV clearance in vivo. In conclusion, donor NKG2C homozygosity contributes to CMV clearance by promoting the quantitative and qualitative reconstruction of adaptive NKG2C+ NK cells after haploidentical allo-HSCT.

Donor activating killer cell immunoglobulin-like receptors genes correlated with Epstein-Barr virus reactivation after haploidentical haematopoietic stem cell transplantation.

Natural killer (NK) cells exert anti-viral effects after haematopoietic stem cell transplantation (HSCT). The balance between inhibition and activation of NK cells determined by the inherited repertoire of killer cell immunoglobulin-like receptors (KIR) genes may influence Epstein-Barr virus (EBV) reactivation after transplantation. To evaluate the relative contributions of KIR genotypes to EBV reactivation, we prospectively enrolled 300 patients with malignant haematological disease who were suitable for haploidentical HSCT. Univariate analysis showed that donors with KIR2DS1, KIR2DS3 or KIR3DS1 genes were associated with an increased risk of EBV reactivation [hazard ratio (HR) 1·86, 95% confidence interval (CI) 1·19-2·9, P = 0·0067; HR 1·78, 95% CI 1·07-2·97, P = 0·027; HR 1·86, 95% CI 1·19-2·91, P = 0·0065 respectively]. Multivariate analysis revealed that the presence of KIR2DS1, KIR2DS3 or KIR3DS1 genes was associated with increased EBV reactivation after HSCT. This effect was more evident in the absence of the cognate ligands for the corresponding activating receptors. Our present data firstly showed that donors with activating KIR genes, specifically activating KIR2DS1, KIR2DS3 and KIR3DS1, had an increased risk of EBV reactivation. Precaution for patients whose donors carry activating genes will help prevent EBV reactivation and improve patient prognosis after HSCT.

Comparison of the clinical outcomes between NIMA-mismatched and NIPA-mismatched haploidentical hematopoietic stem cell transplantation for patients with hematological malignancies.

The objective of this study was to compare clinical outcomes between noninherited maternal antigen (NIMA)-mismatched and noninherited paternal antigen (NIPA)-mismatched haploidentical hematopoietic stem cell transplantation (haplo-HSCT) among patients with hematological malignancies and perform a subgroup analysis. We retrospectively analyzed 378 patients with hematological malignancies who received haplo-HSCT from NIMA-mismatched (n = 201) and NIPA-mismatched (n = 177) donors between January 2012 and December 2017. The cumulative incidence of 100-d grades II-IV acute graft-versus-host disease (aGVHD) (19.2% vs. 32.8%, P = 0.003) was significantly lower in NIMA mismatch. Multivariate analysis showed that NIMA mismatch was associated with lower incidence of grades II-IV aGVHD and better overall survival (OS) and disease-free survival (DFS). According to the subgroup analysis, the clinical outcomes of older and/or female NIMA mismatches were comparable to those of younger and/or male NIPA mismatches with respect to grades II-IV aGVHD, chronic GVHD (cGVHD), nonrelapse mortality (NRM), relapse, DFS, and OS. In conclusion, this study confirmed the NIMA effect on aGVHD and demonstrated that NIMA mismatch was associated with better survival. In the NIMA mismatch context, donor age and sex did not seem to influence haplo-HSCT, which provides a basis for the selection of sibling donors.

Rituximab for desensitization during HLA-mismatched stem cell transplantation in patients with a positive donor-specific anti-HLA antibody.

To define the efficacy of a single dose of 375 mg/m2 rituximab for DSA-positive patients with 2000 ≤ MFI < 10,000, we enrolled a prospective clinical cohort including patients with positive DSA treated with rituximab (n = 55, cohort A), a matched-pair cohort including cases with negative DSA (n = 110, cohort B) and a historical cohort including subjects with 2000 ≤ MFI < 10,000 without receiving any treatment for DSA (n = 22, cohort C). The incidences of primary poor graft function (PGF) in cohort A and cohort B were 5% and 1% (P = 0.076), respectively, both of which were lower than that in cohort C (27%, P < 0.001, for all). Rituximab was associated with a reduced incidence of primary PGF (HR 0.200, P = 0.023). The 3-year nonrelapse mortality of patients in cohort A and cohort B were 23% and 24%, respectively, both of which were lower than that in the cohort C (37%), although no statistical significance was observed. These results led to a low 3-year overall survival in patients in the cohort C (58%) compared with those in the cohort A (71%) and the cohort B (73%). We suggest that a single dose of rituximab could be effectively used to prevent the onset of primary PGF. The prospective cohort of this study is registered at http://www.chictr.org.cn/ChiCTR-OPC-15006672.

