In a recent case-control study published in scientific report, Researchers have identified single nucleotide polymorphisms (SNPs) in the vitamin D receptor (VDR) gene between patients with mild coronavirus infection (COVID-19) and patients with severe coronavirus infection (COVID-19). compared.
They found that the TT genotype of SNP rs11568820 was significantly less frequent in hospitalized COVID-19 patients, suggesting a protective role against severe disease and hospitalization.
study: Comparison of vitamin D receptor gene polymorphisms of rs11568820, rs7970314, and rs4334089 between patients with novel coronavirus infection with mild and severe symptoms: a case-control study. Image credit: Billion Photos/Shutterstock.com
background
The clinical spectrum of COVID-19 ranges from mild symptoms to severe pneumonia or death. Serum vitamin D levels may not influence susceptibility to COVID-19 infection, but deficiency is more common in severe cases. Vitamin D produced in the lungs modulates the immune response and may influence the severity of COVID-19 infection.
VDR gene polymorphisms that affect VDR function are associated with immune responses. In patients with COVID-19, different VDR polymorphisms are correlated with different symptoms such as shortness of breath, kidney disease, and hypertension. Genetic variations in the vitamin D pathway influence susceptibility to respiratory infections.
Understanding these genetic factors could help inform treatment strategies, identify at-risk individuals, and future research to manage COVID-19 infection.
Therefore, researchers in this study aimed to assess and contrast VDR polymorphisms in patients with mild and severe COVID-19 infection.
About research
The study enrolled participants from the five-year Isfahan Coronavirus Cohort (ICC) study. A total of 176 patients with COVID-19 were included, including 85 hospitalized patients (mean age 59.04 years, 37% male) and 91 non-hospitalized patients (mean age 47.77 years, 44% male). .
Eligible patients aged 19 years and older with positive RT-PCR (abbreviation for reverse transcription polymerase chain reaction) results were selected using convenience sampling from state health center datasets.
Admission criteria were based on the World Health Organization (WHO) definition of moderate or severe cases, but patients who were not hospitalized included asymptomatic patients.
Written informed consent was obtained from all participants, and the National Institute for Medical Research and Development (NIMAD) approved the study protocol in Tehran, Iran.
Data collection was conducted by health center interviewers trained in questionnaire administration and measurement procedures. Demographic, socio-economic, and lifestyle data were collected.
Patient medical history was collected, including non-communicable diseases such as cardiovascular disease, hypertension, diabetes, chronic respiratory disease, chronic kidney disease, and medication history.
Blood samples were collected to isolate deoxyribonucleic acid (DNA). Next, he assessed the quality of the DNA using Nanodrop and agarose gel, followed by genotyping of the VDR polymorphism using Amplification Refractory Mutation System (ARMS) PCR and Sanger sequencing. Ta.
Statistical analysis using chi-square test, Fisher’s exact test, and Student’s test t– tests, Mann-Whitney test, Bonferroni correction, odds ratio (OR), and logistic regression.
Results and discussion
The mean age and waist circumference were higher in the hospitalized group compared with the non-hospitalized group, but physical activity was lower. Furthermore, the hospitalized group had a lower proportion of smokers but higher proportions of hypertension and diabetes compared to the non-hospitalized group.
Among the SNPs studied, the TT genotype of rs11568820 was found to be significantly rarer in the hospitalized group (3.5%) compared to the non-hospitalized group (17.6%; P = 0.018).
Statistical significance was also observed in the recessive model (P = 0.003). However, no significant differences were found in the genotype or allele frequency of SNPs rs7970314 and rs4334089 between the two groups.
Furthermore, the rs11568820 SNP genotype showed a significant inverse association with hospitalization due to COVID-19 even after adjusting for comorbidities such as coronary heart disease, current smoking, and BMI. Specifically, this genotype was associated with an 82% reduced risk of hospitalization (OR 0.18).
Conversely, no significant association was observed between the genotypes of SNPs rs7970314 and rs4334089 and COVID-19 hospitalization. In particular, the recessive model for rs11568820 showed a significant association with hospitalization (OR 0.14), whereas other SNPs showed no significant association.
Although the main strength of this study lies in the investigation of VDR SNP distribution across different severities of coronavirus disease (COVID-19), this perspective mainly focused on serum vitamin D levels and susceptibility. It has not been considered much in previous research.
However, this study is limited by its descriptive nature, which prevents the establishment of a causal relationship between VDR polymorphisms and the severity of COVID-19 infection.
Additionally, the lack of measured serum vitamin D levels and data on immunological factors limits comprehensive interpretation of the findings. This requires larger and more detailed studies targeting diverse patient subgroups.
conclusion
In conclusion, this study identified the TT genotype of rs11568820 as a protective factor against severe COVID-19. Nevertheless, larger studies considering various confounding factors are needed to confirm these findings.
In the future, understanding genetic predispositions could enhance personalized treatment approaches to COVID-19.
