Successful treatment of severe splenic lymphoma­associated hemophagocytic syndrome by splenectomy and subsequent chemotherapy: A case report.

Hemophagocytic lymphohistiocytosis (HLH) represents a fatal immunopathology derived from excessive inflammatory reactions. In particular, lymphoma-associated hemophagocytic syndrome (LAHS) is associated with a dismal prognosis. The current study presented a challenging case of splenic LAHS. A 71-year-old man presented with fatigue and anorexia. Laboratory test results revealed anemia, thrombocytopenia, lactate dehydrogenase elevation and markedly elevated levels of ferritin (6,210 ng/ml) and soluble interleukin 2 receptor (sIL-2R; 11,328 U/ml). Abdominal computed tomography revealed marked splenomegaly, while fluorodeoxyglucose positron emission tomography revealed increased tracer uptake in the spleen. An elective splenectomy was performed, which led to the diagnosis of B-cell splenic lymphoma with transformation from indolent to aggressive lymphoma. Prior to the splenectomy, thrombocytopenia and hepatic dysfunction with rapidly progressing jaundice appeared, accompanying further elevation of ferritin (25,197 ng/ml) and sIL-2R levels (30,420 U/ml). On postoperative day 5, the patient was transferred to a tertiary care institution and corticosteroid pulse therapy was immediately initiated after establishing the diagnosis of LAHS. Liver dysfunction gradually recovered and subsequent chemotherapy resulted in complete remission with improved performance status. At eight months after the onset, the patient remains alive without any signs of residual lymphoma. Although splenic lymphoma typically manifests with low-grade lymphoma, it can transform into high-grade lymphoma associated with severe complications, such as HLH and multiple organ failure. In this case, splenectomy assisted in not only establishing the diagnosis but also in tumor cytoreduction before commencing chemotherapy. Through interdisciplinary collaboration, the patient was successfully treated by performing a timely splenectomy, followed by steroid pulse therapy and chemotherapy.

Genetic manipulation resulting in decreased donor chondroitin sulfate synthesis mitigates hepatic GVHD via suppression of T cell activity.

Donor T cell activation, proliferation, differentiation, and migration are the major steps involved in graft-versus-host disease (GVHD) development following bone marrow transplantation. Chondroitin sulfate (CS) proteoglycan is a major component of the extracellular matrix and causes immune modulation by interacting with cell growth factors and inducing cell adhesion. However, its precise effects on immune function are unclear than those of other proteoglycan families. Thus, we investigated the significance of CS within donor cells in acute GVHD development utilizing CSGalNAc T1-knockout (T1KO) mice. To determine the effects of T1KO, the mice underwent allogenic bone marrow transplantation from major histocompatibility complex-mismatched donors. While transplantation resulted in hepatic GVHD with inflammatory cell infiltration of both CD4+ and CD8+ effector memory T cells, transplantation in T1KO-donors showed milder cell infiltration and improved survival with fewer splenic effector T cells. In vitro T-cell analyses showed that the ratio of effector memory T cells was significantly lower via phorbol myristate acetate/ionomycin stimulation. Moreover, quantitative PCR analyses showed significantly less production of inflammatory cytokines, such as IFN-γ and CCL-2, in splenocytes of T1KO mice. These results suggest that reduction of CS in donor blood cells may suppress the severity of acute GVHD after hematopoietic stem cell transplantation.

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.

Dual inhibition of the MEK/ERK and PI3K/AKT pathways prevents pulmonary GVHD suppressing perivenulitis and bronchiolitis.

