Antibody-mediated pathogenesis of chronic GVHD through DBY/HLA class II complexes and induction of a GVL effect.

Chronic graft-versus-host disease (cGVHD) is a multiorgan syndrome with clinical features resembling those of autoimmune diseases. Thus, understanding commonalities in the pathophysiology of cGVHD and autoimmune diseases, such as the presence of disease-risk HLA alleles, is imperative for developing novel therapies against cGVHD. Alloantibodies against H-Y antigens encoded on the Y-chromosome are well-described risk factors for cGVHD in female-to-male transplantation. However, because H-Y antigens generally localize intracellularly in the male reproductive organs, how they emerge at affected organ levels remains elusive. Here, by analyzing nationwide registry data stratified per donor-recipient sex, we identified specific HLA class II alleles that contributed to susceptibility to male cGVHD after transplantation from HLA-identical female siblings (HLA-DRB1∗15:02: hazard ratio, 1.28; 95% confidence interval, 1.03-1.58; P = .025). Coexpression of HLA-DRB1∗15:02 efficiently transported full-length H-Y antigens, especially DBY, to the surface. The presence of alloantibodies against DBY/HLA class II complexes significantly predicted the occurrence of cGVHD (68.8% vs 31.7% at 1 year; P = .002). Notably, the ability of HLA class II molecules to transport and present DBY to alloantibodies was closely associated with the susceptibility of HLA class II alleles to cGVHD. DBY specifically colocalized with HLA class II molecules on the dermal vascular endothelium in cGVHD and provoked complement-dependent cytotoxicity. Moreover, these complexes were observed in some male leukemic cells. Altogether, these findings suggest that vascular endothelial cells facilitate alloantibody-mediated cGVHD and highlight that alloantibodies against DBY/HLA class II complexes could be common targets for cGVHD and a graft-versus-leukemia effect.

Daratumumab in first-line therapy is cost-effective in transplant-eligible patients with newly diagnosed myeloma.

Triplet regimens, such as lenalidomide, bortezomib, and dexamethasone (RVd) or thalidomide, bortezomib, and dexamethasone (VTd), are standard induction therapies for transplant-eligible patients with newly diagnosed multiple myeloma (NDMM). The addition of daratumumab to RVd and VTd has been investigated in the GRIFFIN and CASSIOPEIA trials, respectively, resulting in improvement in the rate of minimal residual disease (MRD) negativity. In this study, we conducted a cost-effectiveness analysis with a 10-year time horizon to compare first-line and second-line use of daratumumab for transplant-eligible patients with NDMM. Because long-term follow-up data for these clinical trials are not yet available, we developed a Markov model that uses MRD status to predict progression-free survival. Daratumumab was used either in the first-line setting in combination with RVd or VTd or in the second-line setting with carfilzomib plus dexamethasone (Kd). Quality-adjusted life-years (QALYs) and incremental cost-effectiveness ratios were calculated from a Japanese and US payer perspective. In the Japanese analysis, D-RVd showed higher QALYs (5.43 vs 5.18) and lower costs (¥64 479,793 vs ¥71 287 569) compared with RVd, and D-VTd showed higher QALYs (5.67 vs 5.42) and lower costs (¥43 600 310 vs ¥49 471,941) compared with VTd. Similarly, the US analysis demonstrated dominance of a strategy incorporating daratumumab in first-line treatment regimens. Given that overall costs are reduced and outcomes are improved when daratumumab is used as part of a first-line regimen, the economic analysis indicates that addition of daratumumab to first-line RVd and VTd regimens is a dominant strategy compared with reserving its use for the second-line setting.

Cytotoxicity and exhaustion markers of chimeric antigen receptor T cells targeting BCMA in multiple myeloma cell lines between patients and healthy donors.

