Beta 2 microglobulin in kidney failure: A review and an algorithm for renal replacement therapy

For decades, beta 2 microglobulin (B2M) has been a subject of great interest in nephrology and other fields such as multiple myeloma. B2M, a 99 amino acid protein, is associated with amyloid deposits in patients undergoing renal replacement therapy (RRT). The source of information is published articles on B2M in chronic renal failure since 1960. We have reviewed literature published since 1960 to date, highlighting the milestones of the role of B2M in chronic kidney disease (CKD) and B2M serum values in patients treated by various RRTs. B2M deposits associated with the disease include carpal tunnel syndrome, spondyloarthropathy, and arthritis of large joints such as the shoulders. The role of RRT in the removal of B2M in CKD is discussed. Recent reports include factors affecting the process of fibrillation and deposition of B2M in tissues. A comparative report of various modalities of treatment on the serum levels of B2M is provided. The presence of significant residual urine output in continuous ambulatory peritoneal dialysis patients may explain why peritoneal dialysis is a modality that is associated with the lowest level of serum B2M. Patients treated with hemodiafiltration or hemodialysis (HD) using high flux dialyzers have lower levels of B2M than those treated by HD with low flux dialyzers. Finally, based on the literature review, an algorithm for RRT using B2M level monitoring and other variables is proposed and needs evaluation in a controlled trial.