Dual-antigen targeted iPSC-derived chimeric antigen receptor-T cell therapy for refractory lymphoma.

We generated dual-antigen receptor (DR) T cells from induced pluripotent stem cells (iPSCs) to mitigate tumor antigen escape. These cells were engineered to express a chimeric antigen receptor (CAR) for the antigen cell surface latent membrane protein 1 (LMP1; LMP1-CAR) and a T cell receptor directed to cell surface latent membrane protein 2 (LMP2), in association with human leucocyte antigen A24, to treat therapy-refractory Epstein-Barr virus-associated lymphomas. We introduced LMP1-CAR into iPSCs derived from LMP2-specific cytotoxic T lymphocytes (CTLs) to generate rejuvenated CTLs (rejTs) active against LMP1 and LMP2, or DRrejTs. All DRrejT-treated mice survived >100 days. Furthermore, DRrejTs rejected follow-up inocula of lymphoma cells, demonstrating that DRrejTs persisted long-term. We also demonstrated that DRrejTs targeting CD19 and LMP2 antigens exhibited a robust tumor suppressive effect and conferred a clear survival advantage. Co-operative antitumor effect and in vivo persistence, with unlimited availability of DRrejT therapy, will provide powerful and sustainable T cell immunotherapy.

[Immune thrombocytopenia preceded by asymptomatic COVID-19 infection].

Immune thrombocytopenia (ITP) may occur following a viral infection. We report the case of a 30-year-old woman with thrombocytopenia who was subsequently diagnosed with ITP. Although she was asymptomatic, chest computed tomography (CT) showed ground-glass opacities in the lower lung regions. The patient had a positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) real-time polymerase chain reaction (RT-PCR) test. She responded well to 400 mg/kg of intravenous immunoglobulin therapy. Coronavirus disease of 2019 or COVID-19 should be considered as a cause of ITP during the pandemic, and chest CT scans and RT-PCR tests should be performed in patients suspected of ITP.

Long-term eradication of extranodal natural killer/T-cell lymphoma, nasal type, by induced pluripotent stem cell-derived Epstein-Barr virus-specific rejuvenated T cells in vivo.

Functionally rejuvenated induced pluripotent stem cell (iPSC)-derived antigen-specific cytotoxic T lymphocytes (CTL) are expected to be a potent immunotherapy for tumors. When L-asparaginase-containing standard chemotherapy fails in extranodal natural killer/T-cell lymphoma, nasal type (ENKL), no effective salvage therapy exists. The clinical course then is miserable. We demonstrate prolonged and robust eradication of ENKL in vivo by Epstein-Barr virus-specific iPSC-derived antigen-specific CTL, with iPSC-derived antigen-specific CTL persisting as central memory T cells in the mouse spleen for at least six months. The anti-tumor response is so strong that any concomitant effect of the programmed cell death 1 (PD-1) blockade is unclear. These results suggest that long-term persistent Epstein-Barr virus-specific iPSC-derived antigen-specific CTL contribute to a continuous anti-tumor effect and offer an effective salvage therapy for relapsed and refractory ENKL.

[Portal vein thrombosis associated with idiopathic hypereosinophilic syndrome].

A 35-year-old man who previously underwent splenectomy for hereditary spherocytosis at age 29 visited our hospital complaining of fatigue that had started 7 days ago and right upper abdominal pain. Laboratory data showed increased white blood cell and eosinophil count accompanied by severe transaminitis and clotting abnormalities. Computed tomography scan showed multiple embolisms in the portal vein, superior mesenteric vein, right pulmonary artery, and inferior vena cava. Severe liver damage presumably caused by portal vein thrombosis was also observed. Anticoagulant therapies consisting of continuous arterial infusion of urokinase from the superior mesenteric artery and an intravenous infusion of recombinant human thrombomodulin and heparin dissolved the systemic thrombosis. Concurrently administered prednisone decreased the eosinophil count. With regard to eosinophilia, we were unable to find any connective tissue diseases, antibodies to parasites, or genetic anomalies including PDGFRA, PDGFRB, and FGFR1. Hence we diagnosed the patient with idiopathic hypereosinophilic syndrome (HES). Although thromboembolisms in patients with HES have been reported, the literature on portal vein thrombosis associated with HES is scarce. In the present case, the previous splenectomy may have contributed to the portal vein thrombosis.

[Peripheral neuropathy occurring soon after cord blood transplantation].

We experienced two cases of peripheral neuropathy in the early phase following cord blood transplantation. Case 1 was a 66-year-old man with recurrent T-ALL. On day 8, he experienced a sharp pain originating in both the palms and the soles, which worsened spreading to the knees, and was accompanied by muscle weakness. The neurological symptom progressed to the point of being unable to walk. A nerve conduction velocity test showed demyelination and axonopathy. In the CSF analysis, albuminocytologic dissociation and a rise in myelin basic protein were detected. These findings met the diagnostic criteria for chronic inflammatory demyelinating polyneuropathy (CIDP). The symptoms improved with intravenous immunoglobulin (IVIG). He is now able to walk and continues to visit our department. Case 2 was a 42-year-old man with primary mediastinal large B-cell lymphoma. As the disease was refractory, he underwent reduced intensity cord blood transplantation (RICBT). Flare and numbness started in the palms and soles on day 26, with the symptoms progressing thereafter. A nerve conduction velocity test showed demyelination and axonopathy. The symptoms improved after IVIG administration. The diagnosis of peripheral neuropathy after transplantation is often difficult, but when an immunologic disorder is suspected to be the cause, early administration of IVIG may be effective.

