First reported case of Lachnoanaerobaculum gingivalis bacteremia in an acute myeloid leukemia patient with oral mucositis during high dose chemotherapy.

CASE DESCRIPTION: Lachnoanaerobaculum gingivalis is an obligate anaerobe identified in a human dental plaque in 2019. Here, we report the first case of L. gingivalis bacteremia in a patient with oral mucositis during chemotherapy. L. gingivalis was confirmed by 16S rRNA gene analysis but not by MALDI-TOF-MS. CONCLUSION: During chemotherapy in patients with oral mucositis, we should consider the possibility of L. gingivalis bacteremia.

[Primary cutaneous anaplastic large cell lymphoma with systemic progression responding to low-dose methotrexate therapy].

The standard therapies for primary cutaneous anaplastic large cell lymphoma (pcALCL) in an advanced stage remain undefined. A 71-year-old man presented with multiple erythema and nodules. He was diagnosed with lymphomatoid papulosis (LyP) through a skin biopsy from the left postauricular area. All skin lesions achieved complete response by electron beam irradiation. However, nodular lesions appeared in both inner canthi 5 months later. Histopathological evaluation of the lesional biopsy revealed dominant infiltration of CD30-positive large cells. Positron emission tomography/computed tomography revealed fluorodeoxyglucose-positive cervical and inguinal lymph node swelling and right tonsillitis, followed by the diagnosis of pcALCL and TNM classification T3bN3M0. Since the patient had severe chronic obstructive pulmonary disease and recurrent pneumonia, he received low-dose methotrexate (MTX) (15 mg/week) therapy. Low-dose MTX effectively debulked the lymphadenopathies over time without particular adverse effects. Although the standard therapies for pcALCL are not established, low-dose MTX was effective and considered safe for patients with frailty and compromised respiratory function. Further study is warranted on the pathophysiology of pcALCL after the development of LyP and mechanisms of action of low-dose MTX against LyP and pcALCL.

TAK1 is a pivotal therapeutic target for tumor progression and bone destruction in myeloma.

Along with the tumor progression, the bone marrow microenvironment is skewed in multiple myeloma (MM), which underlies the unique pathophysiology of MM and confers aggressiveness and drug resistance in MM cells. TGF-ß-activated kinase-1 (TAK1) mediates a wide range of intracellular signaling pathways. We demonstrate here that TAK1 is constitutively overexpressed and phosphorylated in MM cells, and that TAK1 inhibition suppresses the activation of NF-κB, p38MAPK, ERK and STAT3 to decrease the expression of critical mediators for MM growth and survival, including PIM2, MYC, Mcl-1, IRF4, and Sp1, along with a substantial reduction in the angiogenic factor VEGF in MM cells. Intriguingly, TAK1 phosphorylation was also induced along with upregulation of vascular cell adhesion molecule-1 (VCAM-1) in bone marrow stromal cells (BMSCs) in cocultures with MM cells, which facilitated MM cell-BMSC adhesion while inducing IL-6 production and receptor activator of nuclear factor κ-Β ligand (RANKL) expression by BMSCs. TAK1 inhibition effectively impaired MM cell adhesion to BMSCs to disrupt the support of MM cell growth and survival by BMSCs. Furthermore, TAK1 inhibition suppressed osteoclastogenesis enhanced by RANKL in cocultures of bone marrow cells with MM cells, and restored osteoblastic differentiation suppressed by MM cells or inhibitory factors for osteoblastogenesis overproduced in MM. Finally, treatment with the TAK1 inhibitor LLZ1640-2 markedly suppressed MM tumor growth and prevented bone destruction and loss in mouse MM models. Therefore, TAK1 inhibition may be a promising therapeutic option targeting not only MM cells but also the skewed bone marrow microenvironment in MM.

Cryptosporidiosis in a transplant recipient with severe intractable diarrhea: Detection of Cryptosporidium oocysts by intestinal biopsies.

Disseminated Cryptosporidium infection results in manifestations similar to those of graft-versus-host disease (GVHD), which hampers the detection of Cryptosporidium infection after allogeneic hematopoietic stem cell transplantation. Surveillance of oocysts on the surface of intestinal epithelial cells is needed for early and appropriate detection of Cryptosporidium infection in transplant recipients on immunosuppressants with severe intractable diarrhea. We present the first case of Cryptosporidium meleagridis infection in Japan after allogeneic cord blood transplantation.

