The clinical and functional effects of TERT variants in myelodysplastic syndrome.

Germline pathogenic TERT variants are associated with short telomeres and an increased risk of developing myelodysplastic syndrome (MDS) among patients with a telomere biology disorder. We identified TERT rare variants in 41 of 1514 MDS patients (2.7%) without a clinical diagnosis of a telomere biology disorder who underwent allogeneic transplantation. Patients with a TERT rare variant had shorter telomere length (P < .001) and younger age at MDS diagnosis (52 vs 59 years, P = .03) than patients without a TERT rare variant. In multivariable models, TERT rare variants were associated with inferior overall survival (P = .034) driven by an increased incidence of nonrelapse mortality (NRM; P = .015). Death from a noninfectious pulmonary cause was more frequent among patients with a TERT rare variant. Most variants were missense substitutions and classified as variants of unknown significance. Therefore, we cloned all rare missense variants and quantified their impact on telomere elongation in a cell-based assay. We found that 90% of TERT rare variants had severe or intermediate impairment in their capacity to elongate telomeres. Using a homology model of human TERT bound to the shelterin protein TPP1, we inferred that TERT rare variants disrupt domain-specific functions, including catalysis, protein-RNA interactions, and recruitment to telomeres. Our results indicate that the contribution of TERT rare variants to MDS pathogenesis and NRM risk is underrecognized. Routine screening for TERT rare variants in MDS patients regardless of age or clinical suspicion may identify clinically inapparent telomere biology disorders and improve transplant outcomes through risk-adapted approaches.

Short telomere length predicts nonrelapse mortality after stem cell transplantation for myelodysplastic syndrome.

Allogeneic hematopoietic stem cell transplantation is the only potentially curative treatment for patients with myelodysplastic syndrome (MDS), but long-term survival is limited by the risk of transplant-related complications. Short telomere length, mediated by inherited or acquired factors, impairs cellular response to genotoxic and replicative stress and could identify patients at higher risk for toxicity after transplantation. We measured relative telomere length in pretransplant recipient blood samples in 1514 MDS patients and evaluated the association of telomere length with MDS disease characteristics and transplantation outcomes. Shorter telomere length was significantly associated with older age, male sex, somatic mutations that impair the DNA damage response, and more severe pretransplant cytopenias, but not with bone marrow blast count, MDS treatment history, or history of prior cancer therapy. Among 1267 patients ≥40 years old, telomere length in the shortest quartile was associated with inferior survival (P < .001) because of a high risk of nonrelapse mortality (NRM; P = .001) after adjusting for significant clinical and genetic variables. The adverse impact of shorter telomeres on NRM was independent of recipient comorbidities and was observed selectively among patients receiving more intensive conditioning, including myeloablative regimens and higher dose melphalan-based reduced-intensity regimens. The effect of shorter telomeres on NRM was prominent among patients who developed severe acute graft-versus-host disease, suggesting that short telomere length may limit regenerative potential of mucosal tissues after acute injury. MDS patients with shorter telomere length, who have inferior survival driven by excess toxicity, could be considered for strategies focused on minimizing toxic effects of transplantation.

Correction: Clinical associations with telomere length in chronic spinal cord injury.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Telomere length in COPD: Relationships with physical activity, exercise capacity, and acute exacerbations.

RATIONALE: Shorter leukocyte telomere length (LTL) is associated with reduced health-related quality of life and increased risk for acute exacerbations (AEs) and mortality in chronic obstructive pulmonary disease (COPD). Increased physical activity and exercise capacity are associated with reduced risk for AEs and death. However, the relationships between LTL and physical activity, exercise capacity, and AEs in COPD are unknown. METHODS: Data from 3 COPD cohorts were examined: Cohort 1 (n = 112, physical activity intervention trial), Cohorts 2 and 3 (n = 182 and 294, respectively, separate observational studies). Subjects completed a 6-minute walk test (6MWT) and provided blood for LTL assessment using real-time PCR. Physical activity was measured as average daily step count using an accelerometer or pedometer. Number of self-reported AEs was available for 1) the year prior to enrollment (Cohorts 1 and 3) and 2) prospectively after enrollment (all cohorts). Multivariate models examined associations between LTL and average daily step count, 6MWT distance, and AEs. RESULTS: A significant association between longer LTL and increased 6MWT distance was observed in the three combined cohorts (ß = 3x10-5, p = 0.045). No association between LTL and average daily step count was observed. Shorter LTL was associated with an increased number of AEs in the year prior to enrollment (Cohorts 1 and 3 combined, ß = -1.93, p = 0.04) and with prospective AEs (Cohort 3, ß = -1.3388, p = 0.0003). CONCLUSIONS: Among COPD patients, increased LTL is associated with higher exercise capacity, but not physical activity. Shorter LTL was associated with AEs in a subgroup of cohorts.

