Efficient granulocyte collection method using high concentrations of medium molecular weight hydroxyethyl starch.

BACKGROUND: Granulocyte transfusion therapy is a rational therapeutic option for patients with prolonged, severe neutropenia. Although high molecular weight hydroxyethyl starch (hHES) facilitates the separation of red blood cells during granulocyte collection, renal dysfunction has been noted as a potential side effect. HES130/0.4 (Voluven®) is a medium molecular weight HES (mHES) with superior safety profiles compared to hHES. Although HES130/0.4 is reportedly effective in the collection of granulocytes, we lack studies comparing the efficiency of granulocyte collection using HES130/0.4 and hHES. STUDY DESIGN AND METHODS: We retrospectively collected the data from 60 consecutive apheresis procedures performed on 40 healthy donors at the Okayama University Hospital between July 2013 and December 2021. All procedures were performed using the Spectra Optia system. Based on the HES130/0.4 concentration in the separation chamber, granulocyte collection methods using HES130/0.4 were classified into m0.46, m0.44, m0.37, and m0.8 groups. We used HES130/0.4 and hHES groups to compare the various sample collection methods. RESULTS: The median granulocyte collection efficiency (CE) was approximately 24.0% and 28.1% in the m0.8 and hHES groups, respectively, which were significantly higher than those in the m0.46, m0.44, and m0.37 groups. One month following granulocyte collection with HES130/0.4, no significant changes were observed in serum creatinine levels compared to those before the donation. CONCLUSION: Therefore, we propose a granulocyte collection approach employing HES130/0.4, which is comparable to the use of hHES in terms of the granulocyte CE. A high concentration of HES130/0.4 in the separation chamber was considered crucial for granulocyte collection.

Low hematocrit reduces the efficiency of CD34+ cell collection when using the Spectra Optia continuous mononuclear cell collection procedure.

BACKGROUND: CD34+ cell collection efficiency (CE) is the determining factor when calculating processed blood volume (PBV) for leukapheresis (LP). However, the factors affecting CE in the continuous mononuclear cell collection (cMNC) protocol performed by the Spectra Optia apheresis system are not well established. STUDY DESIGN AND METHODS: We retrospectively collected the data from 147 consecutive apheresis procedures across 106 healthy donors and 27 patients completed between July 2016 and December 2020 at the Okayama University Hospital. All procedures were performed using the Optia cMNC protocol. RESULTS: The median CD34+ CE2 was significantly higher in the donor samples (64.3%) than in the patient samples (46.8%) (p < .0001). WBC counts, hematocrit, and platelet counts were all significantly higher in the donors than in the patients, and there was a moderate positive correlation between CD34+ CE2 and hematocrit (r = .47, p < .0001), with the equation of the line being y = 1.23x + 12.23. In contrast, there was only a very weak correlation between CD34+ CE2 and WBC or platelet count. In addition, low hematocrit correlated with an increased time to interface formation. CONCLUSION: These data revealed the negative impact of low hematocrit on the efficiency of CD34+ cell collection when using the Optia cMNC protocol and suggest that hematocrit values should also be considered when determining PBV.

Successful neutrophil engraftment supported by granulocyte transfusion in adult allogeneic transplant patients with peri-transplant active infection.

Active infection at the time of allogeneic hematopoietic stem cell transplantation (HSCT) is a risk for non-relapse mortality (NRM) after HSCT. Granulocyte transfusion (GTX) has been used to prevent or treat life-threatening infections in patients with severe neutropenia. However, data are limited on the clinical benefits of GTX during HSCT. We retrospectively analyzed the transplant outcomes of HSCT patients who had undergone GTX between 2012 and 2020. Altogether, 20 patients with documented infection had received 55 GTXs during HSCT. No adverse events were observed during the GTX infusion. The average number of granulocytes was 0.40 (range, 0.10-1.59) × 109/kg. The median neutrophil increment one day after GTX was 515 (range, -6 to 6630)/µl, which was significantly correlated with the infused granulocyte dose (p = 0.0007). A total of 17 of 20 patients achieved neutrophil engraftment. The number of infused granulocytes tended to higher in clinical responders (p = 0.12), and patients receiving ≥ 0.5 × 109/kg showed trend toward to better transplant outcomes (GTX-high vs. GTX-low, 1-year OS; 33% vs. 11%, p = 0.19. 1-year NRM; 44% vs.77%, p = 0.11). The type of red blood sedimenting agents was significantly correlated with the amounts of granulocyte collection. In conclusion, GTX, especially with a high amount of containing granulocytes, could be a safe bridging therapy for neutrophil engraftment after HSCT in patients with active infection.

