Impact of the presence of HLA 1-locus mismatch and the use of low-dose antithymocyte globulin in unrelated bone marrow transplantation.

HLA 1-locus-mismatched unrelated donors (1MMUD) have been used in allogeneic hematopoietic stem cell transplantation (allo-HCT) for patients who lack an HLA-matched donor. We retrospectively analyzed 3313 patients with acute leukemia or myelodysplastic syndrome who underwent bone marrow transplantation from an HLA allele-matched unrelated donor (MUD) or 1MMUD between 2009 and 2014. We compared the outcomes of MUD (n=2089) and 1MMUD with antithymocyte globulin (ATG) (1MM-ATG(+); n=109) with those of 1MMUD without ATG (1MM-ATG(-); n=1115). The median total dose of ATG (thymoglobulin) was 2.5 mg/kg (range 1.0-11.0 mg/kg) in the 1MM-ATG(+) group. The rates of grade III-IV acute GvHD, non-relapse mortality (NRM) and overall mortality were significantly lower in the MUD group than in the 1MM-ATG(-) group (hazard ratio (HR) 0.77, P=0.016; HR 0.74; P<0.001; and HR 0.87, P=0.020, respectively). Likewise, the rates of grade III-IV acute GVHD, NRM and overall mortality were significantly lower in the 1MM-ATG(+) group than in the 1MM-ATG(-) group (HR 0.42, P=0.035; HR 0.35, P<0.001; and HR 0.71, P=0.042, respectively). The outcome of allo-HCT from 1MM-ATG(-) was inferior to that of allo-HCT from MUD even in the recent cohort. However, the negative impact of 1MMUD disappeared with the use of low-dose ATG without increasing the risk of relapse.

Relationship of physical activity with physical function and health-related quality of life in patients having undergone allogeneic haematopoietic stem-cell transplantation.

In this study, we investigated the differences in physical activity before and after transplantation, and the relationship between physical activity and physical function and health-related quality of life (QOL) in 30 patients who underwent allogeneic haematopoietic stem cell transplantation (allo-HSCT). Duration and intensity of physical activity were quantified using a three-dimensional accelerometer. Physical function was quantified by handgrip and knee-extensor strength, with the 6-minute walk test (6MWT) used as a measure of exercise capacity. Health-related QOL was assessed using the 36-item Short-Form Health Survey. The proportion of daily activities performed at an intensity >3.0 metabolic equivalents (METs) increased significantly after allo-HSCT (p < .05). Daily activity time performed at an intensity of 1.6-2.9 METs significantly correlated only with left knee strength (p < .05). In contrast, the total number of daily steps and the proportion of activity performed at 1.6-2.9 METs and >3.0 METs were positively correlated with the 6MWT (p < .05). Additionally, physical functioning and general health subscales in health-related QOL positively correlated with daily activities performed at >3.0 METs (p < .05). Physical activity was associated with 6MWT and health-related QOL. These findings have implications for rehabilitation planning for patients undergoing allo-HSCT.

Low-dose thymoglobulin as second-line treatment for steroid-resistant acute GvHD: an analysis of the JSHCT.

A nationwide retrospective study for the clinical outcomes of 99 patients who had received thymoglobulin at a median total dose of 2.5 mg/kg (range, 0.5-18.5 mg/kg) as a second-line treatment for steroid-resistant acute GvHD was conducted. Of the 92 evaluable patients, improvement (complete or partial response) was observed in 55 patients (60%). Multivariate analysis demonstrated that male sex and grade III and IV acute GvHD were associated with a lower improvement rate, whereas thymoglobulin dose (<2.0, 2.0-3.9 and ⩾4.0 mg/kg) was NS. Factors associated with significantly higher nonrelapse mortality included higher patient age (⩾50 years), grade IV acute GvHD, no improvement of GvHD and higher dose of thymoglobulin (hazard ratio, 2.55; 95% confidence interval, 1.34-4.85; P=0.004 for 2.0-3.9 mg/kg group and 1.79; 0.91-3.55; P=0.093 for ⩾4.0 mg/kg group). Higher dose of thymoglobulin was associated with a higher incidence of bacterial infections, CMV antigenemia and any additional infection. Taken together, low-dose thymoglobulin at a median total dose of 2.5 mg/kg provides a comparable response rate to standard-dose thymoglobulin reported previously, and <2.0 mg/kg thymoglobulin is recommended in terms of the balance between efficacy and adverse effects.

