Lower Respiratory Tract Infection Caused by Respiratory Syncytial Virus in Infants: The Role Played by Specific Antibodies

Abstract

Vieira SE, Gilio AE, Durigon EL, B Ejzenberg. Lower respiratory tract infection caused by respiratory syncytial virus in infants: the role played by specific antibodies. Clinics. 2007; 62(6):709-16. INTRODUCTION:Respiratory syncytial virus (RSV) is a major etiological agent of lower respiratory tract infection in infants. Genotypes of this virus and the role of the infants' serum antibodies have yet to be fully clarified. This knowledge is important for the development of effective therapeutic and prophylactic measures. OBJECTIVES: To evaluate the types and genotypes of RSV causing respiratory tract infection in infants, to analyze the association of subtype-specific serum antibodies with the occurrence of infection and to evaluate the presence of subtype-specific antibodies in the infants' mothers and their association with the profile of the childrens' serum antibodies. METHODS:This was a prospective study on infants hospitalized with respiratory infection. Nasopharyngeal secretions were collected for viral investigation using indirect immunofluorescence and viral culture and blood was collected to test for antibodies using the Luminex Multiplex system. RESULTS: 192 infants were evaluated, with 60.9% having RSV (73.5%-A and 20.5% B). Six genotypes of the virus were identified: A5, A2, B3, B5, A7 and B4. The seroprevalence of the subtype-specific serum antibodies was high. The presence and levels of subtype-specific antibodies were similar, irrespective of the presence of infection or the viral type or genotype. The mothers' antibody profiles were similar to their infants'. CONCLUSIONS: Although the prevalence of subtype-specific antibodies was elevated, these antibodies did not provide protection independently of virus type/genotype. The similarity in the profiles of subtype-specific antibodies presented by the mothers and their children was consistent with transplacental passage.

Relationship among epidemiological parameters of six childhood infections in a non-immunized Brazilian community

“…The same is true for RSV, as shown by Vieira et al (2007). In the case of varicella, two different samples from Caieiras (Yu et al 2001, Valentim et al 2008 showed similar seroprofile patterns.…”

Fc gamma receptors in respiratory syncytial virus infections: implications for innate immunity

“…Further, passive transfer of RSV-specific Abs in mice attenuates the titer and the neutralizing activity of Abs against F and G-proteins expressed by vaccinia virus recombinants [31–33]. All together, these data suggest that matAbs alter the humoral response against RSV resulting in a non-protective immune response.…”

Natural killer cell activation by respiratory syncytial virus‐specific antibodies is decreased in infants with severe respiratory infections and correlates with Fc‐glycosylation

“…Some studies show that high RSV‐specific maternal antibody titres are associated with protection against RSV infection or (severe) disease . In contrast, other studies do not show a protective effect or even indicate an association between high maternal antibody titres and an increased risk of recurrent wheezing . Strikingly, the vast majority of studies investigating the role of (maternal) antibodies in RSV infection only look at in vitro binding or neutralisation capacity, while additional antibody effector functions are not taken into account.…”