Early Post-Transplant Torque Teno Virus Load Dynamics: Correlation with Immune Profile and Prediction of Infection in Kidney Transplant Recipients

Background: Torque Teno Virus (TTV) load is an emerging biomarker of net immunosuppression in kidney transplant recipients (KTRs). This study investigated TTV DNA load dynamics, its correlation with immune profiles, and clinical associations in the critical early post-transplant period. Methods: We prospectively analyzed plasma TTV DNA load in 41 KTRs at baseline, day-7, day-14, and 1-month post-transplant. Lymphocyte subsets (CD3+, CD4+, CD8+, CD19+, NK cells) and cytokines (IL-6, IL-10) were assessed at day 14. We analyzed associations among TTV load, immune parameters, and clinical events like infection and rejection. Results: Results showed TTV load significantly increased from baseline to day 14 (p<0.001) and 1 month (p<0.001), with a progressive rise from week 2, consistently exceeding levels in healthy controls (p<0.001 at each point). Patients experiencing infections (n=16) had significantly higher TTV loads at days 7 (p=0.006), 14 (p=0.048), and 30 (p=0.044) than their uninfected counterparts. At day 14, TTV load positively correlated with CD8+ (r=0.677, p<0.001), CD19+ (r=0.433, p=0.005) cell percentages, and IL-10 levels (r=0.668, p<0.001). Conversely, it inversely correlated with CD3+ (r= -0.388, p=0.012), CD4+ (r= -0.478, p=0.002), NK cell percentages (r= -0.340, p=0.030), and IL-6 levels (r= -0.462, p=0.002). NK cells were notably higher in infected patients. Patients experiencing rejection (limited sample) exhibited lower TTV loads on days 7 and 14. Conclusion: These findings indicate that early post-transplant TTV load reflects immunosuppression depth, correlates with distinct immune alterations, and importantly, predicts infection risk. TTV monitoring could be a valuable, non-invasive tool for personalizing immunosuppression strategies in KTRs. Funding: Clinical Revenue Support