V. Deangelis et al., IMMUNOCHEMICAL STUDIES ON RED-CELL AUTO ANTIGENS - USE AND LIMITS OF IMMUNOPRECIPITATION FROM BIOTINYLATED ERYTHROCYTE-MEMBRANE, Autoimmunity, 21(4), 1995, pp. 263-268
Erythrocyte surface was labelled by means of biotin; immunoprecipitati
on technique was then used to localise antigens recognised on red cell
membrane proteins by: a) autoantibodies from 13 patients with antiery
throcyte autoimmunity; b) commercially available anti-D and anti-k (Ce
llano) antierythrocyte alloantibodies. Results with alloantibodies are
comparable to those obtained using radiochemical probes. Immunoprecip
itations with autoantibody containing eluates showed reactivity at dif
ferent molecular weights (the most common at 34-50 kD, others at 100 a
nd 45 kD and a newly described one at 80 kD), thus confirming that man
y membrane proteins may act as target antigens for erythrocyte autoimm
unity. We found a higher percentage of reactive immunoprecipitates tha
n previously reported using the same labelling method. However, critic
al conditions to allow valuable results seem to be a threshold amount
of autoantibody to precipitate any recognisable band and the sensitivi
ty of the detection method. Hence methodological variables must be tak
en into consideration before concluding that ''non protein'' antigens
trigger the autoimmune process.