Journal Article Annotations
2019, 3rd Quarter
Annotations by Paula Zimbrean
September 2019
The finding:
The study assessed brain relaxation in liver transplant recipients using functional MRI. The transplant recipient group was divided by their exposure to calcineurin inhibitors (CNIs) and compared the results with those of a control group of non-transplant patients.
Strength and weaknesses:
This study is the first to report differences in the brain structure in liver transplant recipients using functional MRI, a relatively new neuroimaging technique which allows a more detailed examination of the functioning of the brain cells, in particular of the brain relaxation (assessed by measuring the spin to spin interactions). This study shows differences in the brain functioning of liver transplant recipients compared to the general population, and differences between groups with different exposure to calcineurin inhibitors.
The interpretation of the results is limited as it did not include any clinical measures, so the significance of these MRI findings still needs to be investigated. In addition, otherimmunosuppressants (non CNIs), which were consistently taken by the patients in this study, may have had an impact on the qMRI results of the cerebral tissue. Furthermore, the standard immunosuppressive therapy regime after OLT includes CNI and therefore no group of patients with CNI-free immunosuppressive therapy from the first day after transplantation was available. Other limitations are that this was a single-center observational study with limited transferability to other centers and unfortunately no data from before OLT was available from our patients. Finally, the sample size limits the statistical power.
Relevance:
This study represents a significant step forward in understanding the brain changes that occur after organ transplantation. Clinicians have long known that cognitive and psychiatric status are significantly altered in transplant recipients by various factors, including the medical illness, immunosuppressant medications and psychosocial factors. This study supports the fact that these changes are not mainly due to “adjustment issues” or pre-existing medical problems and opens the field to further exploration.
Type of study: cross sectional, cohort
The finding:
This is a systematic review and meta analysis of 92 studies (over 8000 patients) aiming at identifying the risk factors for alcohol relapse in liver transplant patients. In this study, unmarried status, smoking, psychiatric co-morbidities (but not depression) and length of abstinence (less than 6 months) was associated with higher risk of alcohol relapse after transplantation.
Strength and weaknesses:
This was a systematic review conducted by standard protocols and using systematic statistical tools. The clinical interpretation of these results is limited by the bias of unpublished negative results and by the heterogenity of these studies in terms of length of follow up, assessment of relapse and type of study.
Relevance:
The most memorable finding is the fact that psychiatric co-morbidities (but not depression) was the most significant factor in predicting the alcohol relapse in this group. Interestingly, the impact of the psychiatric co-morbidities upon risk of relapse increased as the time to transplantation increased. For clinicians, this can help guide focusing the mental health services on patients identified at higher risk by the time spent on the waiting list.
Type of study: Systematic review and meta-analysis
The finding:
This is a retrospective study that investigated the significance of non-adherence with hemodialysis in predicting adherence with medical treatment post transplantation. The authors found that non-adherence in the year before transplantation did not predict post-transplant non adherence.
Strength and weaknesses:
The predictive role of pre-transplant adherence has rarely been challenged and in clinical practice lack of adherence with dialysis is often seen as a factor that needs to be corrected before transplantation is considered. The study is limited by its retrospective design and reliance on medical records without a systematic measurement of adherence. In addition, the medication adherence, which is crucial post transplantation, was measured only via the proxy of tacrolimus level, without any behavioural measurement.
Relevance:
The findings of this study question the predictive role of pre transplant non adherence for post transplant adherence and invites to more research on this topic.
Type of study: retrospective cohort