Impact of HLA allele mismatch on the clinical outcome in serologically matched related hematopoietic SCT.

In unrelated hematopoietic SCT (HSCT), HLA allele mismatch has been shown to have a significant role. To clarify the importance of HLA allele mismatch in the GVH direction in related HSCT, we retrospectively evaluated 2377 patients who received stem cells from an HLA serologically matched related donor in the GVH direction using the database of the Japan Society for Hematopoietic Cell Transplantation. The cumulative incidences of grade II-IV and grade III-IV acute GVHD in patients with an HLA allele-mismatched donor (n=133, 5.6%) were significantly higher than those in patients with an HLA allele-matched donor. Multivariate analyses showed that the presence of HLA allele mismatch was associated with increased risks of grade II-IV and grade III-IV acute GVHD. In particular, HLA-B mismatch and multiple allele mismatches were associated with an increased risk of acute GVHD. The presence of HLA allele mismatch was associated with an inferior OS owing to an increased risk of non-relapse mortality (NRM). In conclusion, the presence of HLA allele mismatch in the GVH direction in related HSCT was associated with increased risks of GVHD and NRM, which led to an inferior OS. HLA allele typing is recommended in related HSCT.

Continuing increased risk of oral/esophageal cancer after allogeneic hematopoietic stem cell transplantation in adults in association with chronic graft-versus-host disease.

BACKGROUND: The number of long-term survivors after hematopoietic stem cell transplantation (HSCT) showed steady increase in the past two decades. Second malignancies after HSCT are a devastating late complication. We analyzed the incidence of, risk compared with that in the general population, and risk factors for secondary solid cancers. PATIENTS AND METHODS: Patients were 17 545 adult recipients of a first allogeneic stem cell transplantation between 1990 and 2007 in Japan. Risks of developing secondary solid tumors were compared with general population by using standard incidence ratios (SIRs). RESULTS: Two-hundred sixty-nine secondary solid cancers were identified. The cumulative incidence was 0.7% [95% confidence interval (CI), 0.6%-0.9%] at 5 years and 1.7% (95% CI, 1.4%-1.9%) at 10 years after transplant. The risk was significantly higher than that in the general population (SIR=1.8, 95% CI, 1.5-2.0). Risk was higher for oral cancer (SIR=15.7, 95% CI, 12.1-20.1), esophageal cancer (SIR=8.5, 95% CI, 6.1-11.5), colon cancer (SIR=1.9, 95% CI, 1.2-2.7), skin cancer (SIR=7.2, 95% CI, 3.9-12.4), and brain/nervous system cancer (SIR=4.1, 95% CI, 1.6-8.4). The risk of developing oral, esophageal, or skin cancer was higher at all times after 1-year post-transplant. Extensive-type chronic graft-versus-host disease (GVHD) was a significant risk factor for the development of all solid tumors (RR=1.8, P<0.001), as well as for oral (RR=2.9, P<0.001) and esophageal (RR=5.3, P<0.001) cancers. Limited-type chronic GVHD was an independent risk factor for skin cancers (RR=5.8, P=0.016). CONCLUSION: Recipients of allogeneic HSCT had a significantly higher ∼2-fold risk of developing secondary solid cancers than the general population. Lifelong screening for high-risk organ sites, especially oral or esophageal cancers, is important for recipients with active, or a history of, chronic GVHD.

Reduced-intensity allogeneic stem cell transplantation for patients aged 50 years or older with B-cell ALL in remission: a retrospective study by the Adult ALL Working Group of the Japan Society for Hematopoietic Cell Transplantation.

