Circulating markers of extracellular matrix remodelling in severe COVID-19 patients.

BACKGROUND: Abnormal remodelling of the extracellular matrix (ECM) has generally been linked to pulmonary inflammation and fibrosis and may also play a role in the pathogenesis of severe COVID-19. To further elucidate the role of ECM remodelling and excessive fibrogenesis in severe COVID-19, we examined circulating levels of mediators involved in various aspects of these processes in COVID-19 patients. METHODS: Serial blood samples were obtained from two cohorts of hospitalised COVID-19 patients (n = 414). Circulating levels of ECM remodelling mediators were quantified by enzyme immunoassays in samples collected during hospitalisation and at 3-month follow-up. Samples were related to disease severity (respiratory failure and/or treatment at the intensive care unit), 60-day total mortality and pulmonary pathology after 3-months. We also evaluated the direct effect of inactivated SARS-CoV-2 on the release of the different ECM mediators in relevant cell lines. RESULTS: Several of the measured markers were associated with adverse outcomes, notably osteopontin (OPN), S100 calcium-binding protein A12 and YKL-40 were associated with disease severity and mortality. High levels of ECM mediators during hospitalisation were associated with computed tomography thorax pathology after 3-months. Some markers (i.e. growth differential factor 15, galectin 3 and matrix metalloproteinase 9) were released from various relevant cell lines (i.e. macrophages and lung cell lines) in vitro after exposure to inactivated SARS-CoV-2 suggesting a direct link between these mediators and the causal agent of COVID-19. CONCLUSION: Our findings highlight changes to ECM remodelling and particularly a possible role of OPN, S100A12 and YKL-40 in the pathogenesis of severe COVID-19.

Elevated Levels of Interleukin-1ß and Interleukin-10 Are Associated With Faster Lung Function Decline in People With Well-Treated Human Immunodeficiency Virus.

BACKGROUND: People with human immunodeficiency virus (PWH) have an increased risk of chronic lung diseases and chronic inflammation. We aimed to investigate if inflammatory markers and monocyte activation are associated with faster lung function decline in PWH. METHODS: We included 655 PWH from the Copenhagen Comorbidity in HIV Infection (COCOMO) Study. Eligible participants were aged ≥25 years and had 2 spirometries separated by >2 years. Inflammatory markers (interleukin [IL]-1ß, IL-2, IL-6, IL-10, tumor necrosis factor-α, and interferon-γ) were measured at baseline by Luminex, and soluble CD14 and soluble CD163 by enzyme-linked immunosorbent assay. Using linear mixed models, we investigated whether elevated cytokine levels were associated with faster lung function decline. RESULTS: The majority of PWH were males (85.2%) with undetectable viral replication (95.3%). We found a faster decline in forced expiratory volume in 1 second (FEV1) in PWH with elevated IL-1ß and IL-10, with an additional decline of 10.3 mL/year (95% confidence interval [CI], 2.1-18.6; P = .014) and 10.0 mL/year (95% CI, 1.8-18.2; P = .017), respectively. We found no interaction between smoking and IL-1ß or IL-10 on FEV1 decline. CONCLUSIONS: Elevated IL-1ß and IL-10 were independently associated with faster lung function decline in PWH, suggesting that dysregulated systemic inflammation may play a role in the pathogenesis of chronic lung diseases.

DNA Repair Mechanisms are Activated in Circulating Lymphocytes of Hospitalized Covid-19 Patients.

Purpose: Reactive oxygen species (ROS) are an important part of the inflammatory response during infection but can also promote DNA damage. Due to the sustained inflammation in severe Covid-19, we hypothesized that hospitalized Covid-19 patients would be characterized by increased levels of oxidative DNA damage and dysregulation of the DNA repair machinery. Patients and Methods: Levels of the oxidative DNA lesion 8-oxoG and levels of base excision repair (BER) proteins were measured in peripheral blood mononuclear cells (PBMC) from patients (8-oxoG, n = 22; BER, n = 17) and healthy controls (n = 10) (Cohort 1). Gene expression related to DNA repair was investigated in two independent cohorts of hospitalized Covid-19 patients (Cohort 1; 15 patents and 5 controls, Cohort 2; 15 patients and 6 controls), and by publicly available datasets. Results: Patients and healthy controls showed comparable amounts of oxidative DNA damage as assessed by 8-oxoG while levels of several BER proteins were increased in Covid-19 patients, indicating enhanced DNA repair in acute Covid-19 disease. Furthermore, gene expression analysis demonstrated regulation of genes involved in BER and double strand break repair (DSBR) in PBMC of Covid-19 patients and expression level of several DSBR genes correlated with the degree of respiratory failure. Finally, by re-analyzing publicly available data, we found that the pathway Hallmark DNA repair was significantly more regulated in circulating immune cells during Covid-19 compared to influenza virus infection, bacterial pneumonia or acute respiratory infection due to seasonal coronavirus. Conclusion: Although beneficial by protecting against DNA damage, long-term activation of the DNA repair machinery could also contribute to persistent inflammation, potentially through mechanisms such as the induction of cellular senescence. However, further studies that also include measurements of additional markers of DNA damage are required to determine the role and precise molecular mechanisms for DNA repair in SARS-CoV-2 infection.

