student research day - Case Western Reserve University School of ...

Adam Duvall
Development of a multi-channel serological assay for multiple parasites
Adam DuVall, Jessica Fairley, MD, and Charles King, MD MS
Center for Global Health and Diseases
Case Western Reserve University
The importance of parasitic infections in the realm of international health has already been significantly
documented, but the impact on health and disabilityof multiple parasitic infections – polyparasitism – is only
recently coming to the forefront, and thus the amount of information to be gathered is large and growing. 1 There
have been significant associations seen between different helminth infections (such as between schistosomiasis
and hookworm infection) and between malaria and helminth infections. 2,3,4 This paper will describe the
development of a multi-channel fluorescent antibody detection assay that assesses previous exposure to
schistosomiasis, filariasis, hookworm, and malaria in the context of a large polyparasitism study in coastal
Kenya. IgG4 against Brugia malayi antigen, BMA, was chosen as a marker for filarial exposure, because the IgG4
response against BMA is positively associated with presence and intensity of infection. 5,6,7,8,9 IgG4 against soluble
adult worm antigens, SWAP, was chosen as a marker for exposure to schistosomiasis because IgG4 levels against
adult worm antigens have been shown to be associated with infection intensity in the realm of recurrent infection
giving a good estimation of exposure even when controlled for age. 10 Although the IgG4 level against the excretory
/ secretory proteins, ES, of the hookworm Necator americanus drops significantly after the first year, it is still
present, and in areas where exposure and infection are regular, it will continually be renewed, so it is still ideal for
use in assessing past exposure. 11,12 IgG4 anti-malarial antibodies, AMA, will be used to test for previous exposure
to P. falciparum malaria because their levels are consistent throughout ethnic populations. 13 Brugia malayi have
been obtained from the CDC and BMA prepared from them as well as Schistosoma mansoni SWAP
preparation Plasmodium falciparum AMA preparation from within the Center for Global Health and Diseases. Beads
conjugated with BMA, SWAP, and AMA are currently being adjusted in order to maximize fluorescence. ES proteins
from N. americanus are still in the process of being obtained. Once the beads have been maximized for
fluorescence, they will be tested with serum with known parasite infection history and the results will be published.
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Resources
1. 1. McKenzie, FE. Polyparasitism. Int J Epidemiol 2005 Feb; 34(1): 221-2.
2. 2. Thiong’o FW, et al. Intestinal helminthes and schistosomiasis among school children in a rural district in
Kenya. East Afr Med J 2001 Jun; 78(6): 279-82.
3. 3. Raso G, et al. Multiple parasite infections and their relationship to self-reported morbidity in a community of rural
Côte d'Ivoire. Int J Epidemiol 2004 Oct; 33(5): 1092-1102.
4. 4. Pullan R, Brooker S. The health impact of polyparasitism in humans: are we under-estimating the burden of
parasitic disease? Parasitology 2008; 135: 783-794.
5. 5. Estambale BB, et al. Bancroftian filariasis in Kwale District of Kenya II. Humoral immune responses to filarial
antigens in selected individuals from an endemic community. Ann Trop Med Parasitol 1994; 88: 153-161.
6. 6. Jaoko WG, et al. Filarial-specific antibody response in East African bancroftian filariasis: effects of host infection,
clinical disease, and filarial endemicity. Am J Trop Med Hyg 2006; 75: 97-107.
7. 7. Kurniawan-Atmadja A, et al. Specificity of predominant IgG4 antibodies to adult and microfilarial stages of
Brugia malayi. Parasite Immuno 1998; 20: 155-162.
8. 8. Nicolas L, et al. Filarial antibody responses in Wucheria bancrofti transmission area are related to parasitological
but not clinical status. Parasite Immunol 1999; 21: 73-80.
9. 9. Jaoko WG, et al. Immunoepidemiology of Wucheria bancrofti infection: Parasite transmission intensity, filarial-
specific antibodies, and host immunity in two East African communities. Infection and Immunity 2007 Dec;
75(12): 5651-5662.
10. 10. Naus CWA, et al. Development of antibody isotype responses to Schistosoma mansoni in an immunologically
naïve immigrant population: influence of infection duration, infection intensity, and host age. Infection and
Immunity 1999 July; 67(7): 3444-3451.