Automated red blood cell exchange in preparation for filgrastim mobilization of autologous peripheral blood hematopoietic progenitor cells in a patient with sickle cell anemia.

Increasing survival of patients with sickle cell anemia (SCA) well into adulthood results in a rising likelihood of developing hematological malignancy. High-dose chemotherapy with autologous hematopoietic progenitor cell (HPC) rescue is standard of care for several hematological malignancies, but the risk of severe or life-threatening vaso-occlusive phenomena during filgrastim mobilization of HPC for collection poses a potential barrier to this approach. We report the use of automated red cell exchange in preparation for filgrastim mobilization in a patient with homozygous SCA. Red cell exchange was repeated just prior to high-dose chemotherapy to mitigate the need for red cell transfusion during bone marrow reconstitution. The patient experienced no vaso-occlusive phenomena throughout the entire episode of care and did not become iron overloaded. This approach should be considered for all patients with homozygous or compound heterozygous sickle cell disease who are candidates for auto-HPC rescue therapy.

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.

Therapeutic plasma exchange performed in tandem with hemodialysis without supplemental calcium in the apheresis circuit.

Therapeutic plasma exchange (TPE) and hemopoietic progenitor cell (HPC) collection are apheresis procedures that can safely be performed in tandem with hemodialysis. Despite the return of citrate-anticoagulated blood to the patient during HPC collection, it is not necessary to administer supplemental calcium during these procedures because the ionized calcium concentration is restored as the returning blood passes through the dialyzer. It is not known whether this applies to TPE, in which a mixture of blood and pharmaceutical albumin, an avid binder of plasma ionized calcium, is returned to the patient through the dialyzer. We report on three dialysis-dependent patients who required TPE and underwent tandem treatments without supplemental calcium in the apheresis circuit. Overall, ionized calcium fell 4-12% (P = 0.0.024) and patients reported no symptoms of hypocalcemic toxicity. Tandem hemodialysis/TPE can be performed without supplemental calcium in the apheresis circuit. J. Clin. Apheresis 32:154-157, 2017. © 2016 Wiley Periodicals, Inc.