Perceived racism in relation to telomere length among African American women in the Black Women's Health Study.

PURPOSE: Telomere length is considered a biomarker of human aging and premature morbidity and mortality which has been associated with chronic stress. METHODS: We assessed the relation between perceived racism and telomere length in the Black Women's Health Study, a follow-up study of U.S. black women begun in 1995. Participants were asked about frequency of "everyday racism" (e.g., "people act as if they think you are not intelligent") and "institutional racism" (e.g., "ever treated unfairly due to race by police"). Using quantitative real-time polymerase chain reaction assay, relative telomere lengths (RTL) were measured as the copy number ratio of telomere repeat to a single control gene in 997 participants. Associations of racism variables with log-RTL were estimated by multivariable linear regression, with adjustment for age at blood draw and potential confounders. RESULTS: Participants were aged 40-70 years (mean = 55.6 years), and mean telomere length was 0.77 (range 0.21-1.38). In stratified analyses, there was an inverse association between everyday racism and log-RTL among women who did not discuss their experiences of racism with others (ß = -0.1104; 95% CI = -0.2140 to -0.0067; P = .045). CONCLUSIONS: Everyday racism was associated with shorter telomere length among women who reported not discussing those experiences with others.

Clinical associations with telomere length in chronic spinal cord injury.

STUDY DESIGN: Cross-sectional study OBJECTIVES: To determine clinical factors associated with telomere length in persons with chronic spinal cord injury (SCI). SETTING: Veterans Affairs Medical Center, Boston, MA. METHODS: Two hundred seventy-eight participants with chronic SCI provided blood samples for measurement of C-reactive protein (CRP), interleukin-6 (IL-6), and telomere length, completed respiratory health questionnaires, underwent dual X-ray absorptiometry (DXA) to assess body fat, and completed spirometry. High-throughput real-time PCR assays were used to assess telomere length in leukocyte genomic DNA. Linear regression models were used to assess cross-sectional associations with telomere length. RESULTS: Telomere length was inversely related to age (p < 0.0001). In age-adjusted models, gender, race, injury duration, %-total and %-trunk fat, body mass index (BMI), %-predicted forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1), chronic cough or phlegm, CRP, IL-6, wheeze, smoking, diabetes, heart disease, chronic obstructive pulmonary disease (COPD), skin ulcer, urinary tract infection (UTI), or chest illness history were not significantly associated with telomere length. There was a suggestive age-adjusted association between persons with the most severe SCI (cervical motor complete and AIS C) and shorter telomere length (p = 0.055), an effect equivalent to ~8.4 years of premature aging. There were similar age-adjusted associations with telomere length between persons using a wheelchair (p = 0.059) and persons with chronic urinary catheter use (p = 0.082) compared to persons without these characteristics. CONCLUSIONS: Our results suggest that clinical characteristics such as decreased mobility and bladder dysfunction that are common in individuals with more severe SCI are associated with shorter telomere length.

Posttraumatic Stress Disorder Symptoms, Temperament, and the Pathway to Cellular Senescence.