Identification of a novel HLA-B*40 allele, HLA-B*40:451.

HLA-B*40:451 differs from B*40:06:01:01 by a single nucleotide substitution at position 257 of exon 2.

Donor and host coexpressing KIR ligands promote NK education after allogeneic hematopoietic stem cell transplantation.

The rate and extent of natural killer (NK)-cell education after hematopoietic cell transplantation correlates with leukemia control. To study the effect of donor and host HLA on NK-cell reconstitution, single killer-cell immunoglobulin-like receptor (KIR)+ NK cells (exhibiting KIR2DL1, KIR2DL2/KIR2DL3, or KIR3DL1 as their sole receptor) were grouped into 4 groups based on the interaction between donor/host HLA and donor inhibitory KIR in 2 cohorts (n = 114 and n = 276, respectively). On days 90 to 180 after transplantation, the absolute number and responsiveness against K562 cells (CD107a or interferon-γ expression) of single-KIR+ NK cells were higher in pairs where donor and host HLA both expressed ligands for donor inhibitory KIRs than in pairs where 1 or both of the donor and recipient HLA lacked at least 1 KIR ligand. NK-cell responsiveness was tuned commensurate with the number of inhibitory receptors from the donor. When both donor and host expressed the 3 major KIR ligands (HLA-C1, HLA-C2, and HLA-Bw4), NK cells expressing 3 inhibitory receptors (KIR2DL1/2DL3/3DL1) reached the maximum responsiveness against K562 cells compared with those NK cells expressing only 1 or 2 inhibitory receptors. When donor and host HLA both expressed all ligands for donor inhibitory KIRs, patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) showed the lowest recurrence rate after haploidentical hematopoietic stem cell transplantation (haplo-HSCT). In conclusion, this study demonstrates that when both donors and hosts present all the KIR ligands for donor KIRs, reconstituted NK cells achieve better functional education and contribute to least relapse among patients. This observation study was registered at www.clinicaltrials.gov as #NCT02978274.

Prevalence and risk factors of antibodies to human leukocyte antigens in haploidentical stem cell transplantation candidates: A multi-center study.

We investigated the prevalence of and risk factors for antibodies to HLA in 1663 haploidentical transplant candidates. Among these cases, 349 (21.0%) showed positive panel-reactive antibody (PRA) either for class I or class II HLA. Multivariate analysis showed the following: i) risk factors associated with the prevalence of PRA either for class I or class II HLA were female gender (P = 0.018), prior transfusions (P < 0.001) or pregnancy (P < 0.001), and cases with MDS (P = 0.018); compared to other patients, subjects with ALL had a lower prevalence of class I antibodies (P = 0.017); and ii) risk factors associated with the prevalence of PRA both for class I and class II HLA were female gender (P = 0.014), prior transfusions (P = 0.003), previous pregnancy (P < 0.001), and diagnosis with MDS (P = 0.035). The percentages of antibodies against different antigens coded by the different HLA loci, including HLA-A, -B, -C, -DP, -DQ, and -DR, among all cases were 15.6%, 17.3%, 10.5%, 5.6%, 8.5%, and 9.7%, respectively. Risk factors associated with specific antibodies against HLA-A, -B, -C, -DP, -DQ, and -DR were female gender, prior transfusion, previous pregnancy, and underlying disease. Our findings suggest that gender, prior pregnancy, transfusion and underlying diseases are risk factors for HLA sensitization, which could guide HLA antibody monitor and donor selection.

Evaluation of HistoCheck as a Predictor of Clinical Outcomes after Haploidentical Hematopoietic Stem Cell Transplantation.