We retrospectively assessed the outcome and pretransplantation predictors of the outcome in 118 patients aged ≥ 50 years who received fludarabine-containing reduced-intensity allo-SCT (RIST) for B-cell ALL in the first or second CR. Eighty patients received transplants from unrelated donors. Seventy-eight patients were positive for the Ph chromosome. The median follow-up period was 18 months and the 2-year OS rate was 56%. The 2-year cumulative incidence of relapse and non-relapse mortality was 28% and 26%, respectively. The incidence of grades II-IV and III-IV acute GVHD was 46% and 24%, respectively. After 2 years, the incidence of chronic GVHD was 37%. Multivariate analysis of pretransplant factors showed that a higher white blood cell count (≥ 30 × 10(9)/L) at diagnosis (hazard ratio (HR)=2.19, P=0.007) and second CR (HR=2.02, P=0.036) were significantly associated with worse OS, whereas second CR (HR=3.83, P<0.001) and related donor (HR=2.34, P=0.039) were associated with a higher incidence of relapse. Fludarabine-containing RIST may be a promising strategy for older patients with B-cell ALL in their first remission.

Impact of a donor source on adult Philadelphia chromosome-negative acute lymphoblastic leukemia: a retrospective analysis from the Adult Acute Lymphoblastic Leukemia Working Group of the Japan Society for Hematopoietic Cell Transplantation.

BACKGROUND: We aimed to clarify the impact of the donor source of allogeneic stem cell transplantation (allo-SCT) on Philadelphia chromosome-negative acute lymphoblastic leukemia [Ph(-) ALL] with focus on cord blood (CB). PATIENTS AND METHODS: We retrospectively analyzed data of 1726 patients who underwent myeloablative allo-SCT for adult Ph(-) ALL. The sources of the allo-SCT were related donors (RD; N = 684), unrelated donors (URD; N = 809), and CB (N = 233). RESULTS: Overall survival (OS) in patients after CB allo-SCT in first complete remission (CR1) was comparable with that after RD or URD allo-SCT (RD: 65%, URD: 64% and CB: 57% at 4 years, P = 0.11). CB was not a significant risk factor for relapse or non-relapse mortality as well as for OS in multivariate analyses. Similarly, the donor source was not a significant risk factor for OS in subsequent CR or non-CR (RD: 47%, URD: 39% and CB: 48% in subsequent CR, P = 0.33; RD: 15%, URD: 21% and CB: 18% in non-CR, P = 0.20 at 4 years). CONCLUSION: Allo-SCT using CB led to OS similar to those of RD or URD in any disease status. To avoid missing the appropriate timing, CB is a favorable alternative source for adult Ph(-) ALL patients without a suitable RD or URD.

Allogeneic hematopoietic stem cell transplantation for intermediate cytogenetic risk AML in first CR.

Allogeneic hematopoietic SCT (allo-HCT) from matched sibling donor (MSD) is recommended for younger patients with intermediate cytogenetic risk AML in first CR (CR1), whereas the role of alternative donor transplants in these patients is unknown. We retrospectively analyzed 605 patients with intermediate-risk AML, who received myeloablative allo-HCT in CR1. The 4-year OS for MSD (n=290) and matched unrelated donor (MUD; n=141) was 65% and 68% (P=0.50), respectively. In multivariate analysis, MUD had a similar risk of overall mortality as MSD (hazard ratio=0.90; 95% confidence interval, 0.62-1.30; P=0.58), whereas older age, female donor/male recipient (FDMR) combination, and requiring more than one course of induction chemotherapy to achieve CR1 were poor prognostic factors for OS. Thus, OS after MUD HCT with sex combinations other than FDMR was significantly higher than that after MSD HCT from female donors to male recipients (4-year OS 72% versus 55%, P=0.04). These results suggest that HCT, not only from MSD, but also from MUD, should be considered in younger patients with intermediate-risk AML in CR1, and that the donor-recipient sex combination is more important than the donor type in donor selection.

