title: JC virus infection is acquired very early in life: evidence from a longitudinal serological study.
abstract: JC virus (JCV) is a widespread member of the Polyomaviridae family. Following primary infection, which occurs asymptomatically during childhood, JCV establishes latency in the host. JCV seroprevalence can reach 80 % in healthy adults, but the age of viral exposure has not been yet characterized. This study was conducted to define JCV seroprevalence in Italian infants and to estimate the date of primary infection. A JCV viral protein 1 (VP1)-GST fusion protein was used in conjunction with a homemade indirect enzyme-linked immunosorbent assay (ELISA) to test for the presence of IgG antibodies to JCV in 981 serum samples collected from 644 Italian infants of different ages (1 day to 3 years old) and in 102 breast milk samples. IgM antibody presence was also evaluated in longitudinally collected samples from 17 selected children. JCV antibody prevalence and normalized optical density (nOD) were calculated. For the longitudinal analysis, generalized estimating equation techniques and spline functions were used to estimate the possible non-linear effects of time on antibody production kinetics. JCV IgG was detected in 71.8 % of the sera. Prevalence increased over time from 46.1 % (1 month old) to 80.7 % (12 months old), 85.9 % (24 months old), and 85.5 % (36 months old). As determined by nOD, the longitudinal analysis of serum IgG amounts in children of this study (ages 1 day to 3 years old) illustrated IgG kinetic changes with statistically significant trends (p = 0.001). One-month-old children were largely negative for JCV IgM (82.4 %), and 58.8 % of children produced JCV IgM within the second and sixth months of life. JCV IgG was detected in 27.3 % of breast milk samples. JCV primary infection likely occurs before 6 months of age, and a sizeable percentage of Italian infants will become JCV seropositive within 2 years of age. This study can be used to determine the optimal age for potential future JCV vaccination in infants.
authors.affiliation: Department of Biomedical, Surgery and Dental Sciences, University of Milan, Via Pascal, 36, 20133, Milan, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Elia
authors.affiliation: Department of Biomedical, Surgery and Dental Sciences, University of Milan, Via Pascal, 36, 20133, Milan, Italy.
authors.forename: Sonia
authors.initials: S
authors.lastname: Villani
authors.affiliation: Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy.
authors.forename: Federico
authors.initials: F
authors.lastname: Ambrogi
authors.affiliation: Department of Biomedical, Surgery and Dental Sciences, University of Milan, Via Pascal, 36, 20133, Milan, Italy.
authors.forename: Lucia
authors.initials: L
authors.lastname: Signorini
authors.affiliation: Department of Biomedical, Surgery and Dental Sciences, University of Milan, Via Pascal, 36, 20133, Milan, Italy.
authors.forename: Simone
authors.initials: S
authors.lastname: Dallari
authors.affiliation: Department of Biomedical Sciences for Health, University of Milan, Milan, Italy.
authors.forename: Sandro
authors.initials: S
authors.lastname: Binda
authors.affiliation: Department of Biomedical Sciences for Health, University of Milan, Milan, Italy.
authors.forename: Valeria
authors.initials: V
authors.lastname: Primache
authors.affiliation: Department of Biomedical Sciences for Health, University of Milan, Milan, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Pellegrinelli
authors.affiliation: Department of Biomedical, Surgery and Dental Sciences, University of Milan, Via Pascal, 36, 20133, Milan, Italy.|Istituto Clinico Città Studi Hospital, Milan, Italy.
authors.forename: Pasquale
authors.initials: P
authors.lastname: Ferrante
authors.affiliation: Department of Biomedical, Surgery and Dental Sciences, University of Milan, Via Pascal, 36, 20133, Milan, Italy. Serena.delbue@unimi.it.
authors.forename: Serena
authors.identifier: 0000-0002-3199-9369
authors.initials: S
authors.lastname: Delbue
mesh_terms: D000914:Antibodies, Viral / Q000097:blood*; D058070:Asymptomatic Diseases; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D007075:Immunoglobulin M / Q000097:blood*; D007223:Infant; D007231:Infant, Newborn; D007558:Italy / Q000453:epidemiology; D007577:JC Virus / Q000276:immunology*; D008137:Longitudinal Studies; D008297:Male; D008895:Milk, Human / Q000821:virology; D027601:Polyomavirus Infections / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology* / Q000276:immunology; D015995:Prevalence; D016036:Seroepidemiologic Studies
chemical_list: D000914:Antibodies, Viral; D007074:Immunoglobulin G; D007075:Immunoglobulin M
keywords: JC polyomavirus; Newborns; Primary infection; Seroprevalence