Haploidentical hematopoietic stem cell transplantation (haplo-HSCT) is available for nearly all patients without matching HLA-related or -unrelated donors. There was not a valid evaluation system to predict the most proper donor. HistoCheck was based on the functional similarity of amino acids to estimate the allogenicity of HLA mismatches with a sequence similarity matching (SSM) score. We investigated whether HistoCheck could predict clinical outcomes in 500 patients with acute leukemia or myelodysplastic syndrome receiving haplo-HSCT. The total SSM score of the 5 loci (HLA-A, -B, -C, -DRB1, and -DQB1) had no association with clinical outcomes. HLA-C SSM score was significantly associated with transplant-related mortality (TRM) (hazard ratio [HR], .in691; 95% confidence interval [CI], .520 to .917; P = .011), disease-free survival (DFS) (HR, .714; 95% CI, .586 to .869; P = .001), and overall survival (OS) (HR, .711; 95% CI, .574 to .881; P = .002) by multivariate analysis. No significant associations were observed between other single-locus SSM score and clinical outcomes. In summary, our data demonstrate that a high HLA-C HistoCheck SSM score may lead to lower TRM and improved DFS and OS after haplo-HSCT and inclusion of HLA-C HistoCheck in donor selection criteria may need to be further confirmed in prospective studies.

Impact of HLA allele mismatch at HLA-A, -B, -C, -DRB1, and -DQB1 on outcomes in haploidentical stem cell transplantation.

The impact of human leukocyte antigen (HLA) allele mismatch on transplant outcomes in haploidentical stem cell transplantation (haplo-SCT) has not been established. We retrospectively studied 595 patients with hematologic malignancy who received haplo-SCT. The impact of multiple HLA allele mismatches (HLA-A, -B, -C, -DRB1, and -DQB1) and each HLA allele mismatch on transplant outcomes was analyzed. Greater number of HLA allele disparity does not appear worsen outcome. As for each HLA locus, HLA-A mismatch correlated with decreased rate of platelet engraftment (HR 0.740, P = .003); HLA-B mismatch independently correlated with decreased relapse rate (HR 0.494, P = .032) and improved disease-free survival and overall survival (HR 0.514, P = .003; HR 0.494, P = .002, respectively); HLA-C mismatch appeared to be protective for transplant-related mortality (TRM) (HR 0.567, P = .039); HLA-DRB1 mismatch was associated with increased cumulative incidence of grade II-IV acute graft-vs.-host disease (GVHD) (HR 1.942, P = .002). No associations of any HLA mismatch with delayed neutrophil engraftment or increased cumulative incidence of chronic GVHD were observed. Our data indicated that high degree of HLA allele mismatches did not adversely affect transplant outcomes in haplo-SCT and each HLA allele mismatch had different effect.

Predicted indirectly recognizable HLA epitopes are not associated with clinical outcomes after haploidentical hematopoietic stem cell transplantation.

Haploidentical stem cell transplantation (haplo-SCT) provides an alternative method to cure patients with malignant and nonmalignant hematologic diseases who lack a human leukocyte antigen (HLA) matched related or unrelated donor. HLA disparity between donor and patient was the main reason causing lots of clinical immune response. The aim of this study was to investigate whether indirect recognition of mismatched HLA could predict the clinical outcomes in haplo-SCT. The probability of indirect recognition was predicted by the Predicted Indirectly ReCognizable HLA Epitopes (PIRCHE) model. 577 patients with acute leukemia or myelodysplastic syndrome receiving haplo-SCT were enrolled in the study. Patients were divided into 4 quartiles according to PIRCHE-Ⅰ or PIRCHE-Ⅱ. Although the cumulative incidences of chronic graft-versus-host disease (GVHD) were significantly different among the 4 PIRCHE-Ⅰgroups, with 20.4% for group 0-6, 40.5% for group >6-11, 26.1% for group >11-19 and 23.9% for group >19 (P = .007), PIRCHE-Ⅰ was not significantly associated with chronic GVHD in multivariate models (RR, 0.993; 95% CI, 0.858-1.149; P = .926). And no significant associations were observed between PIRCHE-Ⅰ or PIRCHE-Ⅱ and other clinical outcomes. In summary, PIRCHE did not correlate with clinical outcomes and could not predict haplo-SCT outcomes.

