Long-term outcomes after haploidentical stem cell transplantation for hematologic malignancies.

The introduction of posttransplant cyclophosphamide (PTCy)-based graft-versus-host disease (GVHD) prophylaxis lead to significant improvements in haploidentical stem cell transplantation (haplo-SCT) outcomes over the past decade. We retrospectively assessed long-term outcomes of patients who had their first haplo-SCT between February 2009 and March 2019. Long-term survivors were defined as patients who were alive and disease free at 2 years after transplant. Three hundred thirty-five patients with a median age of 48 (range, 18-72) years were identified. Of these, 142 patients were disease-free and alive at 2 years after transplant. The 4-year progression-free survival (PFS) and overall survival (OS) for all study patients were 42% and 47%, respectively. With a median follow-up of 52 months for the long-term survivor group, the 4-year PFS and OS were 94% and 96%, respectively. The 4-year cumulative incidence of relapse (CIR) and non-relapse mortality (NRM) were 2.9% and 3.3%, respectively. Age>=55 was the only predictive factor in multivariable analysis for inferior PFS (HR 3.41, 95% CI: 1.21-9.60; p=0.020) and OS (HR 3.31, 95% CI: 1.08-10.18; p=0.037). Thirteen patients (9%) died in the long-term survivor group, only two of which died of relapsed disease. Secondary primary malignancy was the most frequent cause of NRM (n=4), followed by infection (n=2). For haplo-SCT with PTCy-based GVHD prophylaxis, our findings suggest an excellent long-term survival for patients who were disease-free and alive at 2 years after transplant. Late relapses were rare, and age was the only predictive factor for long-term outcomes.

Mortality in recipients of allogeneic haematopoietic cell transplantation in the era of cytomegalovirus primary prophylaxis: a single-centre retrospective experience.

OBJECTIVES: Allogeneic haematopoietic cell transplant (allo-HCT) recipients who are cytomegalovirus (CMV)-seronegative have better post-transplant outcomes than CMV-seropositive recipients. Letermovir (LTV) is approved for CMV primary prophylaxis in adults who are CMV-seropositive after allo-HCT, and its use is associated with improved long-term post-transplant outcomes. We analysed whether LTV has affected the relationship between CMV serostatus and post-transplant outcomes. METHODS: We conducted a retrospective single-centre cohort study of allo-HCT recipients, stratified according to donor (D) and recipient (R). CMV serostatus and the use of LTV: D-/R-, R+/LTV-, and R+/LTV+. Outcomes measured were all-cause and non-relapse mortality, clinically significant CMV infection, graft-versus-host disease, and relapse up to week 48 after allo-HCT. The D-/R- group served as the reference for comparisons in univariate, competing risk regression, and cumulative incidence functions. RESULTS: The analysis included 1071 consecutive allo-HCT recipients: 131 D-/R-, 557 R+/LTV-, and 383 R+/LTV+. All-cause mortality by day 100 was 6.1% for the D-/R- group, compared with 14.0% (p 0.024) and 7.8% (p 0.7) for the R+/LTV- and R+/LTV + groups, respectively. Non-relapse mortality by day 100 was 11.0%, 6.8% and 3.8% for R+/LTV-, R+/LTV+, and D-/R- groups, respectively, without significant difference. When including relapse as a competing event, the hazard ratio for non-relapse mortality was 1.83 (95% CI: 1.12-2.99, p 0.017) for R+/LTV- compared with D-/R- and 1.05 (95% CI 0.62-1.77, p 0.85) for R+/LTV + compared with D-/R-. DISCUSSION: CMV primary prophylaxis with LTV abrogated the mortality gap based on CMV serostatus, a protective effect that persisted after discontinuation of primary prophylaxis.

Azacitidine Post-transplant Maintenance Improves Disease Progression in High-Risk Acute Myeloid Leukemia and Myelodysplastic Syndrome.

