Abstract
Objective
This study aimed to investigate the diagnostic value of the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII) in predicting intensive care unit (ICU) requirements in pediatric community-acquired pneumonia (CAP).
Methods
In this retrospective study, demographic data, clinical findings, and laboratory results of pediatric patients diagnosed with CAP were evaluated. Patients were divided into two groups: those treated in the pediatric ward (Group 1) and those managed in the pediatric ICU (PICU) (Group 2). NLR, PLR, and SII calculated from hemogram parameters, as well as arterial blood gas values (pH, serum lactate), C-reactive protein, and procalcitonin (PCT), were analyzed. Their predictive roles in determining disease severity were assessed.
Results
A total of 116 patients were included, of whom 56 (48.3%) were in Group 1 and 60 (51.7%) in Group 2. NLR (p=0.039), PLR (p=0.039), and SII (p=0.026) levels were significantly higher in Group 2. Receiver operating characteristic analysis revealed area under the curve values of 0.718 for NLR, 0.705 for SII, and 0.684 for PLR. NLR, blood pH, serum lactate, and PCT were identified as independent predictors of ICU admission. Hypoxia, comorbid conditions, abnormal vital signs, and elevated inflammatory indices were additional significant risk factors associated with PICU admission.
Conclusion
NLR, PLR, and SII may serve as inexpensive and readily available markers to assess disease severity and predict intensive care needs in pediatric CAP. These indices can support rapid clinical decision-making and facilitate risk stratification in practice.
Keywords: Community-acquired pneumonia, pediatric, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), systemic immune-inflammatory index (SII)
References
GBD 2016 Lower Respiratory Infections Collaborators. Estimates of the global, regional, and national morbidity, mortality, and aetiologies of lower respiratory infections in 195 countries, 1990-2016: a systematic analysis for the Global Burden of Disease Study 2016. Lancet Infect Dis. 2018;18:1191-210.
de Benedictis FM, Kerem E, Chang AB, Colin AA, Zar HJ, Bush A. Complicated pneumonia in children. Lancet. 2020;396:786-98.
Shi T, Chen C, Huang L, et al. Risk factors for mortality from severe community acquired pneumonia in hospitalized children transferred to the pediatric intensive care unit. Pediatr Neonatol. 2020;61:577-83.
Shah SS, Bradley JS. Pediatric community-acquired pneumonia. In: Cherry JD, Harrison G, Kaplan SL, et al. editors. Feigin and Cherry’s Textbook of Pediatric Infectious Diseases, 8th ed. Philadelphia: Elsevier; 2018. p. 208-19.
Subspecialty Group of Respiratory Diseases, The Society of Pediatrics, Chinese Medical Association; Editorial Board, Chinese Journal of Pediatrics. Guidelines for management of community acquired pneumonia in children (the revised edition of 2013) (I) [in Chinese]. Zhonghua Er Ke Za Zhi. 2013;51:745–52.
British Thoracic Society of Standards of Care Committee. BTS guidelines for the community acquired pneumonia in childhood. Thorax. 2002;57(Suppl 1):1-24.
Madhi SA, Kohler M, Kuwanda L, Cutland C, Klugman KP. Usefulness of C-reactive protein to define pneumococcal conjugate vaccine efficacy in the prevention of pneumonia. Pediatr Infect Dis J. 2006;25:30-6.
Perren A, Cerutti B, Lepori M, et al. Influence of steroids on procalcitonin and C-reactive protein in patients with COPD and community-acquired pneumonia. Infection. 2008;36:163-6.
Zhu M, Chen L, Kong X, et al. The systemic ınflammation response index as an independent predictor of survival in breast cancer patients: a retrospective study. Front Mol Biosci. 2022;9:856064.
Urbanowicz T, Michalak M, Olasińska-Wiśniewska A, et al. Neutrophil counts, neutrophil-to-lymphocyte ratio, and systemic inflammatory response index (SIRI) predict mortality after off-pump coronary artery bypass surgery. Cells. 2022;11:1124.
Yang J, Wang H, Hua Q, Wu J, Wang Y. Diagnostic value of systemic inflammatory response index for catheter-related bloodstream infection in patients undergoing haemodialysis. J Immunol Res. 2022;2022:7453354.
Nooh HA, Abdellateif MS, Refaat L, et al. The role of inflammatory indices in the outcome of COVID-19 cancer patients. Med Oncol. 2021;39:6.
Rudan I, Boschi-Pinto C, Biloglav Z, Mulholland K, Campbell H. Epidemiology and etiology of childhood pneumonia. Bull World Health Organ. 2008;86:408-16.
Wardlaw T, Salama P, Johansson EW, Mason E. Pneumonia: the leading killer of children. Lancet. 2006;368:1048-50.
Florin TA, Ambroggio L, Brokamp C, et al. Biomarkers and disease severity in children with community-acquired pneumonia. Pediatrics. 2020;145:e20193728. Erratum in: Pediatrics. 2020;146:e2020011452.
