Chronic Lymphoproliferative Disorder of Natural Killer Cells (CLPD-NK): A Singular Entity Resembling T-Cell Large Granular Lymphocytic Leukemia (T-LGL) or a Heterogeneous Group of Conditions?
Damian J Tagliente, Rebecca L King, Jadee Neff, Grzegorz S Nowakowski, Matthew T Howard, William G Morice II. Mayo Clinic, Rochester, MN; University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
Background: Natural killer cell (NK cell) leukemias that are not EBV-associated are rare, and their clinical attributes are poorly characterized. Early descriptions emphasized aggressive behavior, whereas more recent studies have portrayed a usually indolent condition with variably associated cytopenias, akin to T-cell large granular lymphocytic leukemia (T-LGL). In the most recent WHO classification scheme, these entities are categorized as chronic lymphoproliferative disorders of NK cells (CLPD-NK), yet the disease presentation and outcome remains ill-defined. To address this issue, a group of well-characterized cases were studied.
Design: Clinical and laboratory data from 34 CLPD-NK cases in the files of a major medical center from 1992-2012 were examined and compared.
|Median Age, (y)||59|
|% Hemoglobin<11.0 g/dL||32%|
|%ANC<1.5 x 10(9)/L||36%|
|%Platelet<150 x 10(9)/L||15%|
|%Abs Lymph Count>2.5 x 10(9)||73%|
|%Splenectomy and/or Multi-agent Chemotherapy||18%|
|%ALC>2.5 x 10(9)||74%||57%|
|Average % Marrow Cellularity||56%||81%|
|Average % Marrow Involvement||11%||18%|