Recipient-donor KIR ligand matching prevents CMV reactivation post-haploidentical T cell-replete transplantation.

Licensed natural killer (NK) cells have been demonstrated to have anti-cytomegalovirus (CMV) activity. We prospectively analysed the human leucocyte antigen typing of donor-recipient pairs and the killer cell immunoglobulin-like receptor (KIR) typing of donors for 180 leukaemia patients to assess the predictive roles of licensed NK cells on CMV reactivation post-T-cell-replete haploidentical stem cell transplantation. Multivariate analysis showed that donor-recipient KIR ligand graft-versus-host or host-versus-graft direction mismatch was associated with increased refractory CMV infection (Hazard ratio = 2·556, 95% confidence interval, 1·377-4·744, P = 0·003) post-transplantation. Donor-recipient KIR ligand matching decreased CMV reactivation [51·65% (46·67, 56·62%) vs. 75·28% (70·87, 79·69%), P = 0·012], refractory CMV infection [17·58% (13·77, 21·40%) vs. 35·96% (31·09, 40·82%), P = 0·004] and CMV disease [3·30% (1·51, 5·08%) vs. 11·24% (8·04, 14·43%), P = 0·024] by day 100 post-transplantation. In addition, the percentage of γ-interferon expression on donor-derived NK cells was significantly higher in the recipients among the recipient-donor pairs with a KIR ligand match compared with that in the recipients among the pairs with a KIR ligand graft-versus-host or host-versus-graft direction mismatch on days 30 and 100 post-transplantation (P = 0·036 and 0·047, respectively). These findings have suggested that donor-recipient KIR ligand matching might promote the NK cell licensing process, thereby increasing NK cell-mediated protection against CMV reactivation.

miR-153-3p, a new bio-target, is involved in the pathogenesis of acute graft-versus-host disease via inhibition of indoleamine- 2,3-dioxygenase.

Acute graft-versus-host disease (aGVHD) is a major cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation. Therefore, seeking reliable biomarkers and delineating the potential biological mechanism are important for optimizing treatment strategies and improving their curative effect. In this study, using a microRNA polymerase chain reaction (PCR)-based chip assay, microRNA-153-3p (miR-153-3p) was screened and selected as a potential biomarker of aGVHD. The elevated plasma miR-153-3p levels at +7 d after transplant could be used to predict the upcoming aGVHD. The area under the receiver operating characteristic curve for aGVHD+/aGVHD- patients receiving haploidentical transplant was 0.808 (95% confidence interval, 0.686-0.930) in a training set and 0.809 (95% confidence interval, 0.694-0.923) in a validation set. Interestingly, bioinformatics analysis indicated that indoleamine-2,3-dioxygenase (IDO) is a potential target of miR-153-3p. In vitro study confirmed that IDO could be directly inhibited by miR-153-3p. In a GVHD model, recipient mice injected with a miR-153-3p antagomir exhibited higher IDO expression levels at the early stage after transplantation, as well as delayed aGVHD and longer survival, indicating that the miR-153-3p level at +7 d post-transplant is a good predictor of aGVHD. miR-153-3p participates in aGVHD development by inhibiting IDO expression and might be a novel bio-target for aGVHD intervention.

Donor-specific anti-human leukocyte antigen antibodies were associated with primary graft failure after unmanipulated haploidentical blood and marrow transplantation: a prospective study with randomly assigned training and validation sets.

