[The diagnostic value of combined detection of circulating antigens and antibodies in urine of patients with schistosomiasis japonica].

OBJECTIVE: To assess the value of detecting circulating antigens and antibodies in urine as a noninvasive method for the diagnosis of schistosomiasis. METHODS: A sandwich ELISA and ELISA using McAb were applied to detect circulating schistosomal antigens and specific antibodies in the urine of patients with acute and chronic schistosomiasis. RESULTS: When the urine samples from 10 cases of acute schistosomiasis and 61 cases of chronic schistosomiasis were examined, the positive rates of circulating antigens and specific antibodies were 60%, 40%, and 80%, 60.1%, respectively; when both detection was combined, the positive rates were 100% and 71.7% respectively, whereas a false positive rate of 3% of CAg or CAb was detected in the urine of 100 normal controls. CONCLUSION: The detection of circulating antigen in urine is a practicable and noninvasive method for the diagnosis of schistosomiasis.

[Detection of specific antibodies in saliva of patients with chronic schistosomiasis japonica].

OBJECTIVE: To investigate the feasibility of detecting specific antibodies in the saliva of schistosomiasis patients. METHODS: Specific antibodies in saliva samples of 32 schistosomiasis patients and 140 normal individuals were detected by using ELISA and the results were compared with those detected for specific antibodies in serum. RESULTS: The sensitivity and specificity of the ELISA were 90.6% and 94.4%, respectively, being slightly lower than that of the 100% sensitivity and 96.2% specificity for the serum. No significant difference between them was found (P > 0.05). CONCLUSION: Detecting specific antibodies in saliva can be used for immunodiagnosis of schistosomiasis japonica as a noninvasive method in field surveys.

[Preparation and diagnostic application of monoclonal antibodies against Schistosoma japonicum].

The present paper reported on an anti-CCA monoclonal antibody, McAb-IIID 10, which could be used in determinations of both parasite-oriented circulating antigens and specific anti-CCA antibodies. The established competitive ELISA (C-ELISA) using McAb-IIID 10 to detect schistosome-antibodies showed high sensitivity and specificity in the diagnosis of schistosomiasis with few cross-reactions. In field trials, coincident rates in 3 separate batches of serum samples when subjected to double-blind detections were obtained. A total of 1,915 serum samples had been determined by C-ELISA, among them 113 acute cases achieved a 100% positive rate, 765 chronic and 25 late cases showed 96.3% and 72% positive respectively. 70% of the 66 cured schistosomiasis cases turned to be negative. None of the 750 normal individuals showed positive reactions. No cross reaction was found in 27 sera from hydatidosis, whereas 1 and 2 positive reactions were found in 43 paragonimiasis sera and 126 clonorchiasis sera respectively. The established McAb-IIID 10 involved Dot-ELISA was found of value in the assessment of effective chemotherapy and showed a high negative conversion rate of 97.9% in 48 cured schistosomiasis patients. In 16 experimentally infected rabbits, 12 became negative in Dot-ELISA determinations at the 8th week post treatment, and the remaining 4 treated ones, the titer as well as the reaction intensity were also found reduced. A good coincidence rate was also found between C-ELISA and Dot-ELISA, their detection results may be complementary each other.