Causative vascular abnormalitiesfor renal ischemiaKidney International (2009) 75, 1354; doi:10.1038/ki.2009.106

To the Editor: As a case of The Renal Consult, Sperati et al.1

presented a 46-year-old man with renal infarctions and renalartery stenoses (RASs). Although their clinical diagnosis wasbilateral intimal fibromuscular dysplasia (FMD) complicatedby dissection, several distinctions of the case would indicateother causative abnormalities for the RASs, such as athero-sclerosis and arteritis.

Although the renal arteriographic image is characteristicof intimal FMD, either atherosclerosis or arteritis can presentarteriographic images similar to those seen in intimal FMD.2

A middle-aged man could have atherosclerosis, especially ifhe were a smoker. The intravascular ultrasound image, acrescent-shaped hypoechoic lesion with an echogenic layer onits vascular surface, would indicate lipid-laden atherosclerosiswith a thin fibrous cap.3 Several echogenic clefts inside thehypoechoic lesion would be fibrous or calcified componentsof atherosclerosis rather than dissection flaps. It would beunlikely that dissection flaps had been embedded in a thickthrombus covered by a fibrous cap. Furthermore, theepisodes of fever and spontaneous improvement in vascularlesions while taking prednisone might indicate superimposedinflammatory changes; these episodes are rarely noted inFMD.2

1. Sperati CJ, Aggarwal N, Arepally A et al. Fibromuscular dysplasia. KidneyInt 2009; 75: 333–336.

2. Luscher TF, Lie JT, Stanson AW et al. Arterial fibromuscular dysplasia.Mayo Clin Proc 1987; 62: 931–952.

3. Nissen SE, Yock P. Intravascular ultrasound: novel pathophysiologicalinsights and current clinical applications. Circulation 2001; 103: 604–616.

Masayuki Tanemoto1

1Division of Nephrology, Hypertension, and Endocrinology, Department of

Medicine, Tohoku University Graduate School of Medicine, Miyagi, Japan

Correspondence: Masayuki Tanemoto, Division of Nephrology,

Hypertension, and Endocrinology, Department of Medicine, Tohoku

University Graduate School of Medicine, 1-1 Seiryo-cho, Aoba-ku, Sendai,

Miyagi 980-8574, Japan. E-mail: mtanemoto-tky@umin.ac.jp

Response to ‘Causative vascularabnormalities for renal ischemia’Kidney International (2009) 75, 1354; doi:10.1038/ki.2009.110

Dr Tanemoto suggests that the intravascular ultrasoundimage may be more consistent with a lipid-laden atheroma,indicating that the patient may have actually had athero-sclerotic renal artery stenosis (RAS) rather than intimalfibromuscular dysplasia (FMD). In addition, Dr Tanemotoproposes that the improvement in vascular lesions andfever after the administration of prednisone might suggestan inflammatory etiology to the vascular lesions.1 We agree

that intimal FMD can be difficult to distinguish angio-graphically from atherosclerotic disease.2 The features ofthis case, however, strongly supports FMD rather thanRAS. The patient had multiple areas of stenosis in thedistal, smaller renal vessels—angiographic findingstypical for FMD and unusual in RAS.3 The intravascularultrasound image shows low-intensity echoes withoutsignificant calcification—findings more typical of a dissec-tion than atherosclerotic RAS. Moreover, the relativelyyoung age of this patient who did not smoke, and theabsence of peripheral arterial disease, places him at lowrisk for RAS. The low-grade fevers before admission areconsistent with renal infarction, and the absence ofsignificant markers of infla mmation is consistent with adiagnosis of FMD. Importantly, his clinical improvementwithout ongoing immunosuppressive therapy essentiallyexcludes a diagnosis of polyarteritis nodosa.

1. Tanemoto M. Causative vascular abnormalities for the renal ischemia.Kidney Int 2009; 75: 1354.

2. Luscher TF, Lie JT, Stanson AW et al. Arterial fibromuscular dysplasia.Mayo Clin Proc 1987; 62: 931–952.

3. Safian RD, Textor SC. Renal-artery stenosis. N Engl J Med 2001; 344:431–442.

C. John Sperati1, Nisha Aggarwal2, Aravind Arepally3 andMohamed G. Atta1

1Division of Nephrology, Department of Medicine, Johns Hopkins University

School of Medicine, Baltimore, Maryland, USA; 2Department of Medicine,

Johns Hopkins University School of Medicine, Baltimore, Maryland, USA and3Piedmont Radiology, Atlanta, Georgia, USA

Correspondence: C. John Sperati, 1830 E Monument Street, Room 416,

Baltimore, Maryland 21205, USA. Email: jsperati@jhmi.edu

Treatment with statins may beconsidered in ESRD patients forprimary prevention ofcardiovascular diseaseKidney International (2009) 75, 1354–1355; doi:10.1038/ki.2009.107

To the Editor: In their elegant review, Cachofeiro et al.1

related cardiovascular risk to oxidative stress, inflammation,and atherogenesis and report the results of treatment withstatins on the prevention of cardiovascular disease (CVD) inthe general population and in chronic kidney diseasepatients. Peripheral blood mononuclear cell (PBMC)5-lipoxygenase (5-Lox) activity is involved in low-densitylipoprotein oxidation during the early phases of athero-genesis. 5-Lox activity and expression are upregulated inPBMC of uremic patients under maintenance hemodialysis(MHD).2 The subsequent increase in membrane lipidperoxidation, reactive oxygen species production, and low-density lipoprotein oxidation seems to contribute to thesusceptibility of uremic patients to atherosclerosis and CVD.Antioxidant and anti-inflammatory ‘pleiotropic’ actions of

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& 2009 International Society of Nephrology

1354 Kidney International (2009) 75, 1354–1358