Plasmapheresis and Osteoporosis: The Absence of Evidence Is Not the Evidence of Absence

Plasma and the products derived from it are indispensable to modern medicine, e.g. for immunoglobulins, coagulation factors, and albumin. Apheresis donations allow for selective collection of plasma with minimal loss of red blood cells. However, reliable anticoagulation - usually with citrate - is required because of the length and method of the donation procedure. Citrate complexes calcium and therefore leads to acute hypocalcemia, hyperparathyroidism, and prolongation of the QT interval. Apheresis donors also experience exposure to "endocrine disrupting chemicals" such as pthalates, which leak from the plastic donation sets during the donation and have been implicated with potential adverse effects on fertility and endocrine function. Repetitive apheresis might therefore be a previously unknown risk factor for impaired bone health. The existing data are however sparse and insufficient to confirm or reject this hypothesis.