Persistent T-cell exhaustion in relation to prolonged pulmonary pathology and death after severe COVID-19: Results from two Norwegian cohort studies.

BACKGROUND: T-cell activation is associated with an adverse outcome in COVID-19, but whether T-cell activation and exhaustion relate to persistent respiratory dysfunction and death is unknown. OBJECTIVES: To investigate whether T-cell activation and exhaustion persist and are associated with prolonged respiratory dysfunction and death after hospitalization for COVID-19. METHODS: Plasma and serum from two Norwegian cohorts of hospitalized patients with COVID-19 (n = 414) were analyzed for soluble (s) markers of T-cell activation (sCD25) and exhaustion (sTim-3) during hospitalization and follow-up. RESULTS: Both markers were strongly associated with acute respiratory failure, but only sTim-3 was independently associated with 60-day mortality. Levels of sTim-3 remained elevated 3 and 12 months after hospitalization and were associated with pulmonary radiological pathology after 3 months. CONCLUSION: Our findings suggest prolonged T-cell exhaustion is an important immunological sequela, potentially related to long-term outcomes after severe COVID-19.

Respiratory dysfunction three months after severe COVID-19 is associated with gut microbiota alterations.

BACKGROUND: Although coronavirus disease 2019 (COVID-19) is primarily a respiratory infection, mounting evidence suggests that the gastrointestinal tract is involved in the disease, with gut barrier dysfunction and gut microbiota alterations being related to disease severity. Whether these alterations persist and are related to long-term respiratory dysfunction remains unknown. METHODS: Plasma was collected during hospital admission and after 3 months from the NOR-Solidarity trial (n = 181) and analyzed for markers of gut barrier dysfunction and inflammation. At the 3-month follow-up, pulmonary function was assessed by measuring the diffusing capacity of the lungs for carbon monoxide (DLCO ). Rectal swabs for gut microbiota analyses were collected (n = 97) and analyzed by sequencing the 16S rRNA gene. RESULTS: Gut microbiota diversity was reduced in COVID-19 patients with respiratory dysfunction, defined as DLCO below the lower limit of normal 3 months after hospitalization. These patients also had an altered global gut microbiota composition, with reduced relative abundance of 20 bacterial taxa and increased abundance of five taxa, including Veillonella, potentially linked to fibrosis. During hospitalization, increased plasma levels of lipopolysaccharide-binding protein (LBP) were strongly associated with respiratory failure, defined as pO2 /fiO2 (P/F ratio) <26.6 kPa. LBP levels remained elevated during and after hospitalization and were associated with low-grade inflammation and respiratory dysfunction after 3 months. CONCLUSION: Respiratory dysfunction after COVID-19 is associated with altered gut microbiota and persistently elevated LBP levels. Our results should be regarded as hypothesis generating, pointing to a potential gut-lung axis that should be further investigated in relation to long-term pulmonary dysfunction and long COVID.

Plasma extracellular vesicles in people living with HIV and type 2 diabetes are related to microbial translocation and cardiovascular risk.