OBJECTIVES: Multiple myeloma (MM) accounts for 10% of hematologic malignancies. However, most of the patients suffered from relapsed/refractory disease. We would like to expand CAR T cell therapy to treat MM using our current platform. METHODS: BCMA CAR T lymphocytes were generated for volunteers or MM patients. The transduction efficiency was detected by the ddPCR technique. Immunophenotyping and exhaustion markers were monitored by flow cytometry. The efficacy of BCMA CAR T cells was tested using coculturing with BCMA CAR or mock, and the positive and negative targets, K562/hBCMA-ECTM and K562, respectively. RESULTS: BCMA CAR T cells were generated from consented volunteers or MM patients and could be detected CAR BCMA expression at a mean of 4.07 ± 1.95 or 4.65 ± 1.21 copies/cell, respectively. Those modified T cells were primarily effector memory T cells. Our BCMA CAR T cells could explicitly eradicate the K562/hBCMA-ECTM cell line while the K562 cell line survived. Interestingly, the BCMA CAR, mock T cells, and peripheral blood mononuclear cells from MM patients expressed similar levels of the exhaustion makers, TIM-3, LAG-3, and PD1. CONCLUSIONS: Our BCMA CAR T cells, mainly effector/effector memory, could eliminate BCMA-expressing cells in vitro and had similar levels of exhaustion markers among different populations.

Effects of CD34+ cell dose on engraftment and long-term outcomes after allogeneic bone marrow transplantation.

BACKGROUND: The number of CD34+ cells in the graft is generally associated with time to engraftment and survival in transplantation using cord blood or allogeneic peripheral blood stem cells. However, the significance of abundant CD34+ in bone marrow transplantation (BMT) remained unclear. METHODS: We retrospectively reviewed 207 consecutive adult patients who underwent their first BMT at Jichi Medical University between January 2009 and June 2021. RESULTS: The median nucleated cell count (NCC) and CD34+ cell dose were 2.17 × 108/kg (range .56-8.52) and 1.75 × 106/kg (.21-5.84), respectively. Compared with 104 patients in the low CD34+ group (below the median), 103 patients in the high CD34+ group (above the median) showed faster engraftment at day +28 in terms of neutrophil (84.6% vs. 94.2%; p =  .001), reticulocyte (51.5% vs. 79.6%; p < .001), and platelet (39.4% vs. 72.8%; p < .001). There were no significant differences in overall survival, relapse, nonrelapse mortality, acute or chronic graft-versus-host disease, or infectious complications between the two groups in univariate and multivariate analyses. Low or high NCC had no significant effect on overall survival, nonrelapse mortality, cumulative incidence of relapse and graft-versus-host disease, either. While a positive correlation was observed between NCC and the CD34+ cell dose, a high CD34+ cell dose was associated with rapid hematopoietic recovery, even in patients with NCC below the median. CONCLUSION: Measurement of CD34+ cell dose in addition to NCC was useful for predicting hematopoietic recovery, but seemed to have little influence on the long-term outcome in BMT.

Relapsed and refractory multiple myeloma: A systematic review and network meta-analysis of the efficacy of novel therapies.

The prognosis of multiple myeloma (MM) has dramatically improved with the development of new drugs, and it has become important to determine the appropriate combinations of these novel agents. This study was a systematic review and network meta-analysis (NMA) of randomized trials in patients with relapsed and/or refractory (RR) MM. The PubMed, Cochrane, and Embase databases were searched for randomized trials from 1 January 2002 to 28 February 2022 of patients treated for MM. The primary end-point was progression-free survival (PFS), evaluated as a hazard ratio (HR) with a 95% confidence interval (95% CI) compared to dexamethasone (DEX). The p-score was used to rank treatments. Of a total of 1136 abstracts screened, 37 studies were selected, including 34 treatment options for RRMM. Daratumumab, lenalidomide and DEX was found to be the best treatment for RRMM, with the best HR compared to DEX (HR, 0.13; 95% CI, 0.08-0.20; p-score 0.9796). There was no evidence of significant heterogeneity (I2 , 41.3%; p = 0.146). The current NMA confirmed the excellent efficacy of three-drug regimens including anti-CD38 antibodies to treat RRMM and provides background data to evaluate the efficacy of chimeric antigen receptor T-cell treatments and bispecific T-cell engager therapies.

Early reversal of the lymphocyte-to-monocyte ratio after allogeneic-hematopoietic stem cell transplantation is associated with reduced relapse and improved prognosis.

