Epitope Mismatch at HLA-DRB1 Associates with Reduced Relapse Risk in Cord Blood Transplantation for Standard-Risk Hematologic Malignancy.

Cord blood transplantation (CBT) is an attractive therapeutic option for patients with hematologic malignancies. CBT tolerates HLA mismatches between donors and recipients, but the HLA mismatches that generate graft-versus-tumor (GVT) effects remain unknown. Given that HLA molecules contain epitopes comprising polymorphic amino acids that determine their immunogenicity, we investigated associations between epitope-level HLA mismatches and relapse following single-unit CBT. A total of 492 patients with hematologic malignancies who underwent single-unit, T cell-replete CBT were included in this multicenter retrospective study. HLA epitope mismatches (EMs) were quantified using HLA matchmaker software from donor and recipient HLA-A, -B, -C, and -DRB1 allele data. Patients were dichotomized by median EM value and divided into 2 groups: patients who underwent transplantation in complete/partial remission (standard stage: 62.4%) and others (advanced stage: 37.6%). The median number of EMs in the graft-versus-host direction (GVH-EM) was 3 (range, 0 to 16) at HLA class I and 1 (range, 0 to 7) at HLA-DRB1. Higher HLA class I GVH-EM was associated with increased nonrelapse mortality (NRM) in the advanced stage group (adjusted hazard ratio [HR], 2.12; P = .021), with no significant advantage for relapse in either stage. In contrast, higher HLA-DRB1 GVH-EM was associated with better disease-free survival in the standard stage group (adjusted HR, .63; P = .020), which was attributed to lower relapse risk (adjusted HR, .46; P = .014). These associations also were observed even within HLA-DRB1 allele-mismatched transplantations in the standard stage group, indicating that EM might have an impact on relapse risk independent of allele mismatch. High HLA-DRB1 GVH-EM did not increase NRM in either stage. High HLA-DRB1 GVH-EM may lead to potent GVT effects and a favorable prognosis following CBT, especially in patients who underwent transplantation at the standard stage. This approach may facilitate appropriate unit selection and improve the overall prognosis of patients with hematologic malignancies who undergo CBT.

Coexistence of HLA and KIR ligand mismatches as a risk factor for viral infection early after cord blood transplantation.

Viral infection is one of the lethal adverse events after cord blood transplantation (CBT). Human leukocyte antigen (HLA) and killer immunoglobulin-like receptor (KIR) ligand divergences can increase the risk of viral infection due to conflicting interactions between virus-infected cells and immune cells. However, the relationship between these disparities and the frequency of viral infection after CBT remains to be evaluated. Herein, we have conducted a retrospective multicenter study to assess the effect of HLA and KIR ligand mismatches on viral infections after CBT. The study included 429 patients, among which 126 viral infections occurred before day 100. Viral infection was significantly associated with poorer overall survival (OS; hazard ratio [HR] 1.74, p < 0.01). Patients harboring ≥3 mismatches in the HLA allele and inhibitory KIR ligand mismatches (HLA & KIR mismatches) had a significantly greater prevalence of viral infection (HR 1.66, p = 0.04). Thus, patients with HLA & KIR mismatches had poorer outcomes in terms of non-relapse mortality (HR 1.61, p = 0.05). Our study demonstrates the unfavorable impacts of HLA & KIR mismatches on viral infections and non-relapse mortality after CBT. Evaluating the viral infection risk and performance of an appropriate and early intervention in high-risk patients and optimizing the graft selection algorithm could improve the outcome of CBTs.

Bortezomib-cyclophosphamide-dexamethasone induction/consolidation and bortezomib maintenance for transplant-eligible newly diagnosed multiple myeloma: phase 2 multicenter trial.

