Salivary IgA as a Surrogate Biomarker for Microbial Infections in Postoperative Patients Receiving Chemo-Radio-Therapy for Head and Neck Cancer

Objective Radiotherapy (RT) and chemotherapy (CT) are important treatment options in patients with head and neck cancers. A common complication of this is microbial colonization or infection of mucosal surfaces. These infections may commonly be due to bacteria or yeasts. Salivary proteins with their buffering activity and immunoglobulin, especially immunoglobulin A (IgA), protect oral tissue, mucosal surfaces, and teeth from various microorganisms. This study characterizes the common microorganisms encountered and evaluates the role of salivary IgA in predicting microbial infections in this group of patients with mucositis.

Methods A total of 150 adult head and neck cancer patients on CTRT were evaluated at baseline and at the end of 3 and 6 weeks, respectively. Oral swabs collected from buccal mucosa were processed in the microbiology laboratory for the presence of microorganisms. Saliva was processed for IgA level estimation on Siemens Dimension Automated biochemistry analyzer.

Results Pseudomonas aeruginosa and Klebsiella pneumoniae were the most common organisms found in our patients, followed by Escherichia coli and group A beta-hemolytic Streptococci. A significant increase (p = 0.0203) in the incidence of bacterial infection was observed in post-CTRT patients (61%) compared to pre-CTRT patients (49.33%). There was significant increase in levels of salivary IgA (p = 0.003) in patients with bacterial and fungal infection (n = 135/267) when compared to those in samples showing no growth (n = 66/183).

Conclusion A significant increase in the incidence of bacterial infection in post-CTRT patients was observed in this study. This study also indicated that postoperative head and neck cancer patients with oral mucositis that developed an infection were associated with high salivary IgA levels, and it may serve as a surrogate biomarker of infection in these patients.

The role of cortisol in the association of canine-companionship with blood pressure, glucose, and lipids: a systematic review

INTRODUCTION

The dog is known as man's best friend and canine-companionship is associated with positive effects on cardiovascular health.

AIM

We aim to review the role of cortisol in the association of canine-companionship with human blood pressure, glucose and lipid profile.

METHODS

Electronic databases, and reference lists of the selected articles were searched for original articles in English which evaluate the role of cortisol in the association of canine-companionship with human blood pressure, glucose and lipid profile. Appropriate tools from the National Institute of Health were used for the quality assessment.

RESULTS

Of the 2108 articles included for screening, 6 studies fulfilled the selection criteria. The USA had produced the highest number of studies (50%, 3/6). Pre-post studies (83%, 5/6) were the predominant type, and the overall quality of the selected studies was acceptable. The majority of studies showed a significant reduction of cortisol with dog companionship or therapy (67%, 4/6) along with a significant reduction of heart rate (2/4), systolic blood pressure (1/4), mean arterial blood pressure (1/4), or total cholesterol level (1/4). The role of cortisol in the association of canine-companionship with human blood pressure, glucose and lipid profile was scarcely studied with no studies from lower-middle-income countries, where the disease burden is on the rise.

CONCLUSION

A significant reduction of few cardiovascular risk factors was found along with a significant reduction of cortisol in canine companionship in few studies. Future comparative or higher-level studies are essential on the association between canine companionship, cortisol and cardiovascular risk factors, especially in lower-middle-income countries.