BTK Inhibitors in Chronic Lymphocytic Leukemia: Biological Activity and Immune Effects

Effects of B-Cell Lymphoma on the Immune System and Immune Recovery after Treatment: The Paradigm of Targeted Therapy

B-cell lymphoma and lymphoproliferative diseases represent a heterogeneous and complex group of neoplasms that are accompanied by a broad range of immune regulatory disorder phenotypes. Clinical features of autoimmunity, hyperinflammation, immunodeficiency and infection can variously dominate, depending on the immune pathway most involved. Immunological imbalance can play a role in lymphomagenesis, also supporting the progression of the disease, while on the other hand, lymphoma acts on the immune system to weaken immunosurveillance and facilitate immunoevasion. Therefore, the modulation of immunity can have a profound effect on disease progression or resolution, which makes the immune system a critical target for new therapies. In the current therapeutic scenario enriched by chemo-free regimens, it is important to establish the effect of various drugs on the disease, as well as on the restoration of immune functions. In fact, treatment of B-cell lymphoma with passive immunotherapy that targets tumor cells or targets the tumor microenvironment, together with adoptive immunotherapy, is becoming more frequent. The aim of this review is to report relevant data on the evolution of the immune system during and after treatment with targeted therapy of B-cell lymphomas.

BTK Inhibitors Impair Platelet-Mediated Antifungal Activity

In recent years, the introduction of new drugs targeting Bruton’s tyrosine kinase (BTK) has allowed dramatic improvement in the prognosis of patients with chronic lymphocytic leukemia (CLL) and other B-cell neoplasms. Although these small molecules were initially considered less immunosuppressive than chemoimmunotherapy, an increasing number of reports have described the occurrence of unexpected opportunistic fungal infections, in particular invasive aspergillosis (IA). BTK represents a crucial molecule in several signaling pathways depending on different immune receptors. Based on a variety of specific off-target effects on innate immunity, namely on neutrophils, monocytes, pulmonary macrophages, and nurse-like cells, ibrutinib has been proposed as a new host factor for the definition of probable invasive pulmonary mold disease. The role of platelets in the control of fungal growth, through granule-dependent mechanisms, was described in vitro almost two decades ago and is, so far, neglected by experts in the field of clinical management of IA. In the present study, we confirm the antifungal role of platelets, and we show, for the first time, that the exposure to BTK inhibitors impairs several immune functions of platelets in response to Aspergillus fumigatus, i.e., the ability to adhere to conidia, activation (as indicated by reduced expression of P-selectin), and direct killing activity. In conclusion, our experimental data suggest that antiplatelet effects of BTK inhibitors may contribute to an increased risk for IA in CLL patients.

The Mysterious Actor-γδ T Lymphocytes in Chronic Lymphocytic Leukaemia (CLL)

Chronic lymphocytic leukaemia (CLL) is the most common leukaemia among adults. It is the clonal expansion of B cells expressing CD19 and CD5. Despite significant progress in treatment, CLL is still incurable. γδ T cells comprise an important subset of the cytotoxic T cells. Although γδ T cells in CLL are dysfunctional, they still can possibly be used for immunotherapy. The current paper reviews our understanding of γδ T lymphocytes in CLL.