A complete oral regimen for induction therapy of patients with high-risk APL: An oral etoposide instead of intravenous infusion for cytoreductive chemotherapy.

There is an urgent need for an oral, efficient and safe regimen for high-risk APL under the pandemic of COVID-19. We retrospectively analysed 60 high-risk APL patients. For induction therapy (IT), in addition to all-trans retinoic acid (ATRA) and oral arsenic (RIF), 22 patients received oral etoposide (VP16) as cytotoxic chemotherapy (CC), and 38 patients received intravenous CC as historical control group. The median dose of oral VP16 was 1000 mg [interquartile rage (IQR), 650-1250]. One patient died during IT in the control group, 59 evaluable patients (100%) achieved complete haematological remission (CHR) after IT and complete molecular remission (CMR) after consolidation therapy. The median time to CHR and CMR was 36 days (33.8-44) versus 35 days (32-42; p = 0.75) and 3 months (0.8-3.5) versus 3.3 months (2.4-3.7; p = 0.58) in the oral VP16 group and in the control group. Two (9.1%) and 3 (7.9%) patients experienced molecular relapse in different group respectively. The 2-year estimated overall survival and event-free survival were 100% versus 94.7% (p = 0.37) and 90.9% versus 89.5% (p = 0.97) respectively. A completely oral, efficient and safe induction regimen including oral VP16 as cytoreductive chemotherapy combined with ATRA and RIF is more convenient to administer for patients with high-risk APL.

Targeting TFH cells is a novel approach for donor-specific antibody desensitization of allograft candidates: an in vitro and in vivo study.

The presence of donor-specific antibodies (DSA) are associated with graft failure either following human leukocyte antigen (HLA)-mismatched allogeneic stem cell transplantation or after organ transplantation. Although targeting B cells and plasma cells have been used for desensitization, there have been reports of failure. T-follicular helper (Tfh) cells assist B cells in differentiating into antibody-secreting plasma cells. We used haploidentical allograft as a platform to investigate the possibility of targeting Tfh cells to desensitize DSA. The quantities of circulating Tfh (cTfh) cell subsets in allograft candidates were abnormal, and these cells, including the cTfh2 and cTfhem cell subsets, were positively related to the production of anti-HLA antibodies. Ex vivo experiments showed that the cTfh cells of anti-HLA antibody-positive allograft candidates could induce B cells to differentiate into DSA-producing plasmablasts. The immune synapse could be involved in the assistance of cTfh cells to B cells in antibody production. In vitro experiments and in vivo clinical pilot studies indicated that targeting cTfh cells with sirolimus can inhibit their auxiliary function in assisting B cells. Ex vivo and in vivo studies demonstrated the effect of sirolimus and rituximab on DSA desensitization compared with either sirolimus or rituximab alone (60%, 43.75%, and 30%, respectively). Our findings provide new insight into the role of Tfh cells in the pathogenesis of DSA production in HLA-mismatched transplant candidates. Our data also indicate that targeting Tfh cells is a novel strategy for DSA desensitization and combination of sirolimus and rituximab might be a potential therapy. The prospective cohort of this study is registered at http://www.chictr.org.cn as #ChiCTR-OPC-15006672.

ZNF384 fusion transcript levels for measurable residual disease monitoring in adult B-cell acute lymphoblastic leukemia.

Zinc finger protein 384 (ZNF384) rearrangement defined a novel subtype of B-cell acute lymphoblastic leukemia (B-ALL). The prognostic significance of ZNF384 fusion transcript levels represented measurable residual disease remains to be explored. ZNF384 fusions were screened out in 57 adult B-ALL patients at diagnosis by real-time quantitative polymerase chain reaction and their transcript levels were serially monitored during treatment. The reduction of ZNF384 fusion transcript levels at the time of achieving complete remission had no significant impact on survival, whereas its ≥2.5-log reduction were significantly associated with higher relapse free survival (RFS) and overall survival (OS) rates after course 1 consolidation (p = 0.022 and = 0.0083) and course 2 consolidation (p = 0.0025 and = 0.0008). Compared with chemotherapy alone, allogeneic hematopoietic stem cell transplantation (allo-HSCT) significantly improved RFS and OS of patients with <2.5-log reduction after course 1 consolidation (p < 0.0001 and = 0.0002) and course 2 consolidation (p = 0.0003 and = 0.019), whereas exerted no significant effects in patients with ≥2.5-log reduction (all p > 0.05). ZNF384 fusion transcript levels after course 1 and course 2 consolidation strongly predict relapse and survival and may guide whether receiving allo-HSCT in adult B-ALL.