HIV and type 2 diabetes (T2D) are both associated with gut microbiota alterations, low-grade endotoxemia and increased cardiovascular risk. We investigated the potential role of plasma extracellular vesicles (EVs) in relation to these processes. Plasma EVs were isolated by size exclusion chromatography in fasting individuals with HIV and T2D (n = 16), T2D only (n = 14), HIV only (n = 20) or healthy controls (n = 19), and characterized by transmission electron microscopy, western blot, nanoparticle tracking analysis and quantitative proteomics. The findings were compared to gut microbiota alterations, lipopolysaccharide levels and cardiovascular risk profile. Individuals with concomitant HIV and T2D had higher plasma EV concentration, which correlated closely with plasma lipopolysaccharides, triglycerides and Framingham score, but not with gut microbiota alterations. Proteomic analyses identified 558 human proteins, largely related to cardiometabolic disease genes and upstream regulation of inflammatory pathways, including IL-6 and IL-1ß, as well as 30 bacterial proteins, mostly from lipopolysaccharide-producing Proteobacteria. Our study supports that EVs are related to microbial translocation processes in individuals with HIV and T2D. Their proteomic content suggests a contributing role in low-grade inflammation and cardiovascular risk development. The present approach for exploring gut-host crosstalk can potentially identify novel diagnostic biomarkers and therapeutic targets.

Evaluation of the Effects of Remdesivir and Hydroxychloroquine on Viral Clearance in COVID-19 : A Randomized Trial.

BACKGROUND: New treatment modalities are urgently needed for patients with COVID-19. The World Health Organization (WHO) Solidarity trial showed no effect of remdesivir or hydroxychloroquine (HCQ) on mortality, but the antiviral effects of these drugs are not known. OBJECTIVE: To evaluate the effects of remdesivir and HCQ on all-cause, in-hospital mortality; the degree of respiratory failure and inflammation; and viral clearance in the oropharynx. DESIGN: NOR-Solidarity is an independent, add-on, randomized controlled trial to the WHO Solidarity trial that included biobanking and 3 months of clinical follow-up (ClinicalTrials.gov: NCT04321616). SETTING: 23 hospitals in Norway. PATIENTS: Eligible patients were adults hospitalized with confirmed SARS-CoV-2 infection. INTERVENTION: Between 28 March and 4 October 2020, a total of 185 patients were randomly assigned and 181 were included in the full analysis set. Patients received remdesivir (n = 42), HCQ (n = 52), or standard of care (SoC) (n = 87). MEASUREMENTS: In addition to the primary end point of WHO Solidarity, study-specific outcomes were viral clearance in oropharyngeal specimens, the degree of respiratory failure, and inflammatory variables. RESULTS: No significant differences were seen between treatment groups in mortality during hospitalization. There was a marked decrease in SARS-CoV-2 load in the oropharynx during the first week overall, with similar decreases and 10-day viral loads among the remdesivir, HCQ, and SoC groups. Remdesivir and HCQ did not affect the degree of respiratory failure or inflammatory variables in plasma or serum. The lack of antiviral effect was not associated with symptom duration, level of viral load, degree of inflammation, or presence of antibodies against SARS-CoV-2 at hospital admittance. LIMITATION: The trial had no placebo group. CONCLUSION: Neither remdesivir nor HCQ affected viral clearance in hospitalized patients with COVID-19. PRIMARY FUNDING SOURCE: National Clinical Therapy Research in the Specialist Health Services, Norway.

Independent Associations of Tumor Necrosis Factor-Alpha and Interleukin-1 Beta With Radiographic Emphysema in People Living With HIV.

Background: People living with HIV (PLWH) have increased systemic inflammation, and inflammation has been suggested to contribute to the pathogenesis of emphysema. We investigated whether elevated cytokine concentrations (interleukin (IL)-1ß, IL-1 receptor antagonist (IL-1RA), IL-2, IL-4, IL-6, IL-10, IL-17A, tumor necrosis factor-alpha (TNFα), interferon-gamma (IFNγ), soluble CD14 (sCD14) and sCD163 were independently associated with radiographic emphysema in PLWH. Methods: We included PLWH from the Copenhagen Comorbidity in HIV Infection (COCOMO) Study without hepatitis B and C co-infection and with a plasma sample and a chest computed tomography scan available. Emphysema plus trace emphysema was defined as the percentage of low attenuation area under -950 Houndsfield Unit (%LAA-950) using a cut-off at 5%. Cytokine concentrations were measured by ELISA or Luminex immunoassays. An elevated cytokine concentration was defined as above the 75th percentile. Results: Of 783 PLWH, 147 (18.8%) had emphysema. PLWH were predominantly male (86.0%) and 743 (94.9%) had undetectable viral replication. PLWH with emphysema had higher concentrations of TNFα (median (IQR): 8.2 (6.4-9.8) versus 7.1 (5.7-8.6) pg/ml, p<0.001), IL-1ß (0.21 (0.1-0.4) versus 0.17 (0.1-0.3) pg/ml, p=0.004) and IL-6 (3.6 (2.6-4.9) versus 3.1 (2.0-4.3) pg/ml, p=0.023) than PLWH without. In a logistic regression model adjusted for age, sex, ethnicity, smoking status, BMI and CD4 nadir, elevated TNFα (adjusted odds ratio (aOR): 1.78 [95%CI: 1.14-2.76], p=0.011) and IL-1ß (aOR: 1.81 [95%CI: 1.16-2.81], p=0.009) were independently associated with emphysema. The association between IL-1ß and emphysema was modified by smoking (p-interaction=0.020) with a more pronounced association in never-smokers (aOR: 4.53 [95%CI: 2.05-9.98], p<0.001). Conclusion: Two markers of systemic inflammation, TNFα and IL-1ß, were independently associated with emphysema in PLWH and may contribute to the pathogenesis of emphysema. Importantly, the effect of IL-1ß seems to be mediated through pathways that are independent of excessive smoking. Clinical Trial Registration: clinicaltrials.gov, identifier NCT02382822.

