Immune Response to Invasive Kingella kingae Infections, Age-Related Incidence of Disease, and Levels of Antibody to Outer-Membrane Proteins

Abstract

The immune response to Kingella kingae was determined by enzyme-linked immunosorbent assay, using outer-membrane proteins as coating antigen, in 19 children with invasive infection. The age-related incidence of K. kingae disease in southern Israel during 1988-2002 was calculated and correlated with serum antibody levels in healthy children. Significant increases in immunoglobulin G (IgG) levels were found in children convalescing after invasive infections. The incidence was 1.3, 40.3, 23.9, 5.7, and 1.9 cases/100,000 children among those aged 0-5, 6-11, 12-23, 24-35, and 36-47 months, respectively. A low attack rate and undetectable serum IgA and high IgG levels were found during the first 6 months of life, which indicates that protection was conferred by maternally derived immunity. The high attack rate found among 6-24-month-old children coincides with the age at which antibody levels were lowest. Low incidence of disease and increasing antibody levels were found among older children, which probably represents cumulative experience with K. kingae antigens via colonization or infection.

Oropharyngeal Kingella kingae carriage in children: characteristics and correlation with osteoarticular infections

“…In our population, the colonization rate was greatest among children aged between 12 and 36 mo. After 36 mo, the carriage rate declined, probably due to the maturation of the children's immune system and/or an acquired humeral immunity to K. kingae carriage and invasive infection as a result of previous expositions (15)(16)(17)(18)(19). Our results show marked similarities to a recent study carried out by Amit et al (20) among a large cohort of healthy Israeli children; and previous data (13,16).…”

“…kingae has recently emerged as an important cause of OAI in young children (1)(2)(3)13). This organism belongs to the normal commensal flora of the posterior pharynx (14,15), but rarely penetrates the bloodstreams and invades distant organs (6,16). The K. kingae strains isolated from the pharynx of children with invasive infections are genotypically identical to those recovered from the blood (5).…”

“…Vanishing maternally derived immunity (16), and increased social contacts, especially day-care attendance (21), may result in an increasing acquisition of K. kingae within the two first year of life. The available data suggest that by 24 mo most children who will be infected by K. kingae already have been infected resulting in acquired immunity (15,22). Furthermore, recent investigation demonstrated the presence of a carbohydrate capsule in K kingae (23).…”

30 Years of Study of Kingella Kingae : Post Tenebras , Lux

“…The annual incidence of invasive infections due to K. kingae ranged from 9.4 to 27.4 per 100,000 children aged under 4 years [36,56], and peaked in the 6-11-month-old group (40.3 cases/100,000) [57]. An interesting study has demonstrated that antibody concentrations to K. kingae outer membrane proteins were high at 2 months of age, reached nadir values at 6-7 months of age, remained low until the age of 18 months and gradually increased in older children [57,58]. This pattern represents a mirror image of the age-related incidence of invasive K. kingae infections.…”

A Case of Kingella Kingae Endocarditis Complicated by Native Mitral Valve Rupture

“…Epidemiologically, approximately 90% of invasive disease occurs in children. 3 Considerable variability has been found in RTX toxin production, a potential virulence factor, between strains of Kingella. 4,5 Kingella endocarditis usually occurs in prosthetic and or diseased valves.…”