Immunoepidemiology of the equine tapeworm Anoplocephala perfoliata: age-intensity profile and age-dependency of antibody subtype responses.

The research article studies the relationship between the immune response to the horse intestinal tapeworm, Anoplocephala perfoliata, and the intensity of infection. It particularly focuses on how this relationship changes with age. Main findings of the research include an age-dependent infection pattern, different trends for different antibody subtypes, and the importance of exposure and immunity development.

Understanding Anoplocephala perfoliata and its Effects

• Anoplocephala perfoliata is a type of intestinal cestode (tapeworm) that infests horses.
• There’s a growing interest in studying it, due to the suspicion that it’s associated with intestinal disease in horses.
• The researchers have previously found a positive correlation between the presence of a specific antibody, the IgG(T) subtype, and the intensity of this tapeworm’s infection.

Age-Intensity Profile of Infection

• The study found that the intensity of infection changes with the age of the host.
• A triphasic age-dependency pattern was observed, based on IgG(T) responses. The mean intensity of the worm infestation was highest in horses aged 6 months to 2 years.
• This intensity fell to a lower, steady level from ages 3 to 15 and then rose again in older horses.

Age-Dependency of Antibody Subtype Responses

• Different antibody subtypes showed different patterns of age-dependency.
• The levels of IgG(a) echoed the triphasic pattern seen in the IgG(T) responses. Meanwhile, levels of IgG(c) antibodies increased steadily with age.
• The pattern shown by IgG(b) antibodies was intermediate between those of IgG(a) and IgG(c).

Significance of Infection Exposure and Immunity Development

• The researchers noticed significant correlations between the intensity of the infection (measured by the presence of anti-12/13 kDa IgG(T)) and the levels of both IgG(a) and IgG(b) in many age groups.
• These correlations helped the researchers to understand the impact of both exposure to infection and the development of immunity on the observed age-intensity pattern.