Which of the following is the chemical nature of hemodialysis associated with amyloid

Ref Robbins 9/e p258 b2-Microglobulin, a component of MHC class I mole- cules and a normal serum protein, has been identified as the amyloid fibril subunit (Ab2m) in amyloidosis that com- plicates the course of patients on long-term hemodialysis. Ab2m fibers are structurally similar to normal b2m protein. This protein is present in high concentrations in the serum of patients with renal disease and is retained in the circulation because it is not efficiently filtered through dialysis membranes. In some series, as many as 60% to 80% of patients on long-term dialysis developed amyloid deposits in the synovium, joints, and tendon sheaths. * Amyloid deposits derived from diverse precursors such as hormones (procalcitonin) and keratin also have been repoed.