[Neutrophils without CD16b receptors].
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.
Riera
Norma E
NE
Instituto de Investigaciones Hematológicas, Academia Nacional de Medicina, Buenos Aires.
Saltó
Marisa Rosso
MR
Canalejo
Katia
K
Felippo
Marta E
ME
Arrossagaray
Guillermo
G
Aixala
Mónica
M
de E de Bracco
María M
MM
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
C428200:FCGR3B protein, human; D058851:GPI-Linked Proteins; D017452:Receptors, IgG