BACKGROUND: The early recovery of lymphocyte and monocyte cells is associated with a favorable prognosis after allogeneic stem cell transplantation (allo-HSCT); however, it is not clear whether the balance of lymphocyte and monocyte recovery affects the post-transplant prognosis. METHODS: We examined whether the time-point at which the number of lymphocytes exceeded the number of monocytes, which we termed lymphocyte-to-monocyte ratio reversal (LMRR), affected the prognosis after allo-HSCT. We retrospectively evaluated 235 patients who underwent their first allo-HSCT at our institution. RESULTS: The median number of days from HSCT to LMRR was 46 (range, 0-214), and the patients were divided into two groups according to the occurrence of LMRR by day 45 (LMRR45). In a multivariate analysis, early LMRR contributed favorably to overall survival (hazard ratio [HR] .519; 95% confidence interval [CI] .332-.812; p = .004) with fewer post-transplant relapses (HR .462; 95% CI, .274-.777; p = .004). Differences in the timing of LMRR did not affect non-relapse mortality (HR 1.477; 95% CI .779-2.80; p = .23) or the incidence of grade II-IV acute GVHD (LMRR45(+): 25.0% vs. LMRR45(-) 35.2%. p = .111). In subgroup analyses, LMRR45(+) was found to be a favorable factor for survival with less relapse, regardless of the disease risk, stem cell source, or the recovery of either lymphocyte or monocyte counts. CONCLUSIONS: An early LMRR may be a novel factor that is associated with reduced relapse and improved survival after allo-HSCT.

Clinical interaction between dexamethasone and aprepitant in chemotherapy for lymphoma.

Aprepitant (Apr) is an effective antiemetic agent for chemotherapy-induced nausea and vomiting (CINV). Current CINV guidelines recommend the antiemetic combination of a 5-HT3 receptor antagonist, Apr, and dexamethasone (Dex) for highly emetogenic chemotherapies. Apr inhibits CYP3A4 dose-dependently. Since Dex is metabolized by CYP3A4, the combined use of Apr and Dex inhibits Dex metabolism. CINV guidelines therefore recommend dose-reduction of Dex when Apr and Dex are used together. However, there is some controversy over whether or not Dex should be reduced when administered as an antitumor agent for lymphoid malignancies. We retrospectively compared the antitumor effect of Dex-containing chemotherapy in which Dex is administered at the usual dose without Apr (group A) or administered at a half-dose in combination with Apr (group B). We analyzed 62 consecutive patients with refractory or relapsed CD20 + B cell lymphoma who received R-DHAP therapy in our hospital, including 29 and 33 cases in groups A and B, respectively. The response rate at the end of the first course of R-DHAP was 62.1% and 54.5%, respectively (P = 0.61). As another endpoint to evaluate the effect of Dex, group B tended to show greater suppression of the lymphocyte count (P = 0.05). Therefore, decreasing the dose of Dex by half appeared to be reasonable when combined with Apr.

A phase 2 study of polatuzumab vedotin + bendamustine + rituximab in relapsed/refractory diffuse large B-cell lymphoma.

Polatuzumab vedotin (pola) is a CD79b-targeted antibody-drug conjugate delivering a potent antimitotic agent (monomethyl auristatin E) to B cells. This was an open-label, single-arm study of pola 1.8 mg/kg, bendamustine 90 mg/m2 , rituximab 375 mg/m2 (pola + BR) Q3W for up to six cycles in patients with relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) who received ≥1 prior line of therapy and were ineligible for autologous stem cell transplantation (ASCT) or experienced treatment failure with prior ASCT. Primary endpoint was complete response rate (CRR) at the end of the treatment (EOT) by positron emission tomography-computed tomography (PET-CT) using modified Lugano Response Criteria. Secondary endpoints included efficacy, safety, and pharmacokinetics. Thirty-five patients (median age 71 [range 46-86] years) were enrolled. Twenty-three (66%) patients had refractory disease, and 23 (66%) had ≥2 prior lines of therapy. At a median follow-up of 5.4 (0.7-11.9) months, patients received a median of five treatment cycles. CRR was 34.3% (95% confidence interval [CI] 19.1-52.2) at EOT. Overall response rate was 42.9% at EOT, and median progression-free survival was 5.2 months (95% CI 3.6-not evaluable). Median overall survival was not reached. No fatal adverse events (AEs) were observed. Grade 3-4 AEs were mainly hematological: anemia (37%), neutropenia (31%), white blood cell count decreased (23%), thrombocytopenia/platelet count decreased/neutrophil count decreased (20% each), and febrile neutropenia (11%). Grade 1-2 peripheral neuropathy (PN; sensory and/or motor) was reported in 14% of patients; there were no ≥grade 3 PN events. This study (JapicCTI-184048) demonstrated the efficacy and safety of pola + BR in Japanese patients with R/R DLBCL who were ineligible for ASCT.

