Protective HLA alleles against severe COVID-19: HLA-A*68 as an ancestral protection allele in Tapachula-Chiapas, Mexico.

HLA is a polymorphic antigen presenter which has provided valuable information on the susceptibility of populations to viruses. Therefore, the study of HLA can reveal specific susceptibility or resistance alleles to severe COVID-19 in an ethnically dependent manner. This pilot study investigated HLA alleles associated with COVID-19 severity in Tapachula, Chiapas, Mexico. A total of 146 Mexican Mestizos were typed for HLA class I and II using PCR-SSP. The patients were classified according to the outcome (death or improvement) and the infection's severity (mild or severe). In addition, a group of exposed uninfected individuals was included. HLA-A*68 was found to be a protective allele against the severe infection and fatal outcome; pC = 0.03, OR = 0.4, 95% CI =0.20-0.86, and pC =0.009, OR = 0.3, 95% CI =0.13-0.71 respectively. HLA-DRB1*03 also appears to be a protective factor against fatal outcome pC = 0.009, OR = 0.1, 95%IC = 0.01-0.66; however, the low frequency of this allele in the studied population limits the statistical power. The severity and fatal outcome of COVID-19 patients in Tapachula, Chiapas depend more on the lack of resistance than susceptibility HLA alleles.

Risk Factors and Outcomes for COVID-19 in Autoimmune Inflammatory Diseases during the SARS-CoV-2 Pandemic: A Comparative Study.

BACKGROUND: Patients with autoimmune disease (AID) and coronavirus disease 2019 (COVID-19) could have higher mortality due to the co-morbidity and the use of immunosuppressive therapy. OBJECTIVES: To analyze the risk factors and outcomes of patients with AID and COVID-19 versus a control group. METHODS: A prospective cohort study included patients with and without AID and COVID-19. Patients were paired by age and sex. Clinical, biochemical, immunological treatments, and outcomes (days of hospital stay, invasive mechanical ventilation [IMV], oxygen at discharge, and death) were collected. RESULTS: We included 226 COVID-19 patients: 113 with AID (51.15 ± 14.3 years) and 113 controls (53.45 ± 13.3 years). The most frequent AIDs were Rheumatoid arthritis (26.5%), systemic lupus erythematosus (21%), and systemic sclerosis (14%). AID patients had lower lactate dehydrogenas, C-reactive protein, fibrinogen, IMV (P = 0.027), and oxygen levels at discharge (P ≤ 0.0001) and lower death rates (P ≤ 0.0001). Oxygen saturation (SaO2) ≤ 88% at hospitalization provided risk for IMV (RR [relative risk] 3.83, 95% confidence interval [95%CI] 1.1-13.6, P = 0.038). Higher creatinine and LDH levels were associated with death in the AID group. SaO2 ≤ 88% and CO-RADS ≥ 4 were risk factors for in-hospital mortality (RR 4.90, 95%CI 1.8-13.0, P = 0.001 and RR 7.60, 95%CI 1.4-39.7, P = 0.016, respectively). Anticoagulant therapy was protective (RR 0.36, 95%CI 0.1-0.9, P = 0.041). CONCLUSIONS: Patients with AID had better outcomes with COVID-19 than controls. Anticoagulation was associated with a lower death in patients with AID.

Risk Prediction of Death in Inpatient Adults With COVID-19 from Mexico (preprint)

Background: There is substantial variation in COVID-19 lethality across countries. In addition, in countries with populations with extreme economic inequalities, such as Mexico, there are regional and local differences in risk factors for COVID-19 death. The goal of this study was to test the hypothesis that the risk of death in Mexican COVID-19 patients was associated with the time between symptom onset and hospitalization and/or with the healthcare site. Also, death prognostic models were developed. Methods The study included two COVID-19 inpatient cohorts, one prospective and one retrospective from Chiapas, Mexico. Demographic, clinical and laboratory variables were collected, and the diagnosis of SARS-CoV-2 infection was performed using RT-qPCR in samples collected seven days since symptom onset. The 30-day mortality, since symptom onset, was the outcome, and clinical variables at the first 48 hours of hospitalization were independent factors. Multivariate logistic regression analyses were conducted. Results Of the 392 patients included, 233 died (59.4%). The time between symptom onset and hospitalization, the healthcare site and sex were not related to the 30-day mortality. Three death prognostic models were developed (AUC between 0.726 and 0.807). Age, LDH, AST, and lymphocyte count were included in all models, OSI-WHO Classification (Non-invasive ventilation or high-flow oxygen, and mechanical ventilation with or without organ support/ECMO) and leukocyte count in two models, and diabetes and diarrhea in one model. Conclusion The population evaluated had underlying deteriorated health before COVID-19 compared with regional and country population. The factors that determine the COVID-19 mortality risk in a relatively healthy population are sex, age and comorbidities. However, as this study shows, when populations have underlying poor health, some of these factors lose their associations with mortality risk, and others become more important.