Validated Reference Panel from Renewable Source of Genomic DNA Available for Standardization of Blood Group Genotyping

Extended blood group genotyping is an invaluable tool used for prevention of alloimmunization. Genotyping is particularly suitable when antigens are weak, specific antisera are unavailable, or accurate phenotyping is problematic because of a disease state or recent transfusions. In addition, genotyping facilitates establishment of mass-scale patient-matched donor databases. However, standardization of genotyping technologies has been hindered by the lack of reference panels. A well-characterized renewable reference panel for standardization of blood group genotyping was developed. The panel consists of genomic DNA lyophilized and stored in glass vials. Genomic DNA was extracted in bulk from immortalized lymphoblastoid cell lines, generated by Epstein-Barr virus transformation of peripheral blood lymphocytes harvested from volunteer blood donors. The panel was validated by an international collaborative study involving 28 laboratories that tested each DNA panel member for 41 polymorphisms associated with 17 blood group systems. Overall, analysis of genotyping results showed >98% agreement with the expected outcomes, demonstrating suitability of the material for use as reference. Highest levels of discordance were observed for the genes CR1, CD55, BSG, and RHD. Although limited, observed inconsistencies and procedural limitations reinforce the importance of reference reagents to standardize and harmonize results. Results of stability and accelerated degradation studies support the suitability of this panel for use as reference reagent for blood group genotyping assay development and standardization

Posttransfusion Sepsis Attributable to Bacterial Contamination in Platelet Collection Set Manufacturing Facility, United States.

During May 2018‒December 2022, we reviewed transfusion-transmitted sepsis cases in the United States attributable to polymicrobial contaminated apheresis platelet components, including Acinetobacter calcoaceticus‒baumannii complex or Staphylococcus saprophyticus isolated from patients and components. Transfused platelet components underwent bacterial risk control strategies (primary culture, pathogen reduction or primary culture, and secondary rapid test) before transfusion. Environmental samples were collected from a platelet collection set manufacturing facility. Seven sepsis cases from 6 platelet donations from 6 different donors were identified in patients from 6 states; 3 patients died. Cultures identified Acinetobacter calcoaceticus‒baumannii complex in 6 patients and 6 transfused platelets, S. saprophyticus in 4 patients and 4 transfused platelets. Whole-genome sequencing showed environmental isolates from the manufacturer were closely related genetically to patient and platelet isolates, indicating the manufacturer was the most probable source of recurrent polymicrobial contamination. Clinicians should maintain awareness of possible transfusion-transmitted sepsis even when using bacterial risk control strategies

Posttransfusion Sepsis Attributable to Bacterial Contamination in Platelet Collection Set Manufacturing Facility, United States

During May 2018‒December 2022, we reviewed transfusion-transmitted sepsis cases in the United States attributable to polymicrobial contaminated apheresis platelet components, including Acinetobacter calcoaceticus‒baumannii complex or Staphylococcus saprophyticus isolated from patients and components. Transfused platelet components underwent bacterial risk control strategies (primary culture, pathogen reduction or primary culture, and secondary rapid test) before transfusion. Environmental samples were collected from a platelet collection set manufacturing facility. Seven sepsis cases from 6 platelet donations from 6 different donors were identified in patients from 6 states; 3 patients died. Cultures identified Acinetobacter calcoaceticus‒baumannii complex in 6 patients and 6 transfused platelets, S. saprophyticus in 4 patients and 4 transfused platelets. Whole-genome sequencing showed environmental isolates from the manufacturer were closely related genetically to patient and platelet isolates, indicating the manufacturer was the most probable source of recurrent polymicrobial contamination. Clinicians should maintain awareness of possible transfusion-transmitted sepsis even when using bacterial risk control strategies