We read with interest the retrospective study of Yildiz and Toros to evaluate haematological parameters in patients with idiopathic sudden sensorineural hearing loss (SSNHL).1 Since the number of cases with higher mean platelet volume (MPV) was more in the patient group than in the control group, the researchers suggested that this supports the role of vascular pathologies in patients with idiopathic SSNHL. We would like to express the existence of other factors that might have had a negative impact on the MPV results of this study.
MPV is a platelet parameter, whose measurement is still not standardised.2 The type of anticoagulant used, the time from blood collection to measurement, and the type of devices used in the measurement, may cause variability in MPV results.3,4 Whether the anticoagulant used is ethylenediaminetetraacetic acid (EDTA) or citrate changes the optimal MPV measurement time.5 The time from taking blood until measurement may lead to a change of 2-50%, and the difference of the devices used in the measurement can cause deviation in MPV results of up to 40%.3,4 In this research, the type of anticoagulant used, the time of measurement, and the type of device used in the measurement, which are the main variables of MPV measurement standardisation, were not specified; and therefore, this affects the reliability of MPV results negatively. Likewise, the fact that the study was carried out retrospectively prevented the exclusion of pre-analytical and analytical errors. Moreover, the researchers used the MPV reference values as 4.5-8.5 fL and interpreted the pathological values in their research, according to the reference values they assumed. Depending on the methodological differences, MPV reference values of all laboratories vary; because of that the application of these reference values used, based on assumption, does not seem appropriate to interpret the MPV results of Yildiz and Toros' research.
As a result, MPV values may not be the sole responsible factor for aetiology in patients with idiopathic SSNHL.
CONFLICT OF INTEREST:
The authors declared no conflict of interest.
CB, EB: Contributed to the conception and design of the work, material preparation, data collection and analysis. The manuscript was written, and commented on previous versions of the manuscript.
Both authors approved the final manuscript, accepted their responsibilities to ensure that questions related to any part or whole of the study are properly investigated and resolved.