Safety and efficacy of baricitinib in steroid-resistant or relapsed immune thrombocytopenia: An open-label pilot study.

Patients with steroid-resistant or relapsed immune thrombocytopenia (ITP) suffer increased bleeding risk and impaired quality of life. Baricitinib, an oral Janus-associated kinases (JAK) inhibitor, could alleviate both innate and adaptive immune disorders without inducing thrombocytopenia in several autoimmune diseases. Accordingly, an open-label, single-arm, phase 2 trial (NCT05446831) was initiated to explore the safety and efficacy of baricitinib in ITP. Eligible patients were adults with primary ITP who were refractory to corticosteroids and at least one subsequent treatment, and had platelet counts below 30 × 109/L at enrolment. Participants received baricitinib 4 mg daily for 6 months. The primary endpoint was durable response at the 6-month follow-up. A total of 35 patients were enrolled. Durable response was achieved in 20 patients (57.1%, 95% confidence interval, 39.9 to 74.4), and initial response in 23 (65.7%) patients. For patients responding to baricitinib, the median time to response was 12 (IQR 6-20) days, and the median peak platelet count was 94 (IQR 72-128) × 109/L. Among the 27 patients undergoing extend observation, 12 (44.4%) remained responsive for a median duration of approximately 20 weeks after baricitinib discontinuation. Adverse events were reported in 11 (31.4%) patients, including infections in 6 (17.1%) patients during the treatment period. Treatment discontinuation due to an adverse event was reported in 2 (5.7%) patients. Evidence from this pilot study suggested that baricitinib might be a novel candidate for the armamentarium of ITP-modifying agents. Future studies are warranted to validate the safety, efficacy, and optimal dosing of baricitinib in patients with ITP.

Functional Competence of NK Cells via the KIR/MHC Class I Interaction Correlates with DNAM-1 Expression.

The interaction of inhibitory receptors with self-MHC class I (MHC-I) molecules is responsible for NK cell education. The intensity of DNAM-1 expression correlates with NK cell education. However, whether DNAM-1 expression directly influences the functional competence of NK cells via the KIR/MHC-I interaction remains unclear. Based on allogeneic haploidentical hematopoietic stem cell transplantation, we investigated the intensity of DNAM-1 expression on reconstituted NK cells via the interaction of KIR with both donor HLA and recipient HLA at days 30, 90, and 180 after hematopoietic stem cell transplantation. The reconstituted NK cells educated by donor and recipient HLA molecules showed the highest DNAM-1 expression, whereas DNAM-1 expression on educated NK cells with only recipient HLA molecules was higher than that on educated NK cells with only donor HLA molecules, indicating that NK cells with donor or recipient HLA molecules regulate DNAM-1 expression and thereby affect NK cell education. Additionally, the effects of recipient cells on NK cell education were greater than those of donor cells. However, only when the DNAM-1, NKP30, and NKG2D receptors were blocked simultaneously was the function of educated and uneducated NK cells similar. Therefore, activating receptors may collaborate with DNAM-1 to induce educated NK cell hyperresponsiveness. Our data, based on in vitro and in vivo studies, demonstrate that the functional competence of NK cells via the KIR/MHC-I interaction correlates with DNAM-1 expression in human NK cells.

Donor CSF3R with the rs3917980A/G or G/G genotype is correlated with better leukemia-free survival after allogenic hematopoietic stem cell transplantation.

