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Updated: May 30, 2026
A Neonatal Imaging Model of Gram-Negative Bacterial Sepsis
Published on: August 12, 2020
Neutrophilic myeloperoxidase index and mean light absorbance in neonatal septic and nonseptic foals
Martina Piviani1, Didac Segura, Luis Monreal
1Department of Animal Medicine and Surgery, Universitat Autònoma de Barcelona, Barcelona, Spain.
Background:
Two neutrophilic indices reported by the ADVIA 120 Hematology Analyzer, neutrophilic myeloperoxidase index (MPXI), and mean light absorbance (neutrophil X mean [NXM]) have been proposed as indicators of systemic inflammatory disease in horses and of neutrophil activation in coronary ischemic syndromes in people.
Objective:
The aim of this study was to evaluate NXM and MPXI in healthy, sick nonseptic, and sick septic foals to determine whether conditions likely associated with neutrophil activation result in decreases in these variables.
Methods:
In this retrospective study, CBC data from 61 neonatal foals presented to the Equine Teaching Hospital of Barcelona were evaluated for correlations between MPXI, NXM, percentage of large unstained cells, neutrophil count, and percentage of band neutrophils. Results obtained in septic (n=32), sick nonseptic (n=22), and healthy foals (n=7) were compared. In addition, results recorded in septic/neutropenic (n=12), septic/non-neutropenic (n=20), nonseptic/neutropenic (n=8), nonseptic/non-neutropenic (n=14), and healthy foals (n=7) were also compared.
Results:
A weak negative correlation was found between MPXI and neutrophil count and between NXM and percentage of band neutrophils. Septic/neutropenic foals had significantly higher MPXI values (median 17.9, minimum-maximum 4.7-42.5) than did septic/non-neutropenic (1.5, -24.4 to 22.3), nonseptic/neutropenic (6.6, 0.6-17.9), and nonseptic/non-neutropenic foals (8.8, -10.1 to 16.8) but did not differ significantly from controls (12.8, -8.5 to 20.4).
Conclusions:
Significant differences in NXM or MPXI were not found when disease groups were compared with controls; however, septic/neutropenic foals had significantly higher median MPXI than other groups of sick foals. Further prospective studies are needed to clarify if this finding is related to decreased neutrophil function or activation in septic/neutropenic foals.
Insights
Neutrophil X mean (NXM) and myeloperoxidase index (MPXI) did not significantly differ between healthy and sick foals. However, septic/neutropenic foals showed higher MPXI, suggesting potential neutrophil dysfunction in these cases.
Area of Science:
- Veterinary Hematology
- Neonatal Foal Medicine
- Immunology
Background:
- Neutrophilic indices, myeloperoxidase index (MPXI) and neutrophil X mean (NXM), are potential markers for systemic inflammation and neutrophil activation.
- These indices are measured using the ADVIA 120 Hematology Analyzer.
Purpose of the Study:
- To evaluate NXM and MPXI in healthy, sick nonseptic, and sick septic foals.
- To determine if conditions associated with neutrophil activation decrease these variables in foals.
Main Methods:
- Retrospective analysis of CBC data from 61 neonatal foals.
- Comparison of MPXI and NXM in septic, nonseptic, and healthy foals, including neutropenic subgroups.
- Correlation analysis with neutrophil count and band neutrophils.
Main Results:
- Weak negative correlations were observed between MPXI and neutrophil count, and NXM and band neutrophils.
- Septic/neutropenic foals exhibited significantly higher MPXI compared to other sick foal groups.
- No significant differences in NXM or MPXI were found between overall disease groups and controls.
Conclusions:
- NXM and MPXI did not show significant differences across broad disease categories in foals.
- Elevated MPXI in septic/neutropenic foals warrants further investigation into neutrophil function or activation.
- Prospective studies are recommended to clarify the significance of these findings.