BACKGROUND: Maintenance after allogeneic hematopoietic cell transplantation (alloHCT) with hypomethylating agents has yielded conflicting results. MATERIALS AND METHODS: We conducted a single center retrospective matched-control analysis with the study group (5-azacitidine [AZA] group) including adults with FLT3-negative acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) who received post-transplant AZA maintenance off clinical trial (n = 93). A matched control group was comprised of contemporaneous AML/MDS patients who did not receive any maintenance (n = 357). Primary endpoint was disease progression. RESULTS: The AZA and control groups had comparable patient and disease characteristics except for older age (median: 61 vs. 57 years, P = .01) and lower hematopoietic comorbidity index (median: 2 vs. 3, P = .04) in the AZA group. The 3-year cumulative incidence of progression in the AZA and control groups was 29% vs. 33% (P = .09). The protective effect of AZA on progression was limited to patients with high-risk AML/MDS (HR = 0.4, 95% CI = 0.2-0.8, P = .009). This led to improved progression-free survival both in high-risk AML and MDS patients with maintenance (HR = 0.2, 95% CI = 0.1-0.6, P = .004 and HR = 0.4, 95% CI = 0.2-0.9, P = .04). CONCLUSION: AZA maintenance was associated with a lower progression rate in patients with high-risk FLT3-negative AML or MDS, and AZA maintenance should be considered for post-alloHCT maintenance in this subset.

Safety and long-term survival results of the addition of inotuzumab ozogamicin to the conditioning regimen of allogeneic stem cell transplantation: A single-center phase 1,2 trial.

Here we report on the first prospective study evaluating the safety and long-term survival when an escalating dose of inotuzumab ozogamicin (INO) (0.6, 1.2, or 1.8 mg/m2 on day 13) was added to one alkylator-containing conditioning regimen in patients with relapsed CD22 (+) lymphoid malignancies who were candidates for hematopoietic stem cell transplantation (HSCT). Twenty-six patients were enrolled. Six (23%) of these patients entered the phase 1 study: four were treated at an INO dose of 0.6 mg/m2 and two at dose of 1.2 mg/m2. None of these patients experienced dose-limiting toxicities. The remaining 20 (77%) patients entered the phase 2 part of the study at the maximum dose of 1.8 mg/m2. One patient developed VOD; this patient had received nivolumab immediately before HSCT while simultaneously experiencing hyperacute graft-vs-host disease (GVHD). Treatment-related mortality (TRM) at 5 years was 12%. With a median follow-up of 48.7 months, the 5-year overall survival (OS) and progression-free survival (PFS) rates were 84% and 80%, respectively. Compared with a historical cohort who received same conditioning for HSCT but without INO (n = 56), the INO group showed no significant differences in incidence of liver toxicity, engraftment time, TRM, or risk of acute GVHD. Patients with lymphoma who received INO had a trend for a better 5-year OS (93% versus 68%) and PFS (93% versus 58%) than those in the control group. In conclusion, our results showed that INO is safe with no increased risk of VOD when combined with one alkylator-containing regimen of HSCT.

Incidence and risk factors of early onset VOD/SOS differ in younger vs older adults after stem cell transplantation.

