Visual detection of filaria-specific IgG4 in urine using red-colored high density latex beads

• Published in: Parasitology international Vol. 62; no. 1; pp. 32 - 35
• Main Authors: Nagaoka, Fumiaki, Itoh, Makoto, Samad, Mohammad S, Takagi, Hidekazu, Weerasooriya, Mirani V, Yahathugoda, Thishan C, Hossain, Moazzem, Moji, Kazuhiko, Kimura, Eisaku
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ireland Ltd 01-02-2013
• Subjects: Adolescent; Animals; Antibodies, Helminth - urine; antigens; Child; Child, Preschool; children; Elephantiasis, Filarial - diagnosis; Elephantiasis, Filarial - urine; Enzyme-Linked Immunosorbent Assay; epidemiological studies; Filariasis; Gastroenterology and Hepatology; High density latex beads; Humans; IgG4; immunoglobulin G; Immunoglobulin G - urine; Immunologic Tests - methods; Infectious Disease; latex; Microspheres; parasitology; people; Recombinant Wb-SXP1; Sensitivity and Specificity; serodiagnosis; urine; Urine diagnosis; Wuchereria bancrofti - metabolism; Sri Lanka; Bangladesh; Japan; High density latex beads; IgG4; Filariasis; Urine diagnosis; Recombinant Wb-SXP1
• ISSN: 1383-5769; 1873-0329
• DOI: 10.1016/j.parint.2012.09.002

Abstract The use of urine for the immunodiagnosis of lymphatic filariasis has a definite advantage: the sample collection is not invasive and thus well accepted by people. Urine-based ELISA to detect filaria-specific IgG4 has been used successfully. However, ELISA requires equipment such as a microplate reader, which is often not available in most endemic areas. We have developed a new visual immunodiagnosis that detects urinary IgG4 using red-colored latex beads (bead test). The sensitivity was 87.2% when ICT antigen test positive people were regarded as the standard (136/156), and the specificity was 97.2% with the non-endemic people in Japan and Bangladesh, and the urine ELISA negatives in Sri Lanka (1264/1300). In a prevalence study, the bead test could detect filarial infection more effectively than ICT test among young children in Sri Lanka, indicating the usefulness of the visual test in epidemiological studies.