Independent Association of Interleukin 6 With Low Dynamic Lung Function and Airflow Limitation in Well-Treated People With Human Immunodeficiency Virus.

BACKGROUND: Human immunodeficiency virus (HIV) infection is associated with an increased risk of chronic pulmonary diseases. We compared cytokine concentrations (interleukin 6 [IL-6], interleukin 1ß, 2, 4, 10, and 17A, tumor necrosis factor α, interferon γ, soluble CD14 [sCD14] and soluble CD163 [sCD163]) in people with HIV (PWH) and uninfected controls and investigated whether elevated cytokine concentrations were independently associated with lung function indices in PWH. METHODS: We performed spirometry and measured cytokine concentrations by Luminex immunoassays or enzyme-linked immunoassay in 951 PWH and 79 uninfected controls from the Copenhagen Comorbidity in HIV Infection study. Regression analyses were used to explore associations between elevated cytokine concentrations and lung function indices. RESULTS: PWH were predominantly male (84.6%) and 94.2% had undetectable viral replication. In PWH, elevated IL-6 was associated with lower forced expiratory volume in 1 second (-212 mL [95% confidence interval, -308 to -116 mL]), lower forced vital capacity (-208 mL [-322 to -93 mL]), and airflow limitation (aOR, 2.62 [1.58-4.36]) (all P < .001) in models adjusted for age, sex, ethnicity, smoking status, body mass index, and CD4 T-cell nadir. The association between IL-6 and dynamic lung function was modified by smoking (P for interaction = .005). CONCLUSION: IL-6 levels were elevated and independently associated with low dynamic lung function and airflow limitation in well-treated PWH, suggesting that systemic inflammation may contribute to the pathogenesis of chronic pulmonary diseases.

Soluble T-Cell Immunoglobulin Mucin Domain-3 Is Associated With Hepatitis C Virus Coinfection and Low-Grade Inflammation During Chronic Human Immunodeficiency Virus Infection.

BACKGROUND: In well treated human immunodeficiency virus infection (HIV), there is a residual immune activation and immune exhaustion that may contribute to increased risk of comorbidities. T-cell immunoglobulin mucin domain-3 (Tim-3) is an inhibitory molecule involved in HIV-associated T-cell dysfunction. The Tim-3 can be cleaved to soluble Tim-3 (sTim-3) that may serve as a soluble marker of immune exhaustion. METHODS: We measured sTim-3 with enzyme-linked immunosorbent assay DuoSets in a cross-sectional cohort of 1010 people with HIV (PWH) on antiretroviral therapy (ART), and 76 controls from the Copenhagen Co-Morbidity in HIV Infection (COCOMO) study, and in a longitudinal cohort of 60 PWH before and during ART. RESULTS: In the cross-sectional cohort, levels of sTim-3 were elevated in PWH on ART compared with controls, especially in hepatitis C virus (HCV)-coinfected individuals, and were associated with HCV viremia and inflammation. In the longitudinal cohort, pretreatment sTim-3 correlated with HIV viral load and decreased after ART initiation. Pretreatment sTim-3 correlated inversely with CD4 counts, but it did not predict immunological response in multivariable analyses. CONCLUSIONS: Levels of sTim-3 decreased after ART initiation. In a cross-sectional cohort, levels of sTIM-3 were higher in PWH than in controls and were independently associated with HCV coinfection and high-sensitivity C-reactive protein, representing a potential link between immune exhaustion, inflammation, and risk of comorbidities.