ABSTRACT: Veno-occlusive disease (VOD) is a rare but potentially life-threatening complication after allogeneic hematopoietic stem cell transplantation (allo-SCT). Although increasing awareness and modern transplant techniques have mitigated risk, the interaction of historic risk factors in the current era with posttransplant cyclophosphamide (PTCy) is unknown. We performed a retrospective single-center analysis of adult patients aged ≥18 years undergoing allo-SCT (N = 1561) using predominately PTCy as graft-versus-host disease (GVHD) prophylaxis (72%). We found a higher rate of VOD at 16.8% (20 of 119) in those aged ≤25 years compared with 3.8% (55 of 1442) in those aged >25 years, with unique predictors of VOD within each cohort. Multivariate classification and regression tree (CART) analysis confirmed age as the primary independent determinant of the rate of VOD. Among patients aged 18 to 25 years, disease risk index (DRI; 31% with high/very high DRI vs 12% low/intermediate DRI; P = .03) and prior lines of chemotherapy (24% with >1 vs 6% with ≤1; P = .03) were the strongest predictors of VOD. Incidence of VOD in patients aged >25 years of age consistently ranged between 3% and 5% across most risk factors evaluated, with only hepatic factors (baseline elevation of bilirubin, aspartate transferase, alanine aminotransferase) or gemtuzumab exposure associated with increased rates of VOD. There was no significant difference in rates of VOD in those receiving PTCy compared with those receiving alternate GVHD prophylaxis. Our data highlight the differences in incidence and predictors of VOD between younger (≤25) and older (>25) adults undergoing allo-SCT.

Radiation Therapy Can Be Safely Incorporated into Pretransplantation Treatment Regimens for Patients with Multiple Myeloma.

Primary treatment of multiple myeloma (MM) often involves systemic induction therapy (SIT) followed by autologous stem cell transplantation (ASCT). Radiation therapy (RT) is sometimes used for palliation; however, many practitioners avoid RT out of concern that future peripheral blood progenitor cell (PBPC) collection required for ASCT may be compromised. In this study, we retrospectively examined the possible effect of RT on PBPC collection. We reviewed the charts of 732 patients with MM treated with RT at our institution from 1999 to 2017, including patients who received RT prior to PBPC collection for planned ASCT. RT plans (both MM and non-MM RT) were reviewed to estimate the percentage of bone marrow (BM) treated using published estimates of skeletal BM distribution. Statistics were performed using Pearson correlation and the t-test. The 732 MM patients included 485 planned for ASCT; of these, 223 received RT prior to PBPC collection and were included in the final cohort. The median age at PBPC collection was 59 years (range, 33 to 80 years). For SIT, patients received combination regimens including the following agents: bortezomib (142 patients; 64%), lenalidomide (111 patients; 50%), and alkylators (46 patients; 21%). Nine patients (4%) received dexamethasone alone. The median cumulative %BM treated per patient was 6.7 (range .0 to 47.4). The median RT dose was 24 Gy (range, 10.0 to 75.6 Gy). Mobilization was performed using granulocyte-colony stimulating factor (G-CSF) alone (189 patients; 85%), G-CSF with plerixafor (15 patients; 7%), or chemotherapy (19 patients; 9%). A median of 7.8 × 106 CD34+/kg PBPCs (range, .5 to 54.8× 106 CD34+/kg) were collected in a median of 3 (range, 1 to 9) apheresis procedures. One hundred ninety-six patients (99%) collected ≥2.0 × 106 CD34+/kg PBPCs, and 166 (83%) collected >5.0 × 106 CD34+/kg PBPCs. The number of PBPCs collected was not associated with %BM treated (P = .15) or RT dose (P = .56). The number of apheresis procedures performed was not associated with %BM treated (P = .54) or RT dose (P = .85). The amount of PBPCs collected did not differ significantly between patients receiving RT to the pelvis/sacrum (P = .20) and those receiving RT to the spine (P = .13). The time to platelet engraftment was longer for patients with higher %BM treated (P = .02). Eleven patients did not undergo a confirmed ASCT, owing to patient preference (3 patients), trial therapy (1 patient), comorbidities (1 patient), election for hospice (1 patient), inadequate collection (4 patients), or inadequate follow-up (1 patient). In our study cohort, RT prior to ASCT did not impair successful ASCT. RT must be carefully planned and delivered to ensure safe incorporation into pre-ASCT treatment regimens.

A Nasal Inflammatory Cytokine Signature Is Associated with Early Graft-versus-Host Disease of the Lung after Allogeneic Hematopoietic Cell Transplantation: Proof of Concept.

