Diagnostic Reliability of Salivary C-Reactive Protein as an Alternative Noninvasive Biomarker of Neonatal Sepsis

The diagnostic value of salivary C-reactive protein in neonatal infections: a meta-analysis

PURPOSE

C-reactive protein (CRP), as an acute phase protein, is a sensitive indicator of neonatal bacterial infection. Some recent studies have shown that there is a correlation between CRP levels in serum and saliva, and using saliva to detect CRP levels is expected to be an ideal and non-invasive method to predict neonatal infection. The purpose of this Meta-analysis was to evaluate the diagnostic value of salivary CRP for neonatal infection.

METHODS

We searched PubMed, Embase, Web of Science, and Scopus databases in October 2023 and included observational studies that examined salivary CRP in newborns with bacterial infections. Data was extracted regarding the methodology, participant characteristics, and outcome measures.

RESULTS

Nine articles were included, with a total of 696 newborns. Salivary CRP levels are significantly higher in neonates with infections compared to non-infected group (SMD = 0.58, 95%CI [0.40-0.76], P < 0.001). The accuracy for salivary CRP to predict serum CRP abnormality is high (sensitivity 86%, specificity 88%, area under the curve = 0.94).

CONCLUSIONS

Our meta-analysis suggested that salivary CRP can be used as an alternative biomarker to serum CRP for detecting neonatal infection.

Inflammatory marker levels in children with tobacco smoke exposure

BACKGROUND

Tobacco smoke exposure (TSE) has inflammatory and immunosuppressive effects which may be associated with altered levels of inflammatory markers and pediatric illnesses.

OBJECTIVE

The primary objective was to examine the associations of cotinine-confirmed and parent-reported child TSE patterns and discharge diagnoses with C-reactive protein (CRP), IL-8, and IL-10 in 0-11-year-old pediatric emergency department (PED) patients who lived with ≥ 1 smoker.

METHODS

Saliva samples were obtained from 115 children with a mean (SD) age of 3.5 (3.1) years during the PED visit (T0). Saliva was analyzed for cotinine, CRP, IL-8, and IL-10. Parents self-reported their children's TSE patterns; children's medical records were reviewed to identify and categorize discharge diagnoses. Linear regression models were utilized to find T0 associations of cotinine-confirmed and parent-reported child TSE patterns, and PED diagnoses with each inflammatory marker. All models were adjusted for child race/ethnicity, child sex, annual household income, and housing type. The TSE models also adjusted for child discharge diagnosis.

RESULTS

At T0, the geometric mean (GeoM) of cotinine was 4.1 ng/ml [95 %CI = 3.2-5.2]; the GeoMs of CRP, IL-8, and IL-10 were 3,326 pg/ml [95 %CI = 2,696-4,105], 474 pg/ml [95 %CI = 386-583], and 1.1 pg/ml [95 %CI = 0.9-1.3], respectively. Parent-reported child TSE patterns were positively associated with ln-transformed CRP levels, while adjusting for the covariates (β^ = 0.012 [95 %CI:0.004-0.020], p = 0.037). In the parent-reported child TSE pattern model, there were significant positive associations between the covariate of child age with CRP and IL-8 levels (p = 0.028 and p < 0.001, respectively). Children with a bacterial diagnosis had higher IL-8 levels (p = 0.002) compared to the other diagnosis groups.

CONCLUSIONS

Results indicate that parent-reported child TSE increases the expression of CRP in ill children and supports prior work demonstrating that IL-8 is higher in children with TSE who have bacterial infections. These findings should be examined in future research with ill children with and without TSE.

Advancement in biomarker based effective diagnosis of neonatal sepsis

Neonatal sepsis is considered as alarming medical emergency and becomes the common global reason of neonatal mortality. Non-specific symptoms and limitations of conventional diagnostic methods for neonatal sepsis mandate fast and reliable method to diagnose disease for point of care application. Recently, disease specific biomarkers have gained interest for rapid diagnosis that led to the development of electrochemical biosensor with enhanced specificity, sensitivity, cost-effectiveness and user-friendliness. Other than conventional biomarker C-reactive protein to diagnose neonatal sepsis, several potential biomarkers including Procalcitonin (PCT), Serum amyloid A (SAA) and other candidates are extensively investigated. The present review provides insights on advancements and diagnostic abilities of protein and nucleotide based biomarkers with their incorporation in developing electrochemical biosensors by employing novel fabrication strategies. This review provides an overview of most promising biomarker and its capability for neonatal sepsis diagnosis to fulfil future demand to develop electrochemical biosensor for point-of-care applications.

