A narrative review of exploring potential salivary biomarkers in respiratory diseases: still on its way

State of the art: Alternative overlap syndrome-asthma and obstructive sleep apnea

In the general population, Bronchial Asthma (BA) and Obstructive Sleep Apnea (OSA) are among the most prevalent chronic respiratory disorders. Significant epidemiologic connections and complex pathogenetic pathways link these disorders via complex interactions at genetic, epigenetic, and environmental levels. The coexistence of BA and OSA in an individual likely represents a distinct syndrome, that is, a collection of clinical manifestations attributable to several mechanisms and pathobiological signatures. To avoid terminological confusion, this association has been named alternative overlap syndrome (vs overlap syndrome represented by the chronic obstructive pulmonary disease-OSA association). This comprehensive review summarizes the complex, often bidirectional links between the constituents of the alternative overlap syndrome. Cross-sectional, population, or clinic-based studies are unlikely to elucidate causality or directionality in these relationships. Even longitudinal epidemiological evaluations in BA cohorts developing over time OSA, or OSA cohorts developing BA during follow-up cannot exclude time factors or causal influence of other known or unknown mediators. As such, a lot of pathophysiological interactions described here have suggestive evidence, biological plausibility, potential or actual directionality. By showcasing existing evidence and current knowledge gaps, the hope is that deliberate, focused, and collaborative efforts in the near-future will be geared toward opportunities to shine light on the unknowns and accelerate discovery in this field of health, clinical care, education, research, and scholarly endeavors.

Salivary C-reactive protein and mean platelet volume as possible diagnostic markers for late-onset neonatal pneumonia

BACKGROUND

Neonatal sepsis, a formidable threat to newborns, is a leading cause of neonatal mortality, with late-onset sepsis manifesting after 72 hours post-birth being particularly concerning. Pneumonia, a prevalent sepsis presentation, poses a significant risk, especially during the neonatal phase when lung defenses are compromised. Accurate diagnosis of pneumonia is imperative for timely and effective interventions. Saliva, a minimally invasive diagnostic medium, holds great promise for evaluating infections, especially in infants.

AIM

To investigate the potential of serum C-reactive protein (CRP), salivary CRP (sCRP), and mean platelet volume (MPV) as diagnostic markers for late-onset neonatal pneumonia (LONP).

METHODS

Eighty full-term neonates were systematically examined, considering anthropometric measurements, clinical manifestations, radiology findings, and essential biomarkers, including serum CRP, sCRP, and MPV.

RESULTS

The study reveals noteworthy distinctions in serum CRP levels, MPV, and the serum CRP/MPV ratio between neonates with LONP and healthy controls. MPV exhibited a robust discriminatory ability [area under the curve (AUC) = 0.87] with high sensitivity and specificity at a cutoff value of > 8.8. Correlations between serum CRP, sCRP, and MPV were also identified. Notably, sCRP demonstrated excellent predictive value for serum CRP levels (AUC = 0.89), underscoring its potential as a diagnostic tool.

CONCLUSION

This study underscores the diagnostic promise of salivary and serum biomarkers, specifically MPV and CRP, in identifying and predicting LONP among neonates. These findings advocate for further research to validate their clinical utility in larger neonatal cohorts.

Salivary C-reactive protein and mean platelet volume as possible diagnostic markers for late-onset neonatal pneumonia

BACKGROUND

Neonatal sepsis, a formidable threat to newborns, is a leading cause of neonatal mortality, with late-onset sepsis manifesting after 72 hours post-birth being particularly concerning. Pneumonia, a prevalent sepsis presentation, poses a significant risk, especially during the neonatal phase when lung defenses are compromised. Accurate diagnosis of pneumonia is imperative for timely and effective interventions. Saliva, a minimally invasive diagnostic medium, holds great promise for evaluating infections, especially in infants.

AIM

To investigate the potential of serum C-reactive protein (CRP), salivary CRP (sCRP), and mean platelet volume (MPV) as diagnostic markers for late-onset neonatal pneumonia (LONP).

METHODS

Eighty full-term neonates were systematically examined, considering anthropometric measurements, clinical manifestations, radiology findings, and essential biomarkers, including serum CRP, sCRP, and MPV.

RESULTS

The study reveals noteworthy distinctions in serum CRP levels, MPV, and the serum CRP/MPV ratio between neonates with LONP and healthy controls. MPV exhibited a robust discriminatory ability [area under the curve (AUC) = 0.87] with high sensitivity and specificity at a cutoff value of > 8.8. Correlations between serum CRP, sCRP, and MPV were also identified. Notably, sCRP demonstrated excellent predictive value for serum CRP levels (AUC = 0.89), underscoring its potential as a diagnostic tool.

CONCLUSION

This study underscores the diagnostic promise of salivary and serum biomarkers, specifically MPV and CRP, in identifying and predicting LONP among neonates. These findings advocate for further research to validate their clinical utility in larger neonatal cohorts.

