Immunodiagnosis of bancroftian filariasis—Problems and progress.
Loading...
Date
1984-12
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
The immunodiagnosis of bancroftian filariasis is a major challenge to the
immunoparasitologist. Significant progress is yet to be made in developing convenient
laboratory animal model and in in vitro cultivation of filarial parasites making it very difficult
to obtain required amount of parasite material for research. Parasitological examination
techniques are not useful in low microfilaraemia, occult or chronic .filarial infections. A precise
and accurate immunodiagnostic technique is very much needed for successful filaria control
programmes. Such a test will also avoid the need for laborious night blood examination in
bancroftian filariasis.
Due to comparatively easy availability, a good amount of work has been done to explore
immunodiagnostic potential of heterologous filarial antigens isolated from Litomosoide
carinii, Dirofilaria immitis, Brugia malayi, Setaria digitata, Setaria cervi and number of other
filarial species. However, there has been limited or no significant success due to number of false
negative and false positive reactions.
Extensive study has also been made with antigens isolated from Wuchereria bancrofti
microfilariae. Soluble antigens of microfilariae have been used in different immunological
techniques such as skin test, counter immuno electrophoresis, indirect haemagglutination test,
indirect fluorescent antibody test and enzyme linked immunosorbent assay. Fractionation of
Wuchereria bancrofti microfilarial soluble antigens yielded mfS3e antigen fraction which was
found to be highly reactive in microfilaraemia by enzyme linked immunosorbent assay, but the
yield of the purified antigen was not sufficient enough to make it a practical proposition for
large scale isolation of antigen.
Wuchereria bancrofti microfilarial excretory-secretory antigens were found to be specific and
highly sensitive requiring as little as 0·35 ng antigen protein per well in penicillinase enzyme
linked immunosorbent assay for detection of filarial antibody. One ml of culture fluid was
found to be sufficient for 400,000 tests. Field evaluation of this test showed that it can replace
laborious night blood examination.
Assay systems have been developed for detection of filarial antigen in serum, urine,
hydrocele fluid and immune complexes using immunoglobulins from chronic filarial sera and
antisera to excretory filarial antigens. Further purification of excretory-secretory antigens by
affinity chromatography and production of monoclonal antibodies should hopefully give
suitable reagents for use in sensitive assays such as enzyme immuno assay and immuno
radiometric assay, providing an ideal assay system for detection of active filarial infection in the
not too distant future.
Description
Keywords
Immunodiagnosis, filarial antibody, filarial antigen, enzyme linked immunosorbent assay, bancroftian filariasis
Citation
Harinath Bhaskar C. Immunodiagnosis of bancroftian filariasis—Problems and progress. Journal of Biosciences. 1984 Dec; 6(5): 691-699.