Programmed death-ligand 1 (PD-L1) on tumor cells, including Hodgkin and Reed–Sternberg (HRS) cells in classical Hodgkin’s lymphoma (cHL), suppresses immune responses in the tumor immune microenvironment (TME). We analyzed PD-L1 expression in macrophages and HRS cells of 98 cHL cases and correlated the findings with clinicopathological features, overall survival (OS), and progression-free survival (PFS). Epstein–Barr virus (EBV) was detected by in situ hybridization for EBV-encoded RNA. Ten high-power fields were evaluated to count the total number of macrophages and PD-L1+ macrophages, and to calculate PD-L1 histoscore (H-score) in HRS cells. EBV-positive cHL was found in 22.5% of patients. The median H-score was 80 (range 0–300). Bulky disease was associated with a lower number of PD-L1+ macrophages, and extranodal disease with a higher number (p = 0.05). EBV-positive cHL showed a higher PD-L1 H-score in HRS cells and a greater number of PD-L1⁺ macrophages (p = 0.005); both of these features, along with the proportion of PD-L1⁺ macrophages, were associated with shorter PFS and OS (p < 0.001). High PD-L1 expression in HRS and macrophages may be linked to worse clinical outcomes.

Thymic regulatory lymphocytes (Tregs) are rare in the normal periphery where they mediate immune tolerance but accumulate in the tumor immune microenvironment (TIM), reducing the antitumor response. Subtypes of classical Hodgkin lymphoma (CHL) are characterized by a minority of malignant Hodgkin and Reed–Sternberg cells (HRS) and an abundant TIM that plays a key role in modulating the disease. CHL is related to the Epstein–Barr virus (EBV), whose oncogenes influence the growth of HRS. We analyzed the number of T lymphocytes expressing the regulatory marker FOXP3 in CHL with regard to EBV status. The tumor tissue of 182 patients was stained by double immunohistochemistry for FOXP3, CD4, and CD8, and the number of different phenotypes was analyzed microscopically. EBV status was determined by EBER in situ hybridization. EBV-positive CHL was confirmed in 28% of patients and was associated with mixed cellularity (MC) (p < 0.001), older age (p < 0.001), and unfavorable outcomes (p = 0.038). The number of CD8+ T lymphocytes differed according to the EBV status of MC and nodular sclerosis (NS), and was the lowest in EBV-negative NS (p = 0.001). Likewise, the numbers for FOXP3 and FOXP3/CD4 were different, and were the lowest in EBV-negative MC (p = 0.035 and p = 0.041, respectively). Values above a median of FOXP3 and CD4 are associated with longer progression-free survival (p = 0.039 and p < 0.001, respectively). EBV impacts the composition of T cell phenotypes in TIM, among which the amount of CD4 and FOXP3 is prognostically valuable.

Background/Objectives: Ibrutinib has revolutionized the treatment of chronic lymphocytic leukemia but has off-target side effects, most notably cardiac. In order to evaluate the efficacy and toxicity of ibrutinib treatment, risk factors for adverse outcomes and the influence of pretreatment cardiologic evaluation, KroHem collected data on Croatian patients with chronic lymphocytic leukemia treated with this drug. Methods: This is a retrospective survey performed in order to analyze the efficacy and toxicity of ibrutinib in a real-life setting. Patients starting therapy with ibrutinib for chronic lymphocytic leukemia between the time the drug became reimbursable in 2015 and 31 December 2021 were included, irrespective of treatment line. Results: We identified 436 patients fulfilling entry criteria; 404 (92.7%) responded to treatment. Cardiovascular side effects occurred in 25.0% of patients and hemorrhagic in 15.6%. The dose of ibrutinib was permanently reduced in 22.2% of patients. Median follow-up of the cohort was 29 months (IQR 18–41 months), estimated median overall survival 75 months (IQR 36 months–not reached), progression-free survival 54 months (IQR 24–81 months) and time on ibrutinib treatment 44 months (IQR 14–78 months). Factors significantly related to overall survival in multivariate analysis were stage, treatment line and age. Factors significantly related to progression-free survival in multivariate analysis were treatment line, age and pretreatment history or ECG finding of cardiac arrhythmia. Factors significantly related to time on ibrutinib treatment in multivariate analysis were age, pretreatment history or ECG finding of cardiac arrhythmia, and permanent dose reduction for toxicity. Sex, FISH and the presence of arterial hypertension were not independently significantly related to any of these outcomes. Pretreatment cardiologic consultation did not improve time on ibrutinib therapy, progression-free survival, overall survival, risk of stopping treatment due to cardiovascular side effects or risk of cardiovascular or sudden death, neither in the whole cohort nor in the subgroup of patients with and without pretreatment cardiac arrhythmia. Conclusions: Our analysis confirms the efficacy and tolerability of ibrutinib for the treatment of chronic lymphocytic leukemia. Patients older than 75 do significantly less well. Routine pretreatment cardiologic consultation does not improve outcomes and should not be considered part of standard pretreatment assessment without additional proof of its usefulness. Future investigations should aim at identifying predictive factors, mechanisms, and preventive strategies for reducing cardiotoxicity in chronic lymphocytic leukemia patients taking Bruton tyrosine kinase inhibitors.

