[Diagnosis of chronic schistosomiasis japonicum with the recombinant Sj26GST-Sj32 fusion protein by ELISA].

OBJECTIVE

To study the feasibility of rSj26GST-Sj32-IgG-ELISA for diagnosis of chronic schistosomiasis japonicum.

METHODS

The Escherichia coli BL21 (DE3) with recombinant plasmid pET32alphaSj26GST-Sj32 were induced with isopropy-beta-D-thiogalactopyranosid (IPTG), and the expression product was analyzed by SDS-PAGE and purified by Ni-NTA kits. Schistosoma japonicum (Sj) adult worm antigen(SjAWA) was produced by routine method. The IgG antibodies were detected with the sera of chronic schistosomiasis japonicum by ELISA using recombinant Sj26GST-Sj32 (rSj26GST-Sj32) fusion protein and SjAWA, while the controls included the sera of patients with clonorchiasis, paragonimiasis westermani, alveolar echinococcosis, cystic echinococcosis, hepatitis B, pulmonary tuberculosis and healthy people.

RESULTS

The sensitivity and specificity of rSj26GST-Sj32 fusion protein were 95.00% (38/40) and 97.67% (42/43) respectively, they were 92.50% (37/40) and 97.67% (42/43) respectively in SjAWA groups. There were no difference in sensitivity and specificity between rSj26GST-Sj32 and SjAWA (P > 0.05). There were different cross reactions in clonorchiasis sinensis and paragonimiasis westermani between the two methods. The cross reaction with SjAWA was 20.00% (2/10) in patients with alveolar echinococcosis, but no cross reaction with rSj26GST-Sj32 (P > 0.05).

CONCLUSION

rSj26-Sj32-IgG-ELISA probably could be applied to immunodiagnosis for chronic schistosomiasis japonicum.