Reduced susceptibility to COVID-19 associated with ABO blood group and pre-existing anti-A and anti-B antibodies.

BACKGROUND: Susceptibility to severe acute respiratory syndrome coronavirus 2 shows individual variability in un-vaccinated and previously un-exposed individuals. We investigated the impact of ABO blood group, titers of anti-A and anti-B, other blood group antigens, and the extracellular deposition of ABH antigens as controlled by secretor fucosyltransferase 2 (FUT2) status. STUDY DESIGN AND METHODS: We studied incidents in three different hospitals between April to September 2020, where un-diagnosed coronavirus disease 2019 (COVID-19) patients were cared for by health care workers without use of personal protection and with close contact while delivering therapy. We recruited 108 exposed staff, of whom 34 were diagnosed with COVID-19. ABO blood type, titer of anti-A and -B, blood group specific alleles, and secretor status were determined. RESULTS: Blood group O was associated with lower risk of COVID-19 (OR 0.39, 95 %CI (0.16-0.92), p = 0.03) compared to non-O, i.e., blood groups A, B and AB. High titer anti-A immunoglobulin G (IgG) compared to low titer was associated with lower risk of COVID-19 (OR 0.24 95 %CI (0.07-0.78), p = 0.017). High titer of anti-B immunoglobulin M (IgM) compared to no anti-B (IgM) was associated with lower risk of COVID-19 (OR 0.16, 95 %CI (0.039-0.608), p = 0.006) and the same applies to low titer anti-B (IgM) compared to no titer (OR 0.23, 95 %CI (0.07-0.72), p = 0.012). The 33Pro variant in Integrin beta-3, that is part of human platelet antigen 1b (HPA-1b), was associated with lower risk of COVID-19 (OR 0.23, 95 %CI (0.034-0.86), p = 0.028). CONCLUSION: Our data showed that blood group O, anti-A (IgG) titer, anti-B (IgM) titer as well as HPA-1b are associated with lower risk for COVID-19.

Infections in out-of-hospital and in-hospital post-cardiac arrest patients.

This study aims to describe infectious complications in both out-of-hospital cardiac arrest (OHCA) and in-hospital cardiac arrest (IHCA) patients with sustained return of spontaneous circulation (ROSC) and to compare differences in antimicrobial treatment and outcomes between the two groups. This was a retrospective, single-center, observational study. Adult patients (≥ 18 years) with OHCA or IHCA who had sustained ROSC between December 2007 to March 2015 were included. Blood, urine, sputum, and other fluid cultures, as well as radiologic imaging, were obtained at the discretion of the treating clinical teams. 275 IHCA and 318 OHCA patients were included in the analysis. We found evidence of infection in 181 IHCA and 168 OHCA patients. Significant differences were found between the IHCA and OHCA group in terms of initial rhythm, duration of arrest (10 min vs. 20, p = < 0.001), targeted temperature management (30% vs. 73%, p = < 0.001), and post-arrest infection rates (66% vs 53%, p = 0.001). 95% of IHCA and 82% of OHCA patients received antimicrobial treatment in the post-cardiac arrest period. The source of infection in both groups was largely respiratory, followed by urinary. Gram-positive cocci and gram-negative rods were the most common organisms identified among subjects with culture-proven bacteremia. Infections in the post-arrest period were common in both OHCA and IHCA. We found significantly more infections in IHCA compared to OHCA patients. The most common infection category was respiratory and the most common organism isolated from sputum cultures was Staphylococcus aureus coagulase-positive. The incidence of culture-positive bacteremia was similar in both OHCA and IHCA cohorts but overall lower than previously reported.

The role of computed tomography in the screening of patients presenting with symptoms of an intracranial tumour.

BACKGROUND: To improve the quality of care for brain cancer patients, the Danish Ministry of Health has set standards for the diagnosis and treatment. When a patient is suspected of having a malignant tumour involving the brain, it is required that a magnetic resonance imaging of the cerebrum (MRI-C) be obtained within seven calendar days of referral from a primary care provider. This standard has the potential to consume MR imaging time that might otherwise be used for evaluation or treatment monitoring of other patients. This study primarily aims to assess the sensitivity of computed tomography of the brain (CT-C) for the detection of intracranial tumour as the initial diagnostic imaging. METHODS: This is a single-center retrospective study of patients referred to the IBCP with brain cancer suspicion. The average follow-up was 37 months. All included patients underwent a CT-C scan and subsequently a MRI-C if deemed necessary. The study population was divided into two groups based on the findings: tumour versus non-tumour. Sensitivity and specificity of the CT-C was calculated. RESULTS: Eight hundred seventeen patients were included. Median age was 55 years and 50% were male. CT-C had a sensitivity of 98.5% and a specificity of 98.4%. The overall mortality rate was 7% in the non-tumour group and 58% in the tumour group over the course of the study period. The tumour group was on average older compared to the non-tumour group (65 years [55-75 years] vs 52 years [38-65 years]) p < .001). The only symptom associated with brain tumour was the presence of a focal deficit (p = .002). CONCLUSION: This study shows that CT-C scans are highly sensitive and specific and can be used as the primary screening tool for patients referred with a suspicion for brain cancer.