Frequency of CD4(+)FOXP3(+) regulatory T-cells at early stages after HLA-mismatched allogeneic hematopoietic SCT predicts the incidence of acute GVHD.

Acute GVHD (aGVHD) is a major obstacle to allogeneic hematopoietic SCT (alloHSCT). Although it is thought that aGVHD is initiated in secondary lymphoid organs at a very early stage of alloHSCT, whether CD4(+)FOXP3(+) regulatory T-cells (Tregs) have an impact on aGVHD development during this period remains unclear. Here, we measured Tregs in peripheral blood as early as possible after HLA-mismatched alloHSCT, and assessed the incidence of aGVHD. Flow cytometric analyses revealed that at the second week after HSCT, patients with aGVHD had significantly (P=0.018) lower Treg:CD4(+)T-cell ratios than those without aGVHD. As these differences were seen before the development of aGVHD, these ratios can predict the incidence of aGVHD. The cumulative incidence of aGVHD in patients with ratios of <9% was significantly higher than that in patients with ratios of 9% (P=0.0082, log-rank test). Additionally, the specific ratio of Tregs:CD4(+)T-cells was the most significant value among all other possible lymphocyte-associated ratios and absolute cell counts. These findings suggest that the ratio of Tregs:CD4(+)T-cells at the second week post HLA-mismatched alloHSCT might be a potent predictor of aGVHD in these patients. The practical efficacy of this finding should be verified in further interventional studies.

Safety and feasibility of physical therapy in cytopenic patients during allogeneic haematopoietic stem cell transplantation.

This study aimed to investigate the safety and feasibility of physical therapy in cytopenic patients undergoing allogeneic haematopoietic stem cell transplantation (allo-HSCT), and to investigate the effect of physical therapy on physiological functions and quality of life (QOL) in allo-HSCT patients. The study cohort included 321 patients who underwent allo-HSCT. To investigate the safety and feasibility of physical therapy during cytopenia, patients were assigned to the physical therapy group (n = 227) or the control group (n = 94). To determine the effects of physical therapy, patients were divided according to the frequency with which they underwent physical therapy (n = 51 per group). Handgrip strength, knee extensor strength and a 6-min walk test were used as measures of physiological function. Short-Form 36 was used to assess QOL. The physical therapy group had higher rate of achieving engraftment and lower death rate than the control group (P < 0.05). After HSCT, the high-frequency physical therapy group showed significantly less decline than the low-frequency physical therapy group with respect to physical functioning of QOL (P < 0.01). Physical therapy is quite beneficial and can be performed safely and feasibly in cytopenic patients during allo-HSCT.

Donor-derived HLA antibody production in patients undergoing SCT from HLA antibody-positive donors.

Pre-existing donor-specific HLA antibodies in patients undergoing HLA-mismatched SCT have increasingly been recognized as a risk factor for primary graft failure. However, the clinical implications of the presence of HLA antibodies in donors remain unknown. We prospectively examined 123 related donors for the presence of HLA antibodies by using a Luminex-based single antigen assay. Of these, 1/57 (1.8%) male, 6/27 (22%) parous female and 0/39 (0%) nonparous female donors were HLA antibody-positive. Then, we determined the presence of HLA antibodies in seven patients who received SCT from antibody-positive donors. Of these, four became HLA antibody-positive after SCT. The specificities of the antibodies that emerged in the patients closely resembled those of the antibodies found in the donors, indicating their production by donor-derived plasma cells. Moreover, the kinetics of the HLA antibody levels were similar in all four patients: levels started increasing within 1 week after SCT and peaked at days 10-21, followed by a gradual decrease. These results suggest that donor-derived HLA antibody production frequently occurs in patients undergoing SCT from antibody-positive donors. Further studies are warranted for clarifying the clinical significance of donor-derived HLA antibodies, including the role of these antibodies in post transplant platelet transfusion refractoriness.

Salvage haploidentical transplantation for graft failure using reduced-intensity conditioning.

