Evaluation of A Proliferation-Inducing Ligand (APRIL) Level in Patients with B-cell Chronic Lymphocytic Leukemia

Abstract

CLL is considered the most common form of leukemia in adults over sixty and rarely occurs below forty. The CLL is a malignant proliferation of monoclonal lymphocytes, most commonly of B-cell origin (B-CLL). It is characterized by an accumulation of small, mature appearing functionally incompetent lymphocytes in BM, PB and lymphoid tissue. The diagnosis of CLL requires a lymphocyte count of 5000 or more per cubic millimeters, and a characteristic cell surface phenotype of clonal B-cells; the presence of CD19, CD5, CD23 and weak expression of CD20, CD79b, and either kappa or lambda immunoglobulin light chain. The CLL follows an extremely variable clinical course with overall survival times ranging from months to decades. Some patients have no or minimal signs and symptoms during their entire disease course and have a survival time similar to age-matched controls. Other patients experience rapidly deteriorating blood counts, organomegaly and suffer from symptoms at diagnosis or soon thereafter necessitating therapy. This has led to a search for prognostic indicators that correlate better with survival. Potential prognostic indicators include clinical stage, lymphocyte doubling time, IgVH mutation status, cytogenetic abnormalities, leukemia cell CD38 and Zap-70 expression. Expression of Zap-70, the Rai, and Binet staging systems are still widely used in clinical practice, but they do not predict disease progression or response to therapy. To fill these voids in the management of CLL, serum APRIL was measured in B-CLL patients.