Effectiveness of supplemental oral calcium drink in preventing citrate-related adverse effects in peripheral blood progenitor cell collection.

Peripheral blood progenitor cells (PBPCs) are a predominant graft source in allogeneic hematopoietic cell transplantation. Citrate-induced hypocalcemia remains the most frequent side effect of PBPC apheresis. Although the method for preventing severe adverse events is established, more efficient prophylaxis is required so that volunteer donors can donate PBPCs without pain and anxiety. We studied 80 healthy donors who underwent PBPC harvest between February 2014 and June 2020. Of these, 23 donors who underwent apheresis between February 2014 and December 2015 received only the standard prophylaxis of intravenous calcium gluconate. Oral calcium drinks were provided to 57 donors who underwent apheresis from January 2016 to June 2020 to supplement intravenous calcium gluconate prophylaxis. The ionized calcium (ICa) levels at multiple time intervals and the hypocalcemic symptoms were evaluated. Oral supplementation with a calcium drink maintained significantly higher ICa levels. Analysis using the inverse probability weighted regression adjustment method suggested that calcium drinks reduced the frequency of citrate-related reactions by 39.2 %. Administering a prophylactic oral calcium drink before apheresis with intravenous administration of calcium gluconate is promising to further reduce citrate-induced hypocalcemia in volunteer donors.

Plasma exchange eliminates residual mogamulizumab but does not warrant prompt recovery of peripheral Treg levels.

Mogamulizumab (Mog), a humanized anti-CCR4 antibody, provides an important treatment option for relapsed/refractory adult T cell leukemia/lymphoma. However, administration of Mog before allogenic hematopoietic stem cell transplantation has been reported to be a risk factor for severe acute graft-versus-host disease (GVHD). The etiological hypothesis is Mogamulizumab may eradicate CCR4-positive regulatory T cells (Tregs). Theoretically, Treg homeostasis and course of GVHD can be affected by plasma exchange (PE) with decreasing plasma Mog concentration. Here, we present a case of severe acute GVHD after pretransplantation Mog, in which PE was performed for liver failure. As a result, plasma Mog concentration was decreased but it did not lead to the prompt elevation of Treg levels in peripheral blood and clinical responses of GVHD were limited to partial remission. Our case suggests that recovery of donor-derived Treg in the acute phase after HSCT is multifactorial and the single procedure of PE-based Mog depletion does not necessarily warrant the quick restoration of Treg homeostasis.

[Transfusion-associated circulatory overload with pulmonary alveolar hemorrhage following allogeneic bone marrow transplantation].

A 51-year-old man underwent allogeneic bone marrow transplantation (BMT) for recurrent acute myeloid leukemia. Although the patient developed slight edema, pleural effusion, and cardiac effusion 6 months after BMT, his clinical condition improved with furosemide treatment. The patient was transfused with red blood cells for the management of anemia 8 months after BMT. He developed acute respiratory failure with pulmonary alveolar hemorrhage 80 min after the transfusion. He was diagnosed with transfusion-associated circulatory overload (TACO) due to the presence of acute pulmonary congestion and depressed left ventricular systolic function. Reduced circulatory load due to sufficient furosemide led to ventilator weaning 3 days later. Other causes of pulmonary alveolar hemorrhage were excluded, and the patient's condition improved by cardiac failure treatment only. This clinical course indicated that pulmonary alveolar hemorrhage would breakdown the blood vessels due to acute pulmonary congestion. Chemotherapy and prolonged anemia are high risks for cardiac failure in patients with hematological malignancies. Therefore, the possibility of cardiac failure is considered when patients with hematological malignancies have fluid retention, such as cardiac enlargement, edema, and pleural effusion. Moreover, the body fluids should be monitored before and after blood transfusion.

Fecal microbiota transplantation for patients with steroid-resistant acute graft-versus-host disease of the gut.

