Neonatal heavy metals levels are associated with the severity of neonatal respiratory distress syndrome: a case–control study

Maternal prenatal systemic inflammation indexes predicts premature neonatal respiratory distress syndrome

Neonatal respiratory distress syndrome (NRDS) is one of the leading causes of neonatal mortality in low-income countries. It is caused by a lack of surface-active substances in the lungs, and the maternal inflammatory response plays an important role in the formation of surface-active substances in the fetal lungs. We aimed to investigate the correlation between maternal prenatal systemic inflammatory indices and respiratory distress syndrome in preterm neonates. This is a retrospective case-control study that collected data from all patients who delivered between 28 and 36 weeks of gestation at Longhua District People's Hospital in Shenzhen City and whose infants were admitted to the neonatal unit, newborns with respiratory distress syndrome were in the experimental group (NRDS group), and newborns without NRDS were in the control group (non-NRDS group). To minimize the effect of confounders on the results, propensity score matching was performed on baseline characteristics. Totally, 524 patients were included (93 in the NRDS group and 431 in the non-NRDS group), and 71 matched pairs (142 patients). The neutrophil-to-lymphocyte ratio (NLR), derived neutrophil-to-lymphocyte ratio (dNLR), systemic immune-inflammation index (SII), systemic inflammation response index (SIRI), aggregate index of systemic inflammation (AISI) and neutrophil lymphocyte to platelet ratio (NLPR) were higher in the NRDS group than in the non-NRDS group (p < 0.05). The ROC curves of NLR, dNLR, SII, SIRI, AISI and NLPR for the diagnosis of NRDS were plotted, and it was found that the combined diagnostic efficacy of these six systemic inflammatory markers was better (AUC: 0.643, P = 0.003). Patients were divided into two groups based on the cut-off values determined from the ROC curves, and analysis using binary regression models revealed that SII ≥ 1199.94 (OR, 2.554; 95% CI 1.245-5.239, P = 0.011) and NLPR ≥ 0.0239 (OR, 2.175; 95% CI 1.061-4.459, P = 0.034) were independent risk factors predicting NRDS. Maternal prenatal SII ≥ 1199.94 and NLPR ≥ 0.0239 are independent risk factors for NRDS, and clinicians may be used to prevent neonatal respiratory distress in advance to reduce the incidence of NRDS.

Heavy metal levels are positively associated with serum periostin and miRNA-125b levels, but inversely associated with miRNA-26a levels in pediatric asthma cases. A case-control study

BACKGROUND

The study investigated heavy metals levels [urinary cadmium (U-Cd), erythrocytic cadmium (E-Cd), urinary arsenic (U-As), and whole blood lead (WB-Pb)] in children with bronchial asthma (BA) and tested their associations with serum periostin, miRNA-125b and miRNA-26a levels, and with asthma severity clinically and laboratory [blood eosinophils count (BEC) and serum total immunoglobin E (IgE)]. Also, we tested cut-off points, for the studied parameters, to distinguish BA cases from healthy children.

METHODS

This case-control study included 158 children divided into control group; n = 72 and BA group; n = 86. Heavy metals were measured by an inductively coupled plasma-optical emission spectrophotometer. Serum periostin and IgE levels were measured by their corresponding ELISA kits. miRNAs relative expressions were estimated by RT-qPCR using the 2-ΔΔCT method.

RESULTS

Heavy metals, serum periostin, and miR-125b levels were significantly high in BA group (p < 0.001). Heavy metals levels correlated positively with serum periostin, miR-125b and IgE levels, BEC, and asthma severity. The reverse was observed regarding serum miR-26a levels. Receiver operating characteristics (ROC) curve analysis showed good to excellent abilities of U-Cd, E-Cd, U-As, WB-Pb, serum periostin, miRNA-125b, and miRNA - 26a, and total IgE levels to distinguish BA cases from healthy children.

CONCLUSIONS

Heavy metal toxicity in children is associated with BA severity, increased serum periostin and miRNA-125b levels, and decreased miRNA-26a levels. Specific measures to reduce children's exposure to heavy metals should be taken. Future research should consider blocking miRNA-125b action or enhancing miRNA-26a action to manage BA cases.