Polymorphisms in the granulocyte colony-stimulating factor receptor gene (GCSFR, CSF3R) have been reported to be associated with peripheral blood stem cell enrichment and hematological diseases. The aim of our study was to investigate the effects of donor CSF3R allelic polymorphisms on the outcomes of allogeneic stem cell transplantation. A total of 273 patients who were diagnosed with hematological diseases and treated with allogeneic hematopoietic stem cell transplantation(allo-HSCT) were enrolled in this study. Single-nucleotide polymorphisms in CSF3R were genotyped by targeted next-generation sequencing. There were six types of CSF3R genotypes with percentages over 1%. LFS and OS analyses showed that recipients receiving grafts from healthy donors with a rs3917980 G/G or A/G genotype had higher LFS rates than those receiving grafts from donors carrying a rs22754272 T/C genotype and the double-negative group (p = 0.036). Univariate cox analysis showed that donor CSF3R with the rs2275472 T/C genotype was associated with higher transplantation-related mortality (TRM) rates (HR = 2.853, 95% CI: 1.405-5.792, p = 0.00371) and lower rates of leukemia-free survival (LFS) (HR = 1.846; 95% CI: 1.018-3.347, p = 0.0435). In addition, donor CSF3R with the rs3917980G/G or A/G genotype was associated with better overall survival (OS) rates (HR = 0.560, 95% CI: 0.3162-0.9916, p = 0.047) and lower TRM rates (HR = 0.497, 95% CI: 0.2628-0.9397, p = 0.0315). Furthermore, multivariate cox analysis found that rs2275472 T/C genotype was an independent risk factors for TRM rates (HR = 3.210, 95% CI: 1.573-6.55, p = 0.001), while no statistical difference was found between rs3917980G/G or A/G genotype and clinical outcomes. Our findings demonstrate the important prognostic value of genetic variations in donor CSF3R to predict clinical outcomes in patients undergoing 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.

CMV infection combined with acute GVHD associated with poor CD8+ T-cell immune reconstitution and poor prognosis post-HLA-matched allo-HSCT.

Cytomegalovirus (CMV) infection and acute graft-versus-host disease (aGVHD) are two major complications that contribute to a poor prognosis after hematopoietic stem cell transplantation (HSCT). Superior early immune reconstitution (IR) is associated with improved survival after HSCT. However, when all three factors, CMV infection, aGVHD, and IR, are concomitantly considered, the effects of the triple events on HSCT are still unknown and should be studied further. Thus we enrolled 185 patients who were diagnosed as hematological malignancies and treated with HLA-matched sibling transplantation (MST) between January 2010 and December 2014, of whom 83 were positive for CMV infection and 82 had aGVHD. Results showed that patients with both aGVHD and CMV infection had significantly higher non-relapse mortality (NRM), lower overall survival (OS), and delayed CD8+ T-cell IR. Multivariate analyses showed that both aGVHD combined with CMV infection and delayed CD8+ T-cell IR were independent risk factors for prognosis post-MST. Recurrent CMV infections are associated with poor CD8+ T-cell reconstitution. However, superior IR could protect against the negative effects of aGVHD and CMV infection on the transplant outcomes.

Monitoring of post-transplant MLL-PTD as minimal residual disease can predict relapse after allogeneic HSCT in patients with acute myeloid leukemia and myelodysplastic syndrome.

BACKGROUND: The mixed-lineage leukemia (MLL) gene is located on chromosome 11q23. The MLL gene can be rearranged to generate partial tandem duplications (MLL-PTD), which occurs in about 5-10% of acute myeloid leukemia (AML) with a normal karyotype and in 5-6% of myelodysplastic syndrome (MDS) patients. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is currently one of the curative therapies available for AML and MDS with excess blasts (MDS-EB). However, how the prognosis of patients with high levels of MLL-PTD after allo-HSCT, and whether MLL-PTD could be used as a reliable indicator for minimal residual disease (MRD) monitoring in transplant patients remains unknown. Our study purposed to analyze the dynamic changes of MLL-PTD peri-transplantation and the best threshold for predicting relapse after transplantation. METHODS: We retrospectively collected the clinical data of 48 patients with MLL-PTD AML or MDS-EB who underwent allo-HSCT in Peking University People's Hospital. The MLL-PTD was examined by real-time quantitative polymerase chain reaction (RQ-PCR) at the diagnosis, before transplantation and the fixed time points after transplantation. Detectable MLL-PTD/ABL > 0.08% was defined as MLL-PTD positive in this study. RESULTS: The 48 patients included 33 AML patients and 15 MDS-EB patients. The median follow-up time was 26(0.7-56) months after HSCT. In AML patients, 7 patients (21.2%) died of treatment-related mortality (TRM), 6 patients (18.2%) underwent hematological relapse and died ultimately. Of the 15 patients with MDS-EB, 2 patients (13.3%) died of infection. The 3-year cumulative incidence of relapse (CIR), overall survival (OS), disease-free survival (DFS) and TRM were 13.7 ± 5.2, 67.8 ± 6.9, 68.1 ± 6.8 and 20.3% ± 6.1%, respectively. ROC curve showed that post-transplant MLL-PTD ≥ 1.0% was the optimal cut-off value for predicting hematological relapse after allo-HSCT. There was statistical difference between post-transplant MLL-PTD ≥ 1.0% and MLL-PTD < 1.0% groups (3-year CIR: 75% ± 15.3% vs. 0%, P < 0.001; 3-year OS: 25.0 ± 15.3% vs. 80.7% ± 6.6%, P < 0.001; 3-year DFS: 25.0 ± 15.3% vs. 80.7 ± 6.6%, P < 0.001; 3-year TRM: 0 vs. 19.3 ± 6.6%, P = 0.277). However, whether MLL-PTD ≥ 1% or MLL-PTD < 1% before transplantation has no significant difference on the prognosis. CONCLUSIONS: Our study indicated that MLL-PTD had a certain stability and could effectively reflect the change of tumor burden. The expression level of MLL-PTD after transplantation can serve as an effective indicator for predicting relapse.

