Introduction
Chronic lymphocytic leukemia (CLL) is a chronic lymphoproliferative
disorder characterized by progressive accumulation of functionally
incompetent lymphocytes that are usually monoclonal in
origin.1 Most patients will respond to initial
therapy, but disease relapse invariably occurs and becomes refractory
with each relapse. Venetoclax, which is an orally bioavailable,
selective, small-molecule inhibitor of BCL2, is a new therapeutic agent
for relapsed or refractory CLL.2 Concerning the
toxicity of venetoclax, tumor lysis syndrome (TLS) has been reported as
a severe adverse event due to venetoclax treatment and intensive
prevention and strict monitoring are recommended according to the risk
level of TLS defined by tumor burden and renal function for the use of
venetoclax.3
Chronic kidney disease (CKD) refers to kidney damage or decreased kidney
function for three or more months, regardless of the cause. Decreased
kidney function is defined as a glomerular filtration rate (GFR) of less
than 60 mL/min/1.73 m2, and severe CKD (stage 4) is
defined as a GFR of less than 30
mL/min/1.73 m2.4 To the best of our
knowledge, venetoclax use has not been reported in patients with severe
CKD. Herein, we describe a case of relapsed CLL patient with severe CKD
due to congenital solitary kidney that was successfully treated with
venetoclax.