title: B lymphocyte subsets and their functional activity in the early months of life.
abstract: In the present study we evaluated B-cell subsets and their functional development in 74 newborns from birth to 6 months of life. Moreover, we evaluated natural antibody production in vitro. The results documented a predominance of naive B-lymphocytes at all time-points evaluated, decreasing from birth to 6 months (p=0.009). The percentages of CD27+IgD+ and CD27+IgDneg memory B-cells were very low at birth and significantly increased only at 6 months (p=0.02 and p less than 0.001, respectively). We found a significant increase only in in vitro stimulated IgG production at 6 months as compared to birth (p less than 0.001). Moreover, a lower secretion of anti-Pn IgM antibodies up to 6 months of age, as compared to controls was observed. Our results underline that the susceptibility and severe course of infection in the neonate can be attributed, at least in part, to the lack of pre-existing immunological memory and competent adaptive immunity.
authors.affiliation: Laboratorio Sperimentale Oncoematologia Pediatrica, Fondazione IRCCS Policlinico S. Matteo, Pavia, Italy. ma.avanzini@smatteo.pv.it
authors.forename: M A
authors.initials: MA
authors.lastname: Avanzini
authors.forename: R
authors.initials: R
authors.lastname: Maccario
authors.forename: C
authors.initials: C
authors.lastname: Belloni
authors.forename: G
authors.initials: G
authors.lastname: Carrera
authors.forename: A
authors.initials: A
authors.lastname: Bertaina
authors.forename: M
authors.initials: M
authors.lastname: Cagliuso
authors.forename: M
authors.initials: M
authors.lastname: La Rocca
authors.forename: C
authors.initials: C
authors.lastname: Valsecchi
authors.forename: M
authors.initials: M
authors.lastname: Mantelli
authors.forename: A M
authors.initials: AM
authors.lastname: Castellazzi
authors.forename: I
authors.initials: I
authors.lastname: Quinti
authors.forename: A
authors.initials: A
authors.lastname: De Silvestri
authors.forename: M
authors.initials: M
authors.lastname: Marconi
mesh_terms: D000293:Adolescent; D000907:Antibodies, Bacterial / Q000097:blood; D016175:B-Lymphocyte Subsets / Q000276:immunology*; D016667:Bacterial Capsules / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007136:Immunoglobulins / Q000097:blood; D007156:Immunologic Memory; D007223:Infant; D007231:Infant, Newborn / Q000276:immunology*; D008297:Male; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7 / Q000032:analysis
chemical_list: D000907:Antibodies, Bacterial; D007136:Immunoglobulins; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7; C056696:pneumococcal polysaccharide, type 14