International Journal of Hematology最新文献

Polatuzumab vedotin plus rituximab, cyclophosphamide, doxorubicin, and prednisone (Pola-R-CHP) was approved in Japan for the treatment of previously untreated diffuse large B-cell lymphoma (DLBCL) in 2022, based on findings of the POLARIX study (NCT03274492). Reports on real-world usage of Pola-R-CHP are lacking. Here we report safety and response rates at end of treatment (EOT) for Pola-R-CHP in Japan from the real-world observational POLASTAR study (jRCT1071220082). Patients (≥ 18 years) with previously untreated DLBCL who were scheduled to receive Pola-R-CHP were enrolled. The primary endpoint was overall survival. As of December 20, 2023, the full analysis set (FAS) included 192 of the initial 199 patients enrolled. Median age was 71.0 years (range 30-91). In the FAS, 99 (51.6%) patients had Grade ≥ 3 adverse events (AEs), 29 (15.1%) had serious AEs, and 15 (7.8%) discontinued polatuzumab vedotin due to AEs. In the efficacy-evaluable population at EOT (n = 141), the overall response rate was 95.0% [95% confidence interval (CI), 90.1-97.6], and the complete response rate was 87.9% (95% CI, 81.5-92.3). These results are consistent with published data from POLARIX. The POLASTAR study is ongoing; the recruitment target of 500 patients has been reached.Clinical trial registration: Japan Registry of Clinical Trials (jRCT1071220082).

This study characterized the phenotypic and cytogenetic features of circulating tumor plasma cells (CTPCs) in patients with monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM). A total of 120 patients were analyzed (MGUS, n = 70; SMM, n = 50). CTPCs were detected in 38.2% of MGUS and 61.8% of SMM. Immunophenotypic analysis based on mean fluorescence intensity revealed that CD200, CD117, CD38, CD56, and CD28 were significantly downregulated and CD45 was significantly overexpressed in CTPCs compared with BMPCs, whereas CD138 and CD81 expression levels did not differ. Cytogenetic analysis demonstrated higher prevalence of del(13q) and high-risk chromosomal abnormalities in CTPC-positive patients than CTPC-negative patients (24.0% vs. 4.5%, p = 0.048; 26.5% vs. 7.0%, p = 0.011, respectively). No significant differences were observed in other cytogenetic abnormalities including 1q gain/amplification, t(4;14), t(11;14), t(14;16), or del(17p). Serum soluble B cell maturation antigen levels did not differ between patients with or without detectable CTPCs in MGUS or SMM. These findings highlight the distinct phenotypic and cytogenetic characteristics of CTPCs in MGUS and SMM, and provide insights regarding their biological features and pathogenesis.

Patients with primary plasma cell leukemia (pPCL), particularly those with extramedullary disease (EMD), face a poor prognosis even with chimeric antigen receptor (CAR)-T cell therapy. This case report describes a patient with relapsed/refractory pPCL and life-threatening malignant pleural effusion (PE) treated with intrapleural CAR-T cells targeting B-cell maturation antigens. CAR-T cell expansion within the PE was observed, along with a rapid reduction in leukemia cell count and PE volume. Subsequent lymphodepletion chemotherapy and intravenous CAR-T cell therapy induced complete remission with 9 months of progression-free survival. This case highlights the potential advantages of integrating local and systemic CAR-T cell therapy in managing complex EMD cases.

Cytomegalovirus (CMV) reactivation remains a major complication after hematopoietic cell transplantation (HCT), particularly in high-risk settings. Although the antigenemia (AG) assay has long been the standard CMV monitoring tool in Japan, quantitative PCR (qPCR) offers improved sensitivity and is now widely adopted. We analyzed a total of 1878 samples from 231 HCT recipients who underwent CMV monitoring at multiple centers. We evaluated the correlation between AG and qPCR results, determined qPCR thresholds equivalent to AG positivity, and compared actual AG-guided therapy durations with simulated qPCR-guided therapy. Among 1878 sample sets, AG and qPCR showed strong correlation (r = 0.65) and high concordance (87.6%). Median qPCR values increased with AG positivity level. ROC analysis identified qPCR cut-offs corresponding to 2 and 10 AG-positive cells as 99.5 and 815 IU/mL, respectively. Of 57 qPCR-only episodes, 32 resolved without AG conversion; higher qPCR levels were associated with treatment need. Simulated qPCR-guided therapy durations closely matched AG-guided therapy (median 4 weeks), but some cases required longer treatment. qPCR-based CMV monitoring is concordant with AG and feasible for preemptive therapy. Careful interpretation of low-level viremia is warranted to avoid overtreatment. Further data are needed to refine qPCR thresholds in transplant settings.