Salivary Biomarkers to Differentiate between Streptococcus pneumoniae and Influenza A Virus-Related Pneumonia in Children

Community-acquired pneumonia (CAP) is common among children and can be fatal in certain conditions. In children, CAP can be caused by viral or bacterial infections. Identification of pathogens can help select appropriate therapeutic strategies. Salivary analysis may be a potential diagnostic tool because it is noninvasive, patient-friendly, and easy to perform in children. A prospective study was conducted in children with pneumonia admitted to a hospital. Salivary samples from patients with definite Streptococcus pneumoniae and influenza A strains were used for gel-free (isobaric tag for relative and absolute quantitation (iTRAQ)) proteomics. No statistically significant difference was detected in salivary CRP levels between Streptococcus pneumoniae and influenza A pneumonia in children. Several potential salivary biomarkers were identified using gel-free iTRAQ proteomics to differentiate pneumonia from Streptococcus pneumoniae or influenza A virus infections in pediatric patients. ELISA validated that Streptococcus pneumoniae group has a higher abundance of salivary alpha 1-antichymotrypsin than those in the influenza A group. Whether these salivary biomarkers can be used to distinguish other bacteria from viral pneumonia requires further verification.

The Role of Salivary C-Reactive Protein in Diagnosis of Neonatal Sepsis

Background

Neonatal sepsis remains one of the leading causes of morbidity and mortality among neonates.

Objective

to evaluate the role of salivary C-reactive protein (CRP) as a diagnostic marker in neonatal sepsis.

Methods

This case-control study was carried out on 90 neonates including 45 neonates with symptoms and signs suggestive of neonatal sepsis and 45 healthy neonates as controls. All neonates were subjected to full history taking, thorough clinical examination, laboratory investigations including complete blood count (CBC), serum CRP, blood culture, and salivary CRP.

Results

Septic neonates showed significantly higher salivary CRP compared to controls; it was significantly associated with positive serum CRP, blood culture, and hematological scoring system (HSS). It was significantly higher in neonates who died compared to those who survived. Twenty one cases with positive salivary CRP showed significant positive correlations with the length of the neonatal intensive care unit stay, total white blood cell (WBC) count, mean platelet volume (MPV), neutrophils to lymphocytes ratio (NLR), serum CRP, HSS, significant negative correlations with gestational age, birth weight, APGAR at 1, 5 min, and platelet count. Receiver operating characteristic (ROC) curve for salivary CRP showed that at cut-off value of 0.135 mg/L, the sensitivity was (81.8%) and the specificity was (75.6%) for detecting neonatal sepsis.

Conclusion

Salivary CRP was significantly higher in the septic group, and was associated with positive serum CRP. Hence, salivary CRP could be considered a novel non-invasive biomarker for diagnosing neonatal sepsis.

Examining the Utility of Rapid Salivary C-Reactive Protein as a Predictor for Neonatal Sepsis: An Analytical Cross-Sectional Pilot Study

This study aimed to compare the rapid bedside quantitative assessment of C-reactive protein (CRP) in saliva to serum CRP to predict blood culture-positive sepsis in neonates. The research was carried out over eight months at Fernandez Hospital in India (February 2021-September 2021). The study included 74 randomly selected neonates with clinical symptoms or risk factors of neonatal sepsis requiring blood culture evaluation. SpotSense rapid CRP test was conducted to estimate salivary CRP. In analysis, the area under the curve (AUC) on the receiver operating characteristics (ROC) curve was used. The study population's mean gestational age and median birth weight were 34.1 weeks (SD: ±4.8) and 2370 g (IQR: 1067-3182). The AUC on ROC curve analysis for predicting culture-positive sepsis was 0.72 (95% CI: 0.58 to 0.86, p-value: 0.002) for serum CRP and 0.83 (95% CI: 0.70 to 0.97, p-value: <0.0001) for salivary CRP. The Pearson correlation coefficient between salivary and serum CRP was moderate (r = 0.352, p-value: 0.002). Salivary CRP cut-off scores were comparable to serum CRP in terms of sensitivity, specificity, PPV, NPV, and accuracy in predicting culture-positive sepsis. The rapid bedside assessment of salivary CRP appears to be an easy and promising non-invasive tool in culture-positive sepsis prediction.

Hydrogen Sulfide and Substance P Levels in Patients with Escherichia coli and Klebsiella pneumoniae Bacteraemia

Hydrogen sulfide (H2S) and substance P (SP) are known from animal models and in vitro studies as proinflammatory mediators. In this study, peripheral blood concentrations of H2S and SP were measured in patients with Escherichia coli or Klebsiella pneumoniae bacteraemia. Fifty patients were recruited from general wards at Christchurch Hospital, during 2020–2021. Samples from age- and sex-matched healthy subjects previously recruited as controls for studies of cardiovascular disease were used as controls. The concentrations of H2S were higher than controls on day 0, day 1, and day 2, and SP was higher than controls on all 4 days. The concentrations of H2S were highest on day 0, whereas SP concentrations were higher on day 2 than other days. Interleukin-6 and C-reactive protein were significantly higher on day 0 and day 1, respectively. The concentrations of H2S and SP did not differ between 15 non-septic (SIRS 0-1) and the 35 septic subjects (SIRS ≥ 2). Substance P concentrations were higher in subjects with abdominal infection than urinary tract infections on day 0 (p = 0.0002) and day 1 (p = 0.0091). In conclusion, the peak H2S concentrations precede the SP peak in patients with Gram-negative bacteraemia, but this response varies with the site of infection.