OBJECTIVES: We conducted a phase II trial to prospectively evaluate the efficacy and safety of bortezomib-cyclophosphamide-dexamethasone (VCD) induction, autologous stem cell transplantation (ASCT), VCD consolidation, and bortezomib maintenance in transplant-eligible newly diagnosed multiple myeloma (NDMM) patients in Japan (UMIN000010542). METHODS: From 2013 to 2016, 42 patients with a median age of 58 (range 42-65) years with NDMM were enrolled in 15 centers. The primary endpoint was the complete response (CR) /stringent CR (sCR) rate after transplantation, and overall/progression-free survival rates were also evaluated. RESULTS: Following induction therapy, the overall response rate was obtained in 71% of patients, including a CR/sCR of 10% and a very good partial response (VGPR) of 26%. Twenty-six of the 42 patients completed ASCT following the protocol and CR/sCR and VGPR rate 100 days after ASCT was 26% and 17%, respectively. During consolidation therapy, 3 of the 24 patients achieved deeper responses. Eight of the 18 patients completed 2-year bortezomib maintenance without disease progression and grade 3/4 toxicities. Five patients were VGPR or partial response after ASCT but maintained response with 2-year bortezomib maintenance. Two-year overall and progression-free survival rates were 92.5% (95% confidence interval [CI]: 78.5%-97.5%) and 62.6% (95% CI: 45.8%-75.5%), respectively. Grade 3/4 toxicities (≥ 10%) included neutropenia (19%) and anemia (17%) in induction, and thrombocytopenia (29%) in consolidation. CONCLUSION: VCD induction/consolidation and bortezomib maintenance with ASCT for NDMM resulted in a high CR/sCR rate and provided good overall/progression-free survival in Japan.

Dasatinib-based 2-step induction for adults with Philadelphia chromosome-positive acute lymphoblastic leukemia.

The standard treatment for adults with Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) in Japan is imatinib-based chemotherapy followed by allogeneic hematopoietic stem cell transplantation (HSCT). However, ∼40% of patients cannot undergo HSCT in their first complete remission (CR1) because of chemotherapy-related toxicities or relapse before HSCT or older age. In this study, we evaluated dasatinib-based 2-step induction with the primary end point of 3-year event-free survival (EFS). The first induction (IND1) was dasatinib plus prednisolone to achieve CR, and IND2 was dasatinib plus intensive chemotherapy to achieve minimal residual disease (MRD) negativity. For patients who achieved CR and had an appropriate donor, HSCT during a consolidation phase later than the first consolidation, which included high-dose methotrexate, was recommended. Patients with pretransplantation MRD positivity were assigned to receive prophylactic dasatinib after HSCT. All 78 eligible patients achieved CR or incomplete CR after IND1, and 52.6% achieved MRD negativity after IND2. Nonrelapse mortality (NRM) was not reported. T315I mutation was detected in all 4 hematological relapses before HSCT. Fifty-eight patients (74.4%) underwent HSCT in CR1, and 44 (75.9%) had negative pretransplantation MRD. At a median follow-up of 4.0 years, 3-year EFS and overall survival were 66.2% (95% confidence interval [CI], 54.4-75.5) and 80.5% (95% CI, 69.7-87.7), respectively. The cumulative incidence of relapse and NRM at 3 years from enrollment were 26.1% and 7.8%, respectively. Dasatinib-based 2-step induction was demonstrated to improve 3-year EFS in Ph+ ALL. This study was registered in the UMIN Clinical Trial Registry as #UMIN000012173.

Risk factors and appropriate therapeutic strategies for thrombotic microangiopathy after allogeneic HSCT.

