Letter to the Editor - Letter to the editor regarding - clinical utility of the platelet-to-neutrophil ratio

Sep 30, 2026

Letter to the editor evaluates a recently published observational study on the clinical utility of the platelet-to-neutrophil ratio (PNR) for distinguishing neonatal sepsis from pneumonia. It notes neonatal sepsis’s high mortality burden and the limits of blood culture, emphasizing the need for early recognition. The authors comment that reported diagnostic accuracy is moderate (AUC 0.76) with fair sensitivity and specificity, while biological plausibility is supported by thrombocytopenia and neutrophil dysregulation. The letter also recommends multimarker strategies and prospective multicenter serial measurements.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages2

Reading Time5 min

AccessFree to download

Letter to the editor regarding clinical utility of the platelet-to-neutrophil ratio

Diagnostic performance and limitations

Biological rationale for PNR

Comparison with other hematologic ratios and future directions

Conclusion and study implications

AnnAls of Medicine 2026, Vol. 58, no. 1, 2610904 [https://doi.org/10.1080/07853890.2025.2610904](https://doi.org/10.1080/07853890.2025.2610904) LETTER TO THE EDITOR Letter to the editor regarding: ‘clinical utility of the platelet-toneutrophil ratio in differentiating sepsis from neonatal pneumonia: an observational study’ We read with great interest the recently published article by Li et al. evaluating the clinical usefulness of the platelet-to-neutrophil ratio (PNR) in distinguishing neonatal sepsis among infants with pneumonia [1] . Neonatal sepsis remains one of the leading causes of global infant mortality. Although blood culture is accepted as the diagnostic gold standard, delays in reporting and limited sensitivity create considerable challenges in time-sensitive neonatal care where early recognition is essential [2] . The authors report that PNR demonstrates fair diagnostic accuracy, with an AUC of 0.76 and moderate sensitivity and specificity. While these findings underscore the feasibility of PNR as an inexpensive and readily available biomarker, the moderate sensitivity suggests limitations as a standalone diagnostic measure in high-risk neonatal populations. Given that neonates frequently present with subtle or nonspecific symptoms, biomarkers with higher sensitivity are generally preferred to reduce missed diagnoses [3] . The biological rationale supporting PNR is sound. Thrombocytopenia is well recognized in sepsis, reflecting platelet activation, consumption, and sequestration, and is associated with worse outcomes [4] . Likewise, neutrophil dysregulation constitutes a central component of early sepsis pathophysiology. Because PNR integrates these opposing hematologic responses, its use as an adjunctive marker is conceptually justified. Li et al. further note that PNR outperforms other hematologic ratios previously investigated. However, individual indices capture only select aspects of the immune response. In line with emerging evidence supporting multimarker approaches in sepsis, future research should assess whether combining PNR with additional biomarkers improves diagnostic accuracy [5] . In conclusion, the study contributes meaningful evidence supporting PNR as a promising adjunctive tool for early detection of neonatal sepsis in the setting of pneumonia. Prospective multicenter studies incorporating serial measurements and multivariable biomarker models will further clarify its optimal clinical applicability. Acknowledgements During the preparation and revision of this manuscript, we utilized OpenAI’s ChatGPT (version GPT-4, accessed via ChatGPT in June 2025) to assist with language editing and improving the clarity of certain sections. The tool was not used for generating scientific content, data analysis, or interpretation. All intellectual contributions, ideas, and conclusions are our own. The use of the AI tool was limited to refining English expression and improving the readability of the text. Abdullah Akkuş: data curation, writing – original draft. Authors contributions CRediT: Abdullah Akkuş: Data curation, Writing – original draft. Disclosure statements No potential conflict of interest was reported by the author. Funding The author(s) reported there is no funding associated with the work featured in this article. Data availability statement Data sharing does not apply to this article as no data was created or analyzed in this study. 2 A. AKKUŞ ORCID Abdullah Akkuş [http://orcid.org/0000-0002-0642-8759](http://orcid.org/0000-0002-0642-8759) References [1] Li C, Feng X, Yang L, et al. Clinical utility of the platelet-to-neutrophil ratio in differentiating sepsis from neonatal pneumonia: an observational study. Ann Med. 2025;57(1):2531252 . doi: 10.1080/07853890.2025.2531252 . [2] Shane AL, Sánchez PJ, Stoll BJ. Neonatal sepsis. Lancet. 2017;390(10104):1770–1780 . doi: 10.1016/ S0140-6736(17)31002-4 . [3] Wynn JL. Defining neonatal sepsis.

FAQs

What is the main focus of the letter to the editor?

The letter comments on the clinical usefulness of the platelet-to-neutrophil ratio (PNR) for differentiating neonatal sepsis from neonatal pneumonia.

How does the authors describe the diagnostic accuracy of PNR?

The letter states that PNR shows fair diagnostic accuracy, citing an AUC of 0.76 and moderate sensitivity and specificity.

Why do the authors support using PNR biologically?

They argue that thrombocytopenia and neutrophil dysregulation are central to sepsis pathophysiology, and that PNR integrates these opposing hematologic responses.

Sep 30, 2026

Uploaded by วิน