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Published on: March 14, 2011
A two-phase low-dose ACD-A strategy overcomes hypocalcemia during peripheral blood stem cell collection: a randomized
Zhangbiao Long1, Yutong Jin2, Dinghui Zhao1
1Department of Hematology, The First Affiliated Hospital of Anhui Medical University, Hefei, China.
Background:
Citrate anticoagulation during peripheral blood stem cell (PBSC) collection frequently causes hypocalcemia. Conventional fixed-ratio protocols frequently employ prophylactic calcium supplementation in many centers; however, they are associated with a high citrate burden and have been linked to platelet aggregation in some reports. This randomized controlled study evaluated a two-phase low-dose Acid Citrate Dextrose formula A (ACD-A) strategy designed to reduce hypocalcemia without compromising collection efficiency.
Methods:
Consecutive donors undergoing PBSC collection were randomly assigned to two groups. The Control group (n=22) received a blood-to-ACD-A ratio of 10-12:1 with prophylactic intravenous calcium. The Low ACD-A group (n=21) received initial loading phase at a ratio of 10-12:1 until 1 mL/kg of ACD-A was infused, followed by maintenance at 25:1 without prophylactic calcium. The primary outcome was the incidence of hypocalcemia-related symptoms. Secondary outcomes included collection time, ACD-A intake, CD34+ cell yield, and platelet aggregation.
Results:
The incidence of hypocalcemia-related symptoms was significantly lower in the Low ACD-A group than in the Control group (14% vs. 73%, P = 0.0002). Collection time was shorter (170.8 vs. 199.3 min, P = 0.0029), and ACD-A intake was substantially reduced (6.10 vs. 12.96 mL/kg, P < 0.0001). No significant differences were observed in CD34+ cell yield, enrichment ratio, yield per liter processed, or changes in ionized calcium levels between groups. Mild platelet aggregation occurred less frequently in the Low ACD-A group (9.5% vs. 41%, P = 0.0339).
Conclusions:
A two-phase low-dose ACD-A strategy significantly reduces hypocalcemia-related symptoms, shortens collection time, and decreases platelet aggregation without compromising stem cell yield or product quality. This simple modification represents a meaningful improvement over conventional citrate protocols for PBSC collection.