Respiratory inflammation in bronchiolitis obliterans syndrome (BOS) after hematopoietic cell transplantation (HCT) is poorly understood. Clinical criteria for early-stage BOS (stage 0p) often capture HCT recipients without BOS. Measuring respiratory tract inflammation may help identify BOS, particularly early BOS. We conducted a prospective observational study in HCT recipients with new-onset BOS (n = 14), BOS stage 0p (n = 10), and recipients without lung impairment with (n = 3) or without (n = 8) chronic graft-versus-host disease and measured nasal inflammation using nasosorption at enrollment and then every 3 mo for 1 y. We divided BOS stage 0p into impairment that did not return to baseline values (preBOS, n = 6), or transient impairment (n = 4). We tested eluted nasal mucosal lining fluid from nasosorption matrices for inflammatory chemokines and cytokines using multiplex magnetic bead immunoassays. We analyzed between-group differences using the Kruskal-Wallis method, adjusting for multiple comparisons. We found increased nasal inflammation in preBOS and therefore directly compared patients with preBOS to those with transient impairment, as this would be of greatest diagnostic relevance. After adjusting for multiple corrections, we found significant increases in growth factors (FGF2, TGF-α, GM-CSF, VEGF), macrophage activation (CCL4, TNF-α, IL-6), neutrophil activation (CXCL2, IL-8), T cell activation (CD40 ligand, IL-2, IL-12p70, IL-15), type 2 inflammation (eotaxin, IL-4, IL-13), type 17 inflammation (IL-17A), dendritic maturation (FLT3 ligand, IL-7), and counterregulatory molecules (PD-L1, IL-1 receptor antagonist, IL-10) in preBOS patients compared to transient impairment. These differences waned over time. In conclusion, a transient multifaceted nasal inflammatory response is associated with preBOS. Our findings require validation in larger longitudinal cohorts.

Clinical relevance of MYC/BCL2 expression and cell of origin in patients with diffuse large b-cell lymphoma treated with autologous transplant.

Dual expression of MYC and BCL2 proteins (double-expressor lymphoma [DEL]) as well as cell of origin (COO) are important prognostic factors in patients with diffuse large B-cell lymphoma (DLBCL) after conventional chemotherapy. We studied the prognostic impact of DEL and COO in patients with relapsed DLBCL treated with autologous stem cell transplant (ASCT). Three-hundred and three patients with stored tissue samples were identified. Classification was successful in 267 patients: 161 (60%) were DEL/non-double hit (DHL), 98 (37%) were non-DEL/non-DHL, and 8 (3%) were DEL/DHL. Compared to non-DEL/non-DHL, DEL/DHL had worse overall survival while DEL/non-DHL did not significantly differ in overall survival. On multivariable analysis, DEL/DHL, age >60 years, and >2 prior therapies, but not COO, were important prognostic factors for overall survival. When we explored the interaction of COO and BCL2 expression, patients with germinal center B-cell (GCB)/BCL2 (+) had inferior progression-free survival (PFS) compared to GCB/BCL2 (-) patients (HR, 4.97; P = 0.027). We conclude that the DEL/non-DHL and non-DEL/non-DHL subtypes of DLBCL have similar survival after ASCT. The negative impact of GCB/BCL2 (+) on PFS warrants future trials targeting BCL2 after ASCT. The inferior outcomes in DEL/DHL need to be verified in a larger number of patients.

Bacteroides ovatus alleviates dysbiotic microbiota-induced intestinal graft-versus-host disease.

Acute gastrointestinal intestinal GVHD (aGI-GVHD) is a serious complication of allogeneic hematopoietic stem cell transplantation, and the intestinal microbiota is known to impact on its severity. However, an association between treatment response of aGI-GVHD and the intestinal microbiota has not been well-studied. In a cohort of patients with aGI-GVHD (n=37), we found that non-response to standard therapy with corticosteroids was associated with prior treatment with carbapenem antibiotics and loss of Bacteroides ovatus from the microbiome. In a mouse model of carbapenem-aggravated GVHD, introducing Bacteroides ovatus reduced severity of GVHD and improved survival. Bacteroides ovatus reduced degradation of colonic mucus by another intestinal commensal, Bacteroides thetaiotaomicron, via its ability to metabolize dietary polysaccharides into monosaccharides, which then inhibit mucus degradation by Bacteroides thetaiotaomicron and reduce GVHD-related mortality.