Graft failure is a major concern after cord blood transplantation (CBT) or HLA-haploidentical transplantation (haplo-SCT). As patients who undergo CBT or haplo-SCT almost always lack both matched-related and -unrelated donors, salvage transplantation would also be limited to either CBT or haplo-SCT. In this study, we assessed eight patients who received haplo-SCT as salvage therapy for graft failure. Five and three patients had received haplo-SCT and CBT, respectively, which resulted in graft failure. The median interval from the failed transplantation to salvage transplantation in six patients with primary graft failure was 33.5 days. The reduced-intensity conditioning regimen consisted of fludarabine, thiotepa, rabbit antithymocyte globulin and low-dose TBI. All eight patients achieved neutrophil engraftment, and seven patients achieved platelet recovery. The median times to neutrophil recovery and platelet recovery were 10 and 20 days, respectively. Three patients died from treatment-related causes: two from GVHD and one from rupture of carotid artery aneurysm. Five patients are alive, at a median follow-up of 946 days. The probability of overall survival at 5 years was 75%. These findings may serve as a rationale for giving precedence to haplo-SCT over CBT in salvage SCT after graft failure.

Risk and prevention of graft failure in patients with preexisting donor-specific HLA antibodies undergoing unmanipulated haploidentical SCT.

A role of donor-specific HLA antibodies (DSA) in graft failure after SCT has been suggested, but the relevance of DSA in unmanipulated haploidentical SCT (haplo-SCT) remains unknown. We prospectively examined HLA antibodies using the Luminex-based single Ag assay for 79 adult patients undergoing unmanipulated haplo-SCT. Among them, 16 (20.2%) were HLA Ab-positive, including five patients with antibodies not corresponding to donor HLA Ags and 11 DSA-positive patients. Of the 11 DSA-positive patients, five received treatments to decrease DSA levels, including two, who received plasma exchange and rituximab, two who received platelet transfusions from healthy-related donors having DSA-corresponding HLA Ags and one who received bortezomib. Platelet transfusion was the most simple and effective treatment option for class I DSA. The cumulative incidence of neutrophil recovery was significantly lower in pretransplant (post-treatment) DSA-positive patients than in DSA-negative patients (61.9 vs 94.4%, P=0.026). Notably, three of five patients with high levels of DSA had graft failure. Donors should be selected on the basis of an evaluation of HLA antibodies. If haplo-SCT from donors with HLA Ags that correspond to high levels of DSA must be performed, then recipients should be treated for DSA to improve the chances of successful donor engraftment.

Incidence of extramedullary relapse after haploidentical SCT for advanced AML/myelodysplastic syndrome.

Extramedullary (EM) relapse of leukemia after allo-SCT in patients with AML/myelodysplastic syndrome has been increasingly reported. The reduced effectiveness of the GVL effect in EM sites, as compared with BM, has been suggested to underlie this problem. We retrospectively analyzed the pattern of relapse after haploidentical SCT (haplo-SCT), performed as the first or second SCT. Among 38 patients who received haplo-SCT as their first SCT, the cumulative incidences of BM and EM relapse at 3 years were 40.5 and 10.9%, respectively. Among 19 patients who received haplo-SCT as their second SCT, the cumulative incidences of BM and EM relapse were 30.9 and 31.9%, respectively. Moreover, most of the patients who underwent repeat haplo-SCT for the treatment of EM relapse had further EM relapse at other sites. Post-relapse survival did not differ significantly with different patterns of relapse. The frequent occurrence of EM relapse after haplo-SCT, particularly when performed as a second SCT, suggests that the potent GVL effect elicited by an HLA disparity also occurs preferentially in BM. Our findings emphasize the need for a treatment strategy for EM relapse that recognizes the reduced susceptibility of EM relapse to the GVL effect.

HLA-haploidentical nonmyeloablative stem cell transplantation: induction to tolerance without passing through mixed chimaerism.

