Clinicopathologic Impact of Early Medullary Ray Injury in Patients Following Kidney Transplantation.

BACKGROUND: Previously, we explored the histopathologic characteristics of medullary ray injury (MRI) inducing interstitial fibrosis and tubular atrophy (IF/TA) to determine its etiologies, which include calcineurin inhibitor (CNI) toxicity and urologic complications. However, we did not examine the effects of these etiologies on long-term kidney allograft prognosis, because biopsy timing differed among cases. AIM: We examined the influence of early MRI on kidney allograft prognosis using protocol biopsies taken within a 3-month time frame. METHODS: We defined early MRI as tubular degeneration with interstitial edema or mild fibrosis localized to the medullary ray. We divided 53 protocol biopsies into 2 groups, with and without early MRI. Early MRI+ cases with isometric vacuolization were classified as CNI toxicity; those with Tamm-Horsfall protein in the interstitium and a thyroidlike appearance were classified as urinary tract system abnormalities; remaining cases were classified as "others." We compared changes in serum levels of creatinine (sCr) over 3 years and fibrosis extent at 1 year. RESULTS: The sCr levels were significantly higher in the MRI+ group than the MRI- group at 3 years (P = .024). Examining the 3 MRI+ subgroups, only the MRI+ urinary tract system abnormalities group had significantly high sCr levels compared to the MRI- group (P = .019). The MRI+ group showed significant signs of IF/TA at 1 year. CONCLUSIONS: Early MRI after kidney transplantation was significantly more likely to develop IF/TA at 1 year and had higher sCr levels at 3 years. In such cases, intervention might preserve graft function over the long term.

Large perinephric abscess in a patient on maintenance hemodialysis diagnosed by positron emission tomography combined with computed tomography (PET-CT).

Perinephric abscesses in patients on maintenance hemodialysis (HD) have seldom been reported. The case of a maintenance HD patient with a left perinephric abscess is reported. Although the lesion could not be visualized using other imaging examinations, using FDG and positron emission tomography combined with computed tomography (PET-CT), the patient was diagnosed as having a left perinephric abscess and nephrolithiasis. At the patient's request, the perinephric abscess was treated conservatively with antibiotic therapy alone, and it eventually remitted. This is the first case report of a perinephric abscess diagnosed by FDG PET-CT in a patient on maintenance HD. FDG PET-CT appears to be useful for identifying perinephric abscesses in HD patients, resulting in early diagnosis and appropriate therapy for this severe infection.