SCHISTOSOMA-SPECIFIC 26 KDA PROTEIN FOR A DIAGNOSIS OF ACUTE AND CHRONIC SCHISTOSOMIASIS.

One of the world wide major public health problems is the schistosomiasis that is caused by Schistosoma (S.) heamatobium. It is also one of the main concerns for the public health community in Egypt. There are several immunodiagnostic methods used for that diagnosis of such disease, but some are more sensitive and specific than others. The purified 26 kDa Schistosoma-specific protein (PSPA-26) detection in serum samples is found out to be more valuable in diagnosis; it also helps in the early diagnosis which will lead to the early treatment before the irreversible damage takes place. PSPA-26 was purified from whole worms by DEAE-Sephadex G-75 ion exchange chromatography and then was injected into rabbits to produce specific polyclonal antibodies (anti-PSPA-26 pAb) which were then used as a primary capture in the indirect ELISA technique to reveal its reactivity using infected human sera. The anti-PSPA-26 was then labeled with horse-radish peroxidase (HRP) and used as a secondary capture. Sandwich ELISA was done for serum samples of human and hamsters infected with S. heamatobium. The results revealed a sensitivity of 85% for human and 80% for hamster's samples, and a specificity of 95% for human and 91.1% for hamsters samples by comparing them with those infected with other parasites and control samples. Data obtained concluded that PSPA-26 antigen can be used as a diagnostic marker for S. haematobium infection using the sandwich ELISA which is cost effective and applicable technique.

Immunodiagnosis of Egyptian human fasciolosis gigantica using Fas1 and Fas2 cysteine proteinase antigens.

Fasciolosis caused by Fasciola gigantica is one of the major public health problems in the world including Egypt. Immunodiagnostic methods are more applicable for their better sensitivity and specificity than other methods. The present study was conducted to cysteine proteinase (CP) antigens of F. gigantica in IgG-ELISA to diagnose human fasciolosis. IgG-ELISA with 2 cysteine proteinases of 27 kDa (Fas1) and 29 kDa (Fas2), obtained from the regurgitated materials of adult worms, were evaluated using serum samples from 90 Egyptian patients infected with F. gigantica, 55 patients with other parasitic infections and 50 healthy volunteers. The diagnostic sensitivity and specificity of Fas1 for detection of F. gigantica infection were 91.1% and 89.1%, respectively. The positivity of the assay was 95%. The positive and negative predicted values were 91% and 86%, respectively. These data suggest that IgG-ELISA with Fas1 is highly sensitive and specific assay and could be used for the immunodiagnosis of human fasciolosis.