Impact of Human Immunodeficiency Virus-Related Gut Microbiota Alterations on Metabolic Comorbid Conditions.

BACKGROUND: We aimed to identify a human immunodeficiency virus (HIV)-related microbiota signature, independent of sexual preferences and demographic confounders, in order to assess a possible impact of the microbiome on metabolic comorbid conditions. METHODS: Bacterial 16S ribosomal RNA analyses were performed on stool samples from 405 HIV-infected and 111 uninfected participants of the Copenhagen Comorbidity in HIV Infection (COCOMO) study. Individuals were stratified according to sexual behavior (men who have sex with men [MSM] vs non-MSM). RESULTS: After excluding MSM-associated microbiota traits and adjusting for confounders, we identified an HIV-related microbiota signature, consisting of lower biodiversity, increased relative abundance of the bacterial clades Gammaproteobacteria and Desulfovibrionaceae and decrease in several Clostridia. This microbiota profile was associated with a 2-fold excess risk of metabolic syndrome, driven by increase in Desulfovibrionaceae and decrease in Clostridia (Butyrivibrio, Coprococcus 2, Lachnospiraceae UCG-001 and CAG-56). This association was accentuated (5-fold excess risk) in individuals with previous severe immunodeficiency, which also modified the association between HIV-related microbiota signature and visceral adipose tissue (VAT) area (P for interaction = .01). Accordingly, HIV-related microbiota was associated with 30-cm2 larger VAT in individuals with history of severe immunodeficiency, but not in those without. CONCLUSION: The HIV-related microbiota was associated with increased risk of metabolic syndrome and VAT accumulation, particularly in individuals with previous severe immunodeficiency, driven by increased Desulfovibrionaceae and lower abundance of several Clostridia. Our findings suggest a potential interplay between HIV-related microbiota, immune dysfunction and metabolic comorbid conditions. Interventions targeting the gut microbiome may be warranted to reduce cardiovascular risk, particularly in individuals with previous immunodeficiency.

Soluble Markers of Interleukin 1 Activation as Predictors of First-Time Myocardial Infarction in HIV-Infected Individuals.

People with human immunodeficiency virus (HIV) infection (PWH) have an increased risk of cardiovascular disease (CVD), compared with the general population. In a nested case-control study of 55 PWH with first-time myocardial infarction (MI; cases) and 182 PWH with no CVD (controls), we measured soluble markers of interleukin 1 (IL-1) activation at 4 different time points before the case's MI. Cases had higher levels of IL-1 receptor antagonist (IL-1Ra) at all time points leading up to first-time MI, and higher levels of IL-1Ra were associated with an approximately 1.5-fold increased risk of MI, supporting the rationale to target IL-1 activation to reduce cardiovascular risk in PWH.

Impact of HIV and Type 2 diabetes on Gut Microbiota Diversity, Tryptophan Catabolism and Endothelial Dysfunction.

HIV infection and type 2 diabetes are associated with altered gut microbiota, chronic inflammation, and increased cardiovascular risk. We aimed to investigate the combined effect of these diseases on gut microbiota composition and related metabolites, and a potential relation to endothelial dysfunction in individuals with HIV-infection only (n = 23), diabetes only (n = 16) or both conditions (n = 21), as well as controls (n = 24). Fecal microbiota was analyzed by Illumina sequencing of the 16 S rRNA gene. Markers of endothelial dysfunction (asymmetric dimethylarginine [ADMA]), tryptophan catabolism (kynurenine/tryptophan [KT]-ratio), and inflammation (neopterin) were measured by liquid chromatography-tandem mass spectrometry. The combination of HIV and type 2 diabetes was associated with reduced gut microbiota diversity, increased plasma KT-ratio and neopterin. Microbial genes related to tryptophan metabolism correlated with KT-ratio and low alpha diversity, in particular in HIV-infected with T2D. In multivariate analyses, KT-ratio associated with ADMA (ß = 4.58 [95% CI 2.53-6.63], p < 0.001), whereas microbiota composition per se was not associated with endothelial dysfunction. Our results indicate that tryptophan catabolism may be related to endothelial dysfunction, with a potentially detrimental interaction between HIV and diabetes. The potential contribution of gut microbiota and the impact for cardiovascular risk should be further explored in prospective studies powered for clinical end points.

