Interleukin-37 gene polymorphism and susceptibility to coronavirus disease 19 among Iraqi patients.

Coronavirus disease 19 (COVID-19) is a highly contagious respiratory viral infection. Dysregulated immune response is an important feature of disease, and cytokines are among the most important mediators of dysregulated immunity. Interleukin-37 (IL-37) is one such cytokine and studies have indicated its role in pathogenesis of COVID-19. However, IL37 gene polymorphisms have not been identified in patients with COVID-19. Therefore, this case-control study (100 patients and 100 controls) was performed to understand the role six single nucleotide polymorphisms of IL37 gene (SNPs: rs3811042, rs3811043, rs2466449, rs3811045, rs3811046 and rs3811047) in susceptibility to COVID-19 among cases with severe disease. These polymorphisms were identified by Sanger DNA sequencing. Results revealed that TG genotype of rs3811046 showed a significantly increased frequency in patients compared to controls (61.0 vs. 38.0%; odds ratio [OR] = 2.55; 95% confidence interval [CI] = 1.45-4.50; probability [p] = 0.002; corrected p [pc] = 0.01). GA genotype of rs3811047 also showed an increased frequency in patients but the pc-value was not significant (39.0 vs. 24.0%; OR = 2.02; 95% CI = 1.10-3.71; p = 0.033; pc = 0.165). Haplotype analysis revealed a significantly increased frequency of the haplotype G-C-A-T-T-A (in the order: rs3811042, rs3811043, rs2466449, rs3811045, rs3811046 and rs3811047) in COVID-19 patients compared to controls (0.055 vs. 0.006; OR = 10.23; 95% CI = 1.53-68.14; p = 0.003; pc = 0.03). In conclusion, the study indicated that two variants of IL37 gene (rs3811046 and rs3811047) may be associated with susceptibility to COVID-19 among Iraqi population.

Interleukin-37 is down-regulated in serum of patients with severe coronavirus disease 2019 (COVID-19).

Pro-inflammatory and anti-inflammatory cytokines are indicated to play a prominent role in mediating the immunopathogenesis of coronavirus disease 19 (COVID-19). Interleukin (IL-37) is one of the anti-inflammatory cytokines that has been proposed to be involved in disease progression but the data are not overwhelming. Therefore, a case-control study was performed to analyze IL-37 levels in serum of 100 patients with severe COVID-19 and 100 blood donors (control group). Median age was significantly higher in COVID-19 cases than in controls. Stratification by gender, body mass index and ABO and Rh blood group systems showed no significant differences between patients and controls. Chronic diseases (cardiovascular and diabetes) were observed in 57.0% of patients. Serum levels of IL-37 and vitamin D were significantly decreased in patients compared to controls. The low level of IL-37 was more pronounced in males, overweight/obese cases, blood group B or AB cases, Rh-positive cases, and cases with no chronic disease. Low producers of IL-37 were more likely to develop COVID-19 (odds ratio = 2.66; 95% confidence interval = 1.51-4.70; corrected probability = 0.015). Receiver operating characteristic curve analysis demonstrated that a low serum level of IL-37 was a good predictor of COVID-19. Spearman's rank correlation analysis showed that IL-37 and vitamin D were significantly correlated. In conclusion, IL-37 was down-regulated in serum of patients with severe COVID-19 compared to controls. This down-regulation may be associated with an increased risk of disease. Gender, body mass index, blood groups and chronic disease status may also affect IL-37 levels.

Coronavirus disease 19 and risk of hyperglycemia among Iraqi patients.

A cross-sectional observational study was conducted on 213 patients with COVID-19 who did not have a clinical history of diabetes at hospital admission. One week after hospitalization, they were stratified by random blood glucose levels. It was found that 25.4, 22.5 and 52.1% of COVID-19 patients were classified as normoglycemia, prediabetes and diabetes, respectively. The study indicated that diabetes may be a risk factor for COVID-19 or the disease may be associated with an increased risk of developing diabetes.