We have read the article “Is the red cell distribution width (RDW) strong predictor for treatment response in primary glomerulonephritides (PGN)?” by Turgutalp et al.Citation1 They aimed to investigate the predictive value of RDW for the estimation of response to therapy in adult patients with nephrotic syndrome (NS). They concluded that pre-treatment RDW value is a promising novel biomarker for predicting response to the treatment in adult patients with NS due to PGN. This study gives important information on this clinically relevant condition. The ready availability of this parameter at no additional cost may encourage its wider use in clinical practice in the future. Thanks to the authors for their contribution.
Recently, some markers including C-reactive protein, B-type natriuretic peptide, YKL-40, procalcitonin, IL-6, IL-1b, TNF-a, thrombomodulin, E-selectin, VEGF, total homocysteine (tHcy) had been considered as mortality indicators in many diseases.Citation2 In addition, a complete blood count is a routine, inexpensive, practical and easy examination that supplies additional information. Its subtypes such as RDW can be an indicator of short- and long-term mortalities.Citation3 RDW is very simple and cheap when compared with the other above inflammatory cytokines. Recently, RDW has recently been defined to highly correlate with short- and long-term outcomes in different clinical settings.
However, we think that some points should be discussed. Many studies have reported that elevated RDW levels are associated with poor prognosis in the setting of hypertension,Citation4 diabetes mellitus, coronary artery disease, coronary bypass surgery, heart failure, stroke, peripheral arterial disease, older age.Citation5 RDW may also reflect ethnicity, neurohumoral activation, renal dysfunction, thyroid disease, hepatic dysfunction, nutritional deficiencies (i.e., iron, vitamin B12, and folic acid), bone marrow dysfunction, inflammatory diseases, chronic or acute systemic inflammationCitation6 and use of some medications. The value of RDW is instrument-dependent, forcing each laboratory to establish its own reference values. Finally, it would be better if the authors might define how much time they specified on measuring RDW levels, because of the delaying blood sampling can cause abnormal results in RDW measurements.Citation7
In conclusion, we strongly believe that those findings obtained from the current study will lead to further studies evaluating the relation between RDW and NS. However, one should keep in mind that RDW itself alone without other inflammatory markers may not give accurate information to clinicians about the inflammatory status and prognostic indication of these patients.Citation8 So, from that point of view we think that it should be evaluated accompanied with other serum inflammatory markers.
Declaration of interest
Authors declare that they have no conflict of interests.
References
- Turgutalp K, Kıykım A, Bardak S, et al. Is the red cell distribution width strong predictor for treatment response in primary glomerulonephritides? Ren Fail. 2014;36(7):1083–1089
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