Combination of KIT and FLT3-ITD mutation status with minimal residual disease levels guides treatment strategy for adult patients with inv(16) acute myeloid leukemia in first complete remission.

Although several studies have investigated the benefits of allogeneic hematopoietic stem cell transplantation (allo-HSCT) for patients with inv (16) acute myeloid leukemia (AML) in first complete remission (CR1) individually stratified by KIT or FMS-like tyrosine kinase 3-internal tandem duplication (FLT3-ITD) mutation status or minimal residual disease (MRD) levels, evaluation based on the combination of mutation status and MRD levels remains absent. This study included 157 adult patients with inv (16) AML who were consecutively diagnosed and receiving treatment at our center. A total of 50 (31.6%) patients had KIT mutations (KITMU ), and the risk of relapse was significantly higher in patients with KITMU than in patients with KITWT (p < 0.001). A total of 12 patients (7.6%) had FLT3-ITD, and FLT3-ITD+ tended to be related to a higher risk of relapse (p = 0.14). KITMU , FLT3-ITD and MRD3-H (beta subunit of core binding factor-myosin heavy chain 11 levels >0.2% after course 2 of consolidation therapy) were independent adverse prognostic factors for relapse with patients who received allo-HSCT at CR1 were censored at the time of transplantation. After combination, patients were categorized into molecularly defined high-risk (M-HR; KITMU or FLT3-ITD+ with MRD3-H; n = 30), low-risk (M-LR; KITWT and FLT3-ITD- with MRD3-L; n = 45) and intermediate-risk (M-IR; others; n = 70) groups. For the M-HR group, allo-HSCT significantly improved both cumulative incidence of relapse cumulative incidence of relapse (CIR) and overall survival (OS) (11.1% vs. 92.6%, p < 0.001; 90.0% vs. 34.1%, p = 0.019). For the M-IR group, allo-HSCT significantly improved CIR but did not affect OS (14.1% vs. 62.2%, p = 0.0004; 73.3% vs. 68.3%, p = 0.43). For the M-LR group, allo-HSCT had no significant effect on both CIR and OS (0% vs. 35.1%, p = 0.31; 100% vs. 78.8%, p = 0.22). Therefore, the combination of KIT and FLT3-ITD mutation status with MRD levels may identify inv (16) AML patients with high-risk who can benefit from allo-HSCT in CR1.

Recipient and donor PTX3 rs2305619 polymorphisms increase the susceptibility to invasive fungal disease following haploidentical stem cell transplantation: a prospective study.