Clinical association between thyroid disease and immune thrombocytopenia.

Immune thrombocytopenia (ITP) can coexist with autoimmune thyroid disease. However, the detailed clinical features remain unknown. We retrospectively reviewed 248 patients with newly diagnosed ITP in our institute for whom we had thyroid function data at diagnosis between 2000 and 2019. Of the 248 patients with ITP, 74 patients also had thyroid disease, including 36 with overt thyroid disease (13 Graves' disease and 23 Hashimoto's thyroiditis) and 38 with subclinical thyroid disease (3 hyperthyroidism and 35 hypothyroidism). ITP and thyroid disease were concurrently diagnosed in 54 patients. Female sex and positivity for antinuclear antibodies (ANA) were significantly associated with thyroid diseases. Platelet-associated immunoglobulin G (PAIgG) levels in patients with Graves' disease were higher than those in patients with Hashimoto's thyroiditis. Platelet counts were similar among euthyroid patients and patients with thyroid disease. Thrombopoietin-receptor agonist was administered more frequently in patients with thyroid disease. The cumulative incidences of thrombosis and bleeding and overall survival did not differ between patients with and without thyroid disease. Treatment for thyroid disease in 22 patients improved thrombocytopenia in 21 patients, especially in 4 patients who were not treated for ITP. This study demonstrated that thyroid diseases were commonly found in patients with ITP. Treatment of the underlying thyroid disease may improve thrombocytopenia.

Factors that predict delayed platelet recovery after autologous stem cell transplantation for lymphoma or myeloma.

The amount of infused CD34+ cells has been reported to be the strongest predictor of platelet recovery after autologous stem cell transplantation (ASCT). However, the timing of platelet recovery varies widely among patients even after the infusion of similar amounts of CD34+ cells. Therefore, we retrospectively assessed 99 patients who underwent their first ASCT for lymphoma or myeloma at our center. Thirteen patients (13%) did not achieve platelet engraftment, defined as a platelet count of at least 2.0 × 104/µL without transfusion, at day 28 after transplantation, whereas 58 of 60 patients (97%) who received at least 2.0 × 106/kg CD34+ cells achieved platelet engraftment within 28 days. Multivariate analysis identified the following significant risk factors for delayed platelet recovery: hemoglobin level and platelet count before stem cell harvest, body temperature of > 39 °C within 5 days after ASCT, and infusion of a small amount (< 2.0 × 106/kg) of CD34+ cells. In a subgroup analysis of 39 patients infused with < 2.0 × 106/kg CD34+ cells, a need for repeated apheresis for stem cell harvest and a body temperature of > 39 °C within 5 days after ASCT were identified as independent factors for delayed platelet recovery. In summary, platelet recovery following ASCT was affected by insufficient hematopoietic recovery at stem cell harvest, a need for repeated apheresis, and high fever early after ASCT, particularly when the amount of infused stem cells was insufficient.

Evaluation of thrombotic events in patients with immune thrombocytopenia.

Immune thrombocytopenia (ITP) has been reported to be associated with thrombotic events. The incidence of thrombosis in 303 newly diagnosed ITP patients in our institute between 2000 and 2016 was retrospectively reviewed. During a median follow-up of 3.6 years, 16 thrombotic events (12 arterial and four venous) occurred. The median platelet count at thrombotic events was 102 × 109/l. At 10 years, the cumulative thrombosis incidence was 10%. A univariate analysis showed that smoking, hypertension, male gender, a history of thrombosis, and atrial fibrillation (Af) were significantly associated with the occurrence of thrombosis, and a multivariate analysis identified smoking and Af as independent risk factors. The thrombotic risk was not increased by lupus anticoagulant positivity or ITP treatment. At 5 years, the cumulative incidence of bleeding and overall survival probability was 5.6% and 92%, respectively. This study demonstrates that smoking and Af were associated with an increased risk of thrombosis. Previously identified risk factors were not confirmed in these Japanese ITP patients.

