Infectious Complications in Patients with Chronic Lymphocytic Leukemia

Abstract

Prolymphocytic leukemias (PLLs) of B-and T-cell subtype are rare diseases, whichtogether account for around 2% of all mature lymphoid leukemias. When first describedin the 1970s (1), the different cells of origin were not appreciated, and the disease wascalled a variant of chronic lymphocytic leukemia (CLL). Advances in immunophenotyp-ing and molecular cytogenetics have significantly contributed to a more preciseclassification of the mature lymphoid leukemias, and this has resulted in bettermanagement of patients with these conditions. Recent studies have highlighted the role ofspecific oncogenes such as TCL1, MTCP-1, and ATM in T-cell prolymphocytic leukemia(T-PLL) and TP53 mutations in the case of B-cell prolymphocytic leukemia (B-PLL).However, despite better understanding of the underlying cell biology, prognosis for thesepatients remains poor with no curative therapy and shortened survival. The advent ofmonoclonal antibody therapy and the wider application of nonmyeloablative allogeneictransplantation have increased the treatment options for this group of patients. Table 1summarizes the characteristic features of the PLLs.