Abstract
Background When the newborn brain is exposed to hypoxia, as in hypoxic ischemic encephalopathy
(HIE), it causes an inflammatory response. A wide variety of inflammatory markers
are therefore used in the diagnosis of HIE.
Objective We aimed to determine the diagnostic role of systemic inflammatory indices in infants
with moderate-to-severe HIE. We have also investigated the effect of hypothermia treatment
over those indices.
Study Design A retrospective cohort study of infants suffering from moderate-to-severe HIE was
conducted in a tertiary-level neonatal intensive care unit between September 2019
and March 2021. Systemic inflammatory indices including systemic immune-inflammation
index (SII), pan-immune-inflammation value (PIV), systemic inflammation response index
(SIRI), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR),
and monocyte-to-lymphocyte ratio (MLR) were calculated for infants with HIE and controls
at baseline, and after therapeutic hypothermia in those with HIE.
Results A total of 103 infants (53 in the HIE group and 50 in the control group) were included
in the study. Median gestational ages (GA) were 39 (37–40) and 38 (37–39) weeks, and
median birth weights (BW) were 3,165 (2,890–3,440) and 3,045 (2,850–3,460) g in the
HIE and control groups, respectively. GA, BW, mode of delivery, and gender of infants
were similar between the groups. Infants in the HIE group had significantly higher
NLR (p = 0.001), SII (p = 0.001), PIV (p = 0.001), and SIRI (p = 0.004) values when compared with the control group. Those indices decreased significantly
after hypothermia treatment in the HIE group. Areas under curve for NLR, PLR, MLR,
SII, SIRI, and PIV to predict HIE were found to be 0.808, 0.597, 0.653, 0.763, 0.686,
and 0.663, respectively. Cutoff values having a good ability to predict HIE for SII
and NLR were 410 and 1.12. Elevated NLR level above 1.12 was found to be an independent
predictor for HIE, as revealed by multivariate analyses. No associations were found
between systemic inflammatory indices and amplitude-integrated electroencephalography
(aEEG) patterns, presence of seizures, and death.
Conclusion Systemic inflammatory indices may represent reliable and readily available predictors
of HIE risk. NLR seems to be an independent factor in diagnosing moderate-to-severe
HIE.
Key Points
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Systemic inflammatory incides are readily calculated from the peripheral blood count.
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NLR is an independent and valuable factor in diagnosing moderate-to-severe hypoxic-ischemic
encephalopathy.
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Systemic inflammatory incides might be feasible for diagnosing hypoxic-ischemic encephalopathy.
Keywords
asphyxia - hypoxic ischemic encephalopathy - neutrophil-to-lymphocyte ratio - newborn
- systemic inflammatory indices
