Renal vein thrombosis and the congenital nephrotic syndrome have been associated with nephrotic-range proteinuria/nephrotic syndrome and hypertension in the newborn period. We describe a newborn with severe hypertension and proteinuria secondary to unilateral renal artery stenosis. Proteinuria completely disappeared with blood pressure control (with sodium nitroprusside and an angiotensin-converting enzyme inhibitor). Although renin was not measured, we speculate that proteinuria might have been induced by a high renin state, and was controlled by the angiotensin-converting enzyme inhibito

Bogaru, Alina

Cachat, François

Guignard, Jean-Pierre

Lepori, Domenico

Micheli, Jean-Leopold

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Pediatr Nephrol (2004) 19:544–546DOI 10.1007/s00467-003-1391-yB R I E F R E PORTFranois Cachat · Alina Bogaru ·Jean-Leopold Micheli · Domenico Lepori ·Jean-Pierre GuignardSevere hypertension and massive proteinuria in a newbornwith renal artery stenosisReceived: 23 June 2003 / Revised: 18 November 2003 / Accepted: 18 November 2003 / Published online: 21 February 2004 IPNA 2004Abstract Renal vein thrombosis and the congenitalnephrotic syndrome have been associated with nephrot-ic-range proteinuria/nephrotic syndrome and hypertensionin the newborn period. We describe a newborn withsevere hypertension and proteinuria secondary to unilat-eral renal artery stenosis. Proteinuria completely disap-peared with blood pressure control (with sodium nitro-prusside and an angiotensin-converting enzyme inhibitor).Although renin was not measured, we speculate thatproteinuria might have been induced by a high renin state,and was controlled by the angiotensin-converting enzymeinhibitor.Keywords Renal artery stenosis · Hypertension ·Proteinuria · Nephrotic syndrome · Newborn · ReninIntroductionThe simultaneous occurrence of hypertension and pro-teinuria/nephrotic syndrome in a newborn raises thedifferential diagnosis of a congenital nephrotic syndromeor a renal vein thrombosis (RVT). Renal artery stenosis(RAS) has been associated with proteinuria or evennephrotic syndrome, mainly in adult patients. Recently,Lang and Gowrishankar [1] described a young child withRAS and nephrotic syndrome. We wish to further expandthe rare clinical association of RAS, hypertension, andnephrotic-range proteinuria in a newborn baby.Case reportThe female patient was delivered vaginally at 42 weeks ofgestation, after an uneventful pregnancy. The 24-year-old motherhad no diabetes and was on no medications. The birth weight was3,485 g (50th percentile) and length 50 cm (10th–50th percentile).Apgar scores were 7, 9, and 9 at 1, 5, and 10 min, respectively.Initial blood pressure values (10 h after birth) were high at 85/50 mmHg [2]. Because of mild tachypnea, the child was admittedto a neonatal division and closely monitored. On day 3 of life,blood pressure was 100–105/80 mmHg, and she developed neph-rotic-range proteinuria and microscopic hematuria. Laboratoryresults included plasma creatinine 76 mmol/l, blood urea nitrogen3.9 mmol/l, and albumin 33 g/l. The urinary protein/creatinine ratiowas 5,807 g/mol (66 g/l). Urinalysis revealed 0–1 white blood cells/high-power field (HPF), 10–15 red blood cells/HPF, and no casts.Renal ultrasonography showed two normal-sized kidneys withnormal arterial and venous blood flow and no signs of venousthrombosis. The infant’s condition deteriorated and she wastransferred to our hospital. On admission (day 5 of life), she washypertensive (115/86 mmHg) and in heart failure. There was anenlarged liver and generalized edema. Laboratory investigationsconfirmed the proteinuria (1,176 g/mol), with mild hypoalbumin-emia (30 g/l), no electrolyte abnormalities, creatinine 96 mmol/l,serum glutamic oxaloacetic transaminase 66 U/l, and serumglutamic pyruvic transaminase 110 U/l. Echocardiography showeda slight hypertrophied and dilated left ventricle, with an ejectionfraction of 37%. There was a slight mitral and aortic insufficiency.Because of failure of captopril, furosemide, and hydralazine toadequately control the blood pressure, sodium nitroprusside wasadded. The blood pressure response was immediate (Fig. 1). Orallabetalol was added on day 9 of life, in order to wean the infant offsodium nitroprusside. Two weeks later, the infant’s blood pressurewas controlled with oral labetalol (16 mg three times a day) andcaptopril (0.1 mg twice daily). Proteinuria decreased and thendisappeared as soon as the blood pressure normalized (Fig. 1). Atdischarge, there was no proteinuria and no hematuria. On day 8 oflife, 3 days after a single dose of furosemide, the patient alsopresented with hyponatremia (128 mmol/l) secondary to renal saltwasting (urine sodium 92 mmol/l). Hyponatremia resolved spon-taneously, without sodium supplementation. Duplex Doppler so-nography on day 9 of life showed a small right kidney with adecreased arterial signal, but normal venous flow; the left kidneywas normal. Magnetic resonance angiography revealed a stenotic/hypoplastic right renal artery and a normal left renal artery (Fig. 2).F. Cachat ()) · A. Bogaru · J.