Steroid pulse therapy in patients with encephalopathy associated with severe fever with thrombocytopenia syndrome.

Severe fever with thrombocytopenia syndrome (SFTS) is a tick-borne infectious disease caused by the SFTS virus (SFTSV). Clinical symptoms of SFTS often involve encephalopathy and other central neurological symptoms, particularly in seriously ill patients; however, pathogenesis of encephalopathy by SFTSV is largely unknown. Herein, we present case reports of three patients with SFTS, complicated by encephalopathy, admitted to Tokushima University hospital: one patient was a 63-year-old man, while the other two were 83- and 86-year-old women. All of them developed disturbance of consciousness around the 7th day post onset of fever. After methylprednisolone pulse therapy of 500 mg/day, all of them recovered without any neurological sequelae. SFTSV genome was not detected in the cerebrospinal fluid of 2 out of the 3 patients that were available for examination. In these patients, disturbance of consciousness seemed to be an indirect effect of the cytokine storm triggered by SFTSV infection. We propose that short-term glucocorticoid therapy might be beneficial in the treatment of encephalopathy during early phase of SFTSV infection.

[Analysis of long-term survivors with cardiac AL amyloidosis].

Cardiac AL amyloidosis (CA) is generally known as a severe disease with very poor prognosis. Here we retrospectively examined seven patients with CA in our cohort who achieved long-term survival. All six patients who underwent high-dose melphalan and autologous stem cell transplantation (ASCT) survived for >3 years, whereas four patients survived for >5 years. Patients who underwent ASCT had prompt hematological responses, and five patients showed organ responses. ASCT helps to achieve a quick and deep hematological response required for long-term survival in patients with CA. New agents have been implemented for the treatment of CA. However, the risks and benefits of each treatment modality should be considered according to patient condition, thus making the best use of ASCT in combination with new agents for the treatment of CA.

Acute suppression of translation by hyperthermia enhances anti-myeloma activity of carfilzomib.

Hyperthermia is a unique treatment option for cancers. Multiple myeloma (MM) remains incurable and innovative therapeutic options are needed. We investigated the efficacy of hyperthermia and carfilzomib in combination against MM cells. Although MM cell lines exhibited different susceptibilities to pulsatile carfilzomib treatment, mild hyperthermia at 43℃ induced MM cell death in all cell lines in a time-dependent manner. Hyperthermia and carfilzomib cooperatively induced MM cell death even under suboptimal conditions. The pro-survival mediators PIM2 and NRF2 accumulated in MM cells due to inhibition of their proteasomal degradation by carfilzomib; however, hyperthermia acutely suppressed translation in parallel with phosphorylation of eIF2α to reduce these proteins in MM cells. Recovery of ß5 subunit enzymatic activity from its immediate inhibition by carfilzomib was observed at 24 h in carfilzomib-insusceptible KMS-11, OPM-2, and RPMI8226 cells, but not in carfilzomib-sensitive MM.1S cells. However, heat treatment suppressed the recovery of ß5 subunit activity in these carfilzomib-insusceptible cells. Therefore, hyperthermia re-sensitized MM cells to carfilzomib. Our results support the treatment of MM with hyperthermia in combination with carfilzomib. Further research is warranted on hyperthermia for drug-resistant extramedullary plasmacytoma.

Skeletal muscle mass during chemotherapy for haematological malignancies: a retrospective study.

