Reference intervals of biochemical parameters in Chilean adults

Background

Establishing reference intervals (RIs) in clinical laboratories is essential, as these can vary due to inter-individual variability as well as the analytical methods used. The purpose of this study was to determine RIs for markers and ratios biochemical in apparently healthy Chilean adults.

Methods

A sample of 1,143 data was selected from the Universidad Católica de Temuco, Clinical Laboratory database, La Araucanía Region, Chile, which were analysed by sex. The Tukey's Fences was used to detect outliers and the RIs were established using the non-parametric method.

MicroRNAs as Potential Biomarkers of Environmental Exposure to Polycyclic Aromatic Hydrocarbons and Their Link with Inflammation and Lung Cancer

Exposure to atmospheric air pollution containing volatile organic compounds such as polycyclic aromatic hydrocarbons (PAHs) has been shown to be a risk factor in the induction of lung inflammation and the initiation and progression of lung cancer. MicroRNAs (miRNAs) are small single-stranded non-coding RNA molecules of ~20-22 nucleotides that regulate different physiological processes, and their altered expression is implicated in various pathophysiological conditions. Recent studies have shown that the regulation of gene expression of miRNAs can be affected in diseases associated with outdoor air pollution, meaning they could also be useful as biomarkers of exposure to environmental pollution. In this article, we review the published evidence on miRNAs in relation to exposure to PAH pollution and discuss the possible mechanisms that may link these compounds with the expression of miRNAs.

Obesity Is Associated with Changes in Laboratory Biomarkers in Chilean Patients Hospitalized with COVID-19

BACKGROUND AND AIMS

It is reported that patients with obesity are more frequently hospitalized for COVID-19, and evidence exists that obesity is a risk factor, regardless of other comorbidities. The objective of this study was to evaluate the association of obesity with changes in laboratory biomarkers in hospitalized Chilean patients.

MATERIALS AND METHODS

A total of 202 hospitalized patients (71 with obesity and 131 without obesity) with a diagnosis of COVID-19 were included in the study. Demographic, clinical, and laboratory (days 1, 3, 7, 15) data were obtained. We performed a statistical analysis, assuming significance with a value of p < 0.05.

RESULTS

Significant differences in chronic respiratory pathology are observed between patients with and without obesity. The inflammatory markers CPR, ferritin, NLR, and PLR are elevated during the evaluated period, while changes in leukocyte populations are present on day 1 (eosinophils) and day 3 (lymphocytes). Finally, a persistent elevation of D-dimer level is observed, presenting significant differences on day 7 between patients with and without obesity. Obesity had a positive correlation with admission to the critical patient unit, invasive mechanical ventilation, and length of hospital stay.

CONCLUSION

Patients with obesity hospitalized for COVID-19 present marked elevations of inflammatory and hemostasis parameters, with a correlation between obesity, changes in laboratory biomarkers, and the risk of adverse clinical outcomes also observed.

[Knowledge and HIV/AIDS risk behaviors of Chilean adolescents attending urban and rural schools. Is it necessary to focus the prevention strategies according to territorial relevance?]

BACKGROUND

HIV infection has sustained increased in the Chilean young population. In order to focus on sexual education in adolescents, it is first necessary to establish the degree of knowledge and risk behaviors in this group. Therefore, this study aimed to compare the degree of knowledge and HIV/AIDS risk behaviors in adolescents from rural and urban schools.

MATERIAL AND METHODS

The study included 385 adolescents between 14 and 18 years old. Through an anonymous survey, sociodemographic data, knowledge about HIV/ AIDS, risk behaviors, and ways of accessing information were collected.

RESULTS

A third of the adolescents surveyed (33.6%) reported having initiated sexual activity, primarily men. Rural students showed lower knowledge of HIV/AIDS. 32.2% of individuals who initiated sexual activity reported nonuse or rarely use of condoms, and only 4.4% of students have had an HIV detection/diagnostic test. Although the students had received information mainly from their teachers, they reported that if they needed help, they would go to health centers, youth programs, and, to a lesser extent, to teachers. They also preferred access to information in workshops, on the Internet, and social networks.

CONCLUSIONS

We observed regular knowledge of HIV/AIDS among adolescents. Rural students showed less knowledge and several risk behaviors. These findings emphasize the need to establish sexual education strategies in adolescents, considering the territory and the use of new technologies.

Obesity as a Risk Factor for Severe COVID-19 in Hospitalized Patients: Epidemiology and Potential Mechanisms

SARS-CoV-2 infection is a global public health problem, causing significant morbidity and mortality. Evidence shows that obesity is a recognized risk factor for hospitalization, admission to critical care units, and the development of serious complications from COVID-19. This review analyzes the available epidemiological evidence that relates obesity to a higher risk of severity and mortality from COVID-19, examining the possible pathophysiological mechanisms that explain this phenomenon on a cellular and molecular level.