Patients with pulmonary graft-versus-host disease (pGVHD) have a poor prognosis after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Furthermore, pGVHD pathogenesis is not fully elucidated in humans, and currently available immunosuppressants are inadequately effective. We performed pathologic evaluation of lung specimens from 45 allo-HSCT recipients with pGVHD who underwent lung transplantation. Patient pathology was characterized by bronchiolitis and subpleural perivascular inflammation, with B-cell, monocyte, and T-cell accumulation around bronchioles. Bronchiolitis, perivascular inflammation, and peribronchial macrophage aggregation were also identified in a murine pGVHD model after transplant of bone marrow cells and splenocytes from C57BL/6 to B10.BR mice. Among mitogen-activated protein kinase kinase (MEK) inhibitors, cobimetinib, but not trametinib, improved survival rates. Cobimetinib attenuated bronchiolitis, improved airway resistance and lung compliance in the mice, and suppressed activation of B cells and tumor necrosis factor α production by monocytes in vitro; these features were not suppressed by trametinib or tacrolimus. Furthermore, cobimetinib suppressed activation of phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling, resulting in B-cell and monocyte suppression. Dual inhibition of the MEK/extracellular signal-regulated kinase (ERK) and PI3K/AKT pathways using a combination of trametinib and the PI3K inhibitor taselisib strongly suppressed B-cell activation in vitro and improved mouse survival rates compared with vehicle or monotherapy with trametinib or taselisib. Imaging mass cytometry of human pGVHD revealed that T cells around bronchioles were positive for phosphorylated ERK, whereas B cells were positive for phosphorylated AKT. Thus, perivascular inflammation and bronchiolitis mediated by activation of the MEK/ERK and PI3K/AKT pathways are essential for pGVHD and represent a potential novel therapeutic target in humans.

Oral HDAC inhibitor tucidinostat in patients with relapsed or refractory peripheral T-cell lymphoma: phase IIb results.

Tucidinostat (formerly known as chidamide) is an orally available, novel benzamide class of histone deacetylase (HDAC) inhibitor that selectively blocks class I and class IIb HDAC. This multicenter phase IIb study aimed to investigate the efficacy and safety of tucidinostat, 40 mg twice per week (BIW), in patients with relapsed/refractory (R/R) peripheral T-cell lymphoma (PTCL). The primary endpoint was overall response rate (ORR) assessed by an independent overall efficacy review committee. Between March 2017 and March 2019, 55 patients were treated, and 46 and 55 were evaluated for efficacy and safety, respectively. Twenty-one of 46 patients achieved objective responses with an ORR of 46% (95% confidence interval : 30.9-61.0), including five patients with complete response (CR). Responses were observed across various PTCL subtypes. In angioimmunoblastic T-cell lymphoma, there were two CR and five partial responses (PR) among eight patients, achieving an ORR of 88%. The disease control rate (CR + PR + stable disease) was 72% (33/46). The median progression-free survival, duration of response, and overall survival were 5.6 months, 11.5 months, 22.8 months, respectively. The most common adverse events (AE) (all grades) were thrombocytopenia, neutropenia, leukopenia, anemia, and diarrhea. The grade ≥3 AE emerging in ≥20% of patients included thrombocytopenia (51%), neutropenia (36%), lymphopenia (22%), and leukopenia (20%). Importantly, most of the AE were manageable by supportive care and dose modification. In conclusion, the favorable efficacy and safety profiles indicate that tucidinostat could be a new therapeutic option in patients with R/R PTCL (clinicaltrials gov. Identifier: NCT02953652).

Impact of HLA Epitope Matching on Outcomes After Unrelated Bone Marrow Transplantation.

The significance of antibody-identified epitopes stimulating humoral alloimmunity is not well understood in the identification of non-permissive human leukocyte antigen (HLA) mismatching patterns in hematopoietic stem cell transplantation (HSCT). This was a retrospective study in a cohort of 9,991 patients who underwent their first HSCT for hematologic malignancies from unrelated bone marrow donors in the Transplant Registry Unified Management Program (TRUMP). HLA eplet mismatches (EMM) were quantified using HLAMatchmaker (HLAMM). The median age of patients was 48 years (range, 16 to 77). The number of EMM in recipient-donor pairs in our study population ranged from 0 to 37 in HLA class I (median, 0) and 0 to 60 in HLA class II (median, 1). In addition to the known high-risk mismatch patterns in the Japanese cohort, HLA-C EMM in the GVH direction was associated with a significantly higher risk for grade III-IV aGVHD, leading to a higher risk of non-relapse mortality and lower overall survival (compared with HLA-C matched patients, HR 1.67, 95% CI 1.44-1.95; HR 1.39, 95% CI 1.25-1.54; HR 1.20, 95% CI 1.10-1.30, respectively). HLAMM-based epitope matching might be useful for identifying patients who are at high risk for serious complications after HSCT from HLA mismatched unrelated donors.

Development of a novel Indium-111 radiolabeled mogamulizumab targeting CCR4 for imaging adult T-cell leukemia/lymphoma in vivo.

