Prevalence, risk factors, and ferritin testing to mitigate iron depletion in male plateletpheresis donors.

BACKGROUND: Most single-donor platelet (SDP) donors transition to plateletpheresis after prior red blood cell (RBC) donation. Recruitment may follow identification of a high platelet count, a marker associated with iron depletion (ID). SDP donors may have underrecognized risk for iron depletion. STUDY DESIGN AND METHODS: To assess the prevalence of ID, we performed ferritin testing on male plateletpheresis donors with hemoglobin levels less than 13.5 g/dL. Multivariable logistic regression identified risk factors for low ferritin (LF; ferritin ≤26 ng/mL) and absent iron stores (AIS; ferritin <12 ng/mL). To assess the impact of notifying donors of LF results, we compared donation behavior of "Test" subjects before and after sending an LF notification letter to that of "Control" subjects before and after increasing the minimum hemoglobin for male donors. An electronic survey to Test donors inquired about iron supplementation practices. RESULTS: Prevalence of LF was 50% and AIS was 23%, with increase in risk associated with more frequent SDP donation, both controlling for RBC donation and in donors with no recent RBC donations. Donation frequency after intervention declined less in 1272 Test donors (19%, from 13.9 to 11.2 annualized donations) than in 878 Control donors (49%, from 12.3 to 6.3 donations). Only 20% of Test donors reported taking supplemental iron when they received the LF letter; 64% of those not taking iron initiated iron supplementation following the letter. CONCLUSIONS: Donors were responsive to notification of LF and attendant messaging on iron supplementation. Ferritin testing potentially benefits donor health and a stable platelet supply.

A liquid calcium+vitamin D3 supplement is effective prophylaxis against hypocalcemic toxicity during apheresis platelet donation.

Hypocalcemic toxicity, because of return of citrate anion to the donor, is the major toxicity of apheresis platelet donation. Oral calcium carbonate, given prophylactically at the start of donation, has shown limited ability to alleviate this toxicity. We examined whether repeated prophylactic doses of calcium carbonate, or of a liquid preparation containing calcium citrate, calcium phosphate, and vitamin D3 , would be more effective at preventing symptoms of hypocalcemic toxicity. Symptoms were reported by 48% of donors who received no prophylaxis and 60% of donors who received 1000 mg of oral calcium carbonate at the start of, and every 20 minutes during, donation (P = 0.711). Only 19.2% of donors who received the liquid preparation (1000 mg calcium, 1000 IU vitamin D3 ) reported symptoms (P = 0.040 versus no prophylaxis, P = 0.039 versus calcium carbonate). This difference was not because of gender, weight, age, or blood volume of the donor. Neither calcium preparation prevented a measurable fall in plasma ionized calcium during donation. We conclude that liquid calcium citrate/calcium phosphate/vitamin D3 provides effective prophylaxis against hypocalcemic toxicity during platelet donation, however it does not prevent a fall in plasma ionized calcium.

Study of iron stores in regular plateletpheresis donors.

Plateletpheresis donors will lose up to 100 mL of blood at each donation, leading to concern that they may become iron deficient, particularly if donating at the maximum allowed frequency under National Blood Service policy of every 2 weeks. The serum ferritin levels of 508 regular plateletpheresis donors and 101 non-donors were measured to indicate the level of their iron stores. About 33.9% (156/460) of platelet donors had depleted iron stores compared with 3.1% (3/97) non-donors. Results for male and post-menopausal female donors were similar with 36.2% (131/362) of males and 37.7% (20/53) of post-menopausal females showing iron depletion. There was clear correlation with donation frequency in males with 63.9% (46/72) of males donating at 2 weekly intervals found to be iron depleted. The percentage of iron depleted male subjects decreased as donation intervals increased. Correlation with lifetime donations of platelets was not demonstrated, although no donor who had given fewer than 14 blood and/or platelet donations was found to be iron depleted. In males there was a clear correlation between iron depletion and frequency of donation. There appeared to be no correlation with lifetime number of platelet donations. As a result of this study, we have advised that volunteers should not donate platelets more than 15 times per year, so that red cell loss is no more than the equivalent of three whole blood donations (1500 mL).

Clinical and clinicopathologic effects of plateletpheresis on healthy donor dogs.