Ventilatory Efficiency in Children and Adolescents Born Extremely Preterm.

Purpose: Children and adolescents born extremely preterm (EP) have lower dynamic lung volumes and gas transfer capacity than subjects born at term. Most studies also report lower aerobic capacity. We hypothesized that ventilatory efficiency was poorer and that breathing patterns differed in EP-born compared to term-born individuals. Methods: Two area-based cohorts of participants born with gestational age ≤28 weeks or birth weight ≤1000 g in 1982-85 (n = 46) and 1991-92 (n = 35) were compared with individually matched controls born at term. Mean ages were 18 and 10 years, respectively. The participants performed an incremental treadmill exercise test to peak oxygen uptake with data averaged over 20 s intervals. For each participant, the relationship between exhaled minute ventilation ([Formula: see text]E) and carbon dioxide output ([Formula: see text]CO2) was described by a linear model, and the relationship between tidal volume (VT) and [Formula: see text]E by a quadratic model. Multivariate regression analyses were done with curve parameters as dependent variables, and the categories EP vs. term-born, sex, age, height, weight and forced expiratory volume in 1 s (FEV1) as independent variables. Results: In adjusted analyses, the slope of the [Formula: see text]E-[Formula: see text]CO2 relationship was significantly steeper in the EP than the term-born group, whereas no group difference was observed for the breathing pattern, which was related to FEV1 only. Conclusion: EP-born participants breathed with higher [Formula: see text]E for any given CO2 output, indicating lower ventilatory efficiency, possibly contributing to lower aerobic capacity. The breathing patterns did not differ between the EP and term-born groups when adjusted for FEV1.

Microbiota-Dependent Marker TMAO Is Elevated in Silent Ischemia but Is Not Associated With First-Time Myocardial Infarction in HIV Infection.

OBJECTIVES: HIV infection is associated with increased risk of coronary heart disease beyond that explained by traditional risk factors, and altered gut microbiota has been proposed as a potential trigger. Trimethylamine-N-oxide (TMAO) is a proatherogenic substance formed in the liver from trimethylamine, exclusively generated by gut microbiota from dietary phosphatidylcholine. We aimed to investigate whether TMAO is associated with subclinical and clinical coronary heart disease in HIV infection. METHODS: Two previously described cohorts were examined as follows: (1) cross-sectional cohort of HIV-infected persons and uninfected controls with known atherosclerotic plaque burden as assessed by myocardial perfusion scintigraphy, coronary artery calcium score, and intima-media thickness and (2) nested case-control study of HIV-infected persons with first-time myocardial infarction (MI) compared with HIV-infected persons without MI, assessed at 4 time points from before initiation of antiretroviral therapy (ART) to last sample before the case's MI (median: 51, range: 0-239 days). RESULTS: There was no difference in plasma TMAO when comparing HIV-infected persons and uninfected controls. TMAO was elevated in HIV-infected persons with myocardial perfusion defects but was not associated with coronary artery calcium score, intima media thickness, or Framingham risk score. In the nested case control study, plasma TMAO was not associated with first-time MI. However, TMAO increased after ART introduction and was associated with the use of protease inhibitors in both cohorts. CONCLUSIONS: TMAO was elevated in HIV-infected persons with myocardial perfusion defects, but was not associated with first-time MI. Our data question TMAO as a useful biomarker of cardiovascular risk in HIV infection, at least in ART-treated individuals.

Prevalence of hepatitis B & hepatitis C virus infections in potential blood donors in rural Vietnam.

