Serum antibody titers in rats receiving repeated small subcutaneous injections of hemoglobin or polyhemoglobin: a preliminary report.

Cross-linking hemoglobin (Hb) into Polyhemoglobin (PolyHb) for use as an artificial blood substitute may affect its antigenicity. To investigate this, male Sprague-Dawley rats are immunized with one of the following: rat stroma-free Hb (rSFHb), rat PolyHb (rPolyHb), human stroma-free Hb (hSFHb), and human PolyHb (hPolyHb). Antibody titers are quantified using a double antibody radioimmunoassay. These results show that more antibodies are produced to hPolyHb than to hSFHb, whereas rSFHB and rPolyHb are relatively non-antigenic. Thus, under homologous conditions, cross-linking hemoglobin does not significantly increase its antigenicity, whereas under heterologous conditions the molecule becomes more antigenic.