BACKGROUND: Invasive fungal disease (IFD) is a severe complication after haploidentical stem cell transplantation (haplo-HSCT) and has a poor prognosis. It has been shown that genetic polymorphism may be one possible reason for the increased risk of IFD. This study aimed to assess the role of genetic polymorphism in the level of susceptibility to IFD after haplo-HSCT. METHODS: In this study, we prospectively enrolled 251 patients who received haplo-HSCT at the Peking University Institute of Hematology from 2016 to 2018. Forty-three single nucleotide polymorphisms (SNPs) of the genomic DNA were genotyped in blood samples from both recipient and donor. RESULTS: Twenty-two patients (8.8%) were diagnosed with proven or probable IFD. The independent risk factors for IFD were grades 3-4 acute graft-versus-host disease, cytomegalovirus reactivation, and recipient and donor rs2305619 (PTX3) (P < 0.05) in multivariate analysis. Meanwhile, we combined the variables to develop the IFD risk scoring system and stratified patients into low- (0-2) and high-risk (3-4) groups. The 30-day and 100-day cumulative incidence of IFD in the low- and high-risk groups were 2.1% and 10.2%, 4.2% and 20.3%, respectively (P = 0.015). CONCLUSIONS: PTX3 rs2305619 polymorphism increase the susceptibility of IFD after haplo-HSCT in the Chinese Han population, and the IFD scoring system could be useful in risk stratification for IFD after HSCT.

PML-RARA transcript levels at the end of induction therapy are associated with prognosis in non-high-risk acute promyelocytic leukaemia with all-trans retinoic acid plus arsenic in front-line therapy: long-term follow-up of a single-centre cohort study.

Despite the high cure probability for acute promyelocytic leukaemia (APL), a minority of patients will relapse and the risk factors for relapse are unclear. We retrospectively analysed 212 patients who were diagnosed with non-high-risk APL and received all-trans retinoic acid (ATRA) plus arsenic as front-line therapy at Peking University Institute of Hematology from February 2014 to December 2018. A total of 176 patients (83%) received oral arsenic (realgar-indigo naturalis formula) plus ATRA, 36 patients (17%) received arsenic trioxide plus ATRA and 203 patients were evaluable for relapse. After a median (range) follow-up of 53·6 (24·3-85·4) months, two patients had molecular relapse and eight had haematological relapse. A promyelocytic leukaemia/retinoic acid receptor alpha (PML-RARA) transcript level of ≥6·5% at the end of induction therapy was associated with relapse (P = 0·031). The 5-year cumulative incidence of relapse, event-free survival and overall survival were 5·5%, 92·3% and 96·3% respectively. In conclusion, the present long-term follow-up study further confirmed the high cure probability of ATRA plus oral arsenic as front-line therapy for non-high-risk APL and showed that the PML-RARA transcript level at the end of induction therapy was associated with relapse.

Wilms' tumor gene 1 is an independent prognostic factor for pediatric acute myeloid leukemia following allogeneic hematopoietic stem cell transplantation.

BACKGROUND: Sequential monitoring of Wilms' tumor gene 1 (WT1) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) could predict relapse in adult acute myeloid leukemia (AML). However, the prognostic role of WT1 in pediatric AML after allo-HSCT is unclear. Thus, we determined to see whether sequential monitoring of WT1 after allo-HSCT could predict relapse in AML children. METHODS: Pediatric AML patients receiving allo-HSCT from January 21, 2012 to December 20, 2018 at the Peking University Institute of Hematology were included in this study. WT1 expression level was determined by TaqMan-based reverse transcription-polymerase chain reaction. WT1 sequential monitoring was performed 1, 2, 3, 4.5, 6, 9, and 12 months post-transplantation and at 6-month intervals thereafter. The primary end point was relapse. The secondary end points included disease-free survival (DFS), overall survival (OS), and non-relapse mortality (NRM). Kaplan-Meier analysis was used for DFS and OS estimates, while competing risk analysis was used for estimating relapse and NRM. RESULTS: Of the 151 consecutive patients included, the median age was 10 years (range, 1-17). The optimal cutoff value of WT1 within 1 year after allo-HSCT to predict relapse was 0.8% (80 WT1 copies/104 ABL copies), with a sensitivity of 60% and specificity of 79%. Compared with WT1 expression < 0.8%, WT1 expression ≥0.8% indicated significantly higher 5-year cumulative incidence of relapse (CIR, 35.1% vs. 11.3%; P = 0.001), lower 5-year disease-free survival (DFS, 60.4% vs. 80.8%; P = 0.009), and lower 5-year overall survival (OS, 64.9% vs. 81.6%; P = 0.038) rates. Multivariate analyses showed that WT1 was an independent risk factor for relapse (HR 2.89; 95% confidence interval (CI), 1.25-6.71; P = 0.014). Both the CIR (5-year CIR: 8.3% vs. 11.3%; P = 0.513) and DFS (5-year DFS: 91.7% vs. 80.8%; P = 0.208) were comparable between patients achieving minimal residual disease (MRD) negativity after preemptive interferon-α (IFN-α) treatment and those without MRD after allo-HSCT, which were better than those of MRD-positive patients without preemptive therapies. CONCLUSIONS: Sequential monitoring of WT1 could predict relapse in pediatric AML after allo-HSCT. WT1-directed immunotherapy may have the potential to prevent relapse and improve survival.

