No abstract

Summary In a blind study, 518 serum samples were assayed for serum levels of mammary serum antigen (MSA) by an enzyme immunoassay (EIA) using the 3E1.2 monoclonal antibody. Using 300 IU as the arbitrary cut off to distinguish normal from abnormal individuals, 75% of patients with primary Stage I carcinoma of the breast (n = 12), 89% (Stacker et al., 1987).Other workers have produced monoclonal antibodies which define high molecular weight glycoproteins in the serum of patients with breast cancer (Hayes et al., 1985;Papasidero et al., 1984;Burchell et al., 1984; lacobelli et al., 1986). 3E1.2 can be distinguished from these monoclonal antibodies by its lack of reactivity with high molecular weight glycoproteins in human milk and milk fat globule membranes (Stacker et al., 1987). In this paper we describe the MSA levels found in three separate panels of coded serum samples. Included in this study are: (i) the evaluation of MSA levels in non-breast cancers and non-malignant disorders; (ii) the use of MSA levels for monitoring the clinical course of disease in patients with breast cancer; and (iii) the comparison of MSA and CEA levels in the serum of patients with breast cancer and other diseases.

A multicentre trial was conducted to evaluate a new test for anti-gliadin antibodies (AGA) in serum (Coeliac Screening Kit, CSK, Medical Innovations Limited, Artarmon, NSW, Australia). The test showed excellent reproducibility for both anti-gliadin IgA and IgG detection. The average intraassay coefficient of variation (CV) was 3.0% for IgA and 2.4% for IgG (n = 6), while the average interassay CV was 6.4% for IgA and 4.3% for IgG (n = 3). By defining a positive test as both IgA and IgG elevated, a sensitivity of 93% in untreated coeliacs (n = 75) was observed. The corresponding specificities in healthy adults (n = 130) and healthy children (n = 77) were > 99% and 100% respectively, while in patients with other gastrointestinal disorders (disease controls) the specificity was 94% (n = 129). The test was also useful in monitoring patients, with anti-gliadin IgA and IgG falling for up to a year after commencing a gluten-free diet (GFD) (12 adults). In some patients however, antibody levels did not reach the normal cutpoint after many months on a GFD, which may reflect the patients' poor adherence to their gluten free diet. The test was superior to the Pharmacia anti-gliadin ELISA, and should be useful as an aid to the diagnosis of coeliac disease, as well as in the follow-up of treated patients.