Distinct follicular T cell subsets regulate lymphoma progression and outcomes.

Follicular lymphoma (FL) is characterized by the expansion of neoplastic follicle structures and is suggested to have a distinctive form of T cell immunity. However, the heterogeneity and role of follicular T cells beyond T follicular helper (T) cells remain largely unexplored in FL. Here, we performed multi-omics analyses of follicular T cells in FL leveraging pan-cancer single-cell mapping, spatially resolved single-cell transcriptomics and multiplex protein profiling, and functional characterization.

Real-World Data on the p.Gly17Val RHOA Mutation in Diagnosing T Follicular Helper Cell Lymphomas.

Background: T follicular helper (Tfh) cell lymphomas, including their most prevalent form, angioimmunoblastic T-cell lymphoma, frequently present with clinical symptoms, such as fever and rash, accompanied by substantial immune cell infiltration within the tumor microenvironment. These features often obscure the distinction between Tfh lymphoma and other autoimmune or inflammatory conditions. Notably, the p.

Discrete genetic subtypes and tumor microenvironment signatures correlate with peripheral T-cell lymphoma outcomes.

Peripheral T-cell lymphoma (PTCL) exhibits a diverse clinical spectrum, necessitating methods to categorize patients based on genomic abnormalities or tumor microenvironment (TME) profiles. We conducted an integrative multiomics study in 129 PTCL patients, performing whole-exome sequencing and identifying three genetic subtypes: C1, C2, and C3. C2 was characterized by loss of tumor suppressor genes and chromosomal instability, while C1 and C3 shared T follicular helper (TFH)-related genomic alterations, with C3 also showing a high incidence of IDH2 mutations and chromosome 5 gain.

A Case of Multiple Myeloma in a Patient with Birt-Hogg-Dube Syndrome.

Birt-Hogg-Dubé syndrome (BHDS) is an autosomal dominant disease caused by germline folliculin (FLCN) mutations and it is characterized by skin folliculomas, pulmonary cysts, and renal cell carcinomas (RCC). We herein report the first case of a female patient with BHDS who was diagnosed with multiple myeloma. Daratumumab-based treatment was effective, and the patient remained responsive for over three years.

Association between microenvironment-related genes and prognosis of primary central nervous system lymphoma.

Background: Primary central nervous system lymphoma (PCNSL) is a rare lymphoid malignancy. Systemic profiling of the PCNSL tumor microenvironment (TME) was previously conducted through gene expression analysis. We investigated the prognostic impact of TME on survival to establish novel prognostic biomarkers in PCNSL patients.

Clonal germinal center B cells function as a niche for T-cell lymphoma.

Angioimmunoblastic T-cell lymphoma (AITL) is proposed to be initiated by age-related clonal hematopoiesis (ACH) with TET2 mutations, whereas the G17V RHOA mutation in immature cells with TET2 mutations promotes the development of T follicular helper (TFH)-like tumor cells. Here, we investigated the mechanism by which TET2-mutant immune cells enable AITL development using mouse models and human samples. Among the 2 mouse models, mice lacking Tet2 in all the blood cells (Mx-Cre × Tet2flox/flox × G17V RHOA transgenic mice) spontaneously developed AITL for approximately up to a year, while mice lacking Tet2 only in the T cells (Cd4-Cre × Tet2flox/flox × G17V RHOA transgenic mice) did not.

Salvage Cord Blood Transplantation Using a Short-term Reduced-intensity Conditioning Regimen for Graft Failure.

Objective Graft failure (GF) is a life-threatening complication of hematopoietic stem cell transplantation (HSCT). A standardized conditioning regimen and an appropriate graft source of salvage HSCT for GF have not yet been established. Some case series have shown good hematopoietic recoveries after salvage HSCT using a short-term reduced-intensity preparative regimen consisting of fludarabine (30-90 mg/m), cyclophosphamide (2 g/m), and total-body irradiation (2 Gy).

VAV1 mutations contribute to development of T-cell neoplasms in mice.

Activating mutations in the Vav guanine nucleotide exchange factor 1 (VAV1) gene are reported in various subtypes of mature T-cell neoplasms (TCNs). However, oncogenic activities associated with VAV1 mutations in TCNs remain unclear. To define them, we established transgenic mice expressing VAV1 mutants cloned from human TCNs.

[Fatal exacerbations of chronic active Epstein-Barr virus infection subsequent to cytotoxic chemotherapy].

Chronic active Epstein-Barr virus infection (CAEBV) is critical owing to lethal complications such as hemophagocytic lymphohistiocytosis (HLH), multiple organ failure, and malignant lymphoma. Here we present two cases of CAEBV who developed rapid and life-threatening disease progression after cytotoxic chemotherapy. Case 1: In a 34-year-old male, CAEBV recurred after 4-month remission obtained by initial therapy with etoposide, cyclosporine, and prednisolone.

[A Case of Upper Urinary Tract MALT Lymphoma with Remarkable Thickness of Renal Pelvis and Ureter Wall].

A 78-year-old man was referred to Tsukuba University Hospital for right hydronephrosis. He had undergone ureteroscopy and ureteral stenting in another hospital, but no tumor was revealed in renal pelvis and ureter. The urinary cytology was negative.