ABSTRACT
There is a growing trend in using saliva for SARS-CoV-2 detection with reasonable accuracy. We have studied the responses of IgA, IgG, and IgM in human saliva by directly comparing disease with control analyzing two-trace two-dimensional correlation spectra (2T2D-COS) employing Fourier transform infrared (FTIR) spectra. The findings show the decrease of IgG and IgM salivary antibodies in the 50, 60, 65, and 75-years samples. Among the various COVID-19 populations studied, the female 30 years group reveal defence mechanisms exhibited by IgM and IgA. Lipids and fatty acids decrease, resulting in lipid oxidation due to the SARS-CoV-2 in the samples studied. Study shows salivary thiocyanate plays defence against SARS-CoV-2 in male population in 25 and 35 age groups. The receiver operation characteristics statistical method shows a sensitivity of 98% and specificity 94% for the samples studied. The measure of accuracy computed as F1 score and G score has a high value which supports the validation of our study. The 2T2D-COS analysis has the potential to monitor the progression of immunoglobulin’s response function of COVID-19 with good accuracy, which could help in diagnosing clinical trials.
Subject(s)
COVID-19ABSTRACT
Various immunopathological events characterize the SARS-CoV-2 infection. Nevertheless, it has been reported that T cell response against SARS-CoV-2 is predominated by CD4+ T cells, which could be related to the compromised long-lasting protection. Furthermore, different vaccines have been developed to prevent coronavirus disease 2019 (COVID-19). Therefore, this research aimed to analyze and compare Fourier transform infrared (FTIR) spectra of vaccinated people with a positive (V-COVID-19 group) or negative (V-Healthy group) qPCR test, evaluating the long-lasting immune and T-cell responses through FTIR spectroscopy. Most individuals that integrated the V-Healthy group (88.1%) were asymptomatic; contrary, only 28% of the V-COVID-19 were asymptomatic. Likewise, 68% of the V-COVID-19 group had at least one coexisting illness. About the immunological and T-cell responses analyzed through FTIR spectroscopy, the V-COVID-19 group showed a greater content of IgG and IgA as well as the analyzed cytokines (IFN-γ, TNF-α, IL-1 β, IL-6, and IL-10). Therefore, it was possible to evaluate in saliva the long-lasting immune and T-cell responses through FTIR spectroscopy, showing a statistical significance between the groups. Moreover, we corroborated that the protective role of vaccination is not only by antibodies; the vaccine-induced T cells might contribute to vaccine efficacy against viral variants.
Subject(s)
COVID-19ABSTRACT
The coronavirus disease 2019 (COVID-19) is the latest biological hazard for the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Numerous diagnostic tests for SARS-CoV-2 have been used, which are expensive and require specialized personal. So, new diagnosis strategies are being developed, looking for less expensive methods which could be used as screening for better spread control. Many researchers have described the use of saliva as a potential indicator of COVID-19, and even the same patient could carry out its collection. In this sense, this study aimed to establish specific salivary vibrational modes analyzed by attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy to detect COVID-19 biological fingerprints that allow the discrimination between COVID-19 and healthy patients. Previous written informed consent, clinical dates, laboratories, and saliva samples of COVID-19 patients (n = 255) and healthy persons (n = 1209) were obtained and analyzed through ATR-FTIR spectroscopy. Then, a multivariate linear regression model (MLRM) was developed. The COVID-19 patients showed low SaO2, cough, dyspnea, headache, and fever principally. Obesity was the main comorbidity. Various laboratory blood tests were altered. In the FTIR spectra analysis, changes in amide I and immunoglobulin regions were evidenced, and the MLRM showed clear discrimination between both groups. Specific salivary vibrational modes employing ATR-FTIR spectroscopy were established; moreover, the COVID-19 biological fingerprint in saliva was characterized, allowing the detection for COVID-19 using an MLRM, once it helps to reduce the number of variables, which could be helpful in the future development of diagnostic devices in a faster and cheaper way.