Increasing evidence indicates that the gut microbiota is closely associated with acute graft-versus-host disease (aGVHD) in stem cell transplantation (SCT). Fecal microbiota transplantation (FMT) could represent an alternative treatment option for aGVHD. However, FMT for SCT patients carries a potential risk of infection by infused microbiota because of the severely immunosuppressed status. We therefore conducted a pilot study to evaluate the safety of FMT in SCT. A total of 4 patients with steroid-resistant (n = 3) or steroid-dependent gut aGVHD (n = 1) received FMT. No severe adverse events attributed to FMT were observed. All patients responded to FMT, with 3 complete responses and 1 partial response. Temporal dynamics of microbiota seemed to be linked to the gut condition of patients and peripheral effector regulatory T cells also increased during response to FMT. FMT was safely performed in our patients and might offer a novel therapeutic option for aGVHD. This trial was registered at the University Hospital Medical Information Network (https://upload.umin.ac.jp/cgi-open-bin/icdr_e/ctr_view.cgi?recptno=R000017575) as #UMIN000015115.

Progressive multifocal leukoencephalopathy after T-cell replete HLA-haploidentical transplantation with post-transplantation cyclophosphamide graft-versus-host disease prophylaxis.

A 52-year-old man suffered from progressive multifocal leukoencephalopathy (PML) after human leukocyte antigen (HLA)-haploidentical transplantation with post-transplantation cyclophosphamide (PTCY). Mirtazapine, mefloquine, and cytarabine failed to improve his symptoms, and he finally died 4.5 months after PML onset. This is the first case report of a patient with PML after HLA-haploidentical transplantation with PTCY. Although T-cell replete HLA-haploidentical transplantation with PTCY has enabled early immune reconstitution, PML should be considered if a patient's mental condition deteriorates.

Retrospective analysis of clinical outcomes of the patients with chronic myeloid leukemia who stopped administration of tyrosine kinase inhibitors: a single institution experience.

We describe herein the clinical outcomes of 16 patients with chronic myeloid leukemia in the chronic phase who stopped the administration of tyrosine kinase inhibitors (TKI) after maintaining undetectable levels of major BCR-ABL1, based on real-time quantitative polymerase chain reaction, for prolonged periods (undetectable MR for a median of 2,100 days (822-4,068). The reasons for discontinuing TKI were enrollments in a clinical trial testing discontinuation of these agents (n=9), adverse effects (n=2) or financial problems (n=5). After TKI discontinuation, patients were followed for a median of 551 days (154-2,446). A total of 8 patients (50%) experienced molecular relapse after a median of 119 days (28-171). Among them, 6 patients who lost major molecular response (MMR) were treated with imatinib (n=2) or dasatinib (n=4), while 2 patients who lost undetectable MR after discontinuing TKI (1 each had taken bostinib and imatinib) but maintained MMR were carefully monitored without re-administration of TKI. Of 6 patients who re-started TKI, 4 (67%) achieved undetectable MR but the other 2 achieved only MMR. The results of this small, retrospective study may support the current understanding of treatment discontinuation, possibly leading to a sustained deep molecular response in some patients.

[Chronic myelogenous leukemia initially presenting with multiple subcutaneous tumors due to extramedullary hematopoiesis].

A 53-year-old woman was admitted with right upper-extremity pain and multiple subcutaneous masses. Bone marrow aspirate showed hypercellular marrow with increased myeloid components at all stages of maturation. Cytogenetic analysis of the bone marrow revealed 100% Philadelphia chromosome positivity along with BCR/ABL gene rearrangement, as demonstrated by polymerase chain reaction (PCR). A diagnosis of chronic phase of chronic myeloid leukemia (CML) was therefore made. Biopsy of one of the subcutaneous masses showed proliferation of granulocytes in various stages of differentiation. There were also erythroid cells and megakaryocytes, without p53 and CD34-positive blasts. These results suggested that the subcutaneous masses had developed from extramedullary hematopoiesis, not blastomas. The patient was administered dasatinib (DA) 140 mg, combined with radiation therapy for pain and peripheral neuropathy from the right axial extramedullary tumor. The patient showed complete hematological remission and the subcutaneous masses had disappeared 1 month after starting administration of DA. Because the patient did not achieve a cytogenetic response, the tyrosine kinase inhibitor nilotinib was administered. She will undergo allogeneic stem cell transplantation in the near future. Extramedullary hematopoiesis in the early stages of CML is uncommon. Our case emphasizes the need to elucidate the pathogenesis of extramedullary hematopoiesis in the early stages of CML.