Steep neutrophil recovery following unrelated bone marrow transplantation is a major risk factor for the development of acute graft-vs-host disease-a retrospective study.

The speed of neutrophil recovery following allogeneic hematopoietic cell transplantation (allo-HCT) varies widely among patients. We retrospectively evaluated the slope of neutrophil recovery (N slope) in 120 patients who underwent a first unrelated bone marrow transplantation with granulocyte-colony-stimulating factor support between 2009 and 2018. The median N slope was 205.5/µl/day. We classified patients into low (n = 59) and high (n = 61) N slope groups with a cutoff value of 200/µl/day. The high N slope group correlated with older patients, RIC regimen, high CD34+ cells, and recent transplantation. The cumulative incidence of grade II-IV acute graft-versus-host disease (aGVHD) was significantly higher in the high N slope group than in the low N slope group (44.3% vs. 16.9%, P < 0.001). In multivariate analysis, high N slope was identified as a significant independent risk factor for grade II-IV aGVHD, irrespective of the involved organs. There were no differences in relapse, nonrelapse mortality, or overall survival between the two groups. In conclusion, the difference in N slope after allo-HCT may predict the risk of aGVHD. Prevention and treatment of GVHD according to the changes in the neutrophil count may improve post-transplant complications.

Comparison of Danaparoid Sodium and Synthetic Protease Inhibitors for the Treatment of Disseminated Intravascular Coagulation Associated with Hematological Malignancies: A Retrospective Analysis.

BACKGROUND: Danaparoid sodium and synthetic protease inhibitors (SPIs) have been approved for the treatment of disseminated intravascular coagulation (DIC) in Japan. OBJECTIVES: To compare the clinical results of the treatment of DIC with danaparoid or SPIs. METHODS: We retrospectively examined 188 patients with hematological malignancy-related DIC. RESULTS: DIC resolution rate in the danaparoid group was higher than that in the SPIs group (61.5 vs. 42.6%; p = 0.031) on day 7. Multivariate analysis identified the response to chemotherapy as independent predictive factor for DIC resolution on day 7 (odds ratio, OR, 2.28; 95% confidence interval, CI, 1.21-4.31; p = 0.011). While there was no significant difference in the DIC resolution rate on day 14 (75.0 vs. 62.4%; p = 0.117), in a subgroup analysis of patients who did not show an improvement in the underlying disease, the danaparoid group showed a significantly better DIC resolution rate (OR 3.89; 95% CI 1.15-13.2; p = 0.030). There was no difference in the rate of cumulative mortality from bleeding within 28 days between the 2 groups (6.6 vs. 3.3%; p = 0.278). CONCLUSIONS: Danaparoid may be associated with more frequent resolution of DIC in patients with refractory underlying disease.

Predictive value of soluble interlukin-2 receptor level at diagnosis on the outcome for patients with classical Hodgkin lymphoma treated with ABVD with or without radiotherapy.

We retrospectively analyzed 70 patients with classical Hodgkin lymphoma (cHL) who were treated with doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) with or without radiotherapy to assess the influence of the soluble interleukin-2 receptor (sIL-2R) level at diagnosis on the clinical outcome. Receiver operating characteristic analyses determined that the optimal cutoff value of the sIL-2R level for progression-free survival (PFS) was 2490 U/mL. Using this cutoff value, patients were classified into low (n = 46) and high (n = 24) sIL-2R groups. The patients in the high sIL-2R group exhibited a significantly inferior PFS (44.1% vs. 90.4% at 5 years, P < 0.001) and overall survival (OS) (67.6% vs. 94.7% at 5 years, P = 0.001) compared with those in the low sIL-2R group. Multivariate analysis showed that a high sIL-2R level was an independent prognostic factor for PFS after adjusting for stage, white blood cell, hemoglobin, and B symptoms, and also OS after adjusting for age and stage (hazard ratio (HR) 6.49, P < 0.001 and HR 5.98, P = 0.009, respectively). In patients with advanced-stage cHL, a high sIL-2R level predicted 5-year PFS even after adjustment for international prognostic score > 4 (HR 6.00, P = 0.007). These results demonstrate that the sIL-2R level can be a useful prognostic factor in patients with cHL treated with ABVD with or without radiotherapy.