Role of biochemical markers in the monitoring of COVID-19 patients

COVID-19 is an infectious disease caused by the SARSCoV-2 virus, which has given rise to a global sanitary emergency. The clinical characteristics of COVID-19 are varied and can range from an asymptomatic infection to a mild to severe pneumonia. Recent studies have shown that different laboratory parameters become altered in these patients, and as such are useful as biomarkers to assess the progression of the disease and categorize patients that may present a severe and/or fatal clinical condition. This review analyzes biochemical and immunological markers that become altered in COVID-19 patients and their impact on different organs at a hepatic, cardiac, renal and pancreatic level, as well as markers of inflammation, analyzing their implications in the evolution of the disease.

Workflow optimization in a clinical laboratory using Lean management principles in the pre-analytical phase

Background

The application of the Lean methodology in clinical laboratories can improve workflow and user satisfaction through the efficient delivery of analytical results. The purpose of this study was to optimise delivery times of the test results at a clinical laboratory, using Lean management principles in the pre-analytical phase.

Methods

A prospective study with a quasi-experimental design was implemented. Staff functions were restructured and sample flows were modified. Delivery times of clinical results (glucose and haematocrit; 6648 data) from the Medicine and Adult Emergency services for years 2017 and 2018 were compared.

Results

A reduction (p < 0.05) in turnaround times in the delivery of glucose test results at the adult emergency service was observed (84 to 73 min, 13%, pre and post). In addition, there was a non-significant reduction in the turnaround times for glucose (Medicine) and haematocrit in both services. In the analytical and post-analytical phase (not intervened), an increase in turnaround times was observed in some cases.

Conclusions

Other studies have indicated that the application of the Lean methodology in clinical laboratories improves workflow, increasing effectiveness and efficiency. This study showed an improvement in the delivery time of test results (glucose - Emergency), giving rise to a culture of cooperation and continuous improvement. It would, however, be essential to address the management model integrating the analytical and post-analytical phases.

Circulating MicroRNAs as Biomarkers in Biliary Tract Cancers

Biliary tract cancers (BTCs) are a group of highly aggressive malignant tumors with a poor prognosis. The current diagnosis is based mainly on imaging and intraoperative exploration due to brush cytology havinga low sensitivity and the standard markers, such as carcinoembryonic antigen (CEA) and carbohydrate 19-9 (CA19-9), not having enough sensitivity nor specificity to be used in a differential diagnosis and early stage detection. Thus, better non-invasive methods that can distinguish between normal and pathological tissue are needed. MicroRNAs (miRNAs) are small, single-stranded non-coding RNA molecules of ~20–22 nucleotides that regulate relevant physiological mechanisms and can also be involved in carcinogenesis. Recent studies have demonstrated that miRNAs are detectable in multiple body fluids, showing great stability, either free or trapped in circulating microvesicles, such as exosomes. miRNAs are ideal biomarkers that may be used in screening and prognosis in biliary tract cancers, aiding also in the clinical decisions at different stages of cancer treatment. This review highlights the progress in the analysis of circulating miRNAs in serum, plasma and bile as potential diagnostic and prognostic markers of BTCs.

Association of polymorphisms within the Renin-Angiotensin System with metabolic syndrome in a cohort of Chilean subjects

OBJECTIVE

Metabolic syndrome (MetS) is associated with hypertension, obesity and dyslipidemia. Thus, genetic variants related with these conditions may modulate its development. We evaluated the effect of polymorphisms in the renin-angiotensin system (RAS) on metabolic syndrome risk in a cohort of Chilean subjects.

SUBJECTS AND METHODS

A total of 152 subjects, 83 with MetS (51.2 ± 9.6 years) and 69 without MetS (49.5 ± 9.3 years) of both genders were included, according to the ATP III update criteria. The rs4340 Insertion/Deletion (I/D), rs699 (T>C) and rs5186 (A>C) of the ACE, AGT and AGTR1 genes, respectively, were genotyped.

RESULTS

After adjusting for age and gender, we observed the DD genotype of rs4340 associated with MetS (p = 0.02). Specifically, the DD genotype was associated with MetS risk in women (OR = 4.62, 95%CI, 1.41 - 15.04; p < 0.01). In males, the AA genotype for rs5186 variant was associated with an increased risk for developing MetS when compared with women carrying the same genotype (OR = 3.2; 95%CI, 1.03 - 9.89; p = 0.04). In subjects without MetS, DD genotype was associated with increased waist circumference (p = 0.023) while subjects with MetS carrying the rs5186 TT genotype showed higher levels of HDL-cholesterol (p = 0.031).

CONCLUSION

The present study contributes data highlighting the role for RAS polymorphisms in predisposing to metabolic syndrome in Chilean subjects.

The influence of ethnicity on warfarin dosage requirements in the chilean population

Background

Vitamin K antagonists are drugs that are widely prescribed around the world and their use has helped improve the prognosis of patients with thromboembolic disease. However, a high interindividual variability has been observed in dosage requirements to reach the desired anticoagulation range that could be due to environmental and genetic factors. Studies suggest that ethnicity influences coumarin response, supporting the observed differences in dose requirements across various populations. Studies using mitochondrial DNA (mtDNA) markers have suggested that the Chilean population has a predominantly Amerindian genetic pool.