Molecular disparity of HLA-DPB1 is associated with the development of subsequent solid cancer after allogeneic hematopoietic stem cell transplantation.

BACKGROUND: An increased incidence of subsequent solid cancers (SSCs) has been reported in long-term survivors of allogeneic hematopoietic stem cell transplantation (allo-HSCT), and SSC is associated with inferior mortality and morbidity. Previous studies showed that the incidence of SSC is significantly higher in those who underwent allo-HSCT from HLA-mismatched donors, suggesting that persistent alloimmunity may predispose patients to SSCs. It was recently reported that, in a cohort of patients who received allo-HSCT from an unrelated donor matched at HLA-A, -B, -C, -DRB1/3/4/5, and -DQB1 loci, HLA-DPB1 alloimmunity determined by high mismatched eplets (MEs) and Predicted Indirectly Recognizable HLA Epitopes (PIRCHE) score (PS), was associated with relapse protection and increased risk of acute graft-versus-host disease (GVHD). METHODS: In the present study, the impact of HLA-DPB1 alloimmunity assessed by molecular mismatch algorithms on the development of SSCs in a cohort of 1514 patients who underwent allo-HSCT for hematologic malignancies was further investigated. ME load at the HLA-DPB1 locus was measured using the HLAMatchmaker module incorporated in HLA Fusion software, and the PS for mismatched HLA-DPB1 was calculated using the HSCT module from the PIRCHE online matching service. RESULTS: In multivariable analysis after adjusting for baseline risk factors, higher ME, PS-I, and PS-II in the GVH direction, but not in the HVG direction, were associated with an increased risk of SSCs (ME: subdistribution hazard ratio [SHR] 1.58, p = .01; PS-I: SHR 1.59, p = .009; PS-II: SHR 1.71, p = .003). In contrast, nonpermissive HLA-DPB1 mismatches defined by the conventional T-cell epitope algorithm were not predictive of the risk of SSCs. Moreover, posttransplant cyclophosphamide-based GVHD prophylaxis was associated with a reduced risk of subsequent solid cancer (SHR 0.34, p = .021). CONCLUSIONS: These results indicate for the first time that increased GVH alloreactivity could contribute to the development of SSCs in allo-HSCT survivors.

Risk Factors for Bronchiolitis Obliterans Syndrome after Initial Detection of Pulmonary Impairment after Hematopoietic Cell Transplantation.

Pulmonary chronic graft-versus-host-disease (cGVHD), or bronchiolitis obliterans syndrome (BOS), is a highly morbid complication of hematopoietic cell transplantation (HCT). The clinical significance of a single instance of pulmonary decline not meeting the criteria for BOS is unclear. We conducted a retrospective analysis in a cohort of patients who had an initial post-HCT decline in the absolute value of forced expiratory volume in 1 second (FEV1) of ≥10% or mid-expiratory flow rate of ≥25% but not meeting the criteria for BOS (pre-BOS). We examined the impact of clinical variables in patients with pre-BOS on the risk for subsequent BOS. Pre-BOS developed in 1325 of 3170 patients (42%), of whom 72 (5%) later developed BOS. Eighty-four patients developed BOS without detection of pre-BOS by routine screening. Among patients with pre-BOS, after adjusting for other significant variables, airflow obstruction (hazard ratio [HR], 2.0; 95% confidence interval [CI], 1.1 to 3.7; P = .02), percent-predicted FEV1 on decline (HR, .98; 95% CI, .97 to 1.0; P = .02), active cGVHD (HR, 7.7; 95% CI, 3.1 to 19.3; P < .001), peripheral blood stem cell source (HR, 3.8; 95% CI, 1.7 to 8.6; P = .001), and myeloablative conditioning (HR, 2.0; 95% CI, 1.1 to 3.5; P = .02) were associated with subsequent BOS. The absence of airflow obstruction and cGVHD had a negative predictive value of 100% at 6 months for subsequent BOS, but the positive predictive value of both factors was low (cGVHD, 3%; any obstruction, 4%; combined, 6%). Several clinical factors at the time of pre-BOS, particularly active cGVHD and airflow obstruction, increase the risk for subsequent BOS. These factors merit consideration to be included in screening practices to improve the detection of BOS, with the caveat that the predictive utility of these factors is limited by the overall low incidence of BOS among patients with pre-BOS.