Relapse remains the leading cause of treatment failure after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in acute myeloid leukemia (AML). Early identification of patients at increased post-transplant relapse risk is essential to enable intensified surveillance and pre-emptive therapeutic strategies. Wilms’ tumor 1 (WT1) is overexpressed in most AML cases and represents a broadly applicable molecular marker; however, its utility as a peripheral blood (PB) measurable residual disease (MRD) marker after allo-HSCT remains incompletely defined. In this prospective multicenter cohort study, 43 adults with AML in complete remission underwent allo-HSCT between 2021 and 2023. WT1 expression in PB was quantified using standardized real-time quantitative PCR before transplantation (WT1_pre) and at day +30 (WT1_30). Receiver operating characteristic analysis identified an optimal threshold for relapse prediction. A WT1 cutoff of ≥3 copies/10⁴ ABL discriminated relapse risk. WT1_30 demonstrated strong prognostic performance (AUC 0.79; p = 0.005), whereas WT1_pre showed more modest predictive value (AUC 0.69; p = 0.037). Patients with WT1_30 ≥ 3 had inferior 12-month progression-free survival compared with those with WT1_30 < 3 (52.9% vs. 90.9%, p = 0.0059) and a higher 12-month cumulative incidence of relapse (31% vs. 9%, p = 0.054). WT1_pre ≥ 3 was also associated with inferior progression-free and overall survival (both p = 0.0008). Relapsed patients had significantly higher WT1_30 levels than non-relapsed patients (median 5.0 vs. 2.0 copies/10⁴ ABL; p = 0.018). Peripheral blood WT1 expression, particularly at day +30, is associated with an increased relapse risk after allo-HSCT in AML and may support early post-transplant risk stratification. The identified cutoff should be considered exploratory and requires validation in larger independent cohorts.

Hodgkin lymphoma (HL) is a rare lymphoid neoplasm in which Hodgkin/Reed–Stenberg (HRS) cells are admixed with a population of non-neoplastic inflammatory cells and fibrosis. Dysregulated expressions of cell cycle regulators and transcription factors have been proven as one of the hallmarks of HL. In that context, SATB1 and p16 have been reported as potential regulators of HL progression and survival. However, to date, no studies have assessed the expression levels of SATB1 and p16 in HL in Croatian patients or their prognostic values. Therefore, we investigated the expression pattern of SATB1 and p16 in paraffin-embedded lymph node biopsies using standard immunohistochemistry. We found that 21% of the patients stained positive for SATB1, while 15% of the patients displayed positive staining for p16. Furthermore, we aimed to understand the prognostic value of each protein through the analysis of the overall survival (OS) and progression-free survival (PFS). SATB1 showed a significantly positive correlation with better OS and PFS, while p16 expression had no impact. Interestingly, when patients were stratified by a combination of the two studied markers, we found that patients in the SATB1+/p16- group tended to have the best prognosis in HL, according to statistical significance. In conclusion, SATB1 and p16 might be potentially useful as diagnostic and prognostic markers for HL.