Diagnostic effectiveness of transforming growth factor beta 1 (TGF-β1) at adjustment of tacrolimus individual dose in pediatric liver recipients

Abstract

Blood level of transforming growth factor beta 1 (TGF-β1) is associated with liver function and immune homeostasis, which suggests it as a potential biomarker for immunosuppressant tacrolimus dose requirement at liver transplantation (LT).Aim. To evaluate diagnostic efficacy of TGF-β1 blood level at determination of individual tacrolimus dose requirement in children at LT.Materials and methods. 89 children with end stage liver disease aged from 3 to 73 months were examined. Children underwent living related LT, then the recipients received 2–3 component immunosuppressive therapy, including tacrolimus. Blood concentration of tacrolimus and TGF-β1 was measured by ELISA.Results. TGF-β1 blood level in children before LT was significantly lower than in healthy children: 3.7 (1.3–8.4) and 19.3 (12.6–25.5) ng/ml, p = 0.001. A month after LT, its concentration increased to 8.1 (1.8–15.3) ng/ml (p = 0.02). A year after LT, the cytokine level remained higher than before transplantation: 6.6 (1.9–12.6) ng/ml, p = 0.01. TGF-β1 level did not correlate with tacrolimus blood concentration, determined 12 hours after the last administration of the drug, neither a month, nor a year after transplantation. At the same time, the cytokine level one month after LT was associated with a tacrolimus daily dose one year after the operation (r = –0.23, p = 0.04). In the recipients, who received smaller daily doses (0.4–2.5 mg) of tacrolimus, TGF-β1 level was higher than in those receiving large doses (3.0–6.0 mg) of the drug: 9.1 (2.6–16.2) ng/ml vs. 4.2 (1.3–9.2) ng/ ml, p = 0.04. Evaluation of diagnostic efficacy of the TGF-β1 level as a test for the detection of tacrolimus dose requirement showed that the area under the ROC curve (AUC) was 0.66 ± 0.07; 95% CI [0.53–0.79], the sensitivity and specificity of the test were 60 and 74% at threshold value 6.7 ng/ml. Relative risk of higher tacrolimus dose requirement was 3.14 ± 0.48; 95% CI [1.24–7.96].Conclusion. TGF-β1 blood level in one month after LT less than 6.7 ng/ml is 3 times higher risk factor of tacrolimus dose requirement more than 3.0 mg per day. The likehood of the test is 66%, the sensitivity and specificity – 60 and 74%.

Keywords

• biomarker
• liver cirrhosis
• pediatric recipients
• congenital biliary diseases