Fluoroimmunoassay: an alternative to radioimmunoassay?

Fluoroimmunoassays appear to be an alternative to conventional radioimmunoassays and immunoradiometric assays because of the high specific activity of their label, thus promising high sensitivity and excellent precision. According to IFCC recommendations for the assessment of new laboratory methods, we evaluated precision, accuracy, linearity, lower detection limit and normal reference ranges of commercially available immunofluorometric assays of alpha-fetoprotein, choriongonadotropin and thyrotropin. In addition, thyrotropin content in sera of 147 patients was measured by immunofluorometric assay. Analysis of immunofluorometric assays gained performance data comparable to those of currently used immunoradiometric assays. Regression studies performed against currently employed methods showed accuracy of all three immunofluorometric assays. Results of immunofluorometric assay for thyrotropin demonstrated that sera of hyperthyroid subjects were distinguished from those of euthyroid subjects from basal thyrotropin alone. We conclude that immunofluorometric assays are an alternative to immunoradiometric assays which anybody concerned about the future of in vitro nuclear medicine should be aware of.

Deficiency of antibody formation to HBsAg in the pathogenesis of chronic hepatitis and cirrhosis?

UNLABELLED: Sera of 832 healthy persons and patients suffering from chronic inflammatory liver disease were investigated by radioimmunoassay for HBsAg and anti-HBs. Diagnosis in patients was secured by biopsy. The persons were divided into: 1. Healthy persons: n = 478 blood donors, hospital especially exposed to HBV, patients with healed hepatitis; 2. PATIENTS: n = 354 acute hepatitis, chronic persistent and aggressive hepatitis, post-hepatitic, cryptogenic and alcoholic cirrhosis. The results demonstrate considerable accumulation of HBsAg in chronic liver disease (72% in CAH, 66% in posthepatic liver cirrhosis) whereas anti-HBs was more frequently observed in healthy persons (38% in hospital staff, 49% in healed hepatitis). Furthermore, HBsAg and anti-HBs were frequently observed simultaneously in chronic hepatitis and cirrhosis (23% in CAH). A strong shift in the relation of antigen to antibody to the disadvantage of antibody in the examined collectives of chronic hepatitis and cirrhosis is evident. Chronic inflammatory HBsAg positive liver disease should therefore be regarded as chronic virus infection. We suppose an absolute or relative deficiency of antibody to HBsAg is probably an important factor for the development of chronicity of hepatitis B.