The Effect of Maintenance Treatment with Twice-Daily or Prolonged Once-Daily Tacrolimus Formulation on Visual Evoked Potentials in Stable Kidney Transplant Recipients

Divergent Occurrence of Carotid Intima-Media Thickness and Carotid Arteries Plaques in Stable Kidney Transplant Recipients

Background

Carotid atherosclerosis is one of the main cerebrovascular complications in kidney transplant recipients (KTRs). We analyzed the relationships between carotid intima-media thickness (IMT) and the occurrence and characteristics of carotid plaques in a cohort of KTRs.

Methods

In 500 KTRs (aged 49.9 ± 12.0 years), IMT was measured and carotid plaques were semi-qualitatively assessed. Concomitantly, biochemical and hormonal inflammatory, vascular and calcium-phosphate metabolism parameters were also assessed.

Results

In 10.2% of patients, a side-to-side IMT difference > 0.1 mm was observed, whereas 26.8% of patients with no plaques in one carotid artery had at least one contralateral calcified plaque. Multivariate logistic regression analysis revealed that age ( r partial = 0.409; p < 0.001), male sex ( r partial = 0.199; p < 0.001), and coronary artery disease ( r partial = 0.139; p < 0.01) independently increased IMT ( R 2 = 0.25). For the occurrence of calcified carotid plaques, age ( r partial = 0.544; p < 0.001), male gender ( r partial = 0.127; p < 0.05), and the duration of renal insufficiency prior to transplantation ( r partial = 0.235; p < 0.001) were confirmed as independent variables.

Conclusions

Substantial side-to-side differences in IMT values and carotid plaques distribution are present in a large percentage of stable KTRs. In addition, there are different clinical risk factors profiles associated with IMT and the presence of calcified plaques. Vascular and calcium-phosphate metabolism biomarkers were not associated with any carotid atherosclerosis characteristics.

Visual evoked potentials as a method for the prospective assessment of tacrolimus neurotoxicity in patients after kidney transplantation

INTRODUCTION

Neurotoxicity, including optic nerve injury, is one of the most common adverse effects of tacrolimus, the principal calcineurin inhibitor used after kidney transplantation (KTx). The electrophysiologic measurements of both pattern visual evoked potentials (PVEP) and flash visual evoked potentials (FVEP) are valuable when drug-induced optic neuropathy is suspected.

OBJECTIVES

To determine whether VEP measurement is a sensitive and repeatable method for monitoring tacrolimus neurotoxicity.

MATERIAL AND METHODS

This prospective study focused on 35 patients (20 M, 15F, 69 eyes, mean age 43 ± 11 years) who were at a median of 3.0 (IQR, 2.2-3.7) months after KTx at the time of the initial VEP evaluation and were treated with tacrolimus since KTx. The follow-up VEP examination was done after a median of 24 (22-27) months (both VEP measurements followed the ISCEV standards). The P100 wave latency and amplitude for the 1° and 15' PVEP simulations, and the P2 wave latency and amplitude for the FVEP were analyzed.

RESULTS

For the 1° checks, the P100 wave latency and amplitude values were significantly worse in the follow-up examination compared to the early post-transplant time-point. Independent associations between FVEP parameters and the tacrolimus blood trough level were observed in the follow-up examination but not at the early post-transplant period. The P2 wave latency correlated with the tacrolimus trough level only in patients treated with the twice-daily, but not the once-daily, tacrolimus formulation. The brain derived neurotrophic factor (BDNF) level correlated with the P100 (15') latency (R = 0.499; p = 0.005) and the P2 latency (R = 0.409; p = 0.025) only in patients treated with the once-daily, but not the twice-daily, tacrolimus formulation.

CONCLUSION

The observations in this study may support the rationale for the use of VEP measurements as non-invasive monitoring of subclinical tacrolimus neurotoxicity.

Kidney Disease Symptoms before and after Kidney Transplantation

BACKGROUND AND OBJECTIVES

Patients with kidney failure report a high symptom burden, which likely increases while on dialysis due to physical and mental stressors and decreases after kidney transplantation due to restoration of kidney function.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We leveraged a two-center prospective study of 1298 kidney transplant candidates and 521 recipients (May 2014 to March 2020). Symptom scores (0-100) at evaluation and admission for transplantation were calculated using the Kidney Disease Quality of Life Short-Form Survey, where lower scores represent greater burden, and burden was categorized as very high: 0.0-71.0; high: 71.1-81.0; medium: 81.1-91.0; and low: 91.1-100.0. We estimated adjusted waitlist mortality risk (competing risks regression), change in symptoms between evaluation and transplantation (n=190), and post-transplantation symptom score trajectories (mixed effects models).

RESULTS

At evaluation, candidates reported being moderately to extremely bothered by fatigue (32%), xeroderma (27%), muscle soreness (26%), and pruritus (25%); 16% reported high and 21% reported very high symptom burden. Candidates with very high symptom burden were at greater waitlist mortality risk (adjusted subdistribution hazard ratio, 1.67; 95% confidence interval, 1.06 to 2.62). By transplantation, 34% experienced an increased symptom burden, whereas 42% remained unchanged. The estimated overall symptom score was 82.3 points at transplantation and 90.6 points at 3 months (10% improvement); the score increased 2.75 points per month (95% confidence interval, 2.38 to 3.13) from 0 to 3 months, and plateaued (-0.06 points per month; 95% confidence interval, -0.30 to 0.18) from 3 to 12 months post-transplantation. There were early (first 3 months) improvements in nine of 11 symptoms; pruritus (23% improvement) and fatigue (21% improvement) had the greatest improvements.

CONCLUSIONS

Among candidates, very high symptom burden was associated with waitlist mortality, but for those surviving and undergoing kidney transplantation, symptoms improved.