Comparison of blast percentage calculated based on bone marrow all nucleated cells and non-erythroid cells in myelodysplastic syndromes with erythroid hyperplasia.

It is controversial whether blast percentage based on all nucleated cells (ANC) or non-erythroid cells (NEC) more accurately reflects the prognosis of patients with myelodysplastic syndromes (MDS). We considered that the impact of blast percentage on survival should be similar in MDS with erythroid hyperplasia (MDS-E) and MDS with no erythroid hyperplasia (MDS-NE), and from this perspective, we retrospectively analyzed 322 patients, including 44 with MDS-E and 278 with MDS-NE. Overall survival was similar between the MDS-E and MDS-NE groups (P = 0.94). In a subgroup of patients with bone marrow (BM) blasts of < 5%, no difference in survival was found between MDS-E and MDS-NE by either calculation method. However, in patients with a blast percentage between 5 and 10%, a significant difference in survival was observed only when the blast percentage in MDS-E was calculated from ANC (P < 0.001 by ANC and P = 0.66 by NEC). A similar result was observed when we analyzed the remaining patients with higher blasts together with those with blasts between 5 and 10%. These results suggest that the calculation of the BM blast percentage based on NEC in MDS-E provides a blast percentage value with a clinical impact consistent with that in MDS-NE.

TAFRO Syndrome with an Anterior Mediastinal Mass and Lethal Autoantibody-Mediated Thrombocytopenia: An Autopsy Case Report.

TAFRO syndrome, a rare systemic inflammatory disease, can lead to multiorgan failure without appropriate treatment. Although thrombocytopenia is frequently seen in patients with TAFRO syndrome, little is known about its pathogenesis. Moreover, while recent studies have reported the presence of an anterior mediastinal mass in some patients, the pathological status of this remains unclear. Here, we report a case of fatal bleeding in a patient with TAFRO syndrome accompanied by an anterior mediastinal mass. A 55-year-old female was transferred to our hospital with a 2-week history of fever, epistaxis, and dyspnea. Laboratory tests revealed severe thrombocytopenia, computed tomography (CT) showed pleural effusions, and bone marrow biopsy revealed reticulin myelofibrosis. We suspected TAFRO syndrome, but the CT scan showed an anterior mediastinal mass that required a biopsy to exclude malignancy. She soon developed severe hemorrhagic diathesis and died of intracranial hemorrhage despite intensive treatment. She had multiple autoantibodies against platelets, which caused platelet destruction. An autopsy of the mediastinal mass revealed fibrous thymus tissues with infiltration by plasma cells. Our case suggests that thrombocytopenia could be attributed to antibody-mediated destruction and could be lethal. Hence, immediate treatment is imperative in cases of severe thrombocytopenia, even when accompanied by an anterior mediastinal mass.

Comprehensive Analysis of the Activation and Proliferation Kinetics and Effector Functions of Human Lymphocytes, and Antigen Presentation Capacity of Antigen-Presenting Cells in Xenogeneic Graft-Versus-Host Disease.

Xenogeneic graft-versus-host disease (GVHD) models in highly immunodeficient mice are currently being used worldwide to investigate human immune responses against foreign antigens in vivo. However, the individual roles of CD4+ and CD8+ T cells, and donor/host hematopoietic and nonhematopoietic antigen-presenting cells (APCs) in the induction and development of GVHD have not been fully investigated. In the present study, we comprehensively investigated the immune responses of human T cells and the antigen presentation capacity of donor/host hematopoietic and nonhematopoietic APCs in xenogeneic GVHD models using nonobese diabetic/Shi-scid-IL2rgnull mice. CD4+ T cells and, to a lesser extent, CD8+ T cells individually mediated potentially lethal GVHD. In addition to inflammatory cytokine production, CD4+ T cells also supported the activation and proliferation of CD8+ T cells. Using bone marrow chimeras, we demonstrated that host hematopoietic, but not nonhematopoietic, APCs play a critical role in the development of CD4+ T cell-mediated GVHD. During early GVHD, we detected 2 distinct populations in memory CD4+ T cells. One population was highly activated and proliferated in major histocompatibility complex antigen (MHC)+/+ mice but not in MHC-/- mice, indicating alloreactive T cells. The other population showed a less activated and slowly proliferative status regardless of host MHC expression, and was associated with higher susceptibility to apoptosis, indicating nonalloreactive T cells in homeostasis-driven proliferation. These observations are clinically relevant to donor T cell response after allogeneic hematopoietic stem cell transplantation. Our findings provide a better understanding of the immunobiology of humanized mice and support the development of novel options for the prevention and treatment for GVHD.