HLA Factors versus Non-HLA Factors for Haploidentical Donor Selection.

When multiple haploidentical donors are available for transplantation, those of younger generations are generally selected over those of older generations. However, it is unclear who is the optimal donor when selecting candidates from within a generation, such as father versus mother, son versus daughter, or brother versus sister. Although traditionally male donors are favored over female donors, particularly for male recipients, and significant associations of individual HLA mis(matches) on outcomes are being increasingly recognized, the hierarchy of factors for donor selection is indeterminate. To assess whether HLA factors take precedence over non-HLA factors and to isolate the influence of specific characteristics on outcomes, we analyzed 412 patients stratified by donor relationship: child donor (son [n = 202] versus daughter [n = 96]), parent (father [n = 28] versus mother [n = 29]), and sibling (noninherited maternal [NIMA; n = 29] versus paternal [NIPA; n = 28] mismatched). Among siblings, NIMA mismatch was associated with a lower risk of acute graft-versus-host disease (aGVHD); B-leader mismatch was associated with high nonrelapse mortality (NRM), poor progression-free survival, and a trend toward poor overall survival (OS), whereas A-mismatch was associated with lower aGVHD. Among parent donors, the relationship did not impact any outcome; B-leader mismatch was associated with higher NRM and a trend toward poor OS, whereas A-mismatch was associated with lower NRM and improved progression-free survival and OS. Among child donors, no individual HLA mismatch was predictive of any outcome, and daughter donors were not associated with any adverse outcomes in multivariate analyses. Our data suggest that certain HLA factors may be more significant in some cases and should be given priority over simply selecting a donor based on relationship/sex.

Bottom-up advocacy strategies to abortion access during the COVID-19 pandemic: Lessons learned towards reproductive justice in Brazil.

In Brazil, abortion is only allowed in cases of rape, serious risk to a woman's life or fetal anecephaly. Legal abortion services cover less than 4% of the Brazilian territory and only 1,800 procedures are performed, in average, per year. During the COVID-19 pandemic, almost half of the already few Brazilian abortion clinics shut down and women had to travel even longer distances, reaching abortion services at later gestational ages. In this paper, we describe three bottom-up advocacy strategies that emerged from difficulties deepened during the COVID-19 pandemic at a single abortion service in Brazil, amidst anti-gender policies from the federal government. Telemedicine abortion, outpatient surgical abortion and the provision of abortion after 20 weeks' gestation are important strategies that may reduce inequalities that impact the most vulnerable populations, such as black and indigenous women, children, adolescents and women experiencing domestic violence.

Diet-derived metabolites and mucus link the gut microbiome to fever after cytotoxic cancer treatment.

