Validation of serum C-reactive protein for the diagnosis and monitoring of antibiotic therapy in neonatal sepsis

Biomarkers of Neonatal Sepsis: Where We Are and Where We Are Going

Neonatal sepsis is a bacterial bloodstream infection leading to severe clinical manifestations frequently associated with death or irreversible long-term deficits. Antibiotics are the drug of choice to treat sepsis, regardless of age. In neonates, the lack of reliable criteria for a definite diagnosis and the supposition that an early antibiotic administration could reduce sepsis development in children at risk have led to a relevant antibiotic overuse for both prevention and therapy. The availability of biomarkers of neonatal sepsis that could alert the physician to an early diagnosis of neonatal sepsis could improve the short and long-term outcomes of true sepsis cases and reduce the indiscriminate and deleterious use of preventive antibiotics. The main aim of this narrative review is to summarize the main results in this regard and to detail the accuracy of currently used biomarkers for the early diagnosis of neonatal sepsis. Literature analysis showed that, despite intense research, the diagnosis of neonatal sepsis and the conduct of antibiotic therapy cannot be at present decided on the basis of a single biomarker. Given the importance of the problem and the need to reduce the abuse of antibiotics, further studies are urgently required. However, instead of looking for new biomarkers, it seems easier and more productive to test combinations of two or more of the presently available biomarkers. Moreover, studies based on omics technologies should be strongly boosted. However, while waiting for new information, the use of the clinical scores prepared by some scientific institutions could be suggested. Based on maternal risk factors and infant clinical indicators, sepsis risk can be calculated, and a significant reduction in antibiotic consumption can be obtained.

Plasma D-dimer level in early and late-onset neonatal sepsis

BACKGROUND

Neonatal sepsis is a life-threatening disease. Early diagnosis is essential, but no single marker of infection has been identified. Sepsis activates a coagulation cascade with simultaneous production of the D-dimers due to lysis of fibrin. D-dimer test reflects the activation of the coagulation system.

AIM

To assess the D-dimer plasma level, elaborating its clinicopathological value in neonates with early-onset and late-onset neonatal sepsis.

METHODS

The study was a prospective cross-sectional study that included ninety neonates; divided into three groups: Group I: Early-onset sepsis (EOS); Group II: Late-onset sepsis (LOS); and Group III: Control group. We diagnosed neonatal sepsis according to our protocol. C-reactive protein (CRP) and D-dimer assays were compared between EOS and LOS and correlated to the causative microbiological agents.

RESULTS

D-dimer was significantly higher in septic groups with a considerably higher number of cases with positive D-dimer. Neonates with LOS had substantially higher levels of D-dimer than EOS, with no significant differences in CRP. Neonates with LOS had a significantly longer hospitalization duration and higher gram-negative bacteriemia and mortality rates than EOS (P < 0.01). Gram-negative bacteria have the highest D-dimer levels (Acinetobacter, Klebsiella, and Pseudomonas) and CRP (Serratia, Klebsiella, and Pseudomonas); while gram-positive sepsis was associated with relatively lower levels. D-dimer had a significant negative correlation with hemoglobin level and platelet count; and a significant positive correlation with CRP, hospitalization duration, and mortality rates. The best-suggested cut-off point for D-dimer in neonatal sepsis was 0.75 mg/L, giving a sensitivity of 72.7% and specificity of 86.7%. The D-dimer assay has specificity and sensitivity comparable to CRP in the current study.

CONCLUSION

The current study revealed a significant diagnostic value for D-dimer in neonatal sepsis. D-dimer can be used as an adjunct to other sepsis markers to increase the sensitivity and specificity of diagnosing neonatal sepsis.

Penehyclidine Hydrochloride Alleviates Lipopolysaccharide-Induced Acute Lung Injury by Ameliorating Apoptosis and Endoplasmic Reticulum Stress

BACKGROUND

Penehyclidine hydrochloride (PHC), a novel anticholinergic reagent, has been shown to exert anti-endoplasmic reticulum stress (ERS), antioxidant, and antiinflammation functions in various rat models. However, the definite pathogenesis of lung defensive roles of PHC remains unclear. This study measured the functions of PHC on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in rats.

METHODS

In this research, the LPS-induced ALI model was assessed through the branchial injection of LPS for 24 h. Male Sprague-Dawley rats were randomly allocated into 5 groups: sham, LPS, LPS + PHC (0.5 mg/kg), LPS + PHC (1 mg/kg), and LPS + PHC (2.5 mg/kg). The concentrations of superoxide dismutase, malondialdehyde, myeloperoxidase, and glutathione peroxidase were measured by enzyme-linked immunosorbent assay and immunohistochemistry analysis. Western blotting, real-time PCR, and immunofluorescence analysis were used to determine the ERS-associated protein levels and mRNA expression. The protein levels of Bax, Bcl-2, caspase-3, and caspase-9 were used to measure lung tissue apoptosis.

RESULTS

The results revealed that PHC administration inhibited LPS-induced ALI as indicated by the loss in the ratio of injury production evaluated through hematoxylin-eosin staining, in particular the lung sample sections, compared with the LPS group. PHC administration inhibited LPS-induced lung myeloperoxidase and serum concentrations of malondialdehyde, superoxide dismutase, and glutathione peroxidase in rats. PHC administration repressed the LPS-activated ERS-correlated pathway and apoptosis-associated protein levels in rats.

CONCLUSIONS

In summary, our findings indicated that PHC has a defensive effect on LPS-induced ALI by inhibiting oxidative stress, attenuating PERK and ATF6 signals, and suppressing ERS-mediated apoptosis.

Use of melatonin as adjunctive therapy in neonatal sepsis: A systematic review and meta-analysis

BACKGROUND

Sepsis remains one of the major causes of neonatal mortality and morbidity. Increased production of free radicals and pro-inflammatory cytokines, combined with the innately low levels of plasma antioxidants in neonates, have been implicated in the pathogenesis and complications of neonatal sepsis. To date, few clinical trials on the beneficial effects of exogenous melatonin on improvement of clinical outcomes in septic neonates have been conducted.

METHODS

The electronic databases including PubMed, Embase, and Cochrane Central Register of Controlled Trials were systematically searched on July 2017 for clinical studies that reported the effects of melatonin as an adjuvant therapy in neonatal sepsis. Serum levels of C-reactive protein (CRP) as biomarker endpoint and recovery of sepsis as clinical endpoint were used to compare treatment responses between groups. The Risk of Bias Assessment tool for Non-Randomized Studies (RoBANS) and the Cochrane Collaboration Risk of Bias tool were used to assess the quality of included studies.

RESULTS

Three studies with a total of 120 participants were included in the systematic review and meta-analysis. Pooled analysis revealed statistically significant mean differences in CRP serum levels (mg/L) between groups at 24 h post-adjunctive therapy with melatonin (-1.739 mg/L; 95% CI: -3.205 to -0.273; P = 0.020). Additionally, adjunctive therapy with melatonin significantly improved clinical condition of sepsis in neonates from the intervention group, compared to the control group, within 3 days of therapy (RR: 2.212; 95% CI: 1.452 to 3.371; P < 0.0005).

CONCLUSIONS

Findings showed that administration of melatonin as adjunctive therapy significantly reduced an inflammatory biomarker and improved sepsis status in neonate. Larger scale studies with higher validity are needed to demonstrate clear clinical benefits of the therapy.