Salivary C-Reactive Protein and Mean Platelet Volume in the Diagnosis and Follow-Up of Community-Acquired Pneumonia in Infants

Background: Community-acquired pneumonia (CAP) in infants is a major cause of morbidity and mortality, especially in developing countries. Increased salivary C-reactive protein (CRP) levels have been demonstrated in neonatal pneumonia and other diseases. We investigated the applicability of CRP and mean platelet volume (MPV) in the diagnosis and follow-up of CAP in infants. Methods: This prospective observational study included 45 infants admitted for CAP. We measured serum and salivary CRP levels via ELISA, while MPV was measured using an automated blood cell counter. Results: Both salivary and serum CRP values were significantly different in the studied population between admission and follow-up (P = 0.001 and P < 0.0001, respectively). The same was observed for MPV (P < 0.0001). We found significant positive correlations between serum and salivary CRP (r = 0.652, P < 0.0001) and between serum CRP and MPV (r = 0.495, P = 0.001), as well as between salivary CRP and MPV (r = 0.439, P = 0.003). Receiver operating curve analysis showed that salivary CRP at a cutoff value of 3.2 ng/L had a sensitivity of 97.2% and specificity of 90%, while MPV at a cutoff value of 8.4 fL showed 91% sensitivity and 90% specificity. Conclusions: The present study showed that both salivary CRP and MPV are reliable diagnostic markers of CAP in infants.

Salivary Interleukin-6 and C-Reactive Protein/Mean Platelet Volume Ratio in the Diagnosis of Late-Onset Neonatal Pneumonia

Neonatal pneumonia is a serious respiratory infectious disease with a high rate of case fatality in developing countries. Salivary cytokines could serve as interesting noninvasive markers in the diagnosis of neonatal pneumonia. The aim was to assess the diagnostic role of salivary and serum interleukin-6 (IL-6), C-reactive protein/mean platelet volume (CRP/MPV) ratio, and the combination of these markers in the diagnosis of late-onset neonatal pneumonia in full-term neonates. Seventy full-term neonates, 35 with late-onset neonatal pneumonia and 35 controls, were enrolled in this prospective case-control study. Complete blood count (CBC), salivary and serum IL-6, and CRP concentrations were measured for all the study subjects. The sensitivity, specificity, positive predictive value, and negative predictive value of salivary IL-6, serum IL-6, and CRP/MPV ratio for the diagnosis of late-onset neonatal pneumonia were determined. At the cutoff point of >34 pg/ml, salivary IL-6 showed 82.86% sensitivity and 91.43% specificity. CRP/MPV ratio showed a sensitivity of 97.14% and specificity of 85.71% at a cutoff value > 0.88. The combination of salivary IL-6 and CRP/MPV ratio improved the sensitivity and specificity to 100%. The current study shows for the first time that both salivary IL-6 and CRP/MPV ratio are suitable markers for the diagnosis of late-onset neonatal pneumonia in full-term neonates.

Salivary and Serum Interleukin-10, C-Reactive Protein, Mean Platelet Volume, and CRP/MPV Ratio in the Diagnosis of Late-Onset Neonatal Sepsis in Full-Term Neonates

Salivary markers could serve as potential noninvasive markers in the diagnosis of neonatal infections. We aimed to investigate the diagnostic role of salivary and serum interleukin 10 (IL-10), C-reactive protein (CRP), mean platelet volume (MPV), and CRP/MPV ratio in the diagnosis of late-onset neonatal sepsis in full-term neonates. Seventy full-term neonates were enrolled in this prospective case-control study, 35 with late-onset neonatal sepsis, and 35 controls. Salivary IL-10, serum IL-10, and CRP concentrations were measured by enzyme-linked immunosorbent assay (ELISA). Complete blood (CBC) count was measured by an automated blood cell counter. The salivary IL-10, serum IL-10, CRP, MPV, and CRP/MPV ratio levels were much higher in neonates with late-onset sepsis than in control (220 ± 150 vs. 18 ± 9 pg/ml, P < 0.001), (316 ± 198 vs. 23.7 ± 14 pg/ml, P < 0.001), (78.2 ± 34 vs. 3.3 ± 1.7 mg/L, P < 0.001), (11.2 ± 0.9 vs. 8.6 ± 0.4 fL), and (7.08 ± 3.3 vs. 0.4 ± 0.2, P < 0.001), respectively. At the cutoff point of >31 pg/ml, salivary IL-10 showed 97.1% sensitivity and 94.3% specificity. Serum IL-10 at a cutoff value of ≥33.6 pg/ml had a sensitivity of 97.1% and specificity of 80%. MPV showed a sensitivity of 100% and specificity of 94.4% at a cutoff value ≥ 9.2 fL. CRP/MPV ratio showed a sensitivity of 100% and specificity of 97.1% at a cutoff value > 0.9. Salivary and serum IL-10 showed a positive correlation with CRP and CRP/MPV ratio in septic neonates. The current study shows for the first time that both salivary IL-10 and CRP/MPV showed statistically significant differences between neonates with late-onset sepsis and controls. Accordingly, salivary IL-10 could serve as a potential noninvasive biomarker for the diagnosis of late-onset sepsis in full-term neonates.