Chronic myeloid leukemia relapsing ten years after allogenic bone marrow transplantation.

A 58-year-old female was diagnosed with Philadelphia chromosome positive chronic myeloid leukemia (CML) in blast crisis (BC) in 2004. The patient received imatinib, which quickly induced molecular remission, and subsequently underwent bone marrow transplantation (BMT) from an unrelated human leukocyte antigen (HLA)-identical donor. The post-transplant clinical course was essentially uneventful. In 2014, ten years after the BMT, the patient was admitted to our hospital complaining of lymphadenopathy, and blasts were observed in peripheral blood. The patient was diagnosed as having a CML relapse in myeloid BC, with leukemic infiltration in lymph nodes, and was treated with dasatinib. Subsequently, pleural effusion developed and nilotinib was administered, which induced normal blood counts without blasts and partial cytogenetic remission, one month after administration. Six months after the relapse, this patient underwent a second BMT from an HLA-matched unrelated donor. Recent studies have demonstrated the cumulative incidence of CML relapse more than five years after allogeneic hematopoietic stem cell transplantation (allo-HSCT) to be higher than in acute myeloid leukemia. Although rare, the possibility of late relapse should be considered in patients diagnosed with CML after allo-HSCT.

Donor cell leukemia with bone marrow necrosis.

A 60-year-old man with myelodysplastic syndrome underwent allogeneic transplantation of female umbilical cord blood in 2010 and sustained a complete remission. He experienced severe pain in his left hip joint and was admitted to the orthopedic surgery division of our institution in February 2015. After admission, he was suspected to have hemophagocytic syndrome (HPS) and was thus transferred to the hematology division. Bone marrow aspiration revealed hyper-cellular marrow filled with abnormal collapsed cells, consistent with bone marrow necrosis (BMN). As there was no evidence of infection, collagen disease, or occult cancer, he was diagnosed with HPS of unknown origin and treated with dexamethasone, cyclosporine A, and etoposide according to the HLH-2004 protocol. Although his general condition and laboratory findings showed amelioration, morphologically abnormal cells appeared in peripheral blood two weeks after treatment. Bone marrow aspiration showed BMN with increased abnormal cells, positive for CD117 and MPO. Sex chromosome FISH analysis revealed donor chimerism and cytogenetic analysis showed 46XX, +1, der (1;7) (q10;q10). He was diagnosed with donor cell leukemia (DCL) and received salvage chemotherapy. However, he died because of severe pneumonia and sepsis without neutrophil recovery at day 68. We herein report this rare case of DCL with BMN.

Activated CD4+ T Cell Proportion in the Peripheral Blood Correlates with the Duration of Cytokine Release Syndrome and Predicts Clinical Outcome after Chimeric Antigen Receptor T Cell Therapy.

Objective Chimeric antigen receptor (CAR) T cell therapy is an emerging and effective therapy for relapsed or refractory diffuse large B cell lymphoma (R/R DLBCL). The characteristic toxicities of CAR T cell therapy include cytokine release syndrome (CRS) and prolonged cytopenia. We investigated the factors associated with these complications after CAR T cell therapy by analyzing lymphocyte subsets following CAR T cell infusion. Methods We retrospectively analyzed peripheral blood samples on days 7, 14, and 28 after tisagenlecleucel (tisa-cel) infusion by flow cytometry at our institution between June 2020 and September 2022. Patients Thirty-five patients with R/R DLBCL who received tisa-cel therapy were included. Results A flow cytometry-based analysis of blood samples from these patients revealed that the proportion of CD4+CD25+CD127+ T cells (hereafter referred to as "activated CD4+ T cells" ) among the total CD4+ T cells on day 7 after tisa-cel infusion correlated with the duration of CRS (r=0.79, p<0.01). In addition, a prognostic analysis of the overall survival (OS) using time-dependent receiver operating characteristic curves indicated a significantly more favorable OS and progression-free survival of patients with a proportion of activated CD4+ T cells among the total CD4+ T cells <0.73 (p=0.01, and p<0.01, respectively). Conclusion These results suggest that the proportion of activated CD4+ T cells on day 7 after tisa-cel infusion correlates with the CRS duration and predicts clinical outcomes after CAR T cell therapy. Further studies with a larger number of patients are required to validate these observations.

