Immune status towards Epstein-Barr virus in a group of Sicilian children

Impact of CMV and EBV seropositivity on CD8 T lymphocytes in an old population from West-Sicily

Herpes viruses (particularly CMV and to some extent EBV) might play a role in accelerating the deterioration of immune functions with age. Indeed, it has been demonstrated that chronic infection with CMV causes an expansion of specific CD8 T lymphocytes and that this is related to a shrinkage of the T cell repertoire in very elderly people, predicting mortality. We have analysed CD8 T cells in young and old healthy Sicilians who were both CMV- and EBV-seropositive. Our data confirm expansions of T cells specific for the HLA-A2-restricted pp65 (495-503) CMV epitope up to nearly 14% of total peripheral CD8 cells in certain elderly individuals (range 0-14%). However, the mean percentage of CMV-specific cells in the elderly was not greater than the young (range 0.2-3%). The CMV-specific CD8 cells in the elderly were predominantly CD45RA+, but in the young they were mostly CD45RO+. Our findings are somewhat different from published reports from Northern European populations, both in terms of mean numbers and surface phenotypes. These findings may reflect disparate hygienic and nutritional conditions 70-90 yr ago, which were very different in Northern and Southern Europe at that time, as well as a different genetic background.

Studies on the epidemiology of child infections in the Bari area (south Italy). VII. Epidemiology of Epstein-Barr virus infections

Serological patterns against Epstein-Barr virus (EBV) specific antigens were determined in 3732 healthy babies and children aged 0-10 years living in the Bari area (South Italy). IgG antibodies against EBV capsid antigen (VCA) were found in 2713 subjects (72.7%). Seropositivity rates, high in the first semester of life (83.8%), declined between 6 and 12 months (65.6%) and even further between 1 and 2 years (43.8%). After 2 years the frequency of positive children rose progressively reaching steady levels between 5 and 7 years (80.2%) and between 8 and 10 years (81.9%). IgA antibodies against VCA, IgG anti-early viral antigen (EA) and IgG against virus-associated nuclear antigens (EBNA) were found in 17.9%, 15.9% and 25.7% of the subjects tested, respectively. IgM anti-VCA were found only in 35 (0.9%) children, but 818 (21.9%) exhibited antibody patterns suggestive of a recent infection: IgG anti-VCA > or = 1:160 alone or in association with IgA anti-VCA or IgG anti-EA or both. These results suggest that in this area the primary infection by EBV occur early in life, with immunity to EBV acquired primarily after 4 years.

HLA-B8,DR3 phenotype and the antibody response against Epstein-Barr virus

Antibodies against the viral capsid antigen (VCA) and nuclear antigens (EBNAs) of the Epstein-Barr virus (EBV) were determined in a sample of Sicilian population. A significant correlation was observed between HLA-B8,DR3 phenotype and reduced titres of antibodies to EBNAs, whereas HLA-B8,DR3 positive individuals displayed levels of antibodies to VCA comparable to those of HLA-B8,DR3 negative ones. These results further strengthen the suggestion that HLA-B8,DR3 positive subjects are low responders and that the depth of immune response depends on the fashion of antigenic challenge.