Telomere Length of Peripheral Blood Mononuclear Cells is Associated with Discharge Disposition in Older Trauma Patients.

INTRODUCTION: Little is known regarding peripheral blood mononuclear cell telomere length (PBMC-TL) and response to traumatic injury. The objective of this study was to characterize the role of PBMC-TL in coagulation and clinical outcomes after injury.

METHODS: Plasma and buffy coats were prospectively collected from trauma patients and healthy volunteers. DNA was purified and PBMC-TL quantified by qPCR. Thrombin generation kinetics were expressed as lag time (LT, minutes), peak height (PH, nM), time to peak (ttPeak, min), and endogenous thrombin potential (ETP, nM*min). Results in median and quartiles [Q1, Q3]. Wilcoxon rank sum testing; p < 0.05 considered significant.

RESULTS: Forty-two younger patients (21 [20, 22] years, 69% male) and 39 older patients (62 [61, 64] years, 79% male) were included. There was no significant difference in Clinical Frailty Scores between groups. Younger patients had longer total PBMC-TL (0.40 Mb [0.30, 0.49] vs. 0.29 Mb [0.23, 0.33], p < 0.001) and longer average PBMC-TL per chromosome (4.3 kb [3.3, 5.3] vs. 3.2 kb [2.5, 3.7], p < 0.001). When older patients were stratified by 50th percentile of PBMC-TL, there were no differences in thrombin generation; however, those with shorter telomeres were less likely to be discharged home (29% vs. 77%, p = 0.004). Older patients in the bottom quartile of PBMC-TL had shorter LT (2.78 min [2.33, 3.00] vs. 3.33 min [3.24, 3.89], p = 0.030) and were less likely to be discharged home (22% vs. 90%, p = 0.006) than those in the top quartile of PBMC-TL. Multivariable logistic regression models revealed both increased age and shorter PBMC-TL to be independent predictors of discharge disposition other than home.

CONCLUSION: In older trauma patients, shorter PBMC-TL is associated with accelerated initiation of thrombin generation and lower likelihood of being discharged to home.