To the editor:
Dear editor, we read the publication on “Prognostic significance of preoperative and follow-up neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) in patients with non-metastatic clear cell renal cell carcinoma (NMCCRCC)” with a great interest [1]. In this work, preoperative NLR (pNLR) and PLR (pPLR) and relationship with recurrence-free survival (RFS) are studied. Kim et al. [1] concluded that “pNLR and pPLR are independent prognostic factors for RFS in patients with NMCCRCC.” There are some considerations on the use of pNLR and pPLR. Both pNLR and pPLR might be affected by several confounding factors and this might be pitfall of the present study. This problem is the basic forgotten problem for clinical use of NLR and PLR as prognostic factors in several medical disorders [2,3]. Focusing on basic laboratory medicine principle, the neutrophil, lymphocyte and platelet investigation needs good quality control and the parameters from different analyzers might be variable [4]. The results of differential white blood counts of the same patient's sample from different analyzers are usually different [4]. For example, the result of neutrophil count performed by some analyzers comparing to manual referencing count might be lower [5].
Footnotes
CONFLICTS OF INTEREST: The authors have nothing to disclose.
References
- 1.Kim TW, Lee JH, Shim KH, Choo SH, Choi JB, Ahn HS, et al. Prognostic significance of preoperative and follow-up neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio in patients with non-metastatic clear cell renal cell carcinoma. Investig Clin Urol. 2019;60:14–20. doi: 10.4111/icu.2019.60.1.14. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Wiwanitkit V. Neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio and heart failure. Arq Bras Cardiol. 2016;106:265. doi: 10.5935/abc.20160037. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Wiwanitkit V. Neutrophil to lymphocyte ratio in allergic rhinitis. Eur Arch Otorhinolaryngol. 2016;273:3443. doi: 10.1007/s00405-015-3886-0. [DOI] [PubMed] [Google Scholar]
- 4.Bruegel M, Nagel D, Funk M, Fuhrmann P, Zander J, Teupser D. Comparison of five automated hematology analyzers in a university hospital setting: Abbott Cell-Dyn Sapphire, Beckman Coulter DxH 800, Siemens Advia 2120i, Sysmex XE-5000, and Sysmex XN-2000. Clin Chem Lab Med. 2015;53:1057–1071. doi: 10.1515/cclm-2014-0945. [DOI] [PubMed] [Google Scholar]
- 5.Park Y, Song J, Song S, Song KS, Ahn MS, Yang MS, et al. Evaluation of the Abbott Cell-Dyn Sapphire hematology analyzer. Korean J Lab Med. 2007;27:162–168. doi: 10.3343/kjlm.2007.27.3.162. [DOI] [PubMed] [Google Scholar]