title: Abnormal NK cell lymphocytosis detected after splenectomy: association with repeated infections, relapsing neutropenia, and persistent polyclonal B-cell proliferation.
abstract: 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.
authors.affiliation: Department of Hematology, Hospital S. João, Porto, Portugal. npp46740@mail.telepac.pt
authors.forename: Elisa
authors.initials: E
authors.lastname: Granjo
authors.forename: Margarida
authors.initials: M
authors.lastname: Lima
authors.forename: Manuela
authors.initials: M
authors.lastname: Fraga
authors.forename: Filipe
authors.initials: F
authors.lastname: Santos
authors.forename: Conceição
authors.initials: C
authors.lastname: Magalhães
authors.forename: Maria Luís
authors.initials: ML
authors.lastname: Queirós
authors.forename: Ilidia
authors.initials: I
authors.lastname: Moreira
authors.forename: Sandra
authors.initials: S
authors.lastname: Rocha
authors.forename: Alice Santos
authors.initials: AS
authors.lastname: Silva
authors.forename: Irene
authors.initials: I
authors.lastname: Rebelo
authors.forename: Alexandre
authors.initials: A
authors.lastname: Quintanilha
authors.forename: Maria Letícia
authors.initials: ML
authors.lastname: Ribeiro
authors.forename: Jorge
authors.initials: J
authors.lastname: Candeias
authors.forename: Alberto
authors.initials: A
authors.lastname: Orfão
mesh_terms: 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*