Chimeric antigen receptor T-cell (CAR-T) therapy has shown remarkable efficacy in treating relapsed/refractory B-cell malignancies, as supported by real-world evidence (RWE). However, limited RWE exists on the management of adverse events during the perioperative period following CAR-T infusion. This study was conducted to obtain RWE on perioperative management using the Japanese Diagnosis Procedure Combination database, a comprehensive repository of Japanese health and medical service data. Between November 2019 and March 2022, 388 patients received CAR-T therapy. Of these, 312 had large B-cell lymphoma (LBCL) and 76 had B-cell acute lymphoblastic leukemia (B-ALL). The number of CAR-T infusions increased every 6-month interval, correlating with the rise in LBCL cases. Tocilizumab was administered for cytokine release syndrome in 56.1% of LBCL and 42.1% of B-ALL patients. Steroids were used for 22.9% and 81.3%, respectively. Prophylaxis for fungal infections was administered during CAR-T infusion in most LBCL and B-ALL patients. Treatment intensity was escalated in 2.8% of LBCL and 7.0% of B-ALL patients, and treatment for cytomegalovirus infection was initiated in approximately 7% of patients. This analysis elucidated perioperative management strategies based on patients' medication histories.

Langerhans cell histiocytosis (LCH) is a rare type of histiocytosis with various clinical manifestations. The differential diagnosis for an infiltrative process in the mesentery includes histiocytosis, such as Erdheim-Chester disease (ECD) and Rosai-Dorfman disease (RDD), but mesenteric involvement has never been reported. Here we present the first documented case of LCH. A 24-year-old man presented with diabetes insipidus and was diagnosed with LCH via mesenteric biopsy, which demonstrated mesenteric involvement and the BRAF^N486_P490del mutation. He was treated with trametinib 2 mg once daily, and FDG-PET/CT at 6 months after treatment initiation showed complete remission. Our report suggests that trametinib is a promising treatment option for non-BRAF^V600E mutant LCH with mesenteric involvement.

Idiopathic portal hypertension-related refractory ascites (IRA) is a rare but potentially life-threatening complication following allogeneic hematopoietic cell transplantation (allo-HCT). Its pathogenesis remains unclear, and optimal diagnostic and therapeutic strategies have yet to be established. Here, we report a case of a 58-year-old man who developed progressive ascites after allo-HCT. Although the clinical findings met diagnostic criteria for hepatic veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS), liver histology revealed no hallmark features of VOD/SOS, such as sinusoidal dilatation or central venous fibrosis. Instead, portal venopathy with lymphocytic infiltration and fibrosis suggested a subclinical chronic graft-versus-host disease (GVHD)-like pathology, supporting a diagnosis of IRA by exclusion. Treatment with belumosudil, one of the available treatment options for chronic GVHD, was ineffective. Subsequent treatment with ibrutinib, a Bruton's tyrosine kinase inhibitor, led to resolution of ascites within three days. This is the second reported case of successful treatment of IRA with ibrutinib, and highlights the importance of considering ibrutinib-responsive immune-mediated mechanisms in the differential diagnosis of post-transplant ascites. Given the fundamental differences in treatment strategies between IRA and VOD/SOS, our findings underscore the need for accurate diagnosis, including histopathological evaluation, to guide effective therapy and improve patient outcomes in this challenging clinical scenario.

Immunity acquired before hematopoietic stem cell transplantation (HSCT) may decrease or disappear following HSCT, and it is unclear whether the first vaccination after HSCT in patients with an antigen exposure history before HSCT elicits a primary or secondary immune response. The Quantification of Antigen-Specific Antibody Sequence (QASAS) method enables real-time assessment of responses to SARS-CoV-2 antigen exposure through B-cell receptor (BCR) repertoire analysis. Using this method, we evaluated the disappearance of immunological memory after HSCT. First, in individuals without hematologic disorders, primary SARS-CoV-2 antigen exposure elicited no immune response at 7 days post-exposure but demonstrated activation between 14 to 21 days. In contrast, repeated exposure elicited early responses (secondary immune responses) at 7 days post-exposure. We then enrolled HSCT patients with pre-HSCT SARS-CoV-2 antigen exposure history and collected samples before and after vaccination. Despite prior exposure history, patients receiving their first vaccination after HSCT showed no response around 7 days post-exposure but responded at 14 days. In conclusion, even with pre-HSCT antigen exposure, the first vaccination after HSCT induced a primary immune response. This demonstrates that first vaccination after HSCT should be considered to induce a primary immune response, regardless of previous infection or vaccination history.

Chimeric antigen receptor (CAR) T cell therapy has significantly improved outcomes for patients with refractory B cell lymphoma. However, rare cases of secondary T cell lymphomas have raised safety concerns. Here, we present a case of peripheral T cell lymphoma not otherwise specified (PTCL-NOS) that developed eight months following CD19-directed CAR T cell therapy (lisocabtagene maraleucel) in a 66-year-old male patient with recurrent diffuse large B cell lymphoma. The patient initially achieved complete remission but later developed a subcutaneous mass and systemic lymphadenopathy. Histopathology and flow cytometry confirmed a diagnosis of PTCL-NOS with a CD3 + , CD8 + , and CD30 + phenotype, as well as clonal T cell receptor gene rearrangements. No immunoglobulin rearrangements were detected, ruling out a lineage switch. Furthermore, the CAR transgene was undetectable by RNA-in situ hybridization, and flow cytometry showed no CAR protein expression, suggesting that the lymphoma was not caused by CAR gene integration. This case highlights the importance of re-biopsy in cases of suspected relapse following CAR T cell therapy, and emphasizes the need for long-term monitoring. While a direct causal link remains unclear, industry-academia collaboration is crucial for investigating the mechanisms underlying secondary T cell malignancies and improving the safety of CAR T cell therapy.