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- Pantazis, N, et al.
(author)
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Determining the likely place of HIV acquisition for migrants in Europe combining subject-specific information and biomarkers data
- 2019
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In: Statistical methods in medical research. - : SAGE Publications. - 1477-0334 .- 0962-2802. ; 28:7, s. 1979-1997
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Journal article (peer-reviewed)abstract
- In most HIV-positive individuals, infection time is only known to lie between the time an individual started being at risk for HIV and diagnosis time. However, a more accurate estimate of infection time is very important in certain cases. For example, one of the objectives of the Advancing Migrant Access to Health Services in Europe (aMASE) study was to determine if HIV-positive migrants, diagnosed in Europe, were infected pre- or post-migration. We propose a method to derive subject-specific estimates of unknown infection times using information from HIV biomarkers’ measurements, demographic, clinical, and behavioral data. We assume that CD4 cell count (CD4) and HIV-RNA viral load trends after HIV infection follow a bivariate linear mixed model. Using post-diagnosis CD4 and viral load measurements and applying the Bayes’ rule, we derived the posterior distribution of the HIV infection time, whereas the prior distribution was informed by AIDS status at diagnosis and behavioral data. Parameters of the CD4–viral load and time-to-AIDS models were estimated using data from a large study of individuals with known HIV infection times (CASCADE). Simulations showed substantial predictive ability (e.g. 84% of the infections were correctly classified as pre- or post-migration). Application to the aMASE study ( n = 2009) showed that 47% of African migrants and 67% to 72% of migrants from other regions were most likely infected post-migration. Applying a Bayesian method based on bivariate modeling of CD4 and viral load, and subject-specific information, we found that the majority of HIV-positive migrants in aMASE were most likely infected after their migration to Europe.
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| 2. |
- Samitas, Konstantinos, 1977, et al.
(author)
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Osteopontin expression and relation to disease severity in human asthma.
- 2011
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In: The European respiratory journal. - : European Respiratory Society (ERS). - 1399-3003 .- 0903-1936. ; 37:2, s. 331-341
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Journal article (peer-reviewed)abstract
- Recent studies have associated osteopontin (Opn) with allergic inflammation; however, its role in human asthma remains unclear. We measured Opn levels in serum, bronchoalveolar lavage fluid (BALF) and bronchial tissue of healthy controls and asthmatics, identified cellular sources of Opn and examined possible correlations between Opn expression, disease severity and airway remodeling. Serum samples were obtained from 35 mild-moderate (MMA), 19 severe asthmatics (SA) and 17 healthy controls in steady state and in case of exacerbation. Of these subjects, 29 asthmatics and 9 controls underwent bronchoscopy with endobronchial biopsy and BALF collection. Opn expression was determined by ELISA and immunohistochemistry/immunofluorescence. Reticular basement membrane (RBM) thickness and goblet cell hyperplasia were also determined. Serum and BALF Opn levels were significantly increased in all asthmatics in steady state, while serum levels decreased during exacerbations. Opn was upregulated in the bronchial tissue of all patients and expressed by epithelial, airway and vascular smooth muscle cells, myofibroblasts, T-lymphocytes and mast cells. Opn expression correlated with RBM thickness and was more prominent in subepithelial inflammatory cells in severe compared to mild-moderate asthma. Opn expression is upregulated in human asthma, is associated with remodeling changes and its subepithelial expression correlates to disease severity.
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