Transplant-associated thrombotic microangiopathy (TA-TMA) is a fatal complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, so far, no large cohort study determined the risk factors and the most effective therapeutic strategies for TA-TMA. Thus, the present study aimed to clarify these clinical aspects based on a large multicenter cohort. This retrospective cohort study was performed by the Kyoto Stem Cell Transplantation Group (KSCTG). A total of 2425 patients were enrolled from 14 institutions. All patients were aged ≥16 years, presented with hematological diseases, and received allo-HSCT after the year 2000. TA-TMA was observed in 121 patients (5.0%) on day 35 (median) and was clearly correlated with inferior overall survival (OS) (hazard ratio [HR], 4.93). Pre- and post-HSCT statistically significant risk factors identified by multivariate analyses included poorer performance status (HR, 1.69), HLA mismatch (HR, 2.17), acute graft-versus-host disease (aGVHD; grades 3-4) (HR, 4.02), Aspergillus infection (HR, 2.29), and veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS; HR, 4.47). The response rate and OS significantly better with the continuation or careful reduction of calcineurin inhibitors (CNI) than the conventional treatment strategy of switching from CNI to corticosteroids (response rate, 64.7% vs 20.0%). In summary, we identified the risk factors and the most appropriate therapeutic strategies for TA-TMA. The described treatment strategy could improve the outcomes of patients with TA-TMA in the future.

[Successful treatment of post-allogeneic hematopoietic transplant immune thrombocytopenia with eltrombopag].

A 44-year-old woman in the first remission phase of mixed-phenotype acute leukemia (T-lymphoid and myeloid lineages) suddenly exhibited thrombocytopenia (1.1×104/µl) with generalized petechiae approximately 150 days after bone marrow transplantation (BMT) from a one-locus (HLA-B) mismatched unrelated donor. Until then, the donor bone marrow had smoothly engrafted, and the platelet count had promptly normalized. Despite extensively searching for the triggering agent such as GVHD, graft failure, relapsed leukemia, or adverse drug effects, it could not be determined. Suspecting immune thrombocytopenia secondary to BMT, prednisolone (1 mg/kg/2 days) therapy was initiated, but its effects were unsatisfactory. Next, eltrombopag, a thrombopoietin receptor agonist (TPO-RA), was administered, which exhibited a marked effect on thrombocytopenia, resulting in the withdrawal of prednisolone. Even though the efficacy of eltrombopag against immune thrombocytopenia is well established, limited studies have reported the efficacy and safety of eltrombopag against immune thrombocytopenia after allogeneic stem cell transplantation. Herein we report a case in which thrombocytopenia occurred late after transplantation but was successfully treated with a TPO-RA. In addition, we discuss suspected causative mechanisms and review the literature.

Concurrent Autoimmune Neutropenia and Idiopathic Thrombocytopenic Purpura Associated with IgG4-related Diease.

IgG4-related disease (IgG4RD) is a multi-organ disorder characterized by an elevated serum IgG4 level and IgG4-positive plasma cell infiltration of the affected organs, accompanied by tissue fibrosis and sclerosis. Although it can affect any organ, to our knowledge, no cases involving concurrent autoimmune neutropenia and thrombocytopenia have been reported. A 62-year-old man visited our hospital and was diagnosed with IgG4RD accompanied by interstitial pneumonitis, lymphadenopathy, and interstitial nephritis. During his clinical course, he developed autoimmune neutropenia and idiopathic thrombocytopenic purpura. Our case, invoving multiple hematological abnormalities, might help deepen our understanding of the pathophysiology of IgG4RD.

Sequential Use of Second-Generation Tyrosine Kinase Inhibitor Treatment and Intensive Chemotherapy Induced Long-Term Complete Molecular Response in Imatinib-Resistant CML Patient Presenting as a Myeloid Blast Crisis.

Myeloid blast crisis of chronic myeloid leukemia (CML-MBC) is rarely seen at presentation and has a poor prognosis. There is no standard therapy for CML-MBC. It is often difficult to distinguish CML-MBC from acute myeloid leukemia expressing the Philadelphia chromosome (Ph+ AML). We present a case in which CML-MBC was seen at the initial presentation in a 75-year-old male. He was treated with conventional AML-directed chemotherapy followed by imatinib mesylate monotherapy, which failed to induce response. However, he achieved long-term complete molecular response after combination therapy involving dasatinib, a second-generation tyrosine kinase inhibitor, and conventional chemotherapy.

