AN ENZYME-LINKED-IMMUNOSORBENT-ASSAY FOR COMPLEMENT REGULATORY PROTEINS AND MEMBRANE-BOUND IMMUNOGLOBULINS ON INTACT RED-BLOOD-CELLS

We have developed an ELISA technique to examine RBC-bound molecules in autoimmune disorders. In particular, the technique has enabled us to investigate the role of some complement regulatory proteins in immune complex transport and to suggest that decay accelerating factor (DAF) may be involved in this process. In both autoimmune haemolytic anaemia (AHA) and systemic lupus erythematosus (SLE) a sub-set of individuals was identified, on the basis of patterns of complement receptor 1 (CR 1) expression on RBC. In these patients, CR1 identified using the mono clonal antibody Ell was low or absent whereas CR1 identified using a D AKO monoclonal antibody (C3RTo5) was present at normal levels.