BACKGROUND: Small studies suggest an association of donor-specific anti-human leukocyte antigen (HLA) antibodies (DSAs) with primary graft failure (GF) following haploidentical stem cell transplantation, but primary graft rejection (GR) was not discriminated from primary poor graft function (PGF). In this study, we aimed to determine the association of DSAs with primary GF, including GR and PGF, in patients who underwent unmanipulated haploidentical blood and marrow transplantation. METHODS: A total of 345 subjects were prospectively recruited and randomly selected as training group (n = 173) and validation group (n = 172). Patient plasma/serum was screened. For HLA antibody positive samples with a median fluorescent intensity (MFI) >500, DSAs were further tested using a LABScreen Single Antigen Kit (One Lambda). RESULTS: A total of 342 patients (99.1%) achieved sustained myeloid engraftment. The median times to neutrophil engraftment and platelet engraftment were 13 days (range, 8-28 days) and 18 days (range, 6-330 days), respectively. The cumulative incidence of primary GF was 6.4 ± 1.3% and included GR (0.9 ± 0.5%) and PGF (5.5 ± .2%). Of the 345 cases tested, 39 (11.3%) were DSA positive. Multivariate models showed that DSAs (MFI ≥ 10,000) were correlated to primary GR (P < 0.001) and that DSAs (MFI ≥ 2000) were strongly associated with primary PGF (P = 0.005). All patients were classified into three groups for analysis. Group A included cases that were DSA negative and those with a DSA MFI <2000 (n = 316), group B included cases with a 2000 ≤ MFI < 10,000 (n = 19), and group C included cases with a MFI ≥ 10,000 (n = 10). The DSAs were associated with an increased incidence of the primary GF (3.2 vs. 31.6 vs. 60%, for groups A, B, and C, respectively, P < 0.001), transplant-related mortality (TRM) rate (17.2 vs. 14.7 vs. 33.3%, for groups A, B, and C, respectively, P = 0.022), and inferior overall survival (OS, 77.3 vs. 85.3 vs. 44.4%, for groups A, B, and C, respectively, P = 0.015). The primary GF was independently associated with a higher incidence of TRM (P < 0.001), inferior disease-free survival (P < 0.001), and OS (P < 0.001). CONCLUSIONS: The findings confirmed the effect of DSAs on primary GF, including GR and PGF, and survival. Our results suggest incorporating DSAs in the algorithm for haploidentical donor selection.

Who is the best donor for a related HLA haplotype-mismatched transplant?

The best donor for a related donor for a human leukocyte antigen (HLA) haplotype-mismatched transplant for hematological neoplasms is controversial. We studied outcomes in 1210 consecutive transplant recipients treated on a uniform protocol. Younger donors and male donors were associated with less nonrelapse mortality (NRM; hazard ratio [HR] = 0.30; 95% confidence interval [CI] = 0.01-0.39; P = .008 and HR = 0.65; 95% CI = 0.49-0.85; P = .002) and better survival (HR = 0.73; 95% CI = 0.54-0.97; P = .033 and HR = 0.73; 95% CI = 0.59-0.91; P = .005). Father donors were associated with less NRM (HR = 0.65; 95% CI = 0.45-0.95; P = .02), acute graft-versus-host disease (GVHD) (HR = 0.69; 95% CI = 0.55-0.86; P = .001), and better survival (HR = 0.66; 95% CI = 0.50-0.87; P = .003) compared with mother donors. Children donors were associated with less acute GVHD than sibling donors (HR = 0.57; 95% CI = 0.31-0.91; P = .01). Older sister donors were inferior to father donors with regard to NRM (HR = 1.87; 95% CI = 1.10-3.20; P = .02) and survival (HR = 1.59; 95% CI = 1.05-2.40; P = .03). Noninherited maternal antigen-mismatched sibling donors were associated with the lowest incidence of acute GVHD compared with parental donors and noninherited paternal antigen-mismatched sibling donors. Specific HLA disparities were not significantly correlated with transplant outcomes. Our data indicate which HLA haplotype-mismatched related donors are associated with the best transplant outcomes in persons with hematological neoplasms.

[Cytomegalovirus-specific T cells immune reconstitution after human leukocyte antigen matched sibling donor allogeneic bone marrow plus peripheral blood hematopoietic stem cell transplantation].

