New York-Presbyterian/Weill Cornell Medical Center, New York, United States
Background/Case Studies: Transfusing ABO-incompatible cryoprecipitate is a well-established practice and supported by literature. The recent implementation of Pathogen Reduced Fibrinogen Complex (IFC, INTERCEPT, Cerus, Concord, CA) at our institution prompted a reassessment of this practice’s safety. This is the first study to compare ABO titers in cryoprecipitate-AHF (Cryo-AHF) and IFC.
Study
Design/Methods: The standard fibrinogen dose for adult recipients at our institution, approximately 2 grams, is supplied by either a 5-donor pool of Cryo-AHF or a 6-donor pool of IFC (FC20). A total of 45 cryoprecipitate pools were evaluated: 10 A, 6 B, and 10 O of Cryo-AHF and 5 A, 3 B, and 11 O of IFC. Three mL were sampled from each pool on or before the expiration date, frozen at -30 C, and titers were performed on the frozen specimen up to 19 days after freezing. Serial dilutions from 1 to 512 were tested using the manual gel-card method (Micro Typing System, Inc., Pompano Beach, FL). Additionally, patient (pt) records were examined over a 12-month period for any evidence of reverse hemolysis from incompatible cryo transfusions. Statistical analysis, using a two-tailed t-test with unequal variance assumption, was performed to compare titers between the products and a chi-square analysis for reverse hemolysis rate, with significance set at p < 0.05.
Results/Findings: The median anti-A titers in O pools were significantly lower in IFC than Cryo-AHF (64 vs. 128, p < 0.01). The median anti-B titers in O pools were 32 for IFC and 64 for Cryo-AHF (p=0.09). The anti-B titers for A pools were significantly lower in IFC, with a median of 4 for IFC and 8 for Cryo-AHF (p=0.01). The anti-A titers for B units were 8 for both IFC and Cryo-AHF; but the sample size for B pools was too small to make an inference from findings. None of the IFC pools tested had a titer exceeding 128 for group A, B, or O; however, 1/10 group O Cryo-AHF had a titer of 256 for anti-A (Figure 1). Among the pts who received incompatible transfusions, 5/55 (9%) who received Cryo-AHF and 6/85 (7%) who received IFC showed clinically insignificant but laboratory-detectable increases in indirect bilirubin (above the reference range and at least 1 mg/dL increase) (p = 0.66). Nine of these pts were transfused intraoperatively including 5/9 with out-of-group platelets. Conclusions: ABO titers for IFC FC20 are lower than Cryo-AHF. This is likely due to differences in median (IQR) volume between FC20, 187 mL vs pooled Cryo-AHF 121ml; the difference in donor pool size (6 vs 5); and possible impact of the pathogen inactivation process.Based on our chart review, out-of-group IFC transfusion does not pose a higher risk of reverse hemolysis compared to the current standard of care. These data support the safety and acceptability of transfusing non-blood group matched IFC.
