*Purpose: Drug-induced immunosuppression in kidney transplantation is crucial to prevent allograft rejection, but increases risk for infectious, cardiovascular and malignant disease. Tailoring of immunosuppressive drug dosing to prevent alloreactivity and adverse effects at the same time is thus highly desirable. The apathogenic Torque Teno virus (TTV) reflects the immunocompetence of its host and might act as a potential candidate for immunologic monitoring.

*Methods: We screened all 1002 consecutive patients from the prospective Vienna transplant cohort study for indication biopsy and adequately stored sera for TTV quantification by PCR.

*Results: Patients with acute biopsy-proven alloreactivity (n=33) showed lower levels of TTV in peripheral blood compared to patients without rejection (n=80) at a median of 43 days before biopsy. The odds for alloreactivity decreased by 16% per log level of TTV copies/mL (0.84; 95% confidence interval, 0.75 – 0.95; P=0.004). TTV levels above 1.8×10⁶copies/mL exclude rejection with a sensitivity of 90%. Multivariable logistic regression modeling suggests an independent association between TTV level and alloreactivity.

*Conclusions: TTV quantification is useful as a prospective biomarker for acute biopsy-proven alloreactivity in kidney transplants and might be useful as a potential tool to tailor immunosuppressive drug therapy.

« Back to 2019 American Transplant Congress