Secondary Hyperparathyroidism Induced by Plateletpheresis in Donors As a Result of Divalent Cationic Chelation by Citrate.

Apheresis is an efficient method to collect specific blood components such as platelets, leukocytes, plasma and stem cells. Its advantages include: the collection of standardized and high-quality blood products and a higher collection frequency. However, apheresis is usually accompanied by acute metabolic changes (specially in serum calcium and magnesium concentrations) due to citrate infusion during the whole procedure.

To compare pre and post-plateletpheresis serum level concentrations of calcium, magnesium, zinc, copper and parathyroid hormone among donors and correlate these levels with symptoms that donors may experience during the procedure performance.

This is a prospective study including 105 healthy plateletpheresis donors who attended the National Cancer Institute. Basal and post-procedure serum levels of parathyroid hormone (PTH), calcium (Ca), magnesium (Mg), zinc (Zn) and copper (Cu) were measured by ion selective potentiometry (Ca), final dot (Mg), atomic absorption (Cu, Zn) and solid phase two site chemoluminiscence (PTH) methods. In case of adverse reactions, a blood sample was drawn immediately in order to analyze concentrations of such hormone and minerals. We intended to correlate both, diet and adverse reactions with serum levels of aforementioned elements. Statistical analysis was performed by chi-square and ANOVA. Protocol was approved by the institutional ethical and research committee.

One hundred and five consecutive donors were included in the study conducted from June 28th through July 27^th, 2012. There were 68 males and 37 females. Median age was 31 years (range 18–56). Pre and post-apheresis PTH, Ca, Mg, Zn and Cu serum levels are shown in table 1. Furthermore we found significant differences in women older than 30 years but did not find any relationship between donors' symptoms and diet.

Plateletpheresis induced a secondary hyperparathyroidism state resulting from chelation of calcium and magnesium. We demonstrated that Cu was also chelated by citrate. These results urges us to assess the kinetics of these metabolic changes as well as to follow a cohort of donors with bone densitometry in order to assure that frequent and chronic infusion of citrate during plateletpheresis donations does not become a long-term risk for osteopenia and osteoporosis as already suggested by some authors^1,2. If such a risk is demonstrated other preventive measures must be implemented like: 1.- To restrict the number of apheresis donations per person and 2.- To develop new and safer anticoagulants to be used during the apheresis procedures.

No relevant conflicts of interest to declare.