Malignant cells exhibit elevated rates of protein synthesis and secretion to facilitate tumor growth, proliferation, and tumorigenesis. Upon malignant transformation, the endoplasmic reticulum (ER) experiences stress due to the accumulation of unfolded or misfolded proteins in the ER lumen, lack of nutrient availability and overall hostile tumor microenvironment conditions. The demand for regulated protein turnover and proteostasis reinstatement results in the activation of the unfolded protein response (UPR) pathway for cellular adaptation and survival. The UPR machinery utilizes the BiP chaperone and three ER-bound sensors, PERK, IRE1, and ATF6, to substantiate signal transduction and orchestrate gene expression associated with protein folding, degradation and recycling, inflammation, autophagy, and programmed cell death. The pleiotropic function of UPR emerges as a central mediator for tumor progression, especially in multiple myeloma and glioblastoma pathologies. Numerous studies have recently pointed out that communication of the extracellular matrix (ECM) with surrounding tumor cells dictates in part UPR activity and vice versa. In the context of this dynamic interplay, ER stress and UPR mechanisms have been proposed as potential targets to elicit novel and effective therapeutic approaches in clinical trials.

Background and Objectives: Predominantly antibody deficiencies (PAD) represent the most common type of primary immunodeficiencies in humans, characterized by a wide variation in disease onset, clinical manifestations, and outcome. Considering that the prevalence of PAD in Greece is unknown, and there is limited knowledge on the clinical and laboratory characteristics of affected patients, we conducted a nationwide study. Materials and Methods: 153 patients (male/female: 66/87; median age: 43.0 years; range: 7.0–77.0) diagnosed, and followed-up between August 1979 to September 2023. Furthermore, we classified our cohort into five groups according to their medical history, immunoglobulin levels, and CTLA4-mutational status: 123 had common variable immunodeficiency (CVID), 12 patients with “secondary” hypogammaglobulinemia due to a previous B-cell depletion immunotherapy for autoimmune or malignant disease several years ago (median: 9 years, range 6–14) displaying a typical CVID phenotype, 7 with combined IgA and IgG subclass deficiencies, 5 patients with CVID-like disease due to CTLA4-mediated immune dysregulation syndrome, and 6 patients with unclassified hypogammaglobulinemia. Results: We demonstrated a remarkable delay in PAD diagnosis, several years after the onset of related symptoms (median: 9.0 years, range: 0–43.0). A family history of PAD was only present in 11.8%, with the majority of patients considered sporadic cases. Most patients were diagnosed in the context of a diagnostic work-up for recurrent infections, or recurrent/resistant autoimmune cytopenias. Interestingly, 10 patients (5.6%) had no history of infection, diagnosed due to either recurrent/resistant autoimmunity, or during a work-up of their medical/family history. Remarkable findings included an increased prevalence of lymphoproliferation (60.1%), while 39 patients (25.5%) developed bronchiectasis, and 16 (10.5%) granulomatous disease. Cancer was a common complication in our cohort (25 patients, 16.3%), with B-cell malignancies representing the most common neoplasms (56.7%). Conclusion: Our findings indicate the necessity of awareness about PAD and their complications, aiming for early diagnosis and the appropriate management of affected patients.

Background-Objectives: Although considered standard of care for patients with low-/intermediate-1 risk MDS and isolated del(5q), lenalidomide is not widely used in patients exhibiting additional cytogenetic abnormalities, on top of del(5)q. The aim of this study was to provide real-world evidence for the efficacy of lenalidomide in patients with del(5q), with or without additional cytogenetic abnormalities. Methods: Patients with MDS exhibiting del(5q) in the Greek National Myelodysplastic Syndromes Registry were analyzed if they had received at least one lenalidomide dose and detailed response assessment/follow-up was available. Results: Among 238 patients analyzed, 153 (64.3%) had del(5q) syndrome (Group-I), 34 (14.3%) had an isolated del(5q) abnormality but were not 5q− syndrome (Group-II), 26 (10.9%) had del(5q) plus only one additional cytogenetic abnormality (Group-III), and 25 (10.5%) had del(5q) plus >1 additional abnormality (Group-IV). Among 218 (91.6%) evaluable patients, a major response was achieved by 146 (67.0%) patients, 114/146 (78.1%) in Group-I, 18/31 (58.1%) in Group-II, 10/20 (50.0%) in Group-III, and 4/21 (19.0%) in Group-IV. Overall, hematological response was seen in 177/218 (81.2%) patients, even among those with an excess of bone marrow blasts/frank acute myeloid leukemia. Duration of response was comparable between the four patient groups. A complete cytogenetic response was achieved by 38.0% overall, more commonly in Group-I (42.3%) and -III (35.7%). Transfusion-independent patients and those with a higher MCV or lower marrow blast cells at baseline had a higher probability of achieving a major response. With multivariate analysis, factors associated with overall survival were age, performance status, transfusion dependence, and marrow blast cell percentage at treatment start, as well as time from initial diagnosis to lenalidomide start. Conclusions: Lenalidomide was highly effective in patients with the del(5)q syndrome and also in those with isolated del(5)q, other than del(5)q syndrome, or those exhibiting del(5)q plus only one additional cytogenetic abnormality, not affecting chromosome 7.

