We have read with great interest the recent article by Gulleroglu et al.Citation1 In this excellent study, the authors investigated the mean platelet volume (MPV) as a prognostic biomarker in patients with nephrotic syndrome and clinical importance of the changes of MPV during active and remission phases in children with nephrotic syndrome. They concluded that MPV in nephrotic syndrome patients can be an easy, cheap and simple method for determine the prognosis of the disease and steroid resistance. We appreciate and congratulate the authors for having addressed such an important issue. However, we have some concerns related to the technological limitations and variations in the measurement of the MPV that need to be considered.
Firstly, MPV is one of the hematology parameters for which as yet no universal standardization exists.Citation2 Therefore, different normal ranges for the MPV can result, influenced by factors such as the anticoagulant used in the collection tube and the delay in time from sampling to analysis; notably ethylenediaminetetraacetic acid (EDTA)-induced platelet swelling.Citation3
Secondly, different technologies for measuring MPV give different results.Citation4 Beckman-Coulter systems use impedance technology and derive the MPV from the fitted lognormal platelet curve. Laser-based light scatter technology is another method to measure MPV; the platelet histogram is derived from measurements of high angle light scatter, and the MPV is calculated as the mode of the measured platelet volumes. As a result of this comparison, instruments show MPV differences of up to 40%.Citation4
Furthermore, the most important problem about the clinical validity of MPV is that it increases over time as platelets swell in EDTA, with an increase of 7.9% within 30 min and an overall increase of 13.4% over 24 h. However, some investigators have reported variable increases in MPV with EDTA storage, up to 50%.Citation5
Consequently, at the present time we have not any universally acceptable standard reference ranges, hematology analyzers and technique as well as Standard time window for the analysis of the MPV measurement. We believe that MPV should not be used to evaluate the prognosis of the diseases until universally standardized.
Declaration of interest
The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.
References
- Gulleroglu K, Yazar B, Sakalli H, Ozdemir H, Baskin E. Clinical importance of mean platelet volume in children with nephrotic syndrome. Ren Fail. 2014;36(5):663–665
- Vinholt PJ, Hvas AM, Nybo M. An overview of platelet indices and methods for evaluating platelet function in thrombocytopenic patients. Eur J Hematol. 2014;92(5):367–376
- Bilen Y, Cankaya E, Keles M, et al. Does decreased mean platelet volume predict inflammation in chronic renal failure, dialysis, and transplanted patients? Ren Fail. 2014;36(1):69–72
- Tan BT, Nava AJ, George TI. Evaluation of the Beckman Coulter UniCel DxH 800 and Abbott Diagnostics Cell-Dyn Sapphire hematology analyzers on pediatric and neonatal specimens in a tertiary care hospital. Am J Clin Pathol. 2011;135(6):929–938
- Chu SG, Becker RC, Berger PB, et al. Mean platelet volume as a predictor of cardiovascular risk: A systematic review and meta-analysis. J Thromb Haemost. 2010;8:148–156