Objective

To evaluate the influence of ethnicity, defined by the presence of Amerindian mtDNA haplogroups, on the variability in therapeutic response to warfarin in the Chilean population.

Methods

A total of 191 patients treated with warfarin were included in this study. Analysis of the mitochondrial genome for detecting the presence of Amerindian mtDNA haplogroups was performed using polymerase chain reaction and polymerase chain reaction restriction fragment length polymorphism techniques. The evaluation of warfarin requirements according to each haplogroup was performed by ANOVA with a 95% CI and assuming statistical significance at P < 0.05.

Results

Based on the presence of an mtDNA haplogroup, 91% of the Chilean population had an Amerindian background. There were no significant differences in warfarin dosage requirements among the different Amerindian haplogroups (P = 0.083).

Conclusions

The presence of Amerindian mtDNA haplogroup does not influence warfarin dosage requirements in the Chilean population.

Frequency and specificity of red blood cell alloimmunization in chilean transfused patients

BACKGROUND

Alloimmunization is an adverse effect of blood transfusions. In Chile, alloimmunization frequency is not established, and for this reason the aim of this study was to investigate the prevalence and specificity of red blood cell (RBC) alloantibodies in Chilean transfused subjects.

METHODS

Records from 4,716 multi-transfused patients were analyzed. In these patients, antibody screening was carried out prior to cross-matching with a commercially available two-cell panel by the microcolum gel test, and samples with a positive screen were analyzed for the specificity of the alloantibody with a 16-cell identification panel.

RESULTS

The incidence of RBC alloimmunization in transfused patients was 1.02% (48/4,716) with a higher prevalence in women (40/48). We detected 52 antibodies, the most frequent specificities identified were anti-E (30.8%), anti-K (26.9%), anti-D (7.7%), and anti-Fy(a) (5.8%). The highest incidence of alloantibodies was observed in cancer and gastroenterology patients.

CONCLUSION

The data demonstrated a low alloimmunization frequency in Chilean transfused patients, principally associated with antibodies anti-E, anti-K, anti-D, and anti-Fy(a).

Frequency of prothrombotic risk factors in patients with deep venous thrombosis and controls: their implications for thrombophilia screening in Chilean subjects

In this work, we evaluated the frequency of prothrombotic defects associated with deep venous thrombosis (DVT) in southern Chilean subjects. A total of 261 individuals, 87 patients with DVT confirmed by Doppler ultrasonography and 174 controls, were included in this study. Factor V and factor VIII levels, activated protein C (APC) resistance, and lupus anticoagulant detection were assayed by clotting methods. Basal homocysteine was quantified by immunoassay, and the polymorphisms in factor V (F5), methylenetetrahydrofolate reductase (MTHFR), and cystathionine β-synthase (CBS) genes were genotyped by molecular methods. The most frequent defects were APC resistance, hyperhomocysteinemia, and increased levels of factor VIII. We observed a complete absence of the F5 G1691A variant in the studied population, and the frequency of MTHFR C677T polymorphism was significantly different between patients and controls (odds ratio = 3.2; 95% confidence interval, 1.513-6.735; p = 0.016). In addition, subjects carrying the homozygous MTHFR 677TT genotype exhibited higher levels of plasma homocysteine. Our data suggest that the APC resistance is the most important defect in Chilean patients with DVT. However, this phenotype is not associated with the presence of the F5 G1691A variant. In addition, only MTHFR C677T polymorphism constituted a molecular biomarker of DVT in Chilean population.

Association of -765G>C polymorphism of the COX-2 gene with recurrent embryo implantation failure in Southern Chilean women

BACKGROUND

Embryo implantation failure is considered an important cause of infertility in women undergoing assisted reproductive protocols. Recent studies demonstrated that the cyclooxygenase-2 (COX-2) enzyme is implicated in biosynthesis of prostaglandins and play an important role in the molecular implantation mechanisms. According to this evidence, we evaluated the potential association between the -765G>C (rs20417) polymorphism at the COX-2 gene and the implantation failure susceptibility in a sample of Chilean women.

METHODS

A total of 186 unrelated women matched by age were included in the present study, 106 patients (aged 31.9±4.17 y) with no history of successful pregnancy and a diagnosis of infertility undergoing assisted reproductive protocols and 80 healthy controls (aged 31.4 ± 4.05 y). The COX-2 -765G>C gene polymorphism was analyzed by PCR-RFLP.

RESULTS

Genotype distribution and allelic frequencies for -765G>C polymorphism of COX-2 gene were significantly different between patients and controls (P=0.004 and P=0.002, respectively). The odds ratio for implantation failure associated to the -765C allelic variant was 2.14 (95% C.I., 1.35-3.39, P=0.00071).

CONCLUSION

Our data suggest, by the first time, that the COX-2 -765G>C polymorphism is associated with recurrent implantation failure in Chilean women and may constituted a novel molecular biomarker of reproductive failure.