Alemtuzumab monotherapy for T-cell prolymphocytic leukemia: an observational study in Japan.

Alemtuzumab is recommended as first-line and second-line therapies for T-cell prolymphocytic leukemia (T-PLL). This study retrospectively evaluated the efficacy and safety of alemtuzumab in nine Japanese patients with T-PLL at five participating institutions who were treated between January 2015 and August 2023. The median age at first administration of alemtuzumab was 72 years (range, 39 to 78). Two patients were treatment naïve, and seven had been treated with a median of one (range, 1 to 3) prior systemic therapy. Six patients were refractory to their most recent therapy. Three patients completed 12 weeks of treatment. The overall response rate and the complete response (CR) rate were 78% and 11%, respectively. Among the six patients who achieved a partial response, two achieved clinical CR but did not undergo bone marrow examination. One patient also achieved clinical CR but did not undergo CT or bone marrow examination for response evaluation. The median progression-free survival time was 8.1 months (95% confidence interval, 0.9 to 18.6). Three patients received readministration of alemtuzumab monotherapy after disease progression. There were no treatment-related deaths. The grade 3 or 4 nonhematologic adverse events included infusion reaction (grade 3, n = 2), cytomegalovirus reactivation (grade 3, n = 2), and pulmonary edema (grade 3, n = 1). One patient experienced Epstein‒Barr virus-positive diffuse large B-cell lymphoma 15 months after the last dose of alemtuzumab. These results confirm that the efficacy and safety of alemtuzumab monotherapy in Japanese patients are comparable to those previously reported.

[Spontaneous regression of HIV-associated EBV-positive mucocutaneous ulcer due to immune reconstruction with antiretroviral therapy].

A 24-year-old man was found to have an ileocecal ulcer by colonoscopy. A pathological diagnosis of diffuse large B-cell lymphoma (DLBCL) with diffuse positive reaction of Epstein-Barr encoding region (EBER) by in situ hybridization was made based on analysis of the specimen. Acquired immunodeficiency syndrome (AIDS) complicated by pneumocystis jirovecii pneumonia was also diagnosed. As no other significant lymphomatous lesions were identified by further examination, a clinical diagnosis of EBV-positive mucocutaneous ulcer (EBVMCU) was made. Rather than performing systemic chemotherapy, the lesion was closely monitored and antiretroviral therapy (ART) for AIDS was started with the hope of treating the lesion through immune reconstitution. The lesion had completely disappeared by day 79 after starting ART, and has not recurred for over 3 years. EBVMCU is known to develop secondary to various immunosuppressive states including AIDS. Here we report a rare case of EBVMCU detected at diagnosis of AIDS that entered complete remission after immune reconstitution by ART.

RLTPR Q575E: A novel recurrent gain-of-function mutation in patients with adult T-cell leukemia/lymphoma.

OBJECTIVES: Adult T-cell leukemia/lymphoma (ATL) is an intractable T-cell malignancy caused by long-term infection with human T-cell leukemia virus type-1 (HTLV-1). While ATL pathogenesis has been associated with HTLV-1-derived oncogenic proteins, including Tax and HBZ, the contribution of genomic aberrations remains poorly defined. METHODS: To elucidate the genomic basis of ATL, whole exome sequencing was performed on cells from 47 patients with aggressive ATL. RESULTS: We discovered the novel mutation RLTPR Q575E in four patients (8.5%) with a median variant allele frequency of 0.52 (range 0.11-0.68). Despite being reported in cutaneous T-cell lymphoma, three ATL patients carrying RLTPR Q575E lacked skin involvement. Patients carrying RLTPR Q575E also harbored CARD11 (75%), PLCG1 (25%), PRKCB (25%), or IKBKB (25%) mutations related to TCR/NF-κB signaling. Jurkat cells transfected with RLTPR Q575E cDNA displayed increased NF-κB activity and significantly increased IL-2 mRNA levels under stimulation. RLTPR Q575E increased the interaction between RLTPR and CARD11, while RLTPR directly interacted with Tax. CONCLUSIONS: We identified, and functionally validated, a novel gain-of-function mutation in patients with aggressive ATL. During TCR activation by Tax or gain-of-function mutations, RLTPR Q575E selectively upregulates NF-κB signaling and may exert oncogenic effects on ATL pathogenesis.