1Maha A. Sabry and 2Amal A. El-Shafei
1Department of Zoonoses, Faculty of Veterinary Medicine, Cairo University and 2Department of Parasitology, Faculty of Medicine for girls, El-Azhar University.
Immunodiagnosis of human
fascioliasis depends on detecting specific antibodies in sera of infected
patients. However, cross-reaction with other helminthic infections and false
positivity with normal human sera constitute a major proplem for specific
detection of fascioliasis. In an attempt to develope a specific test for
accurate diagnosis of fascioliasis, three selected F.gigantica purified
excretory / secretory (E/S) antigens of 14-20 KD, 25-30 KD and 55-65 KD were
assessed using enzyme- linked immunosorbent assay (ELISA). None specific
antigens for Schistosoma mansoni adult worm, C. cellulosae
larvae, T. spiralis larvae and S. fusiformis cystizoites were
used to evaluate the presence of cross reacted antibodies. Selected human serum
samples from 50 patients and 10 healthy individuals were tested. The patients
included : 10 with chronic fascioliasis, 15 with suspected fascioliasis, 10
with high titre of antibody to virus C hepatitis (HCV) and 15 with schistosomiasis
mansoni. The F. gigantica purified E/S antigens of 25-30 KD and
55-65 KD reacted specifically (100%) with all sera from Fasciola infected
patients and positive control sera, and showed no cross reactivity with any
other tested sera. There was indirect proportion between the sensitivity of
both antigens and the dilution of the tested sera. It was concluded that 25-30
KD and 55-65 KD antigens are potentially useful for accurate diagnosis of Fasciola
infected patients and can differentiate between fascioliasis and the common
cross-reacting conditions particulary HCV, S. mansoni and C.
cellulosae infections. This differentiation may reflect a new goal for
specific early diagnosis and treatment of the most common liver affection
diseases as HCV.