Worldwide distribution of genetic factors related to severity of COVID-19 infection.

BACKGROUND: Genome-wide association studies of COVID-19 severity have been carried out mostly on European or East Asian populations with small representation of other world regions. Here we explore the worldwide distribution and linkage disequilibrium (LD) patterns of genetic variants previously associated with COVID-19 severity. METHODS: We followed up the results of a large Spanish genome-wide meta-analysis on 26 populations from the 1000 Genomes Project by calculating allele frequencies and LD scores of the nine most significant SNPs. We also used the entire set of summary statistics to compute polygenic risk scores (PRSs) and carried out comparisons at the population and continental level. RESULTS: We observed the strongest differences among continental regions for the five top SNPs in chromosome 3. European, American, and South Asian populations showed similar LD patterns. Average PRSs in South Asian and American populations were consistently higher than those observed in Europeans. While PRS distributions were similar among South Asians, the American populations showed striking differences among them. CONCLUSIONS: Considering the caveats of PRS transferability across ethnicities, our analysis showed that American populations present the highest genetic risk score, hence potentially higher propensity, for COVID-19 severity. Independent validation is warranted with additional summary statistics and phenotype data.

Device-associated multidrug-resistant bacteria surveillance in critically ill children: 10 years of experience.

AIM: Multidrug-resistant bacterial infections are a public health problem worldwide. However, most of the information available refers to adults. The main objectives were to determine the incidence, risk factors, and outcomes for device-associated infections, especially those involving multidrug-resistant bacteria. METHODS: This is a prospective, observational study. Children aged ≥1 month and <18 years admitted to the paediatric intensive care unit from 2008 to 2017, with a device-associated infection microbiologically confirmed were included. Patients infected with resistant bacteria were compared with those who had a drug-susceptible infection. RESULTS: The study included 213 patients. Out of all the device-associated infections, 22% (48 patients) were caused by multidrug-resistant bacteria. The most frequent were extended-spectrum beta-lactamase (ESBL)-producing enterobacteria. Cardiovascular diseases, age under 1year, comorbidity, prolonged use of invasive device, and length of stay until infection were risk factors for resistant bacteria, but not specifically for ESBL-producing bacteria. Length of stay and mortality was increased in patients with multidrug-resistant bacteria. CONCLUSION: Being under 1-year-old and having a cardiovascular disease were the two major risk factors for resistant bacterial infection. ESBL-producing bacteria were the most frequent multidrug-resistant agents. However, patients with ESBL-producing bacteria did not have any additional risk factors, so they may have been colonised in the community.

Sex differences in children with severe health conditions: Causes of admission and mortality in a Pediatric Intensive Care Unit.

OBJECTIVES: Based on the existing sex differences in mortality rates in children, we would like to explore whether girls and boys respond differently under severe health conditions, in terms of mortality and cause of admission. METHODS: We analyzed demographic characteristics (age and sex), causes of admission, clinical parameters, and mortality in a sample of 2,609 patients from a Pediatric Intensive Care Unit (PICU) in a children's hospital in Barcelona, Spain. RESULTS: PICU admittance was significantly higher in boys (57.5% vs. 42.5%) whereas PICU mortality was significantly higher in girls (4.9% vs. 3.3%). Female sex was a risk factor for PICU in-hospital mortality (OR = 1.55, P = 0.033), while increasing age had a protective effect (OR = 0.808, P = 0.021). In cases of PICU mortality, girls died from a broader range of causes and boys were more affected by respiratory and polytraumatic injuries. Boys were affected by polytraumatic injuries throughout the year, less frequently in winter, while girls showed a higher occurrence in holiday months. CONCLUSIONS: Although more boys were admitted to the PICU, a significantly higher number of girls died. Younger age and higher occurrence of nosocomial infection among girls could explain this finding. More frequent polytraumatic injuries in boys could reflect an increased exposure to risky activities and/or more careless behavior.

Usefulness of autosomal STR polymorphisms beyond forensic purposes: data on Arabic- and Berber-speaking populations from central Morocco.