Not all patients with cancer and severe neutropenia develop fever, and the fecal microbiome may play a role. In a single-center study of patients undergoing hematopoietic cell transplant (n = 119), the fecal microbiome was characterized at onset of severe neutropenia. A total of 63 patients (53%) developed a subsequent fever, and their fecal microbiome displayed increased relative abundances of Akkermansia muciniphila, a species of mucin-degrading bacteria (P = 0.006, corrected for multiple comparisons). Two therapies that induce neutropenia, irradiation and melphalan, similarly expanded A. muciniphila and additionally thinned the colonic mucus layer in mice. Caloric restriction of unirradiated mice also expanded A. muciniphila and thinned the colonic mucus layer. Antibiotic treatment to eradicate A. muciniphila before caloric restriction preserved colonic mucus, whereas A. muciniphila reintroduction restored mucus thinning. Caloric restriction of unirradiated mice raised colonic luminal pH and reduced acetate, propionate, and butyrate. Culturing A. muciniphila in vitro with propionate reduced utilization of mucin as well as of fucose. Treating irradiated mice with an antibiotic targeting A. muciniphila or propionate preserved the mucus layer, suppressed translocation of flagellin, reduced inflammatory cytokines in the colon, and improved thermoregulation. These results suggest that diet, metabolites, and colonic mucus link the microbiome to neutropenic fever and may guide future microbiome-based preventive strategies.

Donor selection for KIR alloreactivity is associated with superior survival in haploidentical transplant with PTCy.

With the continuous increase in the use of haploidentical donors for transplantation, the selection of donors becomes increasingly important. Haploidentical donors have been selected primarily based on clinical characteristics, while the effects of killer cell immunoglobulin-like receptors (KIRs) on outcomes of haploidentical-hematopoietic stem cell transplantation (haplo-HSCT) with post-transplant cyclophosphamide (PTCy) remain inconclusive. The present study aimed to thoroughly evaluate the effect of KIRs and binding ligands assessed by various models, in addition to other patient/donor variables, on clinical outcomes in haplo-HSCT. In a cohort of 354 patients undergoing their first haplo-HSCT, we found that a higher Count Functional inhibitory KIR score (CF-iKIR) was associated with improved progression-free survival (adjusted hazard ratio [HR], 0.71; P = .029) and overall survival (OS) (HR, 0.66; P = .016), while none of the other models predicted for survival in these patients. Moreover, using exploratory classification and regression tree analysis, we found that donor age <58 years combined with cytomegalovirus-nonreactive recipient was associated with the best OS, whereas donor age >58 years was associated with the worst OS. In the rest of our cohort (80%), cytomegalovirus-reactive recipients with a donor <58 years old, a higher CF-iKIR was associated with superior OS. The 3-year OS rates were 73.9%, 54.1% (HR, 1.84; P = .044), 44.5% (HR, 2.01; P = .003), and 18.5% (HR, 5.44; P <.001) in the best, better, poor, and worse donor groups, respectively. Our results suggest that KIR alloreactivity assessed by CF-iKIR score can help optimize donor selection in haplo-HSCT.

Mucus-degrading Bacteroides link carbapenems to aggravated graft-versus-host disease.

The intestinal microbiota is an important modulator of graft-versus-host disease (GVHD), which often complicates allogeneic hematopoietic stem cell transplantation (allo-HSCT). Broad-spectrum antibiotics such as carbapenems increase the risk for intestinal GVHD, but mechanisms are not well understood. In this study, we found that treatment with meropenem, a commonly used carbapenem, aggravates colonic GVHD in mice via the expansion of Bacteroides thetaiotaomicron (BT). BT has a broad ability to degrade dietary polysaccharides and host mucin glycans. BT in meropenem-treated allogeneic mice demonstrated upregulated expression of enzymes involved in the degradation of mucin glycans. These mice also had thinning of the colonic mucus layer and decreased levels of xylose in colonic luminal contents. Interestingly, oral xylose supplementation significantly prevented thinning of the colonic mucus layer in meropenem-treated mice. Specific nutritional supplementation strategies, including xylose supplementation, may combat antibiotic-mediated microbiome injury to reduce the risk for intestinal GVHD in allo-HSCT patients.

Post-Transplantation Cyclophosphamide Versus Tacrolimus and Methotrexate Graft-Versus-Host Disease Prophylaxis for HLA-Matched Donor Transplantation.

