Cytotoxic T-lymphocyte associated protein 4 (CTLA4) polymorphisms are linked to systemic lupus erythematosus: an updated meta-analysis.

Cytotoxic T-lymphocyte associated protein 4 (CTLA-4) molecule controls T cell immune response. Functional single nucleotide polymorphisms (SNPs) in the CTLA-4 gene have been associated with several autoimmune diseases, including systemic lupus erythematosus (SLE).  However, the genetic association of the CTLA-4 variants with vulnerability to SLE remained contradictory. We have conducted a current meta-analysis by combining the findings of prior published articles in order to make a conclusive statement. Various literature databases were screened with appropriate keywords to obtain relevant articles, and eligible reports were obtained using well-defined inclusion and exclusion criteria. Meta-analysis was performed by Comprehensive Meta-analysis V 3.3, and various statistical parameters such as odds ratio, 95% confidence interval, and probability values were computed. A total of 3847 SLE patients and 5278 healthy controls were considered in the present meta-analysis from 26 individual reports. A significant association of CTLA-4 +49 A/G (G vs. A: p=0.03, OR=1.47) and -1722 T/C (p=0.02, OR=0.87) polymorphisms were observed with susceptibility and resistance against the development of SLE, respectively. However, the other two SNPs in the CTLA-4 gene (-318 C/T and -1661 A/G) failed to establish a connection. Interestingly, subgroup analysis revealed an association of CTLA-4 +49 A/G with a predisposition to SLE only in the Asian population (G vs. A: p=0.04, OR=1.26, GG vs. AA: p=0.02, OR=1.84, AG vs AA: p=0.01, OR=1.44, GG+AG vs AA: p=0.01, OR=1.52) and not in Caucasians. The current meta-analysis suggests a significant CTLA-4 +49 A/G variant association with susceptibility to SLE development in overall and Asian populations. In contrast, the other variant, -1722 T/C, is linked with protection against SLE. However, further case-control studies in diverse ethnic populations are requisite.

Lower levels of vitamin D are associated with SARS-CoV-2 infection and mortality in the Indian population: An observational study.

BACKGROUND: The role of vitamin D in the susceptibility and severity of various viral diseases has been well documented. Recently, some reports highlighted the possible importance of vitamin D in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Although India receives adequate sunlight throughout the year, the majority of Indians are deficient in vitamin D levels. In the present study, we hypothesized that vitamin D deficiency would be associated with the SARS-CoV-2 infection rate and mortality in the Indian population. MATERIALS AND METHODS: SARS-CoV-2 infection and mortality data were obtained from the Government of India's official website (accessed on 16th August 2020). Various literature databases like PubMed and Google Scholar were searched to find the mean of 25-hydroxyvitamin D [25(OH)D] levels in different states and union territories of India, Pearson correlation was carried out to investigate the possible link between mean 25(OH)D levels and SARS-CoV-2 infection and mortality per million of the population. RESULTS: An inverse correlation was observed between the mean level of 25(OH)D and SARS-CoV-2 infection rate (r = -0.43, p = 0.02) and mortality rate (r = -0.42, p = 0.02). CONCLUSIONS: The present observational study revealed an association of vitamin D with SARS-CoV-2 infection and related mortality. Further studies are required to validate our observations.

ABO blood group system is associated with COVID-19 mortality: An epidemiological investigation in the Indian population.

BACKGROUND: Novel coronavirus disease-19 (COVID-19) has spread worldwide, and to date presence of the virus has been recorded in 215 countries contributing 0.43 million of death. The role of blood groups in susceptibility/resistance to various infectious diseases has been reported. However, the association of blood groups with susceptibility to COVID-19 infections or related death are limited. In the present report, we performed an epidemiological investigation in the Indian population to decipher the importance of blood groups concerning susceptibility or mortality in COVID-19 infection. MATERIALS AND METHODS: Data on COVID-19 infection and mortality was obtained from the website of the Government of India. Prevalence of ABO blood groups in different states and union territories of India were searched using different databases such as PubMed and Google Scholar. Relevant articles were downloaded, and data were extracted. Spearman's rank coefficient analysis was employed to study the correlation between blood group frequencies and COVID-19 infection or mortality rate. RESULTS: A significant inverse correlation was observed between the frequency of O blood group and the COVID-19 mortality rate (Spearman r=-0.36, P=0.03), indicating a possible protective role of O blood group against COVID-19 related death. In contrast, the prevalence of blood group B was positively correlated with COVID-19 death/million (Spearman r=0.67, P<0.0001), suggesting B blood type as a deleterious factor in COVID-19 infection. CONCLUSIONS: ABO blood group system is associated with poor prognosis of COVID-19 infection. Blood group O may protects, and subjects with blood type B could be susceptible to COVID-19 mortality. However, further studies on COVID-19 infected patients in different population are required to validate our findings.