1Mohamed F Tamara, 2Laila A El-Shawarby, 2Zeinab A Galal, 2Suzan S Abd El-Wahab
Departments of 1Internal Medicine, 2Clinical Pathology, Faculty of Medicine, Ain-Shams University, Cairo, Egypt.
In this study 3 different techniques for detection of individual antibodies to extractable nuclear antigens (ENA) were compared, the multiparameter strip assay (based on line immunoassay technique) and countercurrent imunnoelectrophoresis technique (CIE), and enzyme linked immunosorbent assay (ELISA). Screening of antinuclear antibody (ANA) was carried out by indirect imunnofluorescent technique (IIF), while screening for anti-ENA was carried out by ELISA and CIE. Serum from forty-three patients, clinically diagnosed as having systemic Lupus Erythematosus (SLE), 22 patients with other rheumatic disorders and twenty apparently healthy subjects were tested. öAll SLE patients were ANA and ds-DNA positive, while 81.4% and 72% gave positive anti-ENA with ELISA and CIE screening tests for anti-ENA antibodies, respectively. The specificity was 95% and 100% for ELISA screening and CIE screening tests, respectively; while for detection of individual anti-ENA, the specificity of ELISA, CIE and multiparameter assay was 100%for each test. It is concluded that, ELISA is the best screening method for anti-ENA, it is automated, objective and highly sensitive. Although less sensitive than the ELISA, multiparameter assay is the method of choice for individual anti-ENA detection, as several antigens analyzed simultaneously. It is simple, easy to perform, sensitive and informative assay.