Background/objectives: Patients with chronic lymphocytic leukemia (CLL) and multiple myeloma (MM) are susceptible to viral infections, including varicella-zoster virus (VZV) reactivation due to both disease-related and treatment-induced immunosuppression. The recombinant adjuvanted herpes zoster vaccine (RZV) has shown high efficacy in immunocompetent adults, but immunogenicity data in CLL and MM patients are limited. This study evaluates the immunogenicity and safety of RZV in this population. Methods: Patients with CLL and MM vaccinated with RZV (administered in two doses at least one month apart) were included in the study. Pre- and post-vaccination anti-VZV IgM and IgG antibody levels were measured to assess immunogenicity, and adverse events (AEs) were captured for safety evaluation. Results: Seventy-eight patients received both vaccine doses, and 71 had post-vaccination samples. Most of the patients were IgM seronegative and IgG seropositive before vaccination. Pre-vaccination IgG levels were higher in CLL patients compared to MM patients (p = 0.001), while post-vaccination IgG levels significantly increased in both CLL (p < 0.0001) and MM (p < 0.0001) patients. In actively treated CLL patients, pre-vaccination IgG levels were significantly lower than in not actively treated patients (p = 0.002). Post-vaccination IgG levels were lower in MM patients receiving antiviral prophylaxis concurrently with the vaccination (p = 0.013). AEs were reported in 49.4% of patients after the first dose and 48.7% after the second dose, mostly mild (local or low-grade systemic). One case of immune thrombocytopenia was noted. Conclusions: RZV demonstrated strong immunogenicity and acceptable safety in CLL and MM patients, significantly boosting IgG levels, even in actively treated or heavily pretreated patients.

Background: Testicular germ cell tumors (TGCTs) exhibit diverse biological and pathological features and are divided in two main types, seminomas and nonseminomatous germ cell tumors (NSGCTs). CD44 is a cell surface receptor, which is highly expressed in malignancies and is implicated in tumorigenesis affecting cell-matrix interactions and cell signaling. Methods and results: Here, we examined the expression of CD44 in tumor cell lines and in patients’ material. We found that CD44 is over-expressed in TGCTs compared to normal tissues. Immunohistochemical staining in 71 tissue specimens demonstrated increased expression of CD44 in some patients, whereas CD44 was absent in normal tissue. In seminomas, a high percentage of tumor and stromal cells showed cytoplasmic and/or cell surface staining for CD44 as well as increased staining for CD44 in the tumor stroma was found in some cases. The increased expression of CD44 either in tumor cells or in stromal components was associated with tumor size, nodal metastasis, vascular/lymphatic invasion, and disease stage only in seminomas. The increased stromal expression of CD44 in TGCTs was positively associated with angiogenesis. Conclusions: CD44 may exhibit diverse biological functions in seminomas and NSGCTs. The expression of CD44 in tumor cells as well as in tumor stroma fosters an aggressive phenotype in seminomas and should be considered in disease treatment.

Introduction: Patients with chronic lymphocytic leukemia (CLL) and multiple myeloma (MM) are susceptible to viral infections, including varicella-zoster virus (VZV) reactivation due to both disease-related and treatment-induced immunosuppression. The recombinant adjuvanted herpes zoster vaccine (RZV) has shown high efficacy in immunocompetent adults, but immunogenicity data in CLL and MM patients is limited. This study evaluates the immunogenicity and safety of RZV in this population. Methods: Patients with CLL and MM vaccinated with RZV (administered in two doses at least one month apart) were included in the study. Pre- and post-vaccination anti-VZV IgM and IgG antibody levels were measured to assess immunogenicity, and adverse events (AEs) were captured for safety evaluation. Results: Seventy-eight patients received both vaccine doses, and 71 had post-vaccination samples. Most of the patients were IgM seronegative and IgG seropositive before vaccination. Pre-vaccination IgG levels were higher in CLL compared to MM patients (p=0.001), while post-vaccination IgG levels significantly increased in both CLL (p<0.0001) and MM (p<0.0001) patients. In actively treated CLL patients, the pre-vaccination IgG levels were significantly lower than in not actively treated patients (p=0.002). Post-vaccination IgG levels were lower in MM patients receiving antiviral prophylaxis concurrently with the vaccination (p=0.013). AEs were reported in 49.4% after the first dose and 48.7% after the second dose, mostly mild (local or low-grade systemic). One case of immune thrombocytopenia was noted. Conclusion: RZV demonstrated strong immunogenicity and acceptable safety in CLL and MM patients, significantly boosting IgG levels, even in actively treated or heavily pretreated patients.