Response and Decline of Serum IgG Antibodies to Pertussis Toxin, Filamentous Hemagglutinin and Pertactin in Children with Pertussis

Abstract

The serum IgG antibody response and decrease to 3 Bordetella pertussis antigens was compared in children with pertussis. Sera were obtained at the first clinical visit and 1, 3 and 12 months later from 89 children with > or = 3 weeks of paroxysmal cough. IgG antibodies to pertussis toxin (PT), to filamentous hemagglutinin (FHA) and to pertactin were determined with ELISA. Of 54 children with culture-confirmed pertussis or culture-confirmed familial exposure, 45 (83%) had a significant (> or = 3 fold) increase in PT IgG and 40 (74%) in FHA IgG antibodies, while only 29 (54%) had a significant increase in pertactin IgG antibodies. Significant decreases in PT, FHA and pertactin IgG antibodies were found in 34 (63%), 9 (17%) and 28 (52%) children, respectively. In the remaining 35 who did not have culture-confirmed disease, significant PT and/or FHA IgG antibody increases (criteria for pertussis according to the WHO definition) were found in 17 (49%). Only 6 of these 17 children had a significant pertactin IgG antibody increase. Of the remaining 18 children (who did not fulfil WHO criteria for pertussis), significant decreases in PT and/or FHA IgG antibodies were found in 13. We conclude that a serum IgG reaction to PT and FHA occurs in almost all children with pertussis. An increase in pertactin IgG antibodies occurs less frequently than against PT and FHA. Significant decreases in PT or FHA IgG antibodies in children with clinical pertussis might be of use as a diagnostic criterion in children brought late for examination.

Laboratory Diagnosis of Pertussis

“…In serial sera from 71 children, obtained before, during, and after vaccination with a monocomponent Ptx-containing ACV vaccine, maternally derived IgG-Prn and IgG-FHA declined in the first 3 months of life. After the age of 1 year, IgG-Bp-FHA and IgG-Bp-Prn reemerged at relatively low titers, at such a rate that at 36 months, all 71 children had detectable IgG-Bp-FHA and 58 of 71 children had detectable IgG-Bp-Prn, while in this study period, none of the children had had symptoms compatible with pertussis (220). Between the ages of 1 and 2 years, 25% and 31% of children had significant increases (Ն3-fold) of IgG-Bp-FHA and IgG-BpPrn, respectively (endpoint titrations); between 2 and 3 years, those percentages were 21% and 13%.…”

Recent progress in clinical and basic pertussis research

“…There is now convincing evidence that natural infection with B. pertussis does not necessarily provide lifelong immunity [123] and high serum IgG antibodies against PT, ®lamentous haemagglutinin (FHA), pertactin and other B. pertussis antigens are detectable already at the time of onset of symptoms as a result of the rapid secondary immune response [87]. After natural infection, serum IgG antibodies against PT, FHA and pertactin remain at high levels for at least 1 [76] to 3 years [68] before they gradually return close to initial values after approximately 5 years [138]. Interestingly, IgA antibodies, which were previously thought to be reliable indicators of recent or acute infection [106,143], against FHA and pertactin, but not against PT, have also been shown to remain detectable for at least 30 months after infection [68].…”

“…infections and enzyme immunoassays have been most widely applied [105]. Although whole cells of B. pertussis can be used as antigens [57], puri®ed speci®c proteins such as PT, FHA, pertactin and ®mbriae (in chronological order of sensitivity) are preferable for their speci®city [76,129]. In general, IgG antibody assays provide sucient sensitivity for diagnosis in paired acute and convalescent specimens [55], but addition of IgA assays may be considered for optimisation [97,123].…”

Immunization in Adolescents: Past, Present and Future

“…Although cases of diphtheria and tetanus are very rare in countries with successful vaccination programs, in the past two decades resurgence of pertussis has been reported in many areas of the world [51]. This increase in incidence of pertussis reflects different factors (waning in vaccine-induced immunity to pertussis in the 4-12 years after vaccination and a decrease of natural boosting of immunity) and has been associated with a shift in age groups afflicted with pertussis [52,53]. In fact before the introduction of the vaccine, pertussis mostly affected school-age children, but it has now shifted to very young infants not completely vaccinated and to adolescents and adults [54,55].…”