Rejuvenated iPSC-derived GD2-directed CART Cells Harbor Robust Cytotoxicity Against Small Cell Lung Cancer.

Small cell lung cancer (SCLC) is exceptionally aggressive, with limited treatment options. Disialoganglioside (GD2) is highly expressed on SCLC and is considered a good target for chimeric antigen receptor (CAR) T cells (CART). Although GD2-directed CARTs (GD2-CART) exhibit cytotoxicity against various GD2-expressing tumors, they lack significant cytotoxicity against SCLC. To enhance cytotoxicity of GD2-CARTs against SCLC, we introduced GD2-CAR into induced pluripotent stem cells (iPSC)-derived rejuvenated cytotoxic T lymphocytes (GD2-CARrejT). GD2-CARrejTs acted much more strongly against SCLC cells than did GD2-CARTs both in vitro and in vivo. Single-cell RNA sequencing elucidated that levels of expression of TIGIT were significantly lower and levels of expression of genes associated with cytotoxicity were significantly higher in GD2-CARrejTs than those in GD2-CARTs. Dual blockade of TIGIT and programmed death-1 (PD-1) increased the cytotoxicity of GD2-CARTs to some extent, suggesting that low TIGIT and PD-1 expression by GD2-CARrejTs is a major factor required for robust cytotoxicity against SCLC. Not only for robust cytotoxicity but also for availability as "off-the-shelf" T-cell therapy, iPSC-derived GD2-CARrejTs are a promising novel treatment for SCLC. SIGNIFICANCE: This research introduces iPSC-derived rejuvenated GD2-CARTs (GD2-CARrejT) as a novel approach to combat SCLC. Compared with conventional GD2-CARTs, GD2-CARrejTs with reduced TIGIT and PD-1 expression demonstrate robust cytotoxicity against SCLC and would be a promising therapy for SCLC.

Anti-myelin-associated-glycoprotein neuropathy successfully treated with tirabrutinib.

Background: Anti-myelin-associated-glycoprotein (MAG) neuropathy is a distal, predominantly demyelinating, sensory or sensory-motor polyneuropathy most often developing in the context of an IgM-type monoclonal gammopathy due to monoclonal gammopathy of undetermined significance or lymphoplasmacytic lymphoma. Rituximab is considered standard therapy for treatment naïve patients, but optimal treatment methods for relapsed/refractory patients have not been established. Case presentation: We demonstrate that tirabrutinib, a second-generation Burton kinase inhibitor, led to drastic improvements of polyneuropathy that were affirmed by nerve conduction studies in a rituximab-refractory anti-MAG neuropathy patient. Tirabrutinib continues to give excellent disease control with no apparent adverse events at 11 months since initiation, and the patient remains free of plasmapheresis sessions which were originally mandatory. Conclusion: Tirabrutinib is an extremely promising treatment option for anti-MAG neuropathy.

Primary Skeletal Muscle Peripheral T-cell Lymphoma: An Autopsy Case Report and Review of the Literature.

Primary skeletal muscle lymphoma is extremely uncommon, and there have only been eight previous case reports on primary skeletal muscle peripheral T-cell lymphoma, not otherwise specified (PSM-PTCL, NOS). We herein report an autopsy case of a 71-year-old woman with PSM-PTCL, NOS, who had a 24-year history of systemic sclerosis treated with immunosuppressive drugs. A post-mortem examination revealed infiltration of lymphoma cells positive for T-cell markers, cytotoxic markers, and p53. This case was considered to be one of other iatrogenic immunodeficiency-associated lymphoproliferative disorder (OIIA-LPD). This is the first case categorized under both PSM-PTCL, NOS, and OIIA-LPD.

High-grade Primary Central Nervous System Lymphomatoid Granulomatosis: Successful Rituximab Monotherapy.

The primary central nervous system (CNS) presentation of lymphomatoid granulomatosis (LYG) is rare, and no standard therapy for LYG with primary CNS symptoms exists. CNS-LYG patients usually survive for only less than a year from diagnosis. This is the first report of high-grade primary CNS-LYG with monoclonality that was successfully treated with rituximab monotherapy, resulting in a durable remission for more than 1 year in a 66-year-old woman with pemphigus vulgaris who was also on immunosuppressive therapy.

Intravascular large B-cell lymphoma as a recurrence of primary central nervous system lymphoma after chemotherapy: A case report.

We report about a 48-year-old woman diagnosed with primary central nervous system lymphoma (PCNSL). After chemotherapy and autologous stem cell transplantation, she presented with a continuous high-grade fever. Positron emission tomography-computed tomography revealed prominent hepatosplenomegaly and high diffuse uptake of 18F-fluorodeoxyglucose in the liver, spleen, and lungs. Intravascular large B-cell lymphoma (IVLBCL) was diagnosed using random skin biopsy. There were no symptoms of IVLBCL at the time of diagnosis of PCNSL. The histopathological features of PCNSL and IVLBCL were nearly similar. These findings suggest that IVLBCL was the recurrence of PCNSL rather than a separate entity.

SCLC-J1, a novel small cell lung cancer cell line.

Small cell lung cancer (SCLC) is a type of high-grade neuroendocrine carcinoma. It initially responds to chemotherapy but rapidly becomes chemoresistant and it is highly proliferative. The prognosis in SCLC is poor. We have established a novel SCLC cell line, SCLC-J1, from a malignant pleural effusion in a patient with advanced SCLC. SCLC-J1 cells express ganglioside GD2, CD276, and Delta-like protein 3. RB1 is lost. These features of the new SCLC cell line may be useful in understanding the cellular and molecular biology of SCLC and in designing better treatment.