ABSTRACT
In addition to the classical functions of the musculoskeletal system and calcium homeostasis, the function of vitamin D as an immune modulator is well established. The vitamin D receptors and enzymes that metabolize vitamin D are ubiquitously expressed in most cells in the body, including T and B lymphocytes, antigen-presenting cells, monocytes, macrophages and natural killer cells that trigger immune and antimicrobial responses. Many in vitro and in vivo studies revealed that vitamin D promotes tolerogenic immunological action and immune modulation. Vitamin D adequacy positively influences the expression and release of antimicrobial peptides, such as cathelicidin, defensin, and anti-inflammatory cytokines, and reduces the expression of proinflammatory cytokines. Evidence suggestss that vitamin D's protective immunogenic actions reduce the risk, complications, and death from COVID-19. On the contrary, vitamin D deficiency worsened the clinical outcomes of viral respiratory diseases and the COVID-19-related cytokine storm, acute respiratory distress syndrome, and death. The study revealed the need for more preclinical studies and focused on well-designed clinical trials with adequate sizes to understand the role of vitamin D on the pathophysiology of immune disorders and mechanisms of subduing microbial infections, including COVID-19.Copyright © 2023 Bentham Science Publishers.
ABSTRACT
Objective: To determine the diagnostic value of rapid COVID-19 antigen test (Panbio, Abbott) in comparison with Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) in suspected community cases of SARS-CoV-2 infection at a tertiary care center in Pakistan Study Design: Cross sectional study. Place and Duration of Study: Pathology Department, Combined Military Hospital, Lahore Pakistan, from Jun 2020 to Jun 2021. Methodology: The diagnostic value of the Panbio®COVID-19 Antigen Rapid Test (Panbio, Abbott), was determined in comparison with RT-PCR in suspected community cases of SARS-CoV-2 infection at a tertiary care center on samples taken simultaneously. 200 individuals reporting to the hospital with signs and symptoms of potential COVID infection or history of significant contact exposure (>1 hour without masking and social distancing) to a RT-PCR positive COVID patient and concurrently requiring a rapid COVID antigen test due to an underlying health condition were included in the study by consecutive sampling. Results: Out of 200 individuals, 53(26.5 %) were COVID positive by RT–PCR whereas 147(73.5%) were clearly negative with no cases of indeterminate viremia on RT PCR. 32(60.3%) out of 53 RT-PCR positive COVID cases were also found to be positive by COVID-19 Antigen Rapid Test, whereas 21(39.6%) were negative. Out of 147 RT-PCR negative COVID cases, 146(99.3%) were negative by COVID-19 Antigen Rapid Test as well whereas 1(0.68%) was positive. Conclusion: COVID-19 Antigen Rapid Test is suitable adjunct to RT-PCR testing in suspected cases in emergent settings in early days of admission. © 2022, Army Medical College. All rights reserved.