Screening for platelet function disorders with Multiplate and platelet function analyzer

Abstract

Light transmission aggregation (LTA) is the gold standard for the diagnosis of platelet function disorders (PFDs), but it is time-consuming and limited to specialized laboratories. Whole-blood impedance aggregometry (Multiplate) and platelet function analyzer (PFA) may be used as rapid screening tools to exclude PFDs. The aim of this study is to assess the diagnostic performance of Multiplate and PFA for PFDs, as detected by LTA.Data from preoperative patients, patients referred to the hematologist for bleeding evaluation, and patients with a diagnosed bleeding disorder were used. PFDs were defined as ≥2 abnormal LTA curves. Diagnostic performance of Multiplate and PFA for detecting PFDs was expressed as sensitivity and specificity. The ability of Multiplate agonists and PFA kits to detect corresponding LTA curve abnormalities was expressed as area under the receiver operating characteristic curve. Prevalence of PFDs was 16/335 (4.8%) in preoperative patients, 10/54 (18.5%) in referred patients, and 3/25 (12%) in patients with a diagnosed bleeding disorder. In preoperative and referred patients, the sensitivity of Multiplate and PFA for detecting mild PFDs varied between 0% and 40% and AUCs for detecting corresponding LTA curve abnormalities were close to 0.50. In patients with a diagnosed bleeding disorder, both assays could detect Glanzmann thrombasthenia (GT) with sensitivity of 100% and AUCs of 0.70-1.00. Multiplate and PFA cannot discriminate between preoperative and referred patients with and without mild PFDs, meaning that they cannot be used as screening tests to rule out mild PFDs in these populations. Both Multiplate and PFA can detect GT in previously diagnosed patients.

Diagnostic work up of patients with increased bleeding tendency

“…It was not until later that physicians started to incorporate the BAT into their standard anamnesis. However, this tool might not be as usable in screening for other haemostatic disorders as previously thought . Another disadvantage of BAT scores is that these scores increase in time and are not based on time intervals.…”

“…In previous studies, measuring PFA was found to be an insensitive screenings assay, especially for patients with mild PFD’s . It was considered not very useful since the PFA cannot differentiate between different PFD’s and vWD.…”

“…However, this tool might not be as usable in screening for other haemostatic disorders as previously thought. 27 Another disadvantage of BAT scores is that these scores increase in time and are not based on time intervals. Longitudinal BAT scores may overcome this.…”

Comparison of light transmission aggregometry and multiple electrode aggregometry for the evaluation of patients with mucocutaneous bleeding

“…5,8,24 The agonist concentrations used for MEA in the present study are, therefore, lower than concentrations used in previous studies of normal controls or patients. 15,[19][20][21]25 The threshold concentrations for ADP, collagen, and TRAP used in the present study are similar to those identified by Toth et al, 13 although the anticoagulant used for the present study was different (sodium heparin rather than citrate or hirudin). Reference intervals were developed for these agonist concentrations using healthy control subjects, with cutoff values determined as two SDs below the mean.…”

Preoperative screening for bleeding disorders: A comprehensive laboratory assessment of clinical practice

“…The value of the PFA was assessed as it is often used to screen for platelet function disorders (PFDs), 28 even though previous studies demonstrated low sensitivity for mild PFDs. 29,30 The aPTT is quite often prolonged due to the presence of lupus anticoagulant activity, which can lead to an extensive but unnecessary coagulation work-up. 31 Our findings underpin the advice of the ESA 5 and the SFAR 6 guidelines that in case of a positive bleeding history, hematologist consultation is preferred over measurement of PT or aPTT.…”