The operational impact of introducing cold stored platelets

BACKGROUND

Cold stored platelets (CSP) undergo physical changes that make them better at initiating a clot. While cold stored platelets are superior for reducing bleeding in actively bleeding patients, room temperature platelets (RTP) are better for increasing platelet count in patients requiring a prophylactic transfusion. However, whether the overhead required to maintain a dual platelet inventory of both RTP and CSP could be compensated by reduced platelet wastage resulting from the longer shelf life of CSP has not been determined.

STUDY DESIGN AND METHODS

A simulation model of a regional blood supply was built, with focus on the operations of a case hospital. Two scenarios were considered: "No-CSP," in which the hospital issues only RTP, and "CSP," in which the hospital issues both RTP and CSP Within the CSP scenario, conditions were tested under which the hospital receives only RTP and converts some to cold stored platelets and a second strategy where the hospital receives CSP from the regional supplier in addition to converting RTP.

RESULTS

A centralized supply of CSP is necessary since on-site conversion is limited by platelet age. Product shortages decrease with increased CSP inventory, but CSP wastage increases. It was also determined that, because relatively few RTP units can be converted on-site, RTP wastage is not significantly decreased with the introduction of CSP.

CONCLUSION

Given the clinical benefits for treatment of trauma, CSP is a desirable addition to a blood formulary. However, it is unlikely that significant reductions in RTP wastage will occur because of the introduction of CSP.

The First North American Experience Using Glycosorb Immunoadsorption Columns for Blood Group-Incompatible Kidney Transplantation

Background:

Blood group incompatibility (ABOi) is the most common barrier to living donor kidney transplantation. Options for such recipients include kidney paired donation (KPD) or desensitization methodology to reduce blood antibody response.

Objective:

The objective of this study is to report on the first North America experience in ABOi living donor kidney transplantation using Glycosorb ABO immunoadsorption columns.

Design:

Retrospective observational cohort study.

Setting:

Renal transplant program at St. Michael’s Hospital, Unity Health Toronto, University of Toronto.

Patients:

Twenty-six ABOi living donor transplants from August 2011 through February 2020 were undertaken at our center.

Measurements:

Renal allograft and patient survival postdesensitization for ABOi living donor transplants and isohemagglutinin titer reduction.

Methods:

Preoperative immunosuppressive regimen consisted of a single dose of Rituximab 375 mg/m² IV on day −28; tacrolimus, mycophenolic acid, and prednisone to start on day −7. Immunoadsorption treatments with Glycosorb A or B columns were performed on day −7 through day −1 based on anti-A or anti-B titers on Spectra Optia Apheresis System. Immunosuppression included basiliximab, solumedrol followed by oral prednisone, once-daily tacrolimus, and mycophenolic acid. The mean follow-up was 53 months (3-96 months).

Results:

A total of 26 individuals underwent an attempt at desensitization of whom 24 patients underwent immediate transplant. One patient had a rebound in titers and subsequently was transplanted from a blood group compatible living donor. A second patient had an unrelated medical issue and desensitization was discontinued. Five-year patient survival was 96% and death censored allograft survival was 92%. Posttransplant anti-A or anti-B titers were monitored daily for the first 7 days posttransplant and every 2 days from days 7 to 14. There were no acute rejections seen in this cohort of transplant recipients.

Limitations:

As our protocol was first initiated as proof of concept, a few recipients had low initial isohemagglutinin titers. This may have contributed to improved clinical outcomes.

Conclusions:

ABO column immunoadsorption with specific columns is a safe and effective method for ABOi living donor kidney transplantation, and an option when KPD is less than ideal.

Trial not registered as this was a retrospective cohort review.

A curious case of delayed hemolytic transfusion reaction with evanescent antibodies in a patient with hereditary hemorrhagic telangiectasia

BACKGROUND

Delayed hemolytic reactions are potential complications of incompatible transfusions and are usually associated with the identification of a new antibody on serologic studies, following a second immunization event. However, in rare cases, the antibody investigation remains negative even if the clinical presentation would lead one to suspect otherwise.

CASE REPORT

A 44-year-old woman with hereditary hemorrhagic telangiectasia presented to the emergency department with hematuria and low back pain after she had received three units of RBCs 2 weeks earlier. Hematology and biochemistry results were consistent with delayed hemolytic transfusion reaction, but surprisingly, serologic antibody investigations were negative. It was only when her plasma was tested with enzyme (ficin)-treated panel cells that anti-e was finally detected, with a 3+ reaction with all homozygous e+ cells. No reaction was seen with heterozygous e+ cells. Four months later, an anti-K was also detected on standard panels, while the anti-e remained detectable only with ficin-treated panel cells. Three years later, both antibodies had vanished and remained undetectable. The weakness of anti-e reaction, combined with the quick evanescence of both antibodies led to the suspicion of a potential underlying immunodeficiency disorder, which was confirmed by low immunoglobulin levels on two occasions.

CONCLUSION

To our knowledge, this is the first case of immunodeficiency disorder diagnosed after the identification of evanescent antibody reactions. This case also outlines the importance of a good clinical history that should lead to further investigations when a hemolytic transfusion reaction is suspected.

Multi-Center Evaluation of the Automated Immunohematology Instrument, the ORTHO VISION Analyzer

BACKGROUND

ORTHO VISION Analyzer (Vision), is an immunohematology instrument using ID-MT gel card technology with digital image processing. It has a continuous, random sample access with STAT priority processing. The efficiency and ease of operation of Vision was evaluated at 5 medical centers.

METHODS

De-identified patient samples were tested on the ORTHO ProVue Analyzer (ProVue) and repeated on the Vision mimicking the daily workload pattern. Turnaround times (TAT) were collected and compared. Operators rated key features of the analyzer on a scale of 1 to 5.

RESULTS

A total of 507 samples were tested on both instruments at the 5 trial sites. The mean TAT (SD) were 31.6 minutes (5.5) with Vision and 35.7 minutes (8.4) with ProVue, which renders a 12% reduction. Type and screens were performed on 381 samples; the mean TAT (SD) was 32.2 minutes (4.5) with Vision and 37.0 minutes (7.4) with ProVue. Antibody identification with eleven panel cells was performed on 134 samples on Vision; TAT (SD) was 43.2 minutes (8.3). The installation, training, configuration, maintenance and validation processes are all streamlined to provide a short implementation time. The average rating of main functions by the operators was 4.1 to 4.8. Opportunities for improvement, such as flexibility with editing QC results, maintenance schedule, and printing options were identified. The capabilities to perform serial dilutions, to accept pediatric tubes, and review results by e-Connectivity are enhancements over the ProVue.

CONCLUSIONS

Vision provides shorter TAT compared to ProVue. Every site described a positive experience using Vision.