Blood Cell Count Derived Inflammation Indexes in Patients with Idiopathic Pulmonary Fibrosis

Abstract

Purpose Inflammation and immunity play a pivotal but yet unclear role in idiopathic pulmonary fibrosis (IPF), a chronic disorder characterized by progressive damage of lung parenchyma and severe loss of lung function despite optimal treatment. However, the pathophysiological and predictive role of combined blood cell count indexes of inflammation in IPF is uncertain. Methods Seventy-three patients with IPF and 62 healthy subjects matched for age, gender and smoking status were included in this cross-sectional study. Results We found significant differences in neutrophil to lymphocyte ratio (NLR), derived neutrophil to lymphocyte ratio (dNLR), monocyte to lymphocyte ratio (MLR), platelet to lymphocyte ratio (PLR), systemic inflammation response index (SIRI) and aggregate index of systemic inflammation (AISI) between IPF patients and healthy controls. In logistic regression, all combined blood inflammation indexes, barring PLR, were independently associated with the presence of IPF after adjusting for age, gender, body mass index and smoking status. Furthermore, significant associations between FVC% and NLR, LMR, SIRI and AISI, and between DLCO% and NLR, dNLR, LMR, SIRI and AISI, were observed. Conclusions In conclusion, our data indicate significant alterations of combined blood cell count indexes of inflammation in IPF.

The Aggregate Index of Systemic Inflammation (AISI): A Novel Prognostic Biomarker in Idiopathic Pulmonary Fibrosis

“…Similar properties have also been exhibited by some blood cell dimensional indexes, such as the red blood cell distribution width (RDW), which has been reported to be an indicator of poor prognosis in IPF [ 10 , 35 ]. The values of combined blood cell count indexes in the present study were similar to those recently described in IPF patients [ 20 , 21 ]. In addition, by univariate correlation analysis, we found significant relationships between ratios of blood cell counts and lung functional parameters FEV1%, FVC% and DLCO%, indicating that the deterioration in lung function may be related to a higher inflammatory state in IPF patients.…”

“…Therefore, a predictive tool such as the AISI, that includes lymphocytes, neutrophils, platelets, and monocytes, might be superior to simpler indexes as it better reflects the inflammatory status in the context of specific disease states. This proposition is supported by other reports on the association between the AISI and hospital stay in open elective thoracic surgery [ 12 ], age-related macular degeneration [ 15 ], IPF [ 21 ], and COVID-19 [ 38 ]. The significant association between AISI and mortality remained after correction for potential confounding factors, including age, gender, smoking status, antifibrotic drug treatment, disease stage, and BMI (that, at higher values, was instead related to a more favourable prognosis).…”

“…Although the pathophysiology of IPF remains to be fully elucidated, several immune cells are likely to be involved, particularly lymphocytes, neutrophils, and monocytes. Alterations in lymphocytes and neutrophils levels have previously been reported in IPF [20,21], as well as the association between increased monocytes values and poor prognosis [37]. Therefore, a predictive tool such as the AISI, that includes lymphocytes, neutrophils, platelets, and monocytes, might be superior to simpler indexes as it better reflects the inflammatory status in the context of specific disease states.…”

“…Given the established relationship between IPF condition and some inflammation biomarkers [ 20 , 21 , 23 , 24 , 25 , 26 , 27 , 28 ], we sought to determine the prognostic capacity of the combined blood cell count indexes, a group of well-recognized biomarkers of inflammation obtained by the complete blood cell count test, that is routinely provided in clinical practice. Ratios of blood cell counts have shown to be effective in predicting the survival of those with acute and chronic diseases [ 29 , 30 , 31 , 32 , 33 , 34 ].…”

“…The complete blood cell count is routinely performed and relatively inexpensive. Combined haematological indexes of inflammation, particularly the neutrophil-to-lymphocyte ratio (NLR), derived neutrophil-to-lymphocyte ratio (dNLR), monocyte-to-lymphocyte ratio (MLR), platelet-to-lymphocyte ratio (PLR), systemic inflammation index (SII), systemic inflammation response index (SIRI), and aggregate inflammation systemic index (AISI) are increasingly studied as biomarkers in several disorders [ 12 , 13 , 14 , 15 , 16 ] including respiratory pathologies such as COPD (chronic obstructive pulmonary disease), asthma [ 17 , 18 , 19 ], and more recently, IPF [ 20 , 21 ]. However, no information is currently available regarding their ability to predict mortality in the latter group.…”