The average predialysis β2M concentration in patients dialyzing with non-reused HF membranes was 31.1 ± 0.99 mg/l; β2M was non-significantly increased by FHA, GAH or HCA reprocessing: 1.57 ± 1.15 mg/l (p = 0.17), 1.59 ± 1.39 mg/l (p = 0.23), 1.54 ± 1.40 mg/l (p = 0.27) respectively. Here, B2M is linked to hydrops fetalis.