OBJECTIVE: To investigate the regular pattern of Cytomegalovirus (CMV)-specific T cells (CTL) immune reconstitution after human leukocyte antigen (HLA) matched sibling donor allogeneic bone marrow(BM) plus peripheral blood hematopoietic stem cell (PBSC) transplantation. METHODS: CTL from seventeen patients after transplantation was detected by flow cytometry, the IFN-γ secretion ability of CTL by enzyme-linked immunospot (ELISPOT) assay, and clonal analysis of TCR Vß subfamily by gene scan assays. The relationship between CTL reconstitution and CMV infection was studied. RESULTS: Both number and function of recipients CTL reached to normal control level at 30 d post-transplantation. The recipients achieved a high frequency CTL with IFN-γ response and restoration of T-cell receptor ß (TCR Vß) repertoire at one year post-transplantation. CTL with the central memory CD45RO(+)CD62L(+) cell phenotype expanded in PB when CMV was reactivated. The incidence of CMV reactivation was 35.83% (17.91% - 63.10%) after transplantation, and none of them developed CMV disease. CONCLUSION: After HLA matched related donor transplantation using mixed grafts, immune recovery to CMV seems to be early and fast. The incidence of CMV infection and disease are low.

The effect of HLA disparity on clinical outcome after HLA-haploidentical blood and marrow transplantation.

The relative importance of various human leukocyte antigen (HLA) loci has not been established for unmanipulated HLA-mismatched/haploidentical transplantation. To address this question, we analyzed the impact of HLA-A, HLA-B, HLA-DRB1, HLA-DRB3, HLA-DRB4, and HLA-DRB5 on the outcome of HLA-haploidentical transplantation. Four hundred and eighty-one donor-recipient pairs were fully typed before transplantation. In univariate analysis, HLA-B mismatch not only demonstrated significant adverse effects on acute graft-versus-host disease (GVHD) and transplant-related mortality but also was associated with reduced overall survival and leukemia-free survival (LFS). In multivariate analysis, HLA-B mismatch remained the independent risk factor for acute GVHD and transplant-related mortality. The high risk of disease and the female donor were found to be significant factors for reduced overall survival and LFS. Furthermore, multiple mismatch of the HLA locus was found to have no synergistic adverse effect on outcomes. Our results suggest that prospective matching of patients and donors for HLA-B antigen in the unshared HLA haplotype is warranted for HLA-mismatched/haploidentical transplantation.

Immune reconstitution following unmanipulated HLA-mismatched/haploidentical transplantation compared with HLA-identical sibling transplantation.

In this study, we prospectively investigated the immune reconstitution in patients with hematological malignancies after human leukocyte antigen (HLA)-mismatched/unmanipulated haploidentical transplantation (50 cases) and HLA-matched transplant (25 cases). Transplant-related mortality, relapse, leukemia-free survival, and overall survival were similar between the two transplant strategies, although the cumulative incidence of CMV antigenemia was significantly higher in haploidentical recipients than in HLA-matched recipients (49.9 ± 7.2% versus 13 ± 7%, P = 0.007). Compared with HLA-matched recipients, T-cell subset and dendritic cell subgroup cell counts in the first 90 days after grafting were lower in haploidentical recipients. The difference was most striking for CD4(+) and CD4(+) naïve T cells. Reconstitution of B cells and monocytes was comparable between groups. T cells appeared equally functional in both groups among patients without graft-versus-host disease. Our results suggest that the clinical outcomes were not compromised by the early delayed immune reconstitution following haploidentical transplantation.

[Association of HLA DRB1 polymorphism with susceptibility to myelodysplastic syndrome and aplastic anemia in Chinese Han population].

OBJECTIVE: To investigate the association of the HLA-DRB1 polymorphism with susceptibility to myelodysplastic syndrome (MDS) and aplastic anemia (AA) in Chinese Han population. METHODS: The polymorphism of HLA-DRB1 alleles in 242 patients with MDS, 115 patients with AA and 2264 umbilical cord blood control samples were tested by polymerase chain reaction-sequence specific primer (PCR-SSP). RESULTS: Compared with normal controls, the frequency of HLA-DRB1*15 was significantly increased in the MDS group and AA group (22.93% vs. 17.25%, Chi-square = 9.662, OR= 1.428, P= 0.003; 26.52% vs. 17.25%, Chi-square = 12.924, OR= 1.732, P= 0.001). And this is mainly due to the increase in the male patients in both patient groups: in the MDS males, 24.68% vs. 17.25%, Chi-square= 11.194, OR= 1.572, P= 0.001, and in the AA males, 29.29% vs. 17.25%, Chi-square= 13.563, OR= 1.987, P= 0.001. No significant difference between the controls and the female patients in both groups was observed. CONCLUSION: The HLA-DRB1*15 could be a susceptibility allele for MDS and AA male patients.

