Determining the genome-wide kinship coefficient seems unhelpful in distinguishing consanguineous couples with a high versus low risk for adverse reproductive outcome

Background: Offspring of consanguineous couples are at increased risk of congenital disorders. The risk increases as parents are more closely related. Individuals that have the same degree of relatedness according to their pedigree, show variable genomic kinship coefficients. To investigate whether we can differentiate between couples with high- and low risk for offspring with congenital disorders, we have compared the genomic kinship coefficient of consanguineous parents with a child affected with an autosomal recessive disorder with that of consanguineous parents with only healthy children, corrected for the degree of pedigree relatedness. Methods: 151 consanguineous couples (73 cases and 78 controls) from 10 different ethnic backgrounds were genotyped on the Affymetrix platform and passed quality control checks. After pruning SNPs in linkage disequilibrium, 57,358 SNPs remained. Kinship coefficients were calculated using three different toolsets: PLINK, King and IBDelphi, yielding five different estimates (IBDelphi, PLINK (all), PLINK (by population), King robust (all) and King homo (by population)). We performed a one-sided Mann Whitney test to investigate whether the median relative difference regarding observed and expected kinship coefficients is bigger for cases than for controls. Furthermore, we fitted a mixed effects linear model to correct for a possible population effect. Results: Although the estimated degrees of genomic relatedness with the different toolsets show substantial variability, correlation measures between the different estimators demonstrated moderate to strong correlations. Controls have higher point estimates for genomic kinship coefficients. The one-sided Mann Whitney test did not show any evidence for a higher median relative difference for cases compared to controls. Neither did the regression analysis exhibit a positive association between case–control status and genomic kinship coefficient. Conclusions: In this case–control setting, in which we compared consanguineous couples corrected for degree of pedigree relatedness, a higher degree of genomic relatedness was not significantly associated with a higher likelihood of having an affected child. Further translational research should focus on which parts of the genome and which pathogenic mutations couples are sharing. Looking at relatedness coefficients by determining genome-wide SNPs does not seem to be an effective measure for prospective risk assessment in consanguineous parents

Abundance of Early Functional HIV-Specific CD8+ T Cells Does Not Predict AIDS-Free Survival Time

Background T-cell immunity is thought to play an important role in controlling HIV infection, and is a main target for HIV vaccine development. HIV-specific central memory CD8+ and CD4+ T cells producing IFNγ and IL-2 have been associated with control of viremia and are therefore hypothesized to be truly protective and determine subsequent clinical outcome. However, the cause-effect relationship between HIV-specific cellular immunity and disease progression is unknown. We investigated in a large prospective cohort study involving 96 individuals of the Amsterdam Cohort Studies with a known date of seroconversion whether the presence of cytokine-producing HIV-specific CD8+ T cells early in infection was associated with AIDS-free survival time. Methods and Findings The number and percentage of IFNγ and IL-2 producing CD8+ T cells was measured after in vitro stimulation with an overlapping Gag-peptide pool in T cells sampled approximately one year after seroconversion. Kaplan-Meier survival analysis and Cox proportional hazard models showed that frequencies of cytokine-producing Gag-specific CD8+ T cells (IFNγ, IL-2 or both) shortly after seroconversion were neither associated with time to AIDS nor with the rate of CD4+ T-cell decline. Conclusions These data show that high numbers of functional HIV-specific CD8+ T cells can be found early in HIV infection, irrespective of subsequent clinical outcome. The fact that both progressors and long-term non-progressors have abundant T cell immunity of the specificity associated with low viral load shortly after seroconversion suggests that the more rapid loss of T cell immunity observed in progressors may be a consequence rather than a cause of disease progression

Quantifying the impact of human immunodeficiency virus-1 escape from cytotoxic T-lymphocytes.

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Experience of hypoglycaemia is associated with changes in beliefs about diabetes in patients with type 2 diabetes.

AIM: Hypoglycaemia may have a detrimental impact on quality of life for patients with Type 2 diabetes. There are few clinical studies exploring the impact of experiencing hypoglycaemia on beliefs about diabetes and health status. The aim of this study was to explore associations between experience of hypoglycaemia and changes in diabetes beliefs and self-reported health status in patients with non-insulin-treated Type 2 diabetes using a blood glucose meter. METHODS: One-year prospective cohort analysis of 226 patients recruited to a randomized trial evaluating the impact of self-monitoring of blood glucose. Self-reported hypoglycaemia over 1 year was categorized into three groups: (1) no experience of hypoglycaemia; (2) blood glucose measurements < 4 mmol/l with no associated symptoms of hypoglycaemia (grade 1); and (3) symptomatic hypoglycaemia (grade 2 and 3). Measures of beliefs about diabetes (Revised Illness Perception Questionnaire) and health status (EuroQol-5D) were assessed at baseline and 1 year. Differences in mean changes over 1 year were explored with analyses of covariance. RESULTS: There was a significant increase in mean score in beliefs about personal control (1.14; 95%CI 0.14-2.14) among those experiencing grade 1 hypoglycaemia compared with those not experiencing hypoglycaemia. There were no significant differences in changes in health status between groups, with small overall changes that were inconsistent between groups. CONCLUSIONS: This study does not provide support for a long-term adverse impact on beliefs about diabetes or health status from the experience of mild symptomatic hypoglycaemia, in well-controlled, non-insulin-treated patients with Type 2 diabetes using self-monitoring of blood glucose