BACKGROUND & OBJECTIVES: Safe blood and blood products should be offered to all patients in need for blood transfusion. The objectives of the present study were to establish prevalence estimates for hepatitis B and hepatitis C virus infections as a foundation for safe blood transfusion in rural Vietnam, and to check the accuracy of the laboratory analysis used for hepatitis testing of blood donors in Vietnam. METHODS: A cross-sectional study was conducted in two rural communities in Quang Tri, Vietnam. A total of 1,200 blood samples collected from potential blood donors were tested by an enzyme immunoassay technique (EIA) for detection of hepatitis surface antigen (HBsAg), antibodies to hepatitis B core antigen (anti-HBc), and antibodies to hepatitis C antigen (anti-HCV). The EIA test outcome was validated by a chemiluminescent micro particle immunoassay technique (CMIA). RESULTS: The prevalence of HBsAg and anti-HBc in the study population was 11.4 per cent (95% CI 9.6 - 13.2) and 51.7 per cent (95% CI 48.8 - 54.5), respectively, the prevalences being higher in males than females. The prevalence of anti-HCV was 0.17 per cent. The test agreement between the EIA and CMIA techniques was high both for HBsAg detection (κ = 0.91; 95% CI: 0.83 - 0.99) and for anti-HBc detection (κ = 0.89; 95% CI 0.81 - 0.97). Compared to CMIA results, the positive and negative predictive values of the EIA tests were found to be 94.9 per cent (95% CI 87.5 - 98.6) and 97.5 per cent (95% CI 86.8 - 99.9) for HBsAg, and 92.4 per cent (95% CI 84.2 - 97.2) and 100 per cent (95% CI 91.2 - 100) for anti-HBc. INTERPRETATION & CONCLUSIONS: The study shows that hepatitis B virus infection is endemic in rural areas of Vietnam and that almost half of the population is or has been infected. Hepatitis C infection is rare, but false negative test results cannot be ruled out. Also, the results indicate that the EIA performance in blood donor screening in Vietnam may be sub-optimal, missing 2.5 per cent of hepatitis B virus carriers and falsely excluding more than 7 per cent of blood donors. As the prevalence of hepatitis B infection is high, occult hepatitis B infection may represent a threat to safe blood transfusion. Therefore, nucleic acid amplification testing for HBV should be considered for blood donor screening in Vietnam.

Screening test accuracy among potential blood donors of HBsAg, anti-HBc and anti-HCV to detect hepatitis B and C virus infection in rural Cambodia and Vietnam.

The aim of this study was to determine the accuracy of rapid tests for HBsAg, anti-HBc and anti-HCV in rural Cambodia and Vietnam to detect hepatitis B and C. In a cross-sectional epidemiological study of two populations of 1,200 potential blood donors in rural Cambodia and Vietnam the prevalence rates of HBsAg, anti-HBc and anti-HCV as established by enzyme immunoassay (EIA) tests were compared to rapid test outcomes. The EIA reference test results were validated by Architect Chemiluminescent Microparticle Immunoassay (CMIA) technique. The actual rapid test demonstrated high specificity for all three test categories as claimed by the manufacturer. The test sensitivity observed was significantly lower than that claimed by the manufacturer: 86.5% for HBsAg, 86.6% for anti-HBc, and 76.4% for anti-HCV. There were large and significant variations in test performance between the two countries, especially for HBsAg detection. The low sensitivity of the actual rapid tests for HBsAg, anti-HBc and anti-HCV make them useless for blood donor screening in rural Southeast Asia. Rapid tests may be useful screening tools in blood transfusion services in low-resource settings, but tests should be carefully validated locally before being used for screening purposes since test performance varies by location.

Prevalence of hepatitis B and hepatitis C virus infections in potential blood donors in rural Cambodia.

The aims of the present study were to provide accurate prevalence of acute and occult hepatis B infection and hepatis C infection among potential blood donors in Cambodia and to study the accuracy of ELISA tests used for blood donor screening. A cross-sectional study was performed on samples collected from potential volunteer blood donors (n = 1,200) in two districts in rural Cambodia. The samples were tested using the ELISA technique for HBsAg, anti-HBc, and anti-HCV at a local blood bank. To validate the ELISA outcomes, a subset (n = 319) was analyzed by Automated Chemiluminescent Microparticle Immunoassay Technique (CMIA) at the University Hospital North Norway. The overall prevalence of the HBsAg positives was 7.7% (95% CI 6.2-9.3); the prevalence of anti-HBc positive samples was 58.6% (95% CI 55.8-61.4), and the prevalence of anti-HCV positive samples was 14.7% (95% CI 12.7-16.7). The prevalence rate of samples being both HBsAg positive and anti-HBc positive was 7.3% (95% CI 5.9 - 9.0), and the prevalence rate of HBsAg negative and anti-HBc positive samples was 51.2% (95% CI 48.4 - 54.1). The overall agreement between the ELISA and the CMIA test results was very high both for HBsAg and anti-HBc (kappa 0.93), and high for anti-HCV measurements (kappa 0.83). However, the false-negative rate for the ELISA anti-HCV test was as high as 15% (95% CI 6 - 30).