Anti-filarial immunity blocks parasite development and plays a protective role

PLoS One. 2018 Jun 21;13(6):e0199090. doi: 10.1371/journal.pone.0199090. eCollection 2018.

Abstract

Lymphatic filariasis is a complex parasitic disease having a spectrum of clinical parameters which are critical in deciding the severity of the pathogenesis. Individuals residing in the endemic areas are categorized into different clinical groups such as: EC (endemic controls-free of disease and infection), AS (asymptomatic carriers- free of disease but carries both antigens and microfilaria (Mf) in circulation), CR (cryptic-free of disease and Mf but having circulatory antigen) and CH (chronic-having manifestations of elephantiasis and hydrocele). The immune response to the parasitic infection is well studied, whereas the protective mechanism explaining the fate of antigenemia and filaremia between AS and CR group remains unexplained. Increased anti-Mf antibodies have been implicated for Mf clearance in experimental infection models whereas its role in clinical filariasis is not known. Here, we followed up two groups of 24 and 33 CR cases for 18 and 36 months respectively and analyzed both the clinical parameters and the anti-filarial antibody response. The humoral response to both whole filarial antigen and Mf antigens as well as recombinant active parasitic antigens was significantly higher in CR cases than AS individuals, whereas the clinical parameters remain unchanged. This study made insights into the protective immune mechanism responsible for the clearance of Mf from circulation in CR individuals.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Helminth*
  • Antigens, Helminth / immunology*
  • Elephantiasis, Filarial / immunology*
  • Humans
  • Immunity, Humoral
  • India
  • Wuchereria bancrofti / immunology*

Substances

  • Antibodies, Helminth
  • Antigens, Helminth

Grants and funding

This study was supported by the Indian Council of Medical Research. SKP was an employee of Regional Medical Research Center, Bhubaneswar, at the time of the study conducted. Medimmune did not play a role in the study design, data collection and analysis, decision to publish or preparation of the manuscript. The funder provided support in the form of salaries for SKP but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ‘author contributions’ section.