OBJECTIVE: Adult T-cell leukemia/lymphoma (ATL), caused by human T-cell lymphotropic virus type I (HTLV-1) infection, is among the most aggressive categories and has the worst prognosis among T-cell lymphomas. Mogamulizumab, an anti-CC chemokine receptor 4 (CCR 4), has been shown to be effective in the treatment of ATL; however, some ATL cases are often resistant, particularly the lymphoma-type ATL. To evaluate drug delivery in vivo and identify the distribution of CCR4-positive cells in the body, we developed a novel mogamulizumab tracer labeled with Indium-111 (111In) via diethylenetriaminepentaacetic acid (DTPA) for single-photon emission computerized tomography (SPECT), named [111In]In-DTPA-mogamulizumab, and evaluated its potential for visualizing CCR4 expression in vivo. METHODS: [111In]In-DTPA-mogamulizumab was added to HCT116/CCR4 or HCT116/empty vector (EV) cells, and their radioactivity was measured 1 h after administration. A blocking study was additionally performed by treating HCT116/CCR4 cells with excess mogamulizumab in addition to [111In]In-DTPA-mogamulizumab. The biodistribution and SPECT imaging of [111In]In-DTPA-mogamulizumab in HCT116/CCR4 and HCT116/EV dual-xenografted BALB/c-nu mice were evaluated for 72 h after intravenous injection. RESULTS: [111In]In-DTPA-mogamulizumab was acquired with a radiochemical purity > 95%. The cellular uptake level of [111In]In-DTPA-mogamulizumab by HCT116/CCR4 cells was significantly higher than that by HCT116/EV cells (HCT116/CCR4: 0.951 ± 0.069, HCT116/EV: 0.006 ± 0.001%dose/mg protein, p < 0.01), and the uptake was significantly suppressed by co-incubation with excess mogamulizumab (0.013 ± 0.003%dose/mg protein, p < 0.01). In the in vivo study, the radioactivity of the HCT116/CCR4 tumor tissue was significantly higher than that of the HCT116/EV tumor tissue at 72 h after the administration of [111In]In-DTPA-mogamulizumab (HCT116/CCR4: 20.5 ± 5.4, HCT116/EV: 5.7 ± 1.0%ID/g), and HCT116/CCR4 tumors were clearly and specifically visualized on SPECT imaging. CONCLUSIONS: We have successfully developed a novel SPECT imaging tracer targeting CCR4, [111In]In-DTPA-mogamulizumab, which showed good specificity and pharmacokinetics, indicating potential in visualizing CCR4 expression in vivo.

KIR3DL1 Allotype-Dependent Modulation of NK Cell Immunity against Chronic Myeloid Leukemia.

Tyrosine kinase inhibitor (TKI)-treated chronic myeloid leukemia (CML) patients with increased NK cell number have a better prognosis, and thus, NK cells may suppress CML. However, the efficacy of TKIs varies for reasons yet to be fully elucidated. As NK cell activity is modulated by interactions between their killer cell Ig-like receptors (KIRs) and HLAs of target cells, the combination of their polymorphisms may have functional significance. We previously showed that allelic polymorphisms of KIR3DL1 and HLAs were associated with the prognosis of TKI-treated CML patients. In this study, we focus on differential NK cell activity modulation through KIR3DL1 allotypes. KIR3DL1 expression levels varied according to their alleles. The combination of KIR3DL1 expression level and HLA-Bw4 motifs defined NK cell activity in response to the CML-derived K562 cell line, and Ab-mediated KIR3DL1 blocking reversed this activity. The TKI dasatinib enhanced NK cell activation and cytotoxicity in a KIR3DL1 allotype-dependent manner but did not significantly decrease effector regulatory T cells, suggesting that it directly activated NK cells. Dasatinib also enhanced NK cell cytotoxicity against K562 bearing the BCR-ABL1 T315I TKI resistance-conferring mutation, depending on KIR3DL1/HLA-Bw4 allotypes. Transduction of KIR3DL1*01502 into the NK cell line NK-92 resulted in KIR3DL1 expression and suppression of NK-92 activity by HLA-B ligation, which was reversed by anti-KIR3DL1 Ab. Finally, KIR3DL1 expression levels also defined activation patterns in CML patient-derived NK cells. Our findings raise the possibility of a novel strategy to enhance antitumor NK cell immunity against CML in a KIR3DL1 allotype-dependent manner.

Pharmacological MEK inhibition promotes polyclonal T-cell reconstitution and suppresses xenogeneic GVHD.

