Ultrasound findings of BK polyomavirus-associated nephropathy in renal transplant patients.

BK polyomavirus (BKV) is an emerging pathogen in immunocompromised patients. BKV infection occurs in 1-9 % of renal transplants and causes chronic nephropathy or graft loss. Diagnosis of BKV-associated nephropathy (BKVAN) is based on detection of viruria then viremia and at least a tubule-interstitial nephritis at renal biopsy. This paper describes the ultrasound and color Doppler (US-CD) features of BKVAN. Seventeen patients affected by BKVAN were studied using a linear bandwidth 7-12 MHz probe. Ultrasound showed a widespread streak-like pattern with alternating normal echoic and hypoechoic streaks with irregular edges from the papilla to the cortex. Renal biopsy performed in hypoechoic areas highlighted the typical viral inclusions in tubular epithelial cells. Our experience suggests a possible role for US-CD in the non-invasive diagnosis of BKVAN when combined with blood and urine screening tests. US-CD must be performed with a high-frequency linear probe to highlight the streak-like pattern of the renal parenchyma.

[Karyomegalic interstitial nephritis: an atypical case]. / La nefrite interstiziale cariomegalica: descrizione di un caso clinico atipico.

Karyomegalic interstitial nephritis (KIN) is a rare disease entity that was first described by Burry in 1974. The prevalence of this disease is less than 1% and its pathogenesis is unclear. KIN is characterized by chronic tubulointerstitial nephritis associated with enlarged tubular epithelial cell nuclei, which leads to progressive decline of renal function. The disease has no known treatment. Here, we report on a 50-year-old female patient who presented with asymptomatic progressive decline of renal function. Renal biopsy demonstrated chronic tubulointerstitial nephritis with markedly enlarged and hyperchromic nuclei of tubule epithelial cells the hallmark of karyomegalic nephritis. Clinical and pathologic findings of this case are discussed in light of the available literature.

[Ultrasound-guided renal biopsy: evaluation of different models of biological simulator]. / La biopsia renale-ecoguidata: valutazione di diversi modelli di simulatore biologico.

Percutaneous ultrasound-guided renal biopsy is the gold standard for diagnosis and treatment of renal diseases. Recently, many studies strongly support the role of renal biopsy for the management of small renal mass. The experience of the operator is crucial in reducing the incidence of major complications. The use of simulators can accelerate the learning curve in those individuals who train in renal biopsy. We describe four simple and affordable phantoms for renal biopsy. The first two simulators were constructed by a porcine kidney wrapped in perirenal fat or covered by a flap of abdominal skin. The third simulator was constructed by embedding a porcine kidney in a turkey breast and olives to simulate the presence of small tumors. For the fourth model, we used the loin of a pork. Given the encouraging results of our in vitro study, we believe that simulators allow trainees to familiarize themselves with the handling of the equipment in an environment that is risk-free when compared to the clinical scenario.