OBJECTIVE: This study investigated whether baseline or alteration in muscle mass affects complications during chemotherapy or overall survival (OS) in haematological malignancies. METHODS: Skeletal Muscle Index (SMI) was evaluated by bioimpedance analysis before and after chemotherapy in patients with haematological malignancies, and the association between muscle mass and clinical data was retrospectively analysed. RESULTS: Exactly 104 patients were enrolled, with a mean age of 62.2 years. SMI was 7.85 and 6.08 in male and female patients under 65 years and 7.10 and 5.92 over 65 years, before chemotherapy, respectively. Lower baseline SMI was not correlated with worse OS in total patients (p=0.915). After a median measurement interval of 30 days after chemotherapy (n=67), body weight and SMI decreased by 2.73% and 2.87% (mean), respectively. The decrease in body weight correlated with the loss of trunk muscle mass (R2=0.2107) but was more strongly associated with the loss of lower limbs muscle mass (R2=0.3985). The muscle mass of lower limbs significantly decreased in lymphoma patients who experienced febrile neutropenia (-0.42% vs -6.04%, p=0.040). OS significantly decreased in lymphoma patients with loss of lower limbs muscle ≥2.8% (p=0.0327). CONCLUSIONS: Muscle loss occurred following anticancer treatments, significantly contributing to worse outcomes. Body composition assessment and relevant multimodal prevention of muscle loss may be vital for patients receiving chemotherapy for haematological malignancies.

Ex vivo expansion and activation of Vγ9Vδ2 T cells by CELMoDs in combination with zoledronic acid.

As multiple myeloma (MM) progresses, immune effector cells decrease in number and function and become exhausted. This remains an insurmountable clinical issue that must be addressed by development of novel modalities to revitalize anti-MM immunity. Human Vγ9Vδ2 T (Vδ2+ γδ T) cells serve as the first line of defense against pathogens as well as tumors and can be expanded ex vivo from peripheral blood mononuclear cells (PBMCs) upon treatment with amino-bisphosphonates in combination with IL-2. Here, we demonstrated that next-generation immunomodulators called cereblon E3 ligase modulators (CELMoDs), as well as lenalidomide and pomalidomide, expanded Th1-like Vδ2+ γδ T cells from PBMCs in the presence of zoledronic acid (ZA). However, the expansion of Th1-like Vδ2+ γδ T cells by these immunomodulatory drugs was abolished under IL-2 blockade, although IL-2 production was induced in PBMCs. BTN3A1 triggers phosphoantigen presentation to γδ T-cell receptors and is required for γδ T-cell expansion and activation. ZA but not these immunomodulatory drugs upregulated BTN3A1 in monocytes. These results suggest that immunomodulatory drugs and ZA have cooperative roles in expansion of Th1-like Vδ2+ γδ T cells, and provide the important knowledge for clinical application of human Vδ2+ γδ T cells as effector cells.

Toxoplasmic encephalitis with high 201Tl uptake and retention mimicking malignant lymphoma in a patient with human immunodeficiency virus infection.

Various opportunistic infections develop during immunodeficiency due to human immunodeficiency virus (HIV) infection. The treatment options for malignant lymphoma (ML) and toxoplasmic encephalitis (TE) are completely different; therefore, their discrimination is critical. A 25-year-old female of foreign nationality had been experiencing headaches for several weeks and suddenly developed convulsions. Brain computed tomography revealed multiple intracranial lesions; therefore, the patient was referred to the neurosurgery department. Brain magnetic resonance imaging (MRI) revealed multiple masses with surrounding edema, accompanied by enhanced contrast. The largest mass (2 cm) in the left occipital lobe exhibited ringed contrast enhancement. Her blood test results showed a CD4 count of 40/µL, positive HIV Ag/Ab, HIV-RNA level of 56 × 104 copies/mL, positive anti-Toxoplasma IgG (63 IU/mL), and negative anti-Toxoplasma IgM. 201Tl- single photon emission computed tomography (201Tl-SPECT) revealed abnormal accumulation only in the tumor in the left occipital lobe (early T/N ratio, 3.034; delayed T/N ratio, 2.738; retention index, 0.9), which was suspected to be a ML. Both tumors, with or without high accumulation of 201Tl, were subjected to craniotomy biopsy. Pathological examination revealed infiltration of small lymphocytes with a necrotic background. The patient was diagnosed with TE based on a positive result of a tissue polymerase chain reaction test for Toxoplasma gondii. Two weeks after sulfamethoxazole and trimethoprim combination therapy, MRI imaging showed dramatic improvement in multiple brain tumors. This case is atypical because ML was ruled out despite high 201Tl-SPECT uptake and retention. Careful diagnosis through pathological examination and DNA testing is important.

Acute accumulation of PIM2 and NRF2 and recovery of ß5 subunit activity mitigate multiple myeloma cell susceptibility to proteasome inhibitors.

