Bruce C. McLeod

Platelet transfusions from RhD-positive (D-positive) donors are often given to RhD-negative (D-negative) cancer patients. The low observed rate of alloimmunization has been attributed to disease and therapy-related immunosuppression. We have studied the occurrence of alloimmunization in 16 D-negative patients who did not have detectable anti-D prior to autologous bone marrow transplantation for malignant disease. All received D-positive platelets, but no other D-positive blood product. Three patients (19%) developed anti-D at 13, 24 and 83 days, respectively, after first receiving D-positive platelets, and after a total dose of 53, 65 and 119 D-positive platelet unit equivalents, respectively. Two of them also developed anti-C. The 13 patients in whom anti-D was not detected were also heavily transfused with D-positive platelets (mean +/- SD = 136 +/- 82 platelet unit equivalents). In 6 of them, the last recorded antibody screen was less than 3 months after the first D-positive platelets, and may not exclude a primary immune response. Thus, despite profound immunosuppression associated with autologous marrow transplantation, alloimmune responses to D-positive red cells in platelet concentrates can occur in some D-negative recipients.

BACKGROUND: Therapeutic apheresis was found to be reasonably safe in prior studies using instruments that are now largely obsolete. The incidence of adverse effects with current instruments and techniques has not been assessed in a large multicenter study. STUDY DESIGN AND METHODS: A survey was conducted in 1995 using a uniform questionnaire that asked about 32 specific events but excluded transient paresthesia and mild vasovagal events. Eighteen centers returned 3429 responses concerning 125 to 500 therapeutic apheresis procedures per center. RESULTS: Two hundred forty-two adverse events were reported in 163 procedures (4.75% of all procedures; 6.87% of first-time procedures and 4.28% of repeat procedures). The numbers (incidence) of selected specific events were transfusion reaction, 56 (51 in plasma exchange [PE] with plasma replacement) (1.6%); citrate-related nausea and/or vomiting, 41 (1.2%); systolic blood pressure <80 mmHg, 34 (1.0%); vasovagal nausea and/or vomiting, 17 (0.5%); pallor and/or diaphoresis, 16 (0.5%); pulse >120, 14 (0.4%); respiratory distress, 9 (0.3%); tetany or seizure, 9 (0.2%); and chills or rigors, 6 (0.2%). Rates for other specific events were < or =0.1 percent. Vasovagal phenomena were more frequent in procedures done in neurologic patients than in those done in hematology or oncology patients (p = 0.011) or renal or rheumatic patients (p = 0.038). Procedure-specific rates were red cell exchange, 8 (10.26%) of 78; PE (plasma), 89 (7.81 %) of 1140; PE (no plasma), 42 (3.35%) of 1255; leukapheresis, 4 (5.71%) of 70; plateletpheresis, 0 of 18; and autologous peripheral blood progenitor cell collection, 11 (1.66%) of 664. Three deaths were reported; all were attributed to primary disease. CONCLUSION: Therapeutic apheresis procedures are relatively safe, with a 4.75-percent overall incidence of mostly reversible adverse effects. Among the most commonly performed procedures, the risk is higher for blood component exchanges, especially if allogeneic red cell or plasma transfusion occurs, and lower for peripheral blood progenitor cell collection.

BACKGROUND: Apheresis donation is considered safe, but the incidence of adverse effects has not been determined in a large multicenter series of donations with modern instruments. STUDY DESIGN AND METHODS: The Hemapheresis Committee of the American Association of Blood Banks devised a uniform questionnaire that asked about 32 specific adverse effects. Transient paresthesia and mild vasovagal events were excluded. A survey was conducted in 1995; 17 centers returned 19,611 responses concerning 250 to 2,000 consecutive apheresis donations per center. RESULTS: Six hundred adverse effects were reported in 428 donations (2.18% of donations). Pain or hematoma at a venipuncture site was the most common response (1.15% of donations); only 203 donations had other (nonvenipuncture) adverse effects (1.04%). Total and nonvenipuncture rates were, respectively, 4.84 and 2.92 percent for 2,295 first donations and 1.78 and 0.77 percent for 17,303 repeat donations (p < 0.001). Rates of nonvenipuncture symptoms in first and repeat donations were, respectively, citrate-induced nausea and/or vomiting, 0.87 and 0.27 percent; tetany, 0.09 and 0.04 percent; pallor and/or diaphoresis, 1.87 and 0.32 percent; vasovagal nausea and/or vomiting, 0.87 and 0.13 percent; syncope and/or seizure, 0.39 and 0.04 percent; and chills and/or rigors, 0.31 and 0.01 percent. The overall rate of donor unconsciousness was 0.08 percent. Hemolysis was reported twice. Clotting or leakage occurred in 0.08 percent of donations, and inability to return blood occurred in 0.16 percent. No life-threatening adverse effects were reported. Procedure-specific nonvenipuncture rates were 1.05 percent of 17,584 platelet donations, 0.67 percent of 594 white cell donations, and 0.37 percent of 1,354 plasma donations. Center-specific rates varied from 0.32 to 6.81 percent of donations for total adverse effects and from 0.11 to 2.92 percent of donations for nonvenipuncture events. CONCLUSION: Apheresis donation is a safe undertaking, suitable for voluntary blood donors, with a very low risk of serious adverse effects. The risk of unconsciousness is lower than that found in many studies of whole-blood donation.