BACKGROUND: This work describes, for the first time, the profile of Middle Atlas Berbers and Arabic-speaking central Moroccans for 15 autosomal STR loci widely used in forensic sciences. AIM: The main objectives were to determine the degree of heterogeneity among different Moroccan samples to identify geographic or linguistic patterns and to evaluate the usefulness of forensic STRs in anthropological studies. SUBJECTS AND METHODS: Blood samples were collected from 71 Arabic-speakers and 75 Berbers from the regions of Doukkala (central-west coast) and Khenifra (Middle Atlas), respectively. The AmpFlSTR Identifier kit was used to genotype 15 autosomal STR in both samples. RESULTS: Middle Atlas Berbers showed slightly higher genetic variation values compared to Arabic-speakers, both in the number of alleles and heterozygosity. In order to assess population relationships, data from Morocco, Algeria, Tunisia, Libya, Egypt, Kuwait, Qatar, Palestine, Syria, South-Spain and Turkey were included in the analysis. Within Morocco, genetic distances followed a clear geographic pattern. In the Arabic-speaking sample the genetic proportion of 'Arabian' admixture was estimated in 13%. CONCLUSION: The low value of admixture suggests that the Arabization of Morocco had a reduced demographic impact, which should be taken with caution because it is based on autosomal STRs with low inter-population variation levels.

Prognostic value of biomarkers after cardiopulmonary bypass in pediatrics: The prospective PANCAP study.

OBJECTIVE: To assess the usefulness of procalcitonin, pro-adrenomedullin and pro-atrial natriuretic peptide as predictors of need for mechanical ventilation and postoperative complications (need for inotropic support and bacterial infection) in critically ill pediatric patients after cardiopulmonary bypass. DESIGN: A prospective, observational study. SETTING: Pediatric intensive care unit. PATIENTS: Patients under 18 years old admitted after cardiopulmonary bypass. MEASURAMENTS AND MAIN RESULTS: Serum levels of procalcitonin, pro-adrenomedullin and pro-atrial natriuretic peptide were determined immediately after bypass and at 24-36 hours. Their values were correlated with the need for mechanical ventilation, inotropic support and bacterial infection. One hundred eleven patients were recruited. Septal defects (30.6%) and cardiac valve disease (17.1%) were the most frequent pathologies. 40.7% required mechanical ventilation, 94.6% inotropic support and 15.3% presented invasive bacterial infections. Pro-adrenomedullin and pro-atrial natriuretic peptide showed significant high values in patients needing mechanical ventilation. Cut-off values higher than 1.22 nmol/L and 215.3 pmol/L, respectively for each biomarker, may indicate need for mechanical ventilation with an AUC of 0.721 and 0.746 at admission and 0.738 and 0.753 at 24-36 hours, respectively but without statistical differences. Pro-adrenomedullin and procalcitonin showed statistically significant high values in patients with bacterial infections. CONCLUSIONS: After bypass, pro-adrenomedullin and pro-atrial natriuretic peptide are suitable biomarkers to predict the need for mechanical ventilation. Physicians should be alert if the values of these markers are high so as not to progress to early extubation. Procalcitonin is useful for predicting bacterial infection. This is a preliminary study and more clinical studies should be done to confirm the value of pro-adrenomedullin and pro-atrial natriuretic peptide as biomarkers after cardiopulmonary bypass.

An unexpected world population variation of MCT1 polymorphism 1470T > A involved in lactate transport.

A common missense mutation (1470T > A) in gene SLC16A1 responsible for an amino acid substitution in protein MCT1 has been associated with differential lactate transport and hence, differences in physical performance and muscle injuries in relation to physical exercise. This study describes, for the first time, the worldwide variation of MCT1 variant 1470T > A at an intra- and inter-continental level. Two thousand five hundred and four individual genotypes of 26 populations clustered in 5 population groups have been analysed with data downloaded from the public database 1000 Genomes Phase 3 Browser. Several parameters of population differentiation and structure have been explored as well as selection signatures in the whole gene. Allele T, the common variant, shows extremely high values in Sub-Saharan African groups (frequencies 86-91%) as compared with the remaining world regions (69-49%). TT genotype also predominates in African groups, showing significant differences with the rest of world populations. In view of the evidence that the TT genotype is associated with clinical implications and a better predisposition to sprint/power performances, we suggest that the high presence of the TT genotype in African populations should be taken into account in future association studies at both medical and sports fields.

Cytochrome and sulfotransferase gene variation in north African populations.

AIM: To describe the diversity of four cytochrome and four sulfotransferase polymorphisms in six north African samples. Scarce data have been compiled for these samples despite the rich genetic background of north African populations. MATERIALS & METHODS: CYP3A4*1B, CYP3A4*17, CYP3A4*3, CYP3A5*3, SULT1A1*2, SULT1A2*2, SULT1A2*3 and SULT1E1*2 polymorphisms were explored in 556 individuals from Morocco, Algeria, Tunisia and Libya. RESULTS: Allele frequencies in our samples largely exceeded the variation ranges described for European populations, especially for CYP3A4*1B, SULT1A1*2 and SULT1A2*3. CONCLUSION: North African populations are heterogeneous, genetically diverse and show a considerable sub-Saharan African contribution for markers associated with increased risk of prostate cancer and with differential drug metabolism.