False-positive elevation of 1,3-beta-D-glucan caused by continuous administration of penicillin G.

The 1,3-beta-D-Glucan (BDG) assay is widely used for the diagnosis of fungal infections, especially in patients with hematologic malignancies. Some antimicrobials have been reported to cause false-positive results for BDG, but there has been no report on the effect of penicillin G (PCG) on BDG levels. We experienced a patient who developed false-positive BDG elevation during the administration of PCG for osteomyelitis due to Streptococcus pneumoniae infection. The serum BDG level increased up to 81.0 pg/ml during the continuous administration of PCG at 24 million units per day. However, chest and paranasal CT scan showed no evidence of fungal infection. The BDG level decreased to 38.0 pg/ml at 14 hours after the discontinuation of PCG. The amount of BDG in one vial of PCG inferred from these serum BDG levels is very similar to the actual BDG concentration in a vial of PCG. Therefore, during the administration of PCG, elevated BDG levels should be interpreted with caution, as they may be false-positive results.

[Clinical development of CAR-T therapy for refractory multiple myeloma].

A chimeric antigen receptor (CAR) comprises an extracellular ligand recognition domain linked to CD3ζ and induces T-cell activation upon antigen binding. Recently, the potential of CD19-targeted CAR T-cells (CAR-T) to treat multiple myeloma has been explored. A group in the University of Pennsylvania reported that 4 out of 10 patients with refractory myeloma achieved an objective response (sCR: 1, VGPR: 1, and PR: 2). Although the resultant cancer ablation was an arresting sight, it remains unclear whether CD19 is a suitable target for myeloma. Therefore, CAR-T therapy employing alternative target antigens is being attempted. Some current clinical trials are utilizing CAR against differentiation antigens, including CD138, CD38, and kappa light chain. B-cell maturation antigen (BCMA) is also a potential candidate. A group in the NCI described 12 patients with refractory myeloma enrolled in a BCMA-CAR phase 1 clinical trial. Two patients receiving the highest dosage attained an objective response. Nevertheless, considerable research is required for CAR immunotherapy to become universally available to patients with myeloma. The current enthusiasm for the development of this cutting-edge technology is justified because extraordinary evidence indicates that it is effective, although this may not apply to every case. CAR-T therapy for myeloma is currently undergoing rapid, wide-scale growth both in academia and in industry-sponsored clinical development.

The prognostic significance of rapid peripheral blood blast clearance during the initial course of induction chemotherapy in young patients with de novo acute myeloid leukemia.

The early clearance of blast cells in peripheral blood (PB) during induction chemotherapy can predict the clinical outcome in acute leukemia. We retrospectively analyzed the kinetics of white blood cell (WBC) count, blast cell percentage (BCP), and blast cell count (BCC) in PB in 78 patients with de novo acute myeloid leukemia who underwent a uniform induction chemotherapy between December 2001 and December 2015 at Jichi Medical University. By a repeated-measures analysis of variance, the interaction of the decline in BCP with the achievement of complete remission (CR) was stronger than those of the decline in WBC or BCC. A receiver operating characteristic curve analysis for the achievement of CR showed that the areas under the curve for the decline in WBC, BCP, and BCC were 0.592, 0.703, and 0.634, respectively, and a decline in BCP of 9.25%/day within 4 or 5 days from induction chemotherapy was the optimal cutoff value. A multivariate analysis showed that a rapid decline in BCP (≥9.25%/day) was a significant predictive factor for CR, independent of the cytogenetic risk (p = 0.0096). A rapid decline in BCP during the first 5 days of induction chemotherapy may be a good predictor of CR. Copyright © 2015 John Wiley & Sons, Ltd.