Hematopoietic stem cell-derived Tregs are essential for maintaining favorable B cell lymphopoiesis following posttransplant cyclophosphamide.

Posttransplant cyclophosphamide (PTCy) is associated with a low incidence of chronic graft-versus-host disease (cGVHD) following hematopoietic stem cell (HSC) transplantation. Previous studies have shown the important roles of B cell immunity in cGVHD development. Here, we investigated the long-term reconstitution of B lymphopoiesis after PTCy using murine models. We first demonstrated that the immune homeostatic abnormality leading to cGVHD is characterized by an initial increase in effector T cells in the bone marrow and subsequent B and Treg cytopenia. PTCy, but not cyclosporine A or rapamycin, inhibits the initial alloreactive T cell response, which restores intra-bone marrow B lymphogenesis with a concomitant vigorous increase in Tregs. This leads to profound changes in posttransplant B cell homeostasis, including decreased B cell activating factors, increased transitional and regulatory B cells, and decreased germinal center B cells. To identify the cells responsible for PTCy-induced B cell tolerance, we selectively depleted Treg populations that were graft or HSC derived using DEREG mice. Deletion of either Treg population without PTCy resulted in critical B cytopenia. PTCy rescued B lymphopoiesis from graft-derived Treg deletion. In contrast, the negative effect of HSC-derived Treg deletion could not be overcome by PTCy, indicating that HSC-derived Tregs are essential for maintaining favorable B lymphopoiesis following PTCy. These findings define the mechanisms by which PTCy restores homeostasis of the B cell lineage and reestablishes immune tolerance.

A Case of Relapsed Primary Central Nervous System Lymphoma Treated with CD19-directed Chimeric Antigen Receptor T Cell Therapy.

Although high-dose methotrexate (HD-MTX) is the standard therapy for primary central nervous system lymphoma (PCNSL), the prognosis remains poor. Because 90% of PCNSL is diffuse large B-cell lymphoma (DLBCL), chimeric antigen receptor (CAR)-T cell therapy is expected to be beneficial. However, there are limited reports on CAR-T cell therapy for PCNSL because of the concern of neurotoxicity. Here, we report a case of relapsed PCNSL treated with anti-CD19 CAR-T cell therapy. A 40-year-old woman presenting with visual disturbance in her left eye was initially diagnosed with bilateral uveitis. Her histological diagnosis was DLBCL, and she was positive for CD19. Although she received chemotherapy including HD-MTX, the tumor relapsed in her right occipital lobe. She underwent remission induction therapy and then anti-CD19 CAR-T cell therapy. Cytokine release syndrome (CRS) grade 2 occurred, but there were no complications of CAR-T cell-related encephalopathy syndrome (CRES). She has achieved complete response for more than 1 year. Anti-CD19 CAR-T cell therapy is a revolutionary immunotherapy for treating relapsed or refractory (R/R) B lineage malignancies. Although there are concerns regarding CRS and CRES in central nervous system lymphoma, the use of anti-CD19 CAR-T cells to treat R/R PCNSL is safe and feasible.

Responses of regulatory and effector T-cells to low-dose interleukin-2 differ depending on the immune environment after allogeneic stem cell transplantation.

