ABSTRACT Introduction: Telomere length (TL) is a biomarker of cellular proliferative history. In healthy individuals, leukocyte TL shortens with age and associates with the lifespan of men and women. However, most of studies had used linear regression models to address the association of the TL attrition, aging and sex. Methods: We evaluated the association between the TL, aging and sex in a cohort of 180 healthy subjects by quantile regression. The TL of nucleated blood cells was measured by fluorescent in situ hypridization (flow-FISH) in a cohort of 89 men, 81 women, and 10 umbilical cord samples. The results were validated by quantitative polymerase chain reaction (qPCR) and compared to a linear regression analysis. Results: By quantile regression, telomere dynamics slightly differed between sexes with aging: women had longer telomeres at birth and slower attrition rate than men until the sixth decade of life; after that, TL eroded faster and became shorter than that in men. These differences were not observed by linear regression analysis, as the overall telomere attrition rates in women and men were similar (42 pb per year, p < 0.0001 vs. 45 pb kb per year, p < 0.0001). Also, qPCR did not recapitulate flow-FISH findings, as the telomere dynamics by qPCR followed a linear model. Conclusion: The quantile regression analysis accurately reproduced a third-orderpolynomial TL attrition rate in both women and men, but it depended on the technique applied to measure TL. The Flow-FISH reproduced the expected telomere dynamics through life and, differently from the qPCR, was able to detect the subtle TL variations associated with sex and aging.

ABSTRACT SARS-CoV-2 has a high risk of outbreak in long-term skilled nursing facilities (SNF). Coronavirus disease (COVID-19) has high mortality rates among the elderly with chronic health conditions. Following identification of COVID-19 index case in a SNF, serial point-prevalence was implemented with reverse transcription–polymerase chain reaction (RT-PCR) and immunochromatographic assays. Active surveillance and early isolation of infected patients were implemented. Out of 23 SNF residents and 26 healthcare workers (HCW), 18 (78%) and 12 (46%) tested positive for SARS-CoV-2, respectively. High proportion (38%) of positive patients were asymptomatic and RT-PCR was positive up to six days before symptoms. Five (21.74%) residents were hospitalized with COVID-19, and 2 (9%) died; only 1 (4%) HCW needed to be hospitalized and no staff members died. Active surveillance helped COVID-19 control and management in a SNF. Testing symptomatic individuals only may fail to identify and isolate all persons contributing to transmission. In high-risk elderly, only symptoms screening may not be enough for outbreak control.

ABSTRACT Background: Telomeres, the ends of linear chromosomes, shorten during mitotic cell division and erosion may be aggravated by inflammation or proliferative and oxidative stress. As the bone marrow is under hyperproliferative pressure in sickle cell disease and several tissues are submitted to chronic inflammation, this study sought to determine the telomere length of patients with sickle cell disease. Methods: The mean telomere length was measured in peripheral blood leukocytes by quantitative polymerase chain reaction. The age-adjusted telomere to single copy gene ratio was compared between 91 adult sickle cell disease patients and 188 controls. Results: Sickle cell disease patients had significantly shorter telomeres than the controls (p-value < 0.0001). Moreover, among sickle cell disease genotypes, Hb SS patients had significantly shorter telomeres compared to Hb SC and Hb Sβ patients (p-value < 0.0001). Patients on hydroxyurea also had shorter telomeres in comparison to those off the drug (p-value = 0.02). A positive correlation was observed between telomere length and hemoglobin level (r = 0.3; p-value = 0.004), whereas negative correlations were detected between telomere length and lymphocyte count (r = -0.3; p-value = 0.005) and interleukin-8 serum levels (r = -0.4; p-value = 0.02). Conclusions: The findings of this study indicate that telomeres are short in sickle cell disease patients and that telomere erosion directly correlates with disease genotype, inflammation markers, and the use of hydroxyurea.