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Background: Marked decreases in ionized magnesium (iMg) levels occur during large-volume leukapheresis (LVL); however, the effect of intravenous (IV) magnesium supplementation in this setting has not been carefully studied., Study Design and Methods: Thirty healthy allogeneic peripheral blood progenitor cell donors receiving citrate anticoagulant with IV calcium prophylaxis were randomized to receive either IV magnesium (0.2 mg Mg per mL acid citrate dextrose-A) or placebo during LVL, with a double-blind design., Results: Thirty subjects underwent 75 LVL pro- cedures, 37 with magnesium and 38 with placebo. Group characteristics were similar for sex, weight, citrate infusion rate (1.36 mg/kg/min vs. 1.37 mg/kg/min), and volume processed (16 L vs. 17 L). Serum iMg levels remained within the reference range with magnesium supplementation, but decreased 39+/-11 percent below baseline (p<10(-10)) after placebo, with greater decreases after consecutive procedures. Subjects receiving magnesium had more vigorous parathyroid hormone responses and higher glucose levels and also tended to have higher serum potassium and ionized calcium levels. Mild paresthesias, coldness, and nausea occurred in 28, 20, and 7 percent of donors, respectively, with no significant differences between groups. Severe symptoms (chest tightness) occurred in only one subject receiving placebo., Conclusion: IV magnesium supplementation exerts a significant impact on serum magnesium levels, but does not reduce the frequency or severity of the relatively mild citrate-related effects observed in LVL performed with continuous IV calcium prophylaxis.

Background: Persons with hemochromatosis constitute a plentiful and willing source of blood for transfusion. A program was established and evaluated for treating persons with hemochromatosis in a donor center and making their blood available for transfusion., Study Design and Methods: Phlebotomy therapy was performed free of charge regardless of whether subjects met criteria for allogeneic donation. A Hb level of 12.5 g per dL was used as the threshold for performing phlebotomy, and decreases in the MCV were used to guide the endpoints of therapy., Results: A total of 130 subjects were consecutively enrolled: 74 percent were homozygous for the C282Y mutation in the HFE gene, 76 percent met eligibility criteria for allogeneic donation, and 55 percent were previous blood donors. A median of 20 weekly or biweekly phlebotomies (range, 7-99) were performed before the MCV reached the targeted endpoint of 3 percent below baseline, at which time the ferritin level was less than 30 microg per L and the transferrin saturation was less than 30 percent. The median phlebotomy interval necessary to keep the MCV at this level during maintenance therapy was 10 weeks. No incident seroconversions for agents of transfusion-transmissible disease occurred during 1402 donations. All subjects testing positive for viral agents gave a prior history of deferrable risk. Twenty-seven months after starting the program, hemochromatosis donors were contributing 14 percent of the RBC units collected for allogeneic use., Conclusions: Hemochromatosis subjects can safely and significantly augment the allogeneic blood supply. Provision of phlebotomy therapy unrestricted by considerations of cost or suitability for donation can improve access to care and remove incentives for incomplete risk disclosure.

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.

BACKGROUND: Bacterial contamination of platelet (PLT) components is an important cause of transfusion reactions. Recent efforts have focused on heightened surveillance to detect contamination before transfusion to limit recipient morbidity and mortality. Although identifying the cause of contamination is most often viewed in the context of recipient safety, this case illustrates the importance of a thorough evaluation on donor safety. CASE REPORT: A 68-year-old woman experienced a severe febrile reaction after a plateletpheresis transfusion. Blood cultures from the patient and from the plateletpheresis component were both positive for the presence of Streptococcus agalactiae. No abnormalities were identified on review of collection and processing records. The donor was asymptomatic and had a negative review of systems, a normal physical exam, normal laboratory values, and negative blood and urine cultures. One of three stool samples was positive for the presence of occult blood. Colonoscopy revealed a Dukes Stage B colonic adenocarcinoma. Fifteen months after surgical resection and adjuvant chemotherapy, the donor had no evidence of recurrent tumor. CONCLUSION: Identification of bacteria in blood components should trigger a comprehensive donor evaluation, particularly if donor bacteremia is suspected. Organisms that may be associated with an enteric source should prompt a thorough gastrointestinal evaluation. Because the primary reservoir of S. agalactiae in the human body is the gastrointestinal tract, and because no findings suggested an alternate portal of entry in our male donor, a gastrointestinal source was suspected. In this case, an evaluation for organism-specific pathology led to early identification of a potentially curable large bowel lesion. [ABSTRACT FROM AUTHOR]