RT Journal Article SR Electronic T1 Sequential reactivity of serum against cyst antigens in Toxoplasma infection. JF Journal of Clinical Pathology JO J Clin Pathol FD BMJ Publishing Group Ltd and Association of Clinical Pathologists SP 548 OP 550 DO 10.1136/jcp.46.6.548 VO 46 IS 6 A1 G Woodison A1 A H Balfour A1 J E Smith YR 1993 UL http://jcp.bmj.com/content/46/6/548.abstract AB AIMS--To compare the recognition of Toxoplasma gondii tachyzoites and cysts by sera, from 10 patients. METHODS--Recognition of antigens from purified tachyzoites (RH strain) and bradyzoites (18691 strain) was compared using western immunoblotting. Sequential serum samples from 10 patients and one laboratory acquired RH infection were used. RESULTS--Recognition of cyst antigens was relatively low and occurred late in infection. The two stages were antigenically distinct with only a few shared bands. CONCLUSION--Immunological recognition of the cystic stage of T gondii is low. This implies that either cysts are poorly immunogenic or that cyst antigen is not available for processing and presentation.