Traumatic stress is thought to be associated with shortened telomere length (TL) in leukocytes, an age-related marker of increased risk for cellular senescence, although findings thus far have been mixed. We assessed associations between posttraumatic stress disorder (PTSD) symptom severity, temperament, and TL in a sample of 453 White, non-Hispanic, middle-aged, trauma-exposed male and female veterans and civilians. Given that prior research has suggested an association between PTSD and accelerated cellular age, we also examined associations between TL and an index of accelerated cellular age derived from DNA methylation data (DNAm age). Analyses revealed that, controlling for chronological age, PTSD was not directly associated with TL but rather this association was moderated by age, ß = -.14, p = .003, ΔR2 = .02. Specifically, PTSD severity evidenced a stronger negative association with TL among relatively older participants (≥ 55 years of age). In a subset of veterans with data pertaining to temperament (n = 150), positive emotionality, and, specifically, a drive toward achievement, ß = .26, p = .002, ΔR2 = .06, were positively associated with TL. There was no evidence of an association between age-adjusted TL and accelerated DNAm age. Collectively, these results indicate that older adults may be more vulnerable to the negative health effects of PTSD but that traits such as achievement, resilience, and psychological hardiness may be protective. These findings underscore the importance of identifying reliable biomarkers of cellular aging and senescence and of determining the biological mechanisms that contribute to stress-related disease and decline.

Prospective association between major depressive disorder and leukocyte telomere length over two years.

BACKGROUND: Reduced leukocyte telomere length (LTL) has been found to be associated with multiple common age-related diseases, including heart disease, diabetes, and cancer. A link has also been suggested between shortened LTL and major depressive disorder (MDD), suggesting that MDD may be a disease of accelerated aging. This prospective, longitudinal study examined the association between depression diagnosis at baseline and change in LTL over two years in a well-characterized sample of N = 117 adults with or without MDD at baseline, using rigorous entry criteria. METHODS: Participants aged 18-70 were assessed with validated instruments by trained, doctoral-level clinician raters at baseline and at two-year follow-up, and blood samples were obtained at both visits. LTL was assayed under identical methods using quantitative polymerase chain reaction (qPCR). The effect of an MDD diagnosis at baseline on change in LTL over two years was examined via hierarchical mixed models, which included potential confounders. RESULTS: Individuals with MDD at baseline had greater LTL shortening over two years than individuals without MDD (p = 0.03), even after controlling for differences in age, sex, and body mass index (BMI). In the sub-sample of individuals with MDD diagnoses at baseline, no significant associations between LTL change and symptom severity or duration were found. CONCLUSION: A baseline diagnosis of MDD prospectively predicted LTL shortening over two years. Our results provide further support for MDD as a disease associated with accelerated aging in a well-characterized sample using validated, clinician-rated measures.

A Prospective Study Investigating Prediagnostic Leukocyte Telomere Length and Risk of Developing Rheumatoid Arthritis in Women.

OBJECTIVE: To prospectively examine the association between leukocyte telomere length (LTL) and subsequent rheumatoid arthritis (RA) development in women. METHODS: Using a case-control design nested within the prospective Nurses' Health Study (NHS), NHS II (NHSII), and Women's Health Study (WHS), each validated case of RA with a prediagnostic blood sample was matched to 3 controls by cohort, age, menopausal status, postmenopausal hormone therapy, and blood collection covariates. We measured telomere length in genomic DNA extracted from stored buffy coat samples using quantitative PCR. We used unconditional logistic regression to determine OR and 95% CI, and random-effects metaanalysis to combine study results. RESULTS: In total, we analyzed 296 incident RA cases and 827 matched controls. Mean age of diagnosis among women who developed RA was 60.5 in NHS/NHSII and 61.3 in WHS. Metaanalysis demonstrated that longer prediagnostic LTL was associated with increased RA risk when women in the longest versus shortest LTL tertile were compared (OR 1.51, 95% CI 1.03-2.23, Pheterogeneity = 0.27). However, statistically significant between-study heterogeneity was observed for the intermediate tertile category (Pheterogeneity = 0.008). We did not observe heterogeneity by menopausal status, inflammatory cytokine levels, age at diagnosis, age at blood collection, body mass index, seropositivity, or HLA-DRß1 shared epitope status. CONCLUSION: Our results do not support an involvement for short LTL preceding RA development.

Telomere length and risk of glioma.

