| dc.description.abstract | In northwestern Ontario the Indigenous First Nations (FN) population have an increased
prevalence of chronic kidney disease (CKD). There is an increased rate of infectious disease
caused by Streptococcus pneumoniae (pneumococcus) and Haemophilus influenzae in the FN
population. The 23-valent pneumococcal polysaccharide vaccine (PPV23) and 13-valent
pneumococcal protein-polysaccharide conjugate vaccine (PCV13) are used to prevent
pneumococcal disease in Canada. Since the implementation of H. influenzae type b (Hib)
vaccine programs, invasive H. influenzae type a (Hia) disease has replaced invasive Hib disease
in the FN population. However, there is no vaccine to prevent disease caused by non-Hib strains.
To maintain immunological memory in adults, stimulation of pre-existing memory is
achieved through immunization. To determine if patients with CKD have the ability to respond
to conjugate vaccines specific for Hia or pneumococcus, naturally acquired humoral immunity
against these pathogens must be evaluated. Immunization with PPV23 is recommended for
adults with CKD, however PPV23 is suboptimal at inducing antibody responses in adults with
CKD compared to healthy adults. PCV13 is recommended for certain immunocompromised
adults, but only two studies evaluated the immunogenicity of PCV13 in adults with CKD with
conflicting results. To determine if PCV13 is immunogenic in patients with CKD and the effect
of previous PPV23 immunization on subsequent immunization with PCV13, quantification of Bcell subpopulations, pneumococcal specific B cells and their relationship with antibody
responses to PCV13 must be evaluated.
The results suggest that the increased prevalence of invasive disease caused by
pneumococcus and Hia in the FN population is not due to decreased numbers of B cells or
concentrations of naturally acquired antibodies. The increased prevalence of diseases such as CKD causing immune dysfunction in a higher proportion of the FN population increases their
risk for invasive disease. Results suggest that a new Hia-conjugate vaccine may be immunogenic
in adults with CKD, as it will potentially re-activate Hia specific immunological memory. Our
findings suggest that previous immunization with PPV23 has a negative effect on the humoral
immune response that results in long-term changes in B-cell subpopulations and decreases
antibody responses to subsequent immunization with PCV13 in patients with CKD. | en_US |