BACKGROUND: The safety and feasibility of plateletpheresis using a commercially available apheresis system (COBE Spectra, Gambro BCT) were evaluated in donor dogs, with characterization of its clinical and clinicopathologic effects. STUDY DESIGN AND METHODS: Fourteen adult dogs (18-27.7 kg) underwent a plateletpheresis procedure. Complete blood counts were obtained at baseline, 2 hours after apheresis, and daily for 1 week. Blood was collected every 15 minutes for acid-base and electrolyte analysis and measurement of serum citrate concentration. Dogs were monitored by continuous electrocardiogram and indirect blood pressure measurement. All dogs received prophylactic calcium (Ca) supplementation (10% Ca gluconate infusion at 15 mL/hr [139.5 mg Ca ion/hr]; the rate was increased based on serial measurement of ionized Ca [iCa] concentration). RESULTS: A high-quality platelet concentrate (PC) was collected, with a mean total yield of 3.3 x 10(11) platelets (PLTs). The mean donor PLT count decreased from 356 x 10(9) to 159 x 10(9) per L after apheresis. The procedure was generally well tolerated, with no evidence of hypotension. Serum citrate concentration progressively increased, causing the ionized magnesium concentration to decrease by 45 percent and iCa to decrease to less than 1 mmol per L (mean baseline, 1.2 mmol/L) in 10 dogs, despite receiving 0.9 mg of Ca ion per mL acid-citrate-dextrose formula A. Lip licking was noted in 3 dogs, and generalized tremors and ventricular ectopy were noted in 1 dog. CONCLUSION: Canine plateletpheresis using the COBE Spectra is a feasible option for production of a PC. Hypocalcemia, however, is a potential serious adverse effect of plateletpheresis in dogs. Ca supplementation is recommended to limit clinical signs of hypocalcemia during the procedure.

Hypocalcemic symptoms during plateletpheresis using the COBE Spectra: a comparison of oral combination of 600mg calcium+300mg magnesium+100IU vitamin D3 vs. a 1000mg calcium in symptomatic donors.

BACKGROUND: The aim of this study was to find an effective treatment for hypocalcemic symptoms during plateletpheresis and to evaluate if a combination of calcium, magnesium and vitamin D3 is more effective in comparison to routine calcium supplementation. MATERIAL AND METHODS: A study group consisting of 10 donors, having a history of previous hypocalcemic symptoms during plateletpheresis, donated platelets twice in a one-month period. During the first donation combination tablets (600mg Ca+300mg Mg+100IU vitamin D3) were used to treat hypocalcemic symptoms while routine treatment calcium carbonate tablets (1000mg Ca) were used during the second donation. If symptoms persisted after 10min the same dose was repeated. A control group, with no supplementation, consisting of five donors, with no history of hypocalcemic symptoms, were included. Donor subjective symptoms were graded and recorded on four occasions: at the start of plateletpheresis, when symptoms appeared, 10min after the first tablet and at the end of donation. Samples for analysis of ionized calcium (iCa), magnesium and potassium were also taken at the same occasions. RESULTS: All donors from the study group experienced minor or medium hypocalcemic symptoms and needed a second dose of supplementation. Calcium carbonate tablets completely relieved the hypocalcemic symptoms in six donors, it had no effect on three donors and one donor experienced aggravated symptoms. The combination tablets completely relieved the symptoms in three donors, one donor experienced a partial relief and six donors had no relief of symptoms. There were no significant differences in iCa, potassium and magnesium levels were noted in the study group irrespective of which tablets were used for treatment of hypocalcemic symptoms. After plateletpheresis the median iCa levels declined by 30% and potassium levels declined by 3-11% in all donors while the magnesium levels were not significantly affected. There was no correlation between the presence of symptoms and the changed levels of iCa or magnesium. CONCLUSION: Addition of magnesium and vitamin D3 to calcium seems to have no beneficial effect in the treatment of hypocalcemic symptoms in plateletpheresis donors.

Randomized placebo-controlled study of oral calcium carbonate administration in plateletpheresis: I. Associations with donor symptoms.

BACKGROUND: The effect of oral calcium (Ca) supplements in preventing citrate-induced symptoms during plateletpheresis was evaluated in a randomized, blinded, placebo-controlled trial. STUDY DESIGN AND METHODS: Twenty-three donors (12 men, 11 women) underwent four plateletpheresis procedures each, ingesting either 1 or 2 g of oral Ca carbonate or an equivalent placebo 30 minutes before donation. Ten of these subjects subsequently ingested 4 g of open-label Ca before a fifth procedure. All procedures were conducted at the same citrate infusion rate (1.5 mg/kg/min) for 90 minutes. RESULTS: Ingestion of 2 g of oral Ca resulted in a significant reduction in the severity of paresthesias and a significant, though modest, increase in serum ionized calcium (iCa), but no significant improvement in total symptom scores, compared to placebo. Minimal effects were seen with the 1-g dose. The two factors most highly correlated with development of severe symptoms were decreased levels of iCa and ionized magnesium (iMg) at 30 minutes into apheresis. Lower preapheresis serum albumin, creatinine, vitamin D, iMg, and total Mg concentrations were also significantly associated with symptoms. Women experienced more frequent and severe symptoms than men, however, gender was not associated with symptoms after adjustment for lower serum albumin, creatinine, and Mg levels. Ingestion of 4 g of Ca offered no improvement in symptoms or iCa levels compared with the 2-g dose. CONCLUSION: Prophylactic oral Ca was associated with modest improvements in citrate-induced symptoms and laboratory parameters. Baseline albumin and Mg levels were strongly predictive of the development of symptoms. In donors with a prior history of uncomfortable citrate-related effects, a 2-g oral Ca dose before apheresis is recommended.