Resistance to proteasome inhibitors (PIs) has emerged as an important clinical issue. We investigated the mechanisms underlying multiple myeloma (MM) cell resistance to PIs. To mimic their pharmacokinetic/pharmacodynamic (PK/PD) profiles, MM cells were treated with bortezomib and carfilzomib for 1 h at concentrations up to 400 and 1,000 nM, respectively. Susceptibility to these PIs markedly varied among MM cell lines. Pulsatile treatments with PIs suppressed translation, as demonstrated by incorporation of puromycin at 24 h in PI-susceptible MM.1S cells, but not PI-resistant KMS-11 cells. Inhibition of ß5 subunit activity decreased at 24 h in KMS-11 cells, even with the irreversible PI carfilzomib, but not under suppression of protein synthesis with cycloheximide. Furthermore, the proteasome-degradable pro-survival factors PIM2 and NRF2 acutely accumulated in MM cells subjected to pulsatile PI treatments. Accumulated NRF2 was trans-localized into the nucleus to induce the expression of its target gene, HMOX1, in MM cells. PIM and Akt inhibition restored the anti-MM effects of PIs, even against PI-resistant KMS-11 cells. Collectively, these results suggest that increased synthesis of ß5 proteasome subunit and acute accumulation of PIM2 and NRF2 reduce the anti-MM effects of PIs.

Mechanisms of preferential bone formation in myeloma bone lesions by proteasome inhibitors.

Proteasome inhibitors (PIs) can preferentially restore bone in bone-defective lesions of patients with multiple myeloma (MM) who respond favorably to these drugs. Most prior in vitro studies on PIs used continuous exposure to low PI concentrations, although pharmacokinetic analysis in patients has shown that serum concentrations of PIs change in a pulsatile manner. In the present study, we explored the effects of pulsatile treatment with PIs on bone metabolism to simulate in vivo PI pharmacokinetics. Pulsatile treatment with bortezomib, carfilzomib, or ixazomib induced MM cell death but only marginally affected the viability of osteoclasts (OCs) with F-actin ring formation. Pulsatile PI treatment suppressed osteoclastogenesis in OC precursors and bone resorption by mature OCs. OCs robustly enhanced osteoblastogenesis in cocultures with OCs and MC3T3-E1 pre-osteoblastic cells, indicating OC-mediated coupling to osteoblastogenesis. Importantly, pulsatile PI treatment did not impair robust OC-mediated osteoblastogenesis. These results suggest that PIs might sufficiently reduce MM cell-derived osteoblastogenesis inhibitors to permit OC-driven bone formation coupling while suppressing OC differentiation and activity in good responders to PIs. OC-mediated coupling to osteoblastogenesis appears to be a predominant mechanism for preferential occurrence of bone regeneration at sites of osteoclastic bone destruction in good responders.

Therapeutic efficacy of the resorcylic acid lactone LL-Z1640-2 for adult T-cell leukaemia/lymphoma.

Adult T-cell leukaemia/lymphoma (ATL) remains incurable. The NF-κB and interferon regulatory factor 4 (IRF4) signalling pathways are among the critical survival pathways for the progression of ATL. TGF-ß-activated kinase 1 (TAK1), an IκB kinase-activating kinase, triggers the activation of NF-κB. The resorcylic acid lactone LL-Z1640-2 is a potent irreversible inhibitor of TAK1/extracellular signal-regulated kinase 2 (ERK2). We herein examined the therapeutic efficacy of LL-Z1640-2 against ATL. LL-Z1640-2 effectively suppressed the in vivo growth of ATL cells. It induced in vitro apoptosis and inhibited the nuclear translocation of p65/RelA in ATL cells. The knockdown of IRF4 strongly induced ATL cell death while downregulating MYC. LL-Z1640-2 as well as the NF-κB inhibitor BAY11-7082 decreased the expression of IRF4 and MYC at the protein and mRNA levels, indicating the suppression of the NF-κB-IRF4-MYC axis. The treatment with LL-Z1640-2 also mitigated the phosphorylation of p38 MAPK along with the expression of CC chemokine receptor 4. Furthermore, the inhibition of STAT3/5 potentiated the cytotoxic activity of LL-Z1640-2 against IL-2-responsive ATL cells in the presence of IL-2. Therefore, LL-Z1640-2 appears to be an effective treatment for ATL. Further studies are needed to develop more potent compounds that retain the active motifs of LL-Z1640-2.

