We examined the suitability of high-performance immunoaffinity chromatography (HPIAC) for removing beta 2-microglobulin (beta 2-MG) from plasma of patients (n = 26) undergoing long-term hemodialysis. We used immobilized antibody to beta 2-MG to prepare an immunoaffinity column with a 0.5-mL bed volume. Plasma samples of 0.5 mL were chromatographed at a flow rate of 0.5 mL/min and pressures < 7 kg/cm2. Although only a small amount of beta 2-MG can be removed with a conventional dialyzer, 92.1% +/- 0.4% of the globulin could be removed by HPIAC. The column could be reused after acid elution. After 50 cycles the efficiency of beta 2-MG trapping was 73% of the original efficiency.