Beschreibung:
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<jats:title>Background.</jats:title>
<jats:p>Quantification of torque teno virus (TTV) has been proposed as a surrogate parameter to monitor immunocompetence in kidney transplant recipients (KTRs) early after transplantation. However, its use in monitoring short-term changes of immunosuppression in KTRs late after transplantation requires further investigation.</jats:p>
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<jats:title>Methods.</jats:title>
<jats:p>In this post hoc analysis, we quantified TTV load in sera of 76 KTRs, with 43 pausing mycophenolic acid (MPA) 1 wk before to 4 wk after COVID-19 vaccination to increase vaccine response. TTV load was quantified before, 4 wk, and 3 mo postvaccination. Results were compared to 33 KTRs with continued standard immunosuppressive therapy and with 18 hemodialysis as well as 18 healthy control subjects.</jats:p>
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<jats:title>Results.</jats:title>
<jats:p>TTV load before vaccination was with a median (interquartile range) of 1.39 × 10<jats:sup>4</jats:sup> copies/milliliter (c/mL) (9.17 × 10<jats:sup>1</jats:sup>–2.66 × 10<jats:sup>5</jats:sup> c/mL) highest in KTRs compared to 1.73 × 10<jats:sup>3</jats:sup> c/mL (1.07 × 10<jats:sup>3</jats:sup>–1.31 × 10<jats:sup>4</jats:sup> c/mL) in hemodialysis patients and 1.53 × 10<jats:sup>2</jats:sup> c/mL (6.38–1.29 × 10<jats:sup>3</jats:sup> c/mL) in healthy controls. In KTRs with MPA withdrawal, TTV load decreased significantly from a median (interquartile range) of 1.11 × 10<jats:sup>4</jats:sup> c/mL (4.75 × 10<jats:sup>2</jats:sup>–1.92 × 10<jats:sup>5</jats:sup> c/mL) to 5.24 × 10<jats:sup>3</jats:sup> c/mL (6.92 × 10<jats:sup>2</jats:sup>–6.91 × 10<jats:sup>4</jats:sup> c/mL) 4–5 wk after initiation of MPA withdrawal (<jats:italic toggle="yes">P</jats:italic> = 0.003). In patients with MPA withdrawal, TTV load was significantly inversely correlated with COVID-19 or SARS-CoV-2–specific antibodies 4 wk and 3 mo postvaccination (<jats:italic toggle="yes">P</jats:italic> = 0.009 and <jats:italic toggle="yes">P</jats:italic> = 0.004).</jats:p>
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<jats:title>Conclusions.</jats:title>
<jats:p>TTV load reflects changes in immunosuppressive therapy even late after transplantation, supporting its use to monitor immunocompetence in KTRs.</jats:p>
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