The use of post-transplantation cyclophosphamide (PTCy) for graft-versus-host disease (GVHD) prophylaxis is increasing in patients undergoing HLA-matched sibling (MSD) or unrelated (MUD) donor hematopoietic cell transplantation (HCT), but data about its comparative efficacy against the traditional GVHD prophylaxis are scarce. Two broad questions assessed in this study were (a) comparison of PTCy-based GVHD prophylaxis versus Tac/MTX (without ATG) in the MSD and (b) comparison of PTCy-based GVHD prophylaxis versus Tac/MTX (with ATG) in the MUD group. This retrospective single-center study analyzed the outcomes of 964 patients who received Tac/MTX (n = 578) versus PTCy-based (n = 386) GVHD prophylaxis. All MUD recipients in the Tac/MTX group also received ATG; thus separate analyses were conducted for MSD (n = 412) and MUD (n = 552) cohorts. In the MUD cohort, 306 patients received Tac/MTX/ATG and 246 received PTCy-based GVHD prophylaxis. In the MSD cohort, 272 received Tac/MTX and 140 received PTCy-based prophylaxis. Both PTCy groups included somewhat older patients than the Tac/MTX groups and more patients had myeloid malignancy (85%-90% versus 59%-64%, respectively). A majority of patients in all groups received myeloablative conditioning and peripheral blood graft. Both PTCy groups had a significantly delayed neutrophil engraftment, higher risk of hemorrhagic cystitis, and higher risk of bacterial infections than the Tac/MTX groups. The risks of viral infections and related deaths were significantly higher in Tac/MTX group in the MUD cohort. In multivariate analysis, the risk of grade III-IV acute GVHD was similar in PTCy and Tac/MTX groups in both MSD and MUD cohorts, but the risk of chronic GVHD was significantly lower with PTCy in the MSD cohort. PTCy was associated with a significantly lower risk of non-relapse mortality and better progression-free survival in the MUD. PTCy was associated with improved GVHD-free relapse-free survival in both MSD and MUD groups. Our data suggest a benefit of using PTCy-based GVHD prophylaxis in both MSD (versus Tac/MTX) and MUD (versus Tac/MTX/ATG) HCT.

SIRPα Mismatch Is Associated With Relapse Protection and Chronic Graft-Versus-Host Disease After Related Hematopoietic Stem Cell Transplantation for Lymphoid Malignancies.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a potentially curative therapy for hematologic malignancies. Alloreactivity after HSCT is known to be mediated by adaptive immune cells expressing rearranging receptors. Recent studies demonstrated that the innate immune system could likewise sense the non-self signals and subsequently enhance the alloimmune response. We recently demonstrated that the donor/recipient mismatch of signal regulatory protein α (SIRPα), an immunoglobulin receptor exclusively expressed on innate cells, is associated with a higher risk of cGVHD and relapse protection in a cohort of acute myeloid leukemia patients who underwent allo-HSCT. Whether these effects also occur in other hematologic malignancies remains unclear. In the present study, we compared outcomes by SIRPα match status in a cohort of 310 patients who received allo-HSCT from an HLA matched-related donor for the treatment of lymphoid malignancies. Multivariable analysis showed that SIRPα mismatch was associated with a significantly higher rate of cGVHD (hazard ratio [HR] 1.8, P= .002), cGVHD requiring systemic immunosuppressive therapy (HR 1.9, P= .005), a lower rate of disease progression (HR 0.5, P= .003) and improved progression-free survival (HR 0.5, P= .001). Notably, the effects of SIRPα mismatch were observed only in the patients who achieved >95% of donor T-cell chimerism. The mismatch in SIRPα is associated with favorable relapse protection and concurrently increased risk of cGVHD in patients who undergo allo-HSCT for lymphoid malignancies, and the optimal donor could be selected based on the finding of the study to mitigate the risk of GVHD and relapse.