Natural acquired group B Streptococcus capsular polysaccharide and surface protein antibodies in HIV-infected and HIV-uninfected children

Group B Streptococcus (GBS) is a major cause of invasive disease in young infants and also in older immunocompromised individuals, including HIV-infected persons. We compared naturally acquired antibody titres to GBS polysaccharide and surface protein antigens in HIV-uninfected and HIV-infected children aged 4-7 years. A multiplex Luminex immunoassay was used to measure IgG concentrations against GBS capsular polysaccharides (CPS) for serotypes la, Ib, III and V; and also extracellular localizing proteins which included cell-wall anchored proteins: Fibrinogen binding surface Antigen (FbsA), GBS Immunogenic Bacterial Adhesin (BibA), Surface immunogenic protein (Sip), gbs0393, gbs1356, gbs1539, gbs0392; and lipoproteins gbt0233, gbs2106 and Foldase PsrA. HIV-infected children (n = 68) had significantly lower IgG GMT compared to HIV-uninfected (n = 77) children against CPS of serotype Ib (p = 0.012) and V (p = 0.0045), and surface proteins Sip (p < 0.001) and gbs2106 (p = 0.0014). IgG GMT against GBS surface proteins: FbsA, gbs1539, gbs1356, gbs0392, gbs0393 and Foldase PsrA were significantly higher in HIV-infected children (p < 0.004). Moreover, amongst HIV infected children, IgG GMT to GBS surface proteins were higher in those with CD4(+) lymphocyte counts <500 cell/mu L compared to those who had CD4(+) lymphocyte count >= 500 cell/mu L with the exception of Sip. The increased susceptibility to invasive GBS disease in HIV-infected individuals could be due to the lower serotype specific capsular antibody and possibly due to lower antibody to some of the GBS proteins such as Sip and gbs2106. (C) 2016 Elsevier Ltd. All rights reserved.