Rapid immune reconstitution without developing graft-versus-host disease (GVHD) is required for the success of allogeneic hematopoietic stem cell transplantation. Here, we analyzed the effects of pharmacological MEK inhibition on human polyclonal T-cell reconstitution in a humanized mouse GVHD model utilizing deep sequencing-based T-cell receptor (TCR) repertoire analysis. GVHD mice exhibited a skewed TCR repertoire with a common clone within target organs. The MEK inhibitor trametinib ameliorated GVHD and enabled engraftment of diverse T-cell clones. Furthermore, trametinib also ameliorated GVHD sparing diverse T cell repertoire, even when it was given from day 15 through 28. Although tacrolimus also reduced development of GVHD, it disturbed diverse T cell reconstitution and resulted in skewed TCR repertoire. Thus, trametinib not only suppresses GVHD-inducing T cells but also promotes human T cell reconstitution in vivo, providing a novel rationale for translational studies targeting human GVHD.

Early Elevation of Complement Factor Ba Is a Predictive Biomarker for Transplant-Associated Thrombotic Microangiopathy.

Transplant-associated thrombotic microangiopathy (TA-TMA) is a fatal complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Previous reports suggest that TA-TMA is caused by complement activation by complement-related genetic variants; however, this needs to be verified, especially in adults. Here, we performed a nested case-control study of allo-HSCT-treated adults at a single center. Fifteen TA-TMA patients and 15 non-TA-TMA patients, matched according to the propensity score, were enrolled. Based on a previous report showing an association between complement-related genes and development of TA-TMA, we first sequenced these 17 genes. Both cohorts harbored several genetic variants with rare allele frequencies; however, there was no difference in the percentage of patients in the TA-TMA and non-TA-TMA groups with the rare variants, or in the average number of rare variants per patient. Second, we measured plasma concentrations of complement proteins. Notably, levels of Ba protein on Day 7 following allo-HSCT were abnormally and significantly higher in TA-TMA than in non-TA-TMA cases, suggesting that complement activation via the alternative pathway contributes to TA-TMA. All other parameters, including soluble C5b-9, on Day 7 were similar between the groups. The levels of C3, C4, CH50, and complement factors H and I in the TA-TMA group after Day 28 were significantly lower than those in the non-TA-TMA group. Complement-related genetic variants did not predict TA-TMA development. By contrast, abnormally high levels of Ba on Day 7 did predict development of TA-TMA and non-relapse mortality. Thus, Ba levels on Day 7 after allo-HSCT are a sensitive and prognostic biomarker of TA-TMA.

Next-generation sequencing in two cases of de novo acute basophilic leukaemia.

Acute basophilic leukaemia (ABL) is a rare subtype of acute myeloid leukaemia (AML); therefore, few data are available about its biology. Herein, we analysed two ABL patients using flow cytometry and next-generation sequencing (NGS). Two cell populations were detected by flow cytometry in both patients. In Case no. 1, blasts (CD34+ , CD203c- , CD117+ , CD123dim+ ) and basophils (CD34- , CD203c+ , CD117± , CD123+ ) were identified, both of which were found by NGS to harbour the 17p deletion and have loss of heterozygosity of TP53. In Case no. 2, blasts (CD33+ , CD34+ , CD123- ) and basophils (CD33+ , CD34+ , CD123+ ) were identified. NGS detected NPM1 mutations in either blasts or basophils, and TET2 in both. These data suggest an overlap of the mutational landscape of ABL and AML, including TP53 and TET2 mutations. Moreover, additional mutations or epigenetic factors may contribute for the differentiation into basophilic blasts.

T-cell chimerism prior to graft-versus-host disease.

Graft-versus-host disease (GVHD), a serious complication of haematopoietic stem cell transplantation, can occur following solid organ transplantation. However, diagnosing solid organ transplantation-associated GVHD is difficult, and its risk factors are not fully understood. Here, we report a GVHD case in a 59-year-old woman with dermatomyositis-associated interstitial pneumonia, who took immunosuppressants including corticosteroids before receiving right lung transplantation from a 13-year-old brain-dead male donor. She developed systemic erythema with desquamation and pancytopenia by day 20. Mixed chimerism with donor- and recipient-type cells in the bone marrow and skin led to the diagnosis of GVHD. Corticosteroid pulse therapy reduced the symptoms and decreased donor-type cell percentage. On day 50, the patient developed donor lung injury and was diagnosed with acute rejection, which was treated using steroid pulse therapy again. Although the granulocytes were recipient type, donor chimerism of peripheral blood T cells exacerbated on day 68. Subsequent deterioration of liver function and pulmonary injury in the patient's own lung led to the diagnosis of relapsing GVHD. The patient died of multiple organ failure despite treatment with anti-thymocyte globulin. Thus, repeated steroid pulse therapy and age difference between donors and recipients may predispose to GVHD and T-cell mixed chimerism can be an important diagnostic indicator of GVHD.

