Kyoko Taniguchi

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.

The role of HLA antibodies in allogeneic SCT: is the ‘type-and-screen’ strategy necessary not only for blood type but also for HLA?

The role of HLA antibodies in SCT has drawn increasing attention because of the significantly increased number of patients who receive HLA-mismatched SCT, including cord blood transplantation, haploidentical SCT and unrelated SCT. Technical advancements in the methods of HLA Ab testing have realized rapid, accurate and objective identification, as well as quantification of specific HLA antibodies. Recent clinical studies have suggested that the presence of donor-specific HLA antibodies (DSA) in patients is associated with graft failure in HLA-mismatched SCT when the above-listed stem cell sources are used and results in different impacts. Of note, most of the ‘HLA-matched’ unrelated SCT actually involve HLA mismatches in HLA-DP and the presence of antibodies against this locus has been reported to be associated with graft failure. Thus, HLA Ab should be examined as a work-up for all patients who undergo SCT from ‘alternative donors.’ The simplest route for preventing HLA Ab-mediated graft failure in Ab-positive patients is to avoid donors who possess the target Ag of HLA antibodies. If SCT from such donors must be performed, treatment for DSA before SCT may improve the chances of successful donor engraftment.

Gender differences in health‐related quality of life, physical function and psychological status among patients in the early phase following allogeneic haematopoietic stem cell transplantation

The aim of this study was to examine gender differences in quality of life (QOL), physical function and psychological status before and in the early phase after allogeneic haematopoietic stem cell transplantation (allo‐HSCT).

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.

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.

Irreversible neurological defects in the lower extremities after haploidentical stem cell transplantation: Possible association with nelarabine

Severe peripheral neuropathy and myelopathy are rare complications after stem cell transplantation (SCT). In our institution, seven patients of precursor T lymphoblastic leukemia/lymphoma without the central nervous involvement who had been treated by nelarabine to control their diseases received SCT from HLA‐haploidentical familial donor (HLA‐haploidentical SCT) with the conditioning regimen including high‐dose cytarabine (HDAC). Three of evaluable six patients developed irreversible paresthesia and muscle weakness in both lower extremities after neutrophil engraftment. The results of nerve conduction studies and short latency somatosensory evoked potentials suggested axonal neuropathy of both lower extremities in all three patients and myelopathy in two patients. Negative findings of PET‐CT, and analyses of repeated cerebrospinal fluid samples and the bone marrow also indicated that tumor involvement was improbable. In all three patients, the symptoms worsened or persisted despite administration of corticosteroid and intravenous immunoglobulin. The high frequency of the neurological symptoms in our patients previously treated by nelarabine strongly suggested the association of the nelarabine use. Furthermore, the HLA‐haploidentical SCT setting and the use of a potentially neurotoxic agent, HDAC might augment the neurotoxicity of nelarabine. It may be desirable that HLA‐haploidentical SCT candidates avoid receiving nelarabine. Am. J. Hematol. 88:853–857, 2013.

Impact of the mobilization regimen and the harvesting technique on the granulocyte yield in healthy donors for granulocyte transfusion therapy

BACKGROUND: Granulocyte mobilization and harvesting, the two major phases of granulocyte collection, have not been standardized.

Intrabone Marrow Transplantation of Unwashed Cord Blood Using Reduced-Intensity Conditioning Treatment: A Phase I Study

The outcome of cord blood transplantation following reduced-intensity conditioning is suboptimal because of fatal infection triggered by prolonged neutropenia and graft-versus-host disease (GVHD) in addition to graft rejection. Intrabone marrow injection (IBMI) may improve the outcome by providing better hematopoietic engraftment and less GVHD. We therefore evaluated IBMI safety in reduced-intensity stem cell transplantation. Furthermore, we used unwashed cord blood to avoid stem cell loss. Ten patients (median age = 61 years old) were enrolled. Cord blood cells were thawed at the bedside and injected into 4 iliac bone sites (2 at each hemipelvis). The procedure was well tolerated with no injection-related complications. Nine patients achieved donor engraftment. The median time to neutrophil recovery (>0.5 × 10(9)/L) was 17 days, and platelet recovery was achieved in 8 patients. Early full donor chimerism was achieved (median of 15 and 20 days in T cells and myeloid cells, respectively). Three of 9 evaluable patients developed grade II to III GVHD, and 5 of 10 patients died of treatment-related toxicities. The probability of survival at 1 year was 46.7%. IBMI of unwashed cord blood following reduced-intensity conditioning is safe, well tolerated, and may lead to an increased donor engraftment rate.

Unmanipulated Haploidentical Reduced-Intensity Stem Cell Transplantation Using Fludarabine, Busulfan, Low-Dose Antithymocyte Globulin, and Steroids for Patients in Non–Complete Remission or at High Risk of Relapse: A Prospective Multicenter Phase I/II Study in Japan

This prospective, multicenter phase I/II study of unmanipulated HLA-haploidentical reduced-intensity stem cell transplantation using a low dose of anti-T lymphocyte globulin (ATG) and steroid was conducted in 5 institutions in Japan. Thirty-four patients with hematologic malignancies who were in an advanced stage or at a high risk of relapse at the time of transplantation were enrolled. Among them, 7 patients underwent transplantation as a second transplantation because of relapse after the previous allogeneic stem cell transplantation. The conditioning regimen consisted of fludarabine, busulfan, and ATG (Fresenius, 8 mg/kg), and graft-versus-host disease (GVHD) prophylaxis consisted of tacrolimus and methylprednisolone (1 mg/kg). All patients except 1 (97.1%) achieved donor-type engraftment. Rapid hematopoietic engraftment was achieved, with neutrophils > .5 × 10(9)/L on day 11 and platelets > 20 × 10(9)/L on day 17.5. Treatment was started for ≥grade I GVHD, and the cumulative incidences of acute grade I and grade II to IV GVHD were 27.5% and 30.7%, respectively. The incidence of chronic GVHD (extensive type) was 20%. Fourteen patients (41.2%) had a relapse. The cumulative incidence of transplantation-related mortality at 1 year after transplantation was 26.5%. The survival rate at day 100 was 88.2%. The survival rates at 1 year for patients with complete remission (CR)/chronic phase (n = 8) and non-CR (n = 26) status before transplantation were 62.5% and 42.3%, respectively. In the multivariate analysis, non-CR status before transplantation was the only factor significant prognostic factor of increased relapse (P = .0424), which tended to be associated with a lower survival rate (P = .0524). This transplantation protocol is safe and feasible, if a suitable donor is not available in a timely manner. As the main cause of death was relapse and not GVHD, more intensified conditioning or attenuation of GVHD prophylaxis and/or donor lymphocyte infusion may be desirable for patients with non-CR status.

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.