There are few reports of unmanipulated HLA-haploidentical nonmyeloablative stem cell transplantation (NST) using only pharmacological acute graft-vs.-host disease (GVHD) prophylaxis. We present here a successful case of unmanipulated HLA-haploidentical NST for mediastinal large B cell lymphoma that was resistant to autologous peripheral blood stem cell transplantation (PBSCT). The conditioning regimen consisted of fludarabine, busulfan and rabbit anti-T-lymphocyte globulin (ATG) in addition to rituximab. GVHD prophylaxis was performed using tacrolimus and methylprednisolone 1 mg/kg. The patient had rapid engraftment, with 100% donor chimaerism in the lineages of both T cells and granulocytes on day +12, but developed no GVHD clinically. The patient is still in complete remission past day +1020, with no sign of chronic GVHD without receiving immunosuppressive agents. HLA-haploidentical NST may be performed without utilizing mixed chimaerism.

Th1-biased humoral immune responses against Wilms tumor gene WT1 product in the patients with hematopoietic malignancies.

The Wilms' tumor gene WT1 is highly expressed in leukemias and myelodysplastic syndrome (MDS), and WT1 expression levels increase along with the disease progression in chronic myeloid leukemia and MDS. We previously reported that IgM and IgG WT1 antibodies were detected with significantly higher detection rate and antibody titers in leukemias and MDS compared to those in healthy volunteers. In this study, whether IgG humoral immune responses against WT1 protein were Th1- or Th2-type were determined by measurement of four subclasses of IgG WT1 antibody, IgG1, IgG2, IgG3, and IgG4. In leukemias and MDS, Th1-type WT1 antibodies such as IgG1, IgG2, and IgG3 were significantly increased in both detection rate and antibody titers compared to those in healthy volunteers, whereas Th2-type WT1 antibody such as IgG4 did not increase. These results showed that Th1-biased humoral immune responses against WT1 protein were generated in leukemias and MDS. These results should allow us to consider that Th1-biased cellular immune responses against WT1 protein, which was essentially needed for cancer immunotherapy targeting WT1, should be elicited in patients with hematopoietic malignancies.

Preferential expression of the vasoactive intestinal peptide (VIP) receptor VPAC1 in human cord blood-derived CD34+CD38- cells: possible role of VIP as a growth-promoting factor for hematopoietic stem/progenitor cells.

Primitive hematopoietic progenitor cells such as severe combined immunodeficiency- repopulating cells and long-term culture-initiating cells are enriched in CD34+CD38- cells derived from various stem cell sources. In this study, to elucidate the features of such primitive cells at the molecular level, we tried to isolate genes that were preferentially expressed in umbilical cord blood (CB)-derived CD34+CD38- cells by subtractive hybridization. The gene for VPAC1 receptor, a receptor for the neuropeptide vasoactive intestinal peptide (VIP), was thereby isolated and it was shown that this gene was expressed in both CD34+CD38- and CD34+CD38+ CB cells and that the expression levels were higher in CD34+CD38- CB cells. Next, we assessed the effects of VIP on the proliferation of CD34+ CB cells using in vitro culture systems. In serum-free single-cell suspension culture, VIP enhanced clonal growth of CD34+ CB cells in synergy with FLT3 ligand (FL), stem cell factor (SCF), and thrombopoietin (TPO). In serum-free clonogenic assays, VIP promoted myeloid (colony-forming unit-granulocyte/macrophage (CFU-GM)) and mixed (CFU-Mix) colony formations. Furthermore, in Dexter-type long-term cultures, VIP increased colony-forming cells at week 5 of culture. These results suggest that VIP functions as a growth-promoting factor of CB-derived hematopoetic progenitor cells.

Absence of mutations in the Wilms' tumor gene wt1 in de novo non-small cell lung cancers.

We recently demonstrated that the WT1 gene was overexpressed in the majority of de novo lung cancers regardless of cancer subtypes. Here, we examined WT1 genomic DNA in 38 cases of de novo non-small cell lung cancers (NSCLC) for mutations using direct sequencing. The sequencing analysis showed no mutations of WT1 genomic DNA in any of 38 de novo non-small cell lung cancers examined. These results indicated that the non-mutated, wild-type WT1 gene played an important role in de novo NSCLC.