PB1112 - Optimising light transmission platelet aggregometry: a retrospective and quality improvement study

Tuesday, July 12, 2022

6:30 PM – 7:30 PM

Location: Exhibition

Presentation Format: In-Person

Presenting Author(s)

Xiu Qing Wang, BMLSc, MD

Hematopathology Resident
University of British Columbia
vancouver, British Columbia, Canada

Co-Author(s)

Muntadhar Al Moosawi, MD FRCPC

Coagulation Fellow
The University of British Columbia
Vancouver, British Columbia, Canada
NA

Nicholas Au

Staff Hematopathologist
BC Children's and Women's Hospital
Vancouver, British Columbia, Canada
RO

Rodrigo Onell

Staff Hematopathologist
St Paul's Hospital
Vancouver, British Columbia, Canada
MB

Mohammad Bahmanyar

Staff Hematopathologist
St Paul's Hospital
Vancouver, British Columbia, Canada
SW

Steven Wong

Technical Coordinator
St Paul's Hospital
Vancouver, British Columbia, Canada
SJ

Shannon Jackson

Hematologist, Providence Health Care
Providence Hematology, St. Paul’s Hospital, Vancouver, BC, Canada
Vancouver, British Columbia, Canada
TS

Tyler Smith

Staff Hematopathologist
Vancouver General Hospital
Vancouver, British Columbia, Canada
HN

Hamish Nicolson

Staff Hematopathologist
St Paul's Hospital
Vancouver, British Columbia, Canada

Background: Light transmission aggregometry (LTA) assay can be challenging to standardize. Several international guidelines have attempted to optimise this assay. Following these guidelines can improve the assay performance and interpretation.

Aims: To review the platelet function abnormalities observed in patients tested at two tertiary centres in British Columbia, and to provide suggestions to improve the assay performance.

Methods: After ethics approval, we reviewed the LTA procedure and conducted a retrospective chart review of patients tested at two specialized coagulation laboratories in BC (pediatric and adult centres) between January 1, 2015, and July 30, 2021.

Results: Results from 34 pediatric patients and 54 adults (>18 years) were reviewed. The majority of patients were females (73.5% of pediatrics, 85.1% of adults). The median ages were 15 years (IQR: 8.8 – 16) and 40 years (IQR: 30 – 59), respectively. Bleeding history was not explicitly provided at the time of testing but was attained from the majority of patients’ charts (97.0% of pediatrics, 79.6% of adults). Most patients (94.1% of pediatrics, 98.1% of adults) had been investigated with standard coagulation testing (including factor VIII and von Willebrand factor) prior to LTA. Thrombocytopenia (platelets < 150 x 109/L) was present in 2.9% of pediatric and in 22.2% of adult patients. Platelet morphology was specifically reported in 20.5% of pediatric and 14.8% of adult patients. Overall, 44% of the analyses were reported as normal (50.0% of children, 40.7% of adults). Although both centres utilized platelet agonists that are compatible with the ISTH guidelines, variations were observed between the two laboratories (Table 1).

Conclusion(s): Preliminary results highlight areas in the pre-analytical and analytical phase that can be improved, however additional evaluation will be required.