The inclusion of monoclonal antibodies targeting immune checkpoints such PD-1/PD-L1 or CTLA-4 has revolutionized the landscape of anti-cancer therapy. However, PD-1 and CTLA-4 blockade failed to achieve clinical benefit in CLL, thus attention has been focused on emerging checkpoints in this malignancy. LAG-3 is an immune checkpoint receptor that negatively regulates T cell-mediated responses by inducing an hyporesponsive state, thus promoting tumor escape. Patients with chronic lymphocytic leukemia (CLL) develop a profound immune suppression that leads to lessened immunosurveillance and increased risk of developing a secondary neoplasia. In the study herein, we report the profound dysregulation of LAG-3 on leukemic cells in CLL. Likewise, natural killer (NK) and T cells showed increased LAG-3 expression, hence suggesting a role for this checkpoint in CLL-associated immunosuppression. High LAG-3 expression, as well as high levels of soluble LAG-3 (sLAG-3), correlated with adverse cytogenetics and poor outcome in patients with CLL, highlighting the clinical relevance of this immune checkpoint. Treatment of peripheral blood mononuclear cells (PBMCs) from patients with CLL with relatlimab, a new anti-LAG-3 blocking antibody currently evaluated in numerous clinical trials, depleted leukemic cells and restored NK cell- and T cell-mediated responses. Moreover, combination of LAG-3 with the immunomodulatory drug (IMiD) lenalidomide significantly increased IL-2 production by T cells and antibody-dependent cytotoxicity (ADCC) mediated by NK cells. Altogether, these data provide new insights into the potential anti-leukemic effects of relatlimab, currently in clinical trials in CLL, and provides the rationale to further investigate its combination with IMiDs for the management of hematological malignancies.

Chronic lymphocytic leukemia (CLL) is characterized by progressive immunosuppression and diminished cancer immunosurveillance. Immune checkpoint blockade (ICB)-based therapies, a major breakthrough against cancer, have emerged as a powerful tool to reinvigorate antitumor responses. Herein, we analyzed the role of the novel inhibitory checkpoint BTLA and its ligand, HVEM, in the regulation of leukemic and natural killer (NK) cells in CLL. Flow cytometry analyses showed that BTLA expression is upregulated on leukemic cells and NK cells from patients with CLL, whereas HVEM is downregulated only in leukemic cells, especially in patients with advanced Rai-Binet stage. In silico analysis revealed that increased HVEM, but not BTLA, mRNA expression in leukemic cells correlated with diminished overall survival. Further, soluble BTLA (sBTLA) was found to be increased in the sera of patients with CLL and highly correlated with poor prognostic markers and shorter time to treatment. BTLA blockade with an anti-BTLA monoclonal antibody depleted leukemic cells and boosted NK cell-mediated responses ex vivo by increasing their IFN-γ production, cytotoxic capability, and antibody-dependent cytotoxicity (ADCC). In agreement with an inhibitory role of BTLA in NK cells, surface BTLA expression on NK cells was associated with poor outcome in patients with CLL. Overall, this study is the first to bring to light a role of BTLA/HVEM in the suppression of NK cell-mediated immune responses in CLL and its impact on patient’s prognosis, suggesting that BTLA/HVEM axis may be a potential therapeutic target in this disease.

Background/Objectives: Bence Jones proteins (BJPs) are monoclonal immunoglobulin free light chains (FLCs) that appear in the urine of patients with plasma cell disorders, including multiple myeloma (MM), Waldenström’s macroglobulinemia (WM), or light chain amyloidosis (AL). Their presence can provide valuable information about disease progression and treatment efficacy. These proteins are typically detected through a 24-h urine collection, as recommended by clinical guidelines. However, this method can be inconvenient for both patients and laboratory personnel due to its time-consuming nature and the potential for collection errors. We propose an algorithm based on serum FLC (sFLC) to rule out the presence of BJPs and diminish the need for urine testing. Methods: A retrospective data analysis of 268 serum and urine samples from 44 patients with MM was performed, and cutoffs were established to predict BJP absence: total urine protein (0.115 g/L), sFLC κ/λ ratio (>0.82 λ monoclonality and <1.99 κ monoclonality), and difference of involved–uninvolved FLC (dFLC; <11.93 mg/L). A subsequent algorithm validation was performed in 716 samples from patients who underwent the same testing in routine 2023 other laboratory activity. Results: The validation of these cutoffs to rule out the presence of BJP showed that, if the protocol based on the sFLC κ/λ ratio and dFLC had been applied, 42% of the urine studies would have been avoided, achieving a sensitivity of 93.9% and a false negative rate of 6.11%. Conclusions: We propose a laboratory work protocol that would allow for the avoidance of almost half of the 24-h urine studies based on sFLC measurement, a faster and more objective alternative to urine analysis for screening out the presence of BJP, with a good sensitivity and a low false negative rate.

Revista oficial de la Sociedad Española de Nutrición Parenteral y de la Sociedad Española de Nutrición. Está dedicada al estudio y divulgación de temas relacionados con la nutrición.