[Small B-cell neoplasm responding to ibrutinib after 17 years of cold agglutinin disease symptom].

In this study, we report a case of a 77-year-old woman who was presented with anemia in the winter of 2002. She was diagnosed with cold agglutinin disease (CAD) and treated with corticosteroids. Further, her hemoglobin levels were maintained between 7.0 g/dl and 8.0 g/dl. In May 2019, mature peripheral blood lymphocytes increased with exacerbation of hemolytic anemia. The lymphocytes were positive for CD19 and CD20, but negative for CD5, CD10, and CD23. Additionally, they were positive for cell surface IgM-κ. The B-cell neoplasm could not be further subclassified due to the lack of BCL2-IgH and BCL1-IgH rearrangement and morphology. The IgM-κ-type M-protein was found in serum, and the direct Coombs test was negative for IgG but positive for C3b/C3d. These findings suggested that small B-cell neoplasm-associated M-protein was involved in the development of CAD through complement activation. Based on the presence of TP53 deletion, the patient was treated with ibrutinib monotherapy. Although hemolysis rapidly improved with a dramatic decrease in lymphocytes, she died from a cerebral hemorrhage. It is assumed that ibrutinib improved CAD through suppression of small B-cell neoplasm-related M-protein. CAD can precede lymphoproliferative disorders; however, the risk of ibrutinib-associated hemorrhage should be noted.

Upper Gastrointestinal Langerhans Cell Histiocytosis: A Report of 2 Adult Cases and a Literature Review.

Langerhans cell histiocytosis (LCH) with primary involvement of the upper gastrointestinal (GI) tract is rare. We report 2 adult cases of localized LCH in the upper-GI tract, including the second reported adult case of esophageal LCH and review 11 previously reported cases. Case 1 involved the esophagus of a 61-year-old man; histiocytosis was detected when endoscopy was performed for an examination of epigastric pain. Case 2 involved the stomach of a 56-year-old woman wherein the lesion was detected during a follow-up endoscopy after Helicobacter pylori infection. Both biopsy specimens exhibited diffuse proliferation of mononuclear cells with nuclear convolution and a background of eosinophilic infiltrate. The cells were immunohistochemically positive for CD1a and langerin, and BRAF V600E mutation was detected in Case 2. Follow-up endoscopy for both cases revealed that the lesions disappeared without any treatment. It is important to avoid misdiagnosing LCH of the upper-GI tract as a malignant neoplasm.

GVHD-free, relapse-free survival provides novel clues for optimizing allogeneic-HSCT for adult T-cell leukemia/lymphoma.

The outcome of allogeneic hematopoietic stem cell transplantation (allo-HSCT) for adult T-cell leukemia/lymphoma (ATL) is still unsatisfactory. To illustrate the advantages and disadvantages of each donor source, we performed a nationwide retrospective study of graft-versus-host disease (GVHD)-free, relapse-free survival (GRFS) of patients with allo-HSCT-treated ATL. One-year GRFS did not significantly differ between patients who received related bone marrow transplantation (R-BMT; 26%, n = 117), related peripheral blood stem cell transplantation (R-PBSCT; 22%, n = 225), unrelated bone marrow transplantation (UR-BMT; 26%, n = 619), and cord blood transplantation (CBT; 21%, n = 359; p = 0.09). This was attributable to a low incidence of systemically-treated chronic GVHD after CBT (9% at 1 year) and reduced non-GVHD/relapse mortality after R-PBSCT (9% at 1 year). Among patients transplanted in complete remission (CR), 1-year overall survival after CBT (52%, n = 132) was not inferior to that after R-BMT (55%, n = 51), R-PBSCT (57%, n = 79), and UR-BMT (58%, n = 280; p = 0.15), and relapse rates were equivalent among the four sources (p = 0.19). Our results suggest that all donor sources are feasible for CR patients and that GRFS provides important clues toward optimizing allo-HSCT for ATL.