Abnormal NK cell lymphocytosis detected after splenectomy: association with repeated infections, relapsing neutropenia, and persistent polyclonal B-cell proliferation.
We report the case of a boy with hereditary spherocytosis who presented with mild microcytic hypochromic anemia and recurrent leg ulcers that had been present since childhood. Chronic natural killer (NK) cell and B-cell lymphocytosis was detected 1 year after therapeutic splenectomy during investigation of recurrent episodes of neutropenia and persistent lymphocytosis. NK cells proved to be abnormal at immunophenotyping studies, and B-cells were polyclonal and displayed a normal immunophenotype. Genotypic analysis of T-cell receptor (TCR)-beta and TCR-gamma genes showed a germ-line pattern. The clinical course of this patient was characterized by multiple pulmonary infections and amygdalitis. We discuss the potential roles of persistent immune stimulation due to chronic hemolysis and severe leg ulcers and of splenectomy in the origin of NK cell lymphocytosis and the relationship between NK cells and recurrent infections, relapsing neutropenia, and polyclonal B-cell response.
Granjo
Elisa
E
Department of Hematology, Hospital S. João, Porto, Portugal. npp46740@mail.telepac.pt
Lima
Margarida
M
Fraga
Manuela
M
Santos
Filipe
F
Magalhães
Conceição
C
Queirós
Maria Luís
ML
Moreira
Ilidia
I
Rocha
Sandra
S
Silva
Alice Santos
AS
Rebelo
Irene
I
Quintanilha
Alexandre
A
Ribeiro
Maria Letícia
ML
Candeias
Jorge
J
Orfão
Alberto
A
D001402:B-Lymphocytes / Q000166:cytology; D002648:Child; D006801:Humans; D007107:Immune System / Q000473:pathology; D007239:Infections / Q000150:complications; D007694:Killer Cells, Natural / Q000473:pathology*; D008218:Lymphocytosis / Q000209:etiology* / Q000473:pathology; D008297:Male; D009503:Neutropenia / Q000150:complications; D012008:Recurrence; D013103:Spherocytosis, Hereditary / Q000150:complications / Q000628:therapy; D013156:Splenectomy / Q000009:adverse effects*