Profiles of NK cell subsets are associated with successful tyrosine kinase inhibitor discontinuation in chronic myeloid leukemia and changes following interferon treatment.

Recent studies have shown that approximately 50% of patients with chronic myeloid leukemia (CML) receiving tyrosine kinase inhibitor (TKI) therapy with a sustained deep molecular response (DMR) (BCR-ABL1IS ≤ 0.01%) can achieve treatment-free remission (TFR, stopping TKI without relapse) and that prior interferon (IFN)-α therapy and higher NK cell counts at and after TKI discontinuation are associated with TFR. We recently reported that post-TKI discontinuation of IFN-α therapy could prevent molecular relapse (MR, BCR-ABL1IS > 0.1%). Here, we evaluated whether NK cells are associated with MR and investigated the effects of post-TKI discontinuation IFN-α therapy on lymphocyte subsets. A total of 34 patients measuring blood lymphocyte subclasses were included. In the 22 patients who did not receive IFN-α therapy, at 1 month after TKI discontinuation, the nonrelapsed patients showed a significantly higher proportion and count of NK cells than the relapsed patients. In particular, the proportion and count of CD56dim NK cells were significantly higher in the nonrelapsed patients than in the relapsed patients. In the 12 patients who received IFN-α therapy, the level of CD56bright NK cells increased significantly after 3 and 6 months of IFN-α therapy. In summary, NK cells, in particular CD56dim NK cells, were associated with MR after TKI discontinuation in patients with CML. Additionally, IFN-α therapy gradually increased the level of CD56bright NK cells in patients with CML.

Minimal residual disease monitoring and preemptive immunotherapies for frequent 11q23 rearranged acute leukemia after allogeneic hematopoietic stem cell transplantation.

The prognosis of 11q23/KMT2A-rearranged (KMT2A-r) acute leukemia (AL) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is poor. Minimal residual disease (MRD) is an important prognostic factor for relapse. Thus, we aimed to identify the evolution of KMT2A before and after allo-HSCT and the efficacy of preemptive immunotherapies for KMT2A-r AL patients receiving allo-HSCT. KMT2A expression was determined through TaqMan-based RQ-PCR technology. Preemptive immunotherapies included interferon-α and donor lymphocyte infusion. We collected 1751 bone marrow samples from 177 consecutive KMT2A-r AL patients. Pre-HSCT KMT2A positivity was correlated with post-HSCT KMT2A positivity (correlation coefficient=0.371, P<0.001). The rates of achieving KMT2A negativity after allo-HSCT were 96.6%, 92.9%, and 68.8% in the pre-HSCT low-level group (>0, <0.1%), intermediate-level group (≥ 0.1%, <1%), and high-level group (≥1%), respectively. The rates of regaining KMT2A positivity after allo-HSCT were 7.7%, 35.7%, 38.5%, and 45.5% for the pre-HSCT KMT2A-negative, low-level, intermediate-level, and high-level groups, respectively (P<0.001). The 4-year cumulative incidence of relapse after allo-HSCT was as high as 53.7% in the pre-HSCT KMT2A expression ≥ 0.1% group, which was compared to the KMT2A-negative group (15.1%) and KMT2A <0.1% group (31.2%). The clinical outcomes of patients with post-HSCT KMT2A positivity were poorer than those of patients with persistent KMT2A negativity. Although post-HSCT preemptive immunotherapies might help to achieve KMT2A negativity, the long-term efficacy was unsatisfactory. Thus, pre-HSCT KMT2A positivity was significantly associated with post-HSCT KMT2A positivity. The clinical outcomes of patients with post-HSCT KMT2A positivity were poor, which might not be overcome by commonly used immunotherapies.