CD4+Foxp3+ regulatory T cells (Tregs) play a central role in the maintenance of immune tolerance after allogeneic hematopoietic stem cell transplantation (HSCT). Tregs promptly respond to low concentrations of IL-2 through the constitutive expression of high-affinity IL-2 receptors. It has been reported that low-dose IL-2 therapy increased circulating Tregs and improved clinical symptoms of chronic GVHD. Clinical studies of IL-2 therapy so far have mainly targeted patients in the chronic phase of transplantation when acute immune responses has subsided. However, the biological and clinical effects of exogenous IL-2 in an acute immune environment have not been well investigated. In the current study, we investigated the impact of exogenous IL-2 therapy on the post-transplant homeostasis of T cell subsets which influence the balance between GVHD and GVL in the acute phase, by setting the various immune environments early after HSCT in murine model. We initially found that 5,000 IU of IL-2 was enough to induce the active proliferation of Treg without influencing other conventional T cells (Tcons) when administered to normal mice. However, activated Tcons showed the response to the same dose of IL-2 in recipients after allogeneic HSCT. In a mild inflammatory environment within a threshold, exogenous IL-2 could effectively modulate Treg homeostasis with just limited influence to activated T cells, which resulted in an efficient GVHD suppression. In contrast, in a severely inflammatory environment, exogenous IL-2 enhanced activated T cells rather than Tregs, which resulted in the exacerbation of GVHD. Of interest, in an immune-tolerant state after transplant, exogenous IL-2 triggered effector T-cells to exert an anti-tumor effect with maintaining GVHD suppression. These data suggested that the responses of Tregs and effector T cells to exogenous IL-2 differ depending on the immune environment in the host, and the mutual balance of the response to IL-2 between T-cell subsets modulates GVHD and GVL after HSCT. Our findings may provide useful information in the optimization of IL-2 therapy, which may be personalized for each patient having different immune status.

Retrospective comparison of hematopoietic stem cell transplantation following reduced-intensity conditioning with fludarabine/low-dose melphalan plus 4 Gy TBI versus fludarabine/ busulfan plus 4 Gy TBI.

Fludarabine with intravenous busulfan (6.4 mg/kg; FB2) and fludarabine with intermediate-dose melphalan (140 mg/m2; FM140) are the most widely used reduced-intensity conditioning (RIC) regimens for allogeneic hematopoietic stem cell transplantation. FM140 generally has a lower relapse rate and higher non-relapse mortality (NRM), resulting in overall survival (OS) comparable to that seen with FB2. To evaluate the effect of reducing the melphalan dose, we retrospectively compared transplant outcomes in 156 patients who received FB2 (n = 103) or FM80 (n = 53) at our center (median age: 63 years; range 27-72 years). All patients received 4-Gy total body irradiation. Three-year OS, the cumulative incidence of relapse, and NRM were comparable between groups (FB2 vs. FM80, 58% vs. 47%, p = 0.24; 30% vs. 36%, p = 0.57; 17% vs. 21%, p = 0.44, respectively). There was no significant difference in the cumulative incidence of graft-versus-host disease (GVHD) at day 100, chronic GVHD at 3 years, or the 3-year GVHD-free/relapse-free survival rate. In the high-risk disease group, patients receiving FM80 tended to have lower 3-year OS (FB2 vs. FM80, 48% vs. 17%, p = 0.06). In summary, transplant outcomes following FB2 or FM80 were comparable except in patients with high-risk disease.

Harnessing Treg Homeostasis to Optimize Posttransplant Immunity: Current Concepts and Future Perspectives.

CD4+CD25+Foxp3+ regulatory T cells (Tregs) are functionally distinct subsets of mature T cells with broad suppressive activity and have been shown to play an important role in the establishment of immune tolerance after allogeneic hematopoietic stem cell transplantation (HSCT). Tregs exhibit an activated phenotype from the stage of emigration from the thymus and maintain continuous proliferation in the periphery. The distinctive feature in homeostasis enables Tregs to respond sensitively to small environmental changes and exert necessary and sufficient immune suppression; however, on the other hand, it also predisposes Tregs to be susceptible to apoptosis in the inflammatory condition post-transplant. Our studies have attempted to define the intrinsic and extrinsic factors affecting Treg homeostasis from the acute to chronic phases after allogeneic HSCT. We have found that altered cytokine environment in the prolonged post-HSCT lymphopenia or peri-transplant use of immune checkpoint inhibitors could hamper Treg reconstitution, leading to refractory graft-versus-host disease. Using murine models and clinical trials, we have also demonstrated that proper intervention with low-dose interleukin-2 or post-transplant cyclophosphamide could restore Treg homeostasis and further amplify the suppressive function after HSCT. The purpose of this review is to reconsider the distinctive characteristics of post-transplant Treg homeostasis and discuss how to harness Treg homeostasis to optimize posttransplant immunity for developing a safe and efficient therapeutic strategy.