Leukocyte Telomere Length and Long-Term Clinical Outcomes in Women with Systemic Lupus Erythematosus: A Prospective...

Background/Objectives: Leukocyte telomere length (TL) is a marker of biological aging associated with cardiovascular disease, chronic kidney disease, and malignancy in the general population. Its long-term prognostic significance in systemic lupus erythematosus (SLE) remains unclear. We aimed to evaluate the association between baseline TL and long-term clinical outcomes in patients with SLE. Methods: Prospective cohort study including 97 Caucasian women with SLE. Relative TL was measured in whole blood using quantitative polymerase chain reaction (qPCR) at baseline. A control group of 50 healthy Caucasian women from the same geographical region was included for comparison. Patients were followed for a mean of 9.7 ± 2.8 years. Outcomes included thrombotic cardiovascular events, damage accrual, incident malignancy, and chronic kidney disease. Associations were assessed using multivariable regression models adjusted for potential confounders. Results: Mean age was 51.6 ± 13.8 years and mean relative TL was 4.3 ± 1.0. Relative TL was inversely associated with age (β = -0.20, p = 0.048) and was shorter in patients with hematological manifestations (p = 0.038). No differences in relative TL were observed between SLE patients and controls. Relative TL was not associated with disease activity, cumulative damage, cardiovascular risk factors, vitamin D levels, or subclinical atherosclerosis. During follow-up, 13.4% of patients experienced cardiovascular events, 10.3% developed malignancy, and 11.3% developed chronic kidney disease. Relative TL was initially associated with long-term damage accrual, glomerular filtration rate and cardiovascular events; however, after adjustment for age, only the association with glomerular filtration rate remained at the limit of statistical significance (p = 0.05). Conclusions: In this prospective cohort, relative TL was primarily associated with aging, hematological manifestations, and glomerular filtration rate, but not with disease activity or most long-term clinical outcomes. These findings suggest that TL reflects biological aging rather than disease-specific processes and has limited utility as a prognostic biomarker in SLE.