Trajectory of Immunosuppression-Caused Tremor In Kidney and Lung Transplant Recipients

Kidney and lung transplant recipients have to adhere to a strict immunosuppressive maintenance regime, generally including calcineurin inhibitors (CNIs). These CNIs, including cyclosporine and tacrolimus, are essential to prevent graft rejection, but are associated with multiple side-effects. One of the most frequently reported side-effects of CNIs is the development of tremor: rhythmic, sinusoidal oscillations of the limbs, head or trunk. CNI-induced tremor generally occurs soon after initiation of CNI maintenance therapy, and occurs in up to half of kidney transplant recipients who use CNIs. Higher tacrolimus blood concentration has been associated with more severe tremor, and lung transplant recipients have the highest target trough concentration. Thus, tremor may be especially an import symptom for this patient population. To what extent tremor changes over time and whether this change is objective and/or subjective is currently unknown. In-depth investigation of the course of tremor is therefore warranted, which would add valuable information to previous studies on tremor prevalence. We therefore aim to assess the course of tremor in the first year after kidney- and lung transplantation. We expect tremor to become less severe over time after transplantation, because patients CNI dosage decrease with time after transplantation. However, it may also be hypothesized that CNI neurotoxicity may accumulate with consequent worsening of tremor. More information regarding the course of tremor after transplantation is essential to increase understanding of CNI-induced tremor, as well as for patient counselling and future research to alleviate the burden of CNI-induced tremor.