Human herpesvirus 6 reactivation in unmanipulated haploidentical hematopoietic stem cell transplantation predicts the occurrence of grade II to IV acute graft-versus-host disease.

BACKGROUND: Human herpesvirus 6 (HHV-6) reactivation is relatively common after allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, the incidence of HHV-6 reactivation and the clinical outcomes following unmanipulated haploidentical HSCT (haplo-HSCT) remain unknown. METHOD: We prospectively monitored blood HHV-6 DNA using real-time quantitative polymerase chain reaction weekly until day 100 post unmanipulated haplo-HSCT in patients with hematological malignancies. RESULTS: From November 2016 to March 2017, 102 patients (58 male and 44 female, median age 25(2-58) years old) were enrolled. Within 100 days post-transplantation, 27 patients (27/136, 19.9%) developed HHV-6 viremia with a median onset time of 14 (7-98) days. The cumulative incidence of HHV-6 reactivation on day 100 post-HSCT was 25.5 ± 4.3% in haplo-HSCT. The median HHV-6 copy number was 1.45 × 103 (5.48 × 102 -2.00 × 104 ) copies/ml. The HHV-6 viremia duration time was 7 days in 23 patients, 14 days in one patient and 21 days in one patient. In multivariate analysis, prior HHV-6 reactivation was an independent risk factor for grade 2-4 graft-versus-host disease (GVHD). But it did not influence the overall survival (OS)(HR 1.624, 95%CI 0.768-3.432, P = .204), disease-free survival (DFS) (HR 1.640, 95%CI 0.799-3.367, P = .177) and non-relapse mortality (NRM) (HR 1.644, 95%CI 0.670-4.038, P = .278). CONCLUSION: The reactivation of HHV-6 after unmanipulated haploidentical transplantation predicts the occurrence of grade 2-4 a-GVHD, but it may not influence the overall survival (OS), disease-free survival (DFS) and non-relapse mortality (NRM).

The predictive value of minimal residual disease when facing the inconsistent results detected by real-time quantitative PCR and flow cytometry in NPM1-mutated acute myeloid leukemia.

For acute myeloid leukemia (AML) with nucleophosmin 1 mutation (NPM1m), multiparameter flow cytometry (FCM) and real-time quantitative polymerase chain reaction (RQ-PCR) are used to monitor minimal residual disease (MRD). However, the results of the two methods are sometimes inconsistent. This study was designed to analyze how to address the discordant results of FCM and RQ-PCR in AML patients undergoing chemotherapy, especially when positive FCM (FCM+) and negative NPM1m (NPM1m-) results are detected in the same sample. Our study included 93 AML patients with NPM1m positive (NPM1m+) who received chemotherapy but did not undergo hematopoietic stem cell transplantation. We monitored NPM1m and leukemia-associated immunophenotypes (LAIPs) by RQ-PCR and FCM, respectively, to assess MRD after each chemotherapy course. After each course of chemotherapy, all patients were classified into four groups based on the results of FCM and RQ-PCR: both negative (group 1, FCM-NPM1m-), single positive (group 2, FCM-NPM1m+; group 3, FCM+NPM1m-), or both positive (group 4, FCM+NPM1m+). The results showed that there was not a significant difference in the 2-year cumulative incidence of relapse (CIR) after each course of chemotherapy between group 2 and group 3. Furthermore, patients in groups 2 and 3 had a lower 2-year CIR than those in group 4 and a significantly higher 2-year CIR than those in group 1 after the first two courses. The patients in group 4 had a significantly higher 2-year CIR than those in group 1 after the first two courses. These results suggested that in the MRD monitoring process of AML patients, when the results of FCM and RQ-PCR are inconsistent (especially when FCM is positive and NPM1m is negative), these single-positive results still have predictive significance for relapse.

Delay expression of NKp30 on NK cells correlates with long-term mycophenolate mofetil treatment and higher EBV viremia post allogenic hematological stem cells transplantation.

