Brain MR imaging abnormalities in kidney transplant recipients

Area of Science:

• Neurology
• Nephrology
• Radiology

Background:

• Brain MR imaging abnormalities in kidney transplant recipients (KTRs) have been often attributed to calcineurin inhibitors (CIs).
• Posterior reversible encephalopathy syndrome (PRES) is a characteristic presentation linked to CIs.

Purpose of the Study:

• To investigate the role of CIs in the incidence, nature, and location of brain MR imaging lesions in adult KTRs.
• To compare brain MR imaging findings in KTRs with those in dialysis-dependent patients.

Main Methods:

• Retrospective analysis of 98 brain MR imaging exams in 77 KTRs with neurologic symptoms (1990-2003).
• KTRs categorized into three groups based on time post-transplantation (0-3 months, 3-12 months, >12 months).
• 26 MR imaging exams from 24 dialysis-dependent adults served as controls (group 0).

Main Results:

• Infarcts were the most common acute lesion in both KTRs (24%) and controls (19%).
• Chronic lesions, predominantly vascular, were more frequent (76% in KTRs, 81% in controls).
• No significant differences in PRES or other acute changes were observed between KTRs and dialysis patients.

Conclusions:

• The study does not support the hypothesis that MR imaging brain abnormalities in KTRs are primarily due to direct calcineurin inhibitor toxicity.
• Deep gray matter lesions were more common in KTRs, while frontal white matter was more affected in dialysis patients.