Seropositivity to sarcocystis antigens, in attendants of rheumatology clinic in Sohag, University Hospital

ABSTRACT

Human sarcocystosis is a zoonotic dead end infection. Many cases have been reported recently after muscle biopsy and some were diagnosed clinically as eosinophilic myositis. Cases were chosen randomly among attendants of Sohag University Rheumatology Clinic, 45 were having rheumatoid arthritis and 46 diagnosed as chronic myositis. 10 apparently healthy persons were enrolled as control. Records of the patients gave information about R.F., CRP, ANA and eosinophilic count. Using Sarcocystis of Fusiformis cystozoites as antigen, ELISA was performed for all patients, while Western Blot test was performed for 32 patients chosen randomly among them as 14 rheumatoid and 18 chronic myositis. Seropositivity by ELISA was 18.7% of patients, while that by immunoblotting was 31.2% among chosen cases. Most seropositive patients range between 30-40 years old. Comparison of ELISA and immunoblotting results revealed that all seronegative cases were negative by both tests, and that 9.4% of cases tested by both tests were positive only by ELISA, and they were of the rheumatoid arthritis group. Eosinophilia was more prevalent among seropositive cases, and was absent in the cases which were positive by ELISA and negative by immunoblotting. The conclusion is that Western Blot is more sensitive than ELISA. The latter is a good negative test. As immunoblotting is costy and tideous, ELISA when combined with eosinophilic count is a good indicative of sarcocystosis