Novel antimyeloma therapeutic option with inhibition of the HDAC1-IRF4 axis and PIM kinase.

Multiple myeloma (MM) preferentially expands and acquires drug resistance in the bone marrow (BM). We herein examined the role of histone deacetylase 1 (HDAC1) in the constitutive activation of the master transcription factor IRF4 and the prosurvival mediator PIM2 kinase in MM cells. The knockdown or inhibition of HDAC1 by the class I HDAC inhibitor MS-275 reduced the basal expression of IRF4 and PIM2 in MM cells. Mechanistically, the inhibition of HDAC1 decreased IRF4 transcription through histone hyperacetylation and inhibiting the recruitment of RNA polymerase II at the IRF4 locus, thereby reducing IRF4-targeting genes, including PIM2. In addition to the transcriptional regulation of PIM2 by the HDAC1-IRF4 axis, PIM2 was markedly upregulated by external stimuli from BM stromal cells and interleukin-6 (IL-6). Upregulated PIM2 contributed to the attenuation of the cytotoxic effects of MS-275. Class I HDAC and PIM kinase inhibitors cooperatively suppressed MM cell growth in the presence of IL-6 and in vivo. Therefore, the present results demonstrate the potential of the simultaneous targeting of the intrinsic HDAC1-IRF4 axis plus externally activated PIM2 as an efficient therapeutic option for MM fostered in the BM.

The Xanthine Oxidase Inhibitor Febuxostat Suppresses Adipogenesis and Activates Nrf2.

Xanthine oxidoreductase (XOR) is a rate-limiting enzyme in purine catabolism that acts as a novel regulator of adipogenesis. In pathological states, xanthine oxidoreductase activity increases to produce excess reactive oxygen species (ROS). The nuclear factor erythroid 2-related factor 2 (Nrf2) is a critical inducer of antioxidants, which is bound and repressed by a kelch-like ECH-associated protein 1 (Keap1) in the cytoplasm. The Keap1-Nrf2 axis appears to be a major mechanism for robust inducible antioxidant defenses. Here, we demonstrate that febuxostat, a xanthine oxidase inhibitor, alleviates the increase in adipose tissue mass in obese mouse models with a high-fat diet or ovariectomy. Febuxostat disrupts in vitro adipocytic differentiation in adipogenic media. Adipocytes appeared at day 7 in absence or presence of febuxostat were 160.8 ± 21.2 vs. 52.5 ± 12.7 (p < 0.01) in 3T3−L1 cells, and 126.0 ± 18.7 vs. 55.3 ± 13.4 (p < 0.01) in 10T1/2 cells, respectively. Adipocyte differentiation was further enhanced by the addition of hydrogen peroxide, which was also suppressed by febuxostat. Interestingly, febuxostat, but not allopurinol (another xanthine oxidase inhibitor), rapidly induced the nuclear translocation of Nrf2 and facilitated the degradation of Keap1, similar to the electrophilic Nrf2 activator omaveloxolone. These results suggest that febuxostat alleviates adipogenesis under oxidative conditions, at least in part by suppressing ROS production and Nrf2 activation. Regulation of adipocytic differentiation by febuxostat is expected to inhibit obesity due to menopause or overeating.

The importance of retaining physical functions to prevent skeletal-related events in multiple myeloma patients with bone disease.

This study was undertaken to identify baseline conditions and triggering factors for skeletal-related events (SRE) in multiple myeloma (MM) patients treated with denosumab. During the median follow-up of 17 months, SRE occurred in 6 out of 52 newly diagnosed patients and in 5 out of 23 relapsed/refractory patients. Bone fractures occurred by falling down due to orthostatic hypotension and/or muscle weakness in three out of four cases with amyloid light-chain (AL) amyloidosis. A loss of balance and falling down appear to be triggering factors for SRE, especially in frail MM patients with AL amyloidosis, indicating the importance of retaining physical functions to prevent SRE.