title: [Neutrophils without CD16b receptors].
abstract: Occurrence of the rare CD16b deficiency ("null" phenotype) in neutrophils from two female patients (41 and 15 years old) is reported. The first case was referred with a diagnosis of anemia related to paroxistic nocturnal hemoglobinuria and the second case, with presumptive diagnosis of immune neutropenia. In both cases, absence of CD16b expression was determined by flow cytometry without deficiencies of other neutrophil alloantigens or defects of membrane anchorage through glycosil phosphatydil inositol (GPI) linkage. Clinical manifestations in both patients could not be attributed exclusively to the absence of CD16b, as other receptors for the IgG Fc fragment (CD32 and CD64) could compensate this deficiency that occurs in <1% of the caucasic population. Nevertheless, it is important to take this rare deficiency into account in order to prevent isoantibody formation after eventual blood transfusions, or transient neonatal immune neutropenia in children born to women with the "null" phenotype.
authors.affiliation: Instituto de Investigaciones Hematológicas, Academia Nacional de Medicina, Buenos Aires.
authors.forename: Norma E
authors.initials: NE
authors.lastname: Riera
authors.forename: Marisa Rosso
authors.initials: MR
authors.lastname: Saltó
authors.forename: Katia
authors.initials: K
authors.lastname: Canalejo
authors.forename: Marta E
authors.initials: ME
authors.lastname: Felippo
authors.forename: Guillermo
authors.initials: G
authors.lastname: Arrossagaray
authors.forename: Mónica
authors.initials: M
authors.lastname: Aixala
authors.forename: María M
authors.initials: MM
authors.lastname: de E de Bracco
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D005434:Flow Cytometry; D058851:GPI-Linked Proteins; D006457:Hemoglobinuria, Paroxysmal / Q000175:diagnosis* / Q000276:immunology; D006801:Humans; D009503:Neutropenia / Q000175:diagnosis*; D009504:Neutrophils / Q000276:immunology*; D017452:Receptors, IgG / Q000172:deficiency* / Q000276:immunology
chemical_list: C428200:FCGR3B protein, human; D058851:GPI-Linked Proteins; D017452:Receptors, IgG