Thromb Haemost 2011; 106(04): 675-682
DOI: 10.1160/TH11-06-0378
Platelets and Blood Cells
Schattauer GmbH

A prospective cohort study of light transmission platelet aggregometry for bleeding disorders: Is testing native platelet-rich plasma non-inferior to testing platelet count adjusted samples?

Jean Francois Castilloux
1   Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
,
Karen A. Moffat
2   Department of Medicine, McMaster University, McMaster University, Hamilton, Ontario, Canada
3   The Hamilton Regional Laboratory Medicine Program, McMaster University, Hamilton, Ontario, Canada
,
Yang Liu
2   Department of Medicine, McMaster University, McMaster University, Hamilton, Ontario, Canada
,
Jodi Seecharan
3   The Hamilton Regional Laboratory Medicine Program, McMaster University, Hamilton, Ontario, Canada
,
Menaka Pai
2   Department of Medicine, McMaster University, McMaster University, Hamilton, Ontario, Canada
3   The Hamilton Regional Laboratory Medicine Program, McMaster University, Hamilton, Ontario, Canada
,
Catherine P. M. Hayward
1   Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
2   Department of Medicine, McMaster University, McMaster University, Hamilton, Ontario, Canada
3   The Hamilton Regional Laboratory Medicine Program, McMaster University, Hamilton, Ontario, Canada
› Author Affiliations
Financial support: The research was supported by the Hamilton Regional Laboratory Medicine Program and a Canada Research Chair from the Government of Canada (C.P.M.H.).
Further Information

Publication History

Received: 03 June 2011

Accepted after major revision: 15 June 2011

Publication Date:
29 November 2017 (online)

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Summary

Light transmission platelet aggregometry (LTA) is important to diagnose bleeding disorders. Experts recommend testing LTA with native (N) rather than platelet count adjusted (A) platelet-rich plasma (PRP), although it is unclear if this provides non-inferior, or superior, detection of bleeding disorders. Our goal was to determine if LTA with NPRP is noninferior to LTA with APRP for bleeding disorder assessments. A prospective cohort of patients, referred for bleeding disorder testing, and healthy controls, were evaluated by LTA using common agonists, NPRP and APRP (adjusted to 250 x 109 platelets/l). Recruitment continued until 40 controls and 40 patients with definite bleeding disorders were tested. Maximal aggregation (MA) data were assessed for the detection of abnormalities from bleeding disorders (all causes combined to limit bias), using sample-type specific reference intervals. Areas under receiver-operator curves (AUROC) were evaluated using pre-defined criteria (area differences: <0.15 for non-inferiority, >0 for superiority). Forty-four controls and 209 patients were evaluated. Chart reviews for 169 patients indicated 67 had bleeding disorders, 28 from inherited platelet secretion defects. Mean MA differences between NPRP and APRP were small for most agonists (ranges, controls: −3.3 to 5.8; patients: −3.0 to 13.7). With both samples, reduced MA with two or more agonists was associated with a bleeding disorder. AUROC differences between NPRP and APRP were small and indicated that NPRP were noninferior to APRP for detecting bleeding disorders by LTA, whereas APRP met superiority criteria. Our study validates using either NPRP or APRP for LTA assessments of bleeding disorders.