Double-hit lymphoma with a feature of follicular lymphoma concurrent with clonally related B lymphoblastic leukemia : a preference of transformation for the bone marrow.

We describe a 65-year-old woman with follicular lymphoma (FL), grade 1, stage IV, which occurred concurrently with B lymphoblastic leukemia/lymphoma. Through the evaluation of FL, the cells that were morphologically suspected of having undergone transformation were found in the bone marrow, and flow cytometric and cytogenetic analyses detected the transformed population that suggested concomitant t(8;22) with typical t(14;18) FL cells. Repeated analyses of the lymph nodes demonstrated the typical morphological, phenotypic, and cytogenetic features of FL. The patient received several multiagent chemotherapy regimens, but the disease gradually became resistant, and the patient died of leukemic progression. In B-cell malignancies, cases involving both BCL2 and MYC translocations simultaneously, so-called "double-hit leukemia/lymphoma (DHL)", have occasionally been reported. Patients with this type of translocation have a very poor clinical outcome, and no standard therapy has been established. In our case, FL was supposed to have transformed into B lymphoblastic leukemia via Burkitt's lymphoma-like phase. Our case is unique in that the transformed DHL cells, derived from clonally related FL cells, showed ongoing transformation from Burkitt-like feature to B lymphoblastic leukemia exclusively in the bone marrow, which suggests that the bone marrow may provide a preferable milieu for malignant transformation. Similar cases should be accumulated and analyzed carefully.

Progressive multifocal leukoencephalopathy in myelodysplastic syndrome involving pure red cell aplasia.

Progressive multifocal leukoencephalopathy (PML) is a rare and fatal demyelinating disease of the central nervous system caused by JC polyomavirus (JCV) reactivation in an immunocompromised host. We describe a case of PML in a 76-year-old woman with myelodysplastic syndrome, who had been treated with azathioprine for a pure red cell aplasia-like condition. PML was diagnosed based on the neurologic symptoms, the magnetic resonance imaging patterns and the detection of JCV DNA in the cerebrospinal fluid. She died ten months after the diagnosis. An autopsy confirmed the diagnosis, and JCV DNA was detected in the cerebrum. Azathioprine might have triggered PML.

Refractory Evans syndrome after autologous stem cell transplantation for multiple myeloma: management with a second transplantation.

The development of autoimmune disease after autologous stem cell transplantation (ASCT) is very rare in multiple myeloma (MM). We describe the first case of Evans syndrome after ASCT for MM. A 60-year-old man with MM received ASCT and subsequently developed Evans syndrome following two febrile episodes. The syndrome was refractory to conventional therapies but it was managed with a second ASCT. This unique complication was thought to have been triggered by an infection during the recovery of the immune system. We assumed that reconstructing the immune system via ASCT might eliminate infection-induced autoantibodies to platelets and erythrocytes.

Epstein-Barr virus-induced infectious mononucleosis after two separate episodes of virus-associated hemophagocytic syndrome.

A 24-year-old man, who had suffered previous two episodes of non- Epstein-Barr virus (EBV)-associated hemophagocytic syndrome (HPS) at the ages of 16 and 18, developed EBV-induced infectious mononucleosis. His antibody pattern to EBV highlighted the initial infection. The disease took a self-limited course without developing into HPS. No reactivation of EBV infection was noted over the following 6 years. The patient may have attained immune competency in adulthood, which was somehow impaired during his adolescence.

First case report of sepsis caused by Mycobacterium wolinskyi in chronic myelogenous leukemia.

Infections caused by Mycobacterium wolinskyi have rarely been reported, and essentially all were cellulitis and/or osteomyelitis related with traumatic event or surgical wound. Here, we present the 1st case of septic complication due to this organism in a patient with chronic myelogenous leukemia of the 1st but late chronic phase.