Systemic Immune Inflammation Index, Systemic Inflammation Response Index, Aggregate Index of Systemic Inflammation, and Follistatin-Like Protein-1 Levels in Children Diagnosed with Pneumonia

<b><i>Background:</i></b> This study aims to evaluate systemic immune inflammation index, systemic inflammatory response index (SIRI), aggregate index of systemic inflammation (AISI), and follistatin-like protein-1 (FSTL-1) levels in children with pneumonia and healthy controls. <b><i>Methods:</i></b> The study was carried out at the Seydisehir State Hospital between February 1, 2024 and June 1, 2024. The patient group included 44 children diagnosed with pneumonia and the control group included 45 healthy children without any disease. Index values obtained from hemogram data. Enzyme-linked immunosorbent assay was used to measure FSTL-1 levels. <b><i>Results:</i></b> A total of 89 participants, 44 in the patient group and 45 in the healthy control group, were included in the study. White blood cells, monocyte, eosinophil, neutrophil, c-reactive protein, SIRI, and AISI levels were significantly higher in the patient group than in the control group. FSTL-1 levels were higher in the patient group, but did not differ statistically significant. The patient and control groups were compared in the receiver operating characteristics analysis, we found the highest area under curve (AUC) in the SIRI (AUC: 0.754) and AISI (AUC: 0.713) parameters. <b><i>Conclusion:</i></b> In conclusion, compared to healthy controls, SIRI and AISI levels were significantly higher in the patient group, and the highest AUC values belonged to these indices. Therefore, we believe that SIRI and AISI indices, which are inexpensive and simple tests, are useful for early diagnosis and treatment of pneumonia.