Engineering a Point-of-Care Paper-Microfluidic Electrochemical Device Applied to the Multiplexed Quantitative Detection of Biomarkers in Sputum

Health initiatives worldwide demand affordable point-of-care devices to aid in the reduction of morbidity and mortality rates of high-incidence infectious and noncommunicable diseases. However, the production of robust and reliable easy-to-use diagnostic platforms showing the ability to quantitatively measure several biomarkers in physiological fluids and that could in turn be decentralized to reach any relevant environment remains a challenge. Here, we show the particular combination of paper-microfluidic technology, electrochemical transduction, and magnetic nanoparticle-based immunoassay approaches to produce a unique, compact, and easily deployable multiplex device to simultaneously measure interleukin-8, tumor necrosis factor-α, and myeloperoxidase biomarkers in sputum, developed with the aim of facilitating the timely detection of acute exacerbations of chronic obstructive pulmonary disease. The device incorporates an on-chip electrochemical cell array and a multichannel paper component, engineered to be easily aligned into a polymeric cartridge and exchanged if necessary. Calibration curves at clinically relevant biomarker concentration ranges are produced in buffer and artificial sputum. The analysis of sputum samples of healthy individuals and acutely exacerbated patients produces statistically significant biomarker concentration differences between the two studied groups. The device can be mass-produced at a low cost, being an easily adaptable platform for measuring other disease-related target biomarkers.

Characteristics of salivary microbiota in children with obstructive sleep apnea: A prospective study with polysomnography

Objectives

The present study aimed to investigate the characteristics of salivary microbiota of children with obstructive sleep apnea (OSA) and to assess longitudinal alterations in salivary microbiota before and after adenotonsillectomy.

Methods

A set of cross-sectional samples consisted of 36 OSA children (17 boys and 19 girls, 7.47 ± 2.24 years old) and 22 controls (9 boys and 13 girls, 7.55 ± 2.48 years old) were included in the study, among which eight OSA children (five boys and three girls, 8.8 ± 2.0 years old) who underwent treatment of adenotonsillectomy were followed up after 1 year. Saliva samples were collected, and microbial profiles were analyzed by bioinformatics analysis based on 16S rRNA sequencing.

Results

In cross-sectional samples, the OSA group had higher α-diversity as estimated by Chao1, Shannon, Simpson, Pielou_e, and observed species as compared with the control group (p < 0.05). β-Diversity based on the Bray–Curtis dissimilarities (p = 0.004) and Jaccard distances (p = 0.001) revealed a significant separation between the OSA group and control group. Nested cross-validated random forest classifier identified the 10 most important genera (Lactobacillus, Escherichia, Bifidobacterium, Capnocytophaga, Bacteroidetes_[G-7], Parvimonas, Bacteroides, Klebsiella, Lautropia, and Prevotella) that could differentiate OSA children from controls with an area under the curve (AUC) of 0.94. Linear discriminant analysis effect size (LEfSe) analysis revealed a significantly higher abundance of genera such as Prevotella (p = 0.027), Actinomyces (p = 0.015), Bifidobacterium (p < 0.001), Escherichia (p < 0.001), and Lactobacillus (p < 0.001) in the OSA group, among which Prevotella was further corroborated in longitudinal samples. Prevotella sp_HMT_396 was found to be significantly enriched in the OSA group (p = 0.02) with significantly higher levels as OSA severity increased (p = 0.014), and it had a lower abundance in the post-treatment group (p = 0.003) with a decline in each OSA child 1 year after adenotonsillectomy.

Conclusions

A significantly higher microbial diversity and a significant difference in microbial composition and abundance were identified in salivary microbiota of OSA children compared with controls. Meanwhile, some characteristic genera (Prevotella, Actinomyces, Lactobacillus, Escherichia, and Bifidobacterium) were found in OSA children, among which the relationship between Prevotella spp. and OSA is worth further studies.

Current Insights on the Impact of Proteomics in Respiratory Allergies

Respiratory allergies affect humans worldwide, causing extensive morbidity and mortality. They include allergic rhinitis (AR), asthma, pollen food allergy syndrome (PFAS), aspirin-exacerbated respiratory disease (AERD), and nasal polyps (NPs). The study of respiratory allergic diseases requires new technologies for early and accurate diagnosis and treatment. Omics technologies provide the tools required to investigate DNA, RNA, proteins, and other molecular determinants. These technologies include genomics, transcriptomics, proteomics, and metabolomics. However, proteomics is one of the main approaches to studying allergic disorders' pathophysiology. Proteins are used to indicate normal biological processes, pathogenic processes, or pharmacologic responses to a therapeutic intervention. In this field, the principal goal of proteomics has been to discover new proteins and use them in precision medicine. Multiple technologies have been applied to proteomics, but that most used for identifying, quantifying, and profiling proteins is mass spectrometry (MS). Over the last few years, proteomics has enabled the establishment of several proteins for diagnosing and treating respiratory allergic diseases.