BACKGROUND: Telomere length in blood or buccal cell DNA has been associated with risk of various cancers. Glioma can be a highly malignant brain tumor and has few known risk factors. Genetic variants in or near RTEL1 and TERT, key components of telomere biology, are associated with glioma risk. Therefore, we evaluated the association between relative telomere length (RTL) and glioma in a prospective study. MATERIALS AND METHODS: We performed a nested case-control study within the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial. RTL was determined by quantitative PCR on blood or buccal cell DNA obtained at least 2 years prior to diagnosis from 101 individuals with glioma cases. Healthy controls (n=198) were matched to cases (2:1) on age, gender, smoking status, calendar year, and DNA source. Conditional logistic regression was used to investigate the association between RTL and glioma. RESULTS: As expected, RTL declined with increasing age in both cases and controls. There was no statistically significant association between RTL and glioma overall. An analysis stratified by gender suggested that short RTL (1st tertile) in males was associated with glioma (odds ratio, [OR]=2.29, 95% confidence interval [CI] 1.02-5.11); this association was not observed for females (OR=0.41, 95% CI 0.14-1.17). CONCLUSIONS: This prospective study did not identify significant associations between RTL and glioma risk, but there may be gender-specific differences. Larger, prospective studies are needed to evaluate these findings.

Loving-Kindness Meditation practice associated with longer telomeres in women.

Relatively short telomere length may serve as a marker of accelerated aging, and shorter telomeres have been linked to chronic stress. Specific lifestyle behaviors that can mitigate the effects of stress might be associated with longer telomere lengths. Previous research suggests a link between behaviors that focus on the well-being of others, such as volunteering and caregiving, and overall health and longevity. We examined relative telomere length in a group of individuals experienced in Loving-Kindness Meditation (LKM), a practice derived from the Buddhist tradition which utilizes a focus on unselfish kindness and warmth towards all people, and control participants who had done no meditation. Blood was collected by venipuncture, and Genomic DNA was extracted from peripheral blood leukocytes. Quantitative real time PCR was used to measure relative telomere length (RTL) (Cawthon, 2002) in fifteen LKM practitioners and 22 control participants. There were no significant differences in age, gender, race, education, or exposure to trauma, but the control group had a higher mean body mass index (BMI) and lower rates of past depression. The LKM practitioners had longer RTL than controls at the trend level (p=.083); among women, the LKM practitioners had significantly longer RTL than controls, (p=.007), which remained significant even after controlling for BMI and past depression. Although limited by small sample size, these results offer the intriguing possibility that LKM practice, especially in women, might alter RTL, a biomarker associated with longevity.

Computed tomography pulmonary angiography: an assessment of the radiology report.

RATIONALE AND OBJECTIVE: The aim of this study was to evaluate the uncertainty in computed tomographic pulmonary angiography (CTPA) radiology reports, manifested by descriptions of report limitations and image quality. MATERIALS AND METHODS: CTPA reports between 2004 and 2006 were reviewed for patient demographic data (age, gender, pregnancy state), radiologist data (years of experience, subspecialty, final dictation by an attending radiologist vs a resident being present and dictating the report), the presence of pulmonary embolism (PE), and key words describing examination quality and limitations. RESULTS: There were 2151 CTPA reports. Patterns of reporting CTPA in the impression sections of radiology reports were as follows: (1) PE conclusively positive (10%), (2) PE conclusively negative (29%), (3) PE negative to segmental arteries (27%), (4) PE negative to central pulmonary arteries (21%), (5) PE negative but suboptimal examination (8%), and (6) nondiagnostic examination (5%). Among the last three categories, seven PEs were not initially diagnosed but were found on subsequent imaging examinations. Limitations in image quality, respiratory motion artifact, and contrast enhancement were most frequently mentioned as limitations in image quality (62% and 28% of all reports, respectively). Radiologists tended to report limitations in image quality if they were thoracic radiology subspecialists, had >10 years of experience, or worked independently (P < .001). CONCLUSION: Different patterns of reporting CTPA exist and vary on the basis of individual radiologists' subspecialties, experience, and whether they work independently or with residents. Certain wording regarding the presence of PE may falsely imply negativity of PE in a limited examination.