Mycophenolate mofetil (MMF) is an immunosuppressive agent that is widely used in graft-versus-host disease prophylaxis because of its inhibitory function on T cells and B cells. However, the effect of MMF on natural killer cell reconstitution after allogenic hematological transplantation is largely unknown. The present study examined the effects of different MMF administration durations after haploidentical allo-HSCT on NK cell reconstitution. Ninety patients were enrolled in this study and defined into two groups in term of MMF duration. We found that MMF patients in the long-term MMF group were associated with a poor reconstitution of NK cells and a significantly lower cytotoxicity from day 30 to day 180 post-transplantation. Especially, the long-term MMF group inhibits reconstitution of NKp30 NK subsets, which correlated with higher risk of EBV viremia. Multivariate analysis showed that a better reconstitution of NKp30 cells was associated with lower EBV viremia (HR0.957, p = .04). In vitro experiments demonstrated that the active metabolite of MMF, mycophenolic acid (MPA), inhibited the proliferation and cytotoxicity of NK cells from healthy donors or patients at day 30 post-transplantation. In summary, our findings demonstrated that long-term MMF administration delayed the quality and quantity of NK cells, especially NKp30 subpopulations, which was associated with decreased EBV viremia post allogeneic HSCT.

The prognostic significance of Wilms' tumor gene 1 (WT1) expression at diagnosis in adults with Ph-negative B cell precursor acute lymphoblastic leukemia.

The prognostic significance of Wilms' tumor gene 1 (WT1) expression at diagnosis in adults with B cell precursor acute lymphoblastic leukemia (BCP-ALL) remains poorly understood. A total of 257 adults with Ph-negative BCP-ALL who were consecutively diagnosed and received at least 1 course of induction therapy at our institute were retrospectively analyzed. The WT1 expression patterns were significantly different among the molecularly and cytogenetically defined groups (E2A-PBX1, TEL-AML1, and MLL rearrangements; high hyperdiploidy and B-other). By considering the WT1 expression pattern and the relapse status, 2 cutoff values, 1.8% and 7.2%, were arbitrarily selected to place patients into WT1-low, WT1-inter, and WT1-high groups. In the B-other patients who achieved complete remission (CR), WT1-low and WT1-high patients had similar 3-year relapse-free survival (RFS), disease-free survival (DFS), and overall survival (OS) rates, which were all significantly lower than those of WT1-inter patients. The combined WT1-low/high expression group (n = 132) had significantly lower 3-year RFS, DFS, and OS rates compared with the WT1-inter group (n = 63) of B-other patients (RFS and DFS all P < 0.0001; OS P = 0.0018 and 0.0008). WT1 low/high expression as well as treating with chemotherapy only was independent poor prognostic factors for RFS, DFS, and OS in the B-other patients who achieved CR. Therefore, the molecularly and cytogenetically defined adult Ph-negative BCP-ALL groups have characteristic WT1 expression patterns, and WT1 low/high expression at diagnosis predicts poor outcome in B-other patients.

Minimal residual disease status determined by multiparametric flow cytometry pretransplantation predicts the outcome of patients with ALL receiving unmanipulated haploidentical allografts.

This study evaluated the effects of pretransplantation minimal residual disease (pre-MRD) on outcomes of patients with acute lymphoblastic leukemia (ALL) who underwent unmanipulated haploidentical stem cell transplantation (haplo-SCT). A retrospective study including 543 patients with ALL was performed. MRD was determined using multiparametric flow cytometry. Both in the entire cohort of patients and in subgroup cases with T-ALL or B-ALL, patients with positive pre-MRD had a higher incidence of relapse (CIR) than those with negative pre-MRD in MSDT settings (P < 0.01 for all). Landmark analysis at 6 months showed that MRD positivity was significantly and independently associated with inferior rates of relapse (HR, 1.908; P = 0.007), leukemia-free survival (LFS) (HR, 1.559; P = 0.038), and OS (HR, 1.545; P = 0.049). The levels of pre-MRD according to a logarithmic scale were also associated with leukemia relapse, LFS, and OS, except that cases with MRD <0.01% experienced comparable CIR and LFS to those with negative pre-MRD. A risk score for CIR was developed using the variables pre-MRD, disease status, and immunophenotype of ALL. The CIR was 14%, 26%, and 59% for subjects with scores of 0, 1, and 2-3, respectively (P < 0.001). Three-year LFS was 75%, 64%, and 42%, respectively (P < 0.001). Multivariate analysis confirmed the association of the risk score with CIR and LFS. The results indicate that positive pre-MRD, except for low level one (MRD < 0.01%), is associated with poor outcomes in patients with ALL who underwent unmanipulated haplo-SCT.