Lee H, Kim I, Kang BH, Um SJ. Prognostic value of serial neutrophil-to-lymphocyte ratio measurements in hospitalized community-acquired pneumonia. PLoS One. 2021;16:e0250067.
Elmeazawy R, Ayoub D, Morad LM, El-Moazen AMF. Role of systemic immune-inflammatory index and systemic inflammatory response index in predicting the diagnosis of necrotizing pneumonia in children. BMC Pediatr. 2024;24:496.
Wu J, Yan L, Chai K. Systemic immune-inflammation index is associated with disease activity in patients with ankylosing spondylitis. J Clin Lab Anal. 2021;35:e23964.
Li L, Miao H, Chen X, Yang S, Yan X. Research on the correlation of peripheral blood inflammatory markers with PCT, CRP, and PCIS in infants with community-acquired pneumonia. Evid Based Complement Alternat Med. 2022;2022:9024969.
Acar E, Gokcen H, Demir A, Yildirim B. Comparison of inflammation markers with prediction scores in patients with community acquired pneumonia. Bratisl Lek Listy. 2021;122:418-23.
Yadav RK, Kumar D, Gupta A, Sharma P. C-reactive protein and procalcitonin: as predictor biomarkers of severity and outcome in children with community-acquired pneumonia. Trop Doct. 2024;54:262-67.
Esposito S, Tagliabue C, Picciolli I et al. Procalcitonin measurements for guiding antibiotic treatment in pediatric pneumonia. Respir Med. 2011;105:1939-45.
Wang RH, Wen WX, Jiang ZP, et al. The clinical value of neutrophil-to-lymphocyte ratio (NLR), systemic immune-inflammation index (SII), platelet-to-lymphocyte ratio (PLR) and systemic inflammation response index (SIRI) for predicting the occurrence and severity of pneumonia in patients with intracerebral hemorrhage. Front Immunol. 2023;14:1115031.
Shao L, Yu B, Lyu Y, Fan S, Gu C, Wang H. The clinical value of novel inflammatory biomarkers for predicting mycoplasma pneumoniae ınfection in children. J Clin Lab Anal. 2025;39:e25150.
Wang S, Wan Y, Zhang W. The clinical value of systemic immune inflammation ındex (SII) in predicting the severity of hospitalized children with mycoplasma pneumoniae pneumonia: a retrospective study. Int J Gen Med. 2024;17:935-942.
Ozdemir A, Kocak SY, Karabela SN, Yılmaz M. Can systemic immune inflammation index at admission predict in-hospital mortality in chronic kidney disease patients with SARS-CoV-2 infection? Nefrologia (Engl Ed). 2022;42:549-58.
Fois AG, Paliogiannis P, Scano V, et al. The systemic inflammation index on admission predicts ın-hospital mortality in COVID-19 patients. Molecules. 2020;25:5725.
Sayed AA. Assessing the diagnostic values of the neutrophil-to-lymphocyte ratio (NLR) and systematic immunoinflammatory index (SII) as biomarkers in predicting COVID-19 severity: a multicentre comparative study. Medicina (Kaunas). 2024;60:602.
Yuan H, Tian J, Wen L. Meta-analysis of the systemic immune-inflammatory index and in-hospital mortality of COVID-19 patients. Heliyon. 2023;10:e23441.
Chu FL, Li C, Liu Y, Dong B, Qiu Y, Fan G. Peripheral blood parameters for predicting PICU admission and mechanical ventilation in pediatric inpatients with human parainfluenza virus-induced pneumonia. J Med Virol. 2023;95:e28752.
Do Q, Dao TM, Nguyen TNT, Tran QA, Nguyen HT, Ngo TT. Procalcitonin identifies bacterial coinfections in Vietnamese children with severe respiratory syncytial virus pneumonia. Biomed Res Int. 2020;2020:7915158.
Yiğit E, Demir Yiğit Y. Diagnostic importance of serum C-reactive protein and procalcitonin in sepsis after burn. Int J Burns Trauma. 2021;11:391-6.
Ratageri VH, Panigatti P, Mukherjee A, et al. Role of procalcitonin in diagnosis of community acquired pneumonia in Children. BMC Pediatr. 2022;22:217.
McLaughlin JM, Khan F, Schmitt HJ, et al. Respiratory syncytial virus-associated hospitalization rates among us infants: a systematic review and meta-analysis. J Infect Dis. 2022;225:1100-11.
Sauer CM, Gómez J, Botella MR, et al. Understanding critically ill sepsis patients with normal serum lactate levels: results from U.S. and European ICU cohorts. Sci Rep. 2021;11:20076.
Song Y, Wang N, Xie X, Tian Y, Wang Y. Relationship between lactate levels and 28-day mortality in pediatric sepsis: results from the pediatric intensive care database. BMC Pediatr. 2024;24:712.
Xie M, Min Z, Jiang W, He Z, Xia X. Prognostic value of multivariate logistic regression analysis and amyloid a lactate monitoring in patients with severe pneumonia-associated sepsis. BMC Pulm Med. 2025;25:191.