Clinical impact of absolute lymphocyte count on day 30 after unmanipulated haploidentical blood and marrow transplantation for pediatric patients with hematological malignancies.

Currently, limited information is available regarding the effects of early lymphocyte recovery on transplant outcomes in pediatric patients with hematological malignancies after unmanipulated haploidentical transplantation. In this study, we evaluated the association of Day 30 absolute lymphocyte count (ALC-30) with transplant outcomes in 60 consecutive pediatric patients with hematological malignancies receiving T-cell-repleted transplantation from an haploidentical related donors. After median follow-up of 36 months (range, 1.4-75 months), higher relapse rate was observed in patients with an ALC-30 < 300 cells/µL compared to patients with an ALC-30 ≥ 300 cells/µL (35.5% vs. 13.8%, P = 0.049). More patients died of infections in those with an ALC-30 < 300 cells/µL compared with patients with an ALC-30 ≥ 300 cells/µL (25.8% vs. 3.4%, P = 0.015). The ALC-30 above the cutoff value 300 cells/µL was associated with improved overall-survival (HR 0.301, 95% CI 0.117-0.771; P = 0.012), leukemia free survival (HR 0.195, 95% CI 0.078-0.498; P=0.002), less relapse (HR 0.224 95% CI 0.070-0.717; P = 0.012), and less transplant- related mortality (HR=0.166; 95%CI 0.037-0.750; P = 0.020). Our results suggest that a higher ALC-30 ≥ 300 cells/µL) could be a useful and simple tool to predict pediatric patients with a superior outcome after unmanipulated haploidentical transplantation.

[Determination of optimal time to second allogeneic peripheral blood stem cell harvest from healthy donors].

OBJECTIVE: To investigate the optimal time for second allogeneic peripheral blood stem cell grafts (PBSC) harvest from healthy donors after in vivo recombinant human granulocyte colony-stimulating factor application (rhG-CSF). METHODS: Thirty-eight healthy donors of second collection (group A) were treated with subcutaneous rhG-CSF \[5 microgxkg(-1)xd(-1)\] for five consecutive days and followed by leukapheresis on day 5 and 6. The control group (group B) was thirty-eight healthy donors who had received a first PBSC collection previously. Group A was reclassified as group C (< or = 9 months) and group D (> 9 months) according to the 75% quantile of interim time between first and second collection. The quantities of lymphocytes of CD3(+), CD3(+)CD4(+), CD3(+)CD8(+), CD14(+), CD34(+) cells and CD3(+)CD4(-)CD8(-) T cells were determined by multi-color flow cytometry. RESULTS: The median number of CD3(+)CD8(+) (25.51 x 10(8)) and CD34(+) cells (0.51 x 10(8)) in group A were significantly lower than that (31.55 x 10(8) and 0.70 x 10(8) respectively) in group B (P < 0.05), and so did the CD3(+)CD8(+) (23.42 x 10(8)) and CD34(+) cells (0.42 x 10(8)) in group C than that in group B (P < 0.05). There was no statistical difference in median numbers of T cell subsets, monocytes, and CD34(+) cells between group B and group D (P > 0.05). The cell ratios of CD4(+)/CD8(+), CD14(+)/CD3(+) and CD3(+)CD4(-)CD8(-) T/CD3(+) in PBSC in group A, group C, and group D were similar to that in group B (P > 0.05). Sperman analysis showed a positive correlation between the total CD34(+) cells in second collection and the interval time from first to second collection (r = 0.357, P = 0.028). CONCLUSION: Nine months after the first collection maybe an optimal time for the second PBSC collection. For those who undergo second PBSC collection within 9 months, more circulation blood should be extracted to ensure enough immunological and hematopoietic compositions.