-P. GuignardDepartment of Pediatrics, Division of Pediatric Nephrology,University Hospital, Lausanne, Switzerlande-mail: Francois.Cachat@hospvd.chTel.: +41-21-3141111Fax: +41-21-3143626J.-L. MicheliDivision of Neonatology,University Hospital, Lausanne, SwitzerlandD. LeporiDepartment of Radiology, Division of Pediatric Radiology,University Hospital, Lausanne, SwitzerlandRenal scan (Mag3) performed on day 10 of life showed no activityon the right side and a compensatory hyperactivity on the left side.At discharge (day 18 of life), the patient was normotensive, with acreatinine of 56 mmol/l and sodium of 135 mmol/l. Eight monthslater, she is on enalapril 0.6 mg twice daily, her blood pressure isnormal (90/50 mmHg), and she has no proteinuria or hematuria.Follow-up renal ultrasonography, a year later, shows a smallatrophic right kidney (<5th percentile) with a hypertrophied leftkidney (95th percentile). Echocardiography performed 3 monthsafter discharge is also normal, with complete regression of the leftventricular failure. A repeat renal scan confirmed the total absenceof perfusion of the right kidney, and showed a well-functioning leftkidney, with some mild irregularities and a heterogeneous distri-bution of the nuclear tracer.DiscussionThe differential diagnosis of severe hypertension in anewborn baby includes acquired or congenital renalvascular diseases (RAS, renal artery hypo(dys)plasia,thromboembolic events), renal parenchymal/glomerulardisorders, obstructive uropathies, coarctation of the aorta,or drug-induced hypertension [3]. Amongst those causes,only RVT, congenital nephrotic syndrome (of any etiol-ogy), or RAS have been associated with nephrotic-rangeproteinuria or even frank nephrotic syndrome. AlthoughRVT can rarely induce a nephrotic syndrome [4, 5], it ismostly a direct consequence of hemoconcentration andchronic urinary loss of anti-thrombin III secondary to aprimary long-standing nephrotic syndrome. RVT wasexcluded in our patient (no thrombopenia, no macroscop-ic hematuria, normal renal venous blood flow, no en-larged hyperechogenic kidneys). RAS has also beenassociated with mild-to-severe proteinuria [6] or evennephrotic syndrome [1, 7]. The occurrence of proteinuriaafter renal artery occlusion is thought to be secondaryeither to the high renin state and tissue ischemia in theoccluded kidney or to an excessive blood flow in thecontralateral healthy kidney, or both [6]. Focal andsegmental glomerulosclerosis of the healthy contralateralkidney has also been described in patients with long-standing RAS [8]. Proteinuria in that case is secondary tochronic hyperfiltration of the remaining nephrons.Although plasma renin activity was not measured, wesuggest that the nephrotic-range proteinuria and the hyper-tension in our patient were induced or exacerbated by theexaggerated renin production in the ischemic right kidney.Fig. 1 Follow-up of proteinuriaand blood pressure values (SBPsystolic blood pressure, DBPdiastolic blood pressure)Fig. 2 Abdominal aortic magnetic resonance angiography. The leftrenal artery and left kidney are clearly delineated. The right renalartery and kidney are not visible545Proteinuria decreased and then disappeared with theadministration of an angiotensin-converting enzyme inhib-itor. Renin increases angiotensin II, which has been shownto modulate glomerular capillary permselectivity in exper-imental animals [9]. Our patient also presented withtransient renal sodium loss. Renal salt wasting has alsobeen reported in malignant hypertension [10]. The mech-anism of sodium loss is not completely understood. Inanimal experiments, an acute increase in the arterialperfusion pressure in the isolated kidney of the dog led toan increase in urine flow and sodium excretion, whereasthe glomerular filtration rate and renal blood flow wereunchanged [11]. The persistence of hypertension, morethan a year after the initial event, might be explained bypersistent renin secretion in the ipsilateral kidney, or by thecontralateral kidney, which showed numerous irregularitieson renal scan, corresponding probably to renal scars.In summary, we describe a newborn baby with hy-pertension and nephrotic-range proteinuria, secondary toRAS, which responded well to an angiotensin-convertingenzyme inhibitor. We speculate that an excessivelystimulated renin-angiotensin-aldosterone system mighthave been responsible for the heavy proteinuria, throughaltered permeability of the glomerular capillaries. RVT,congenital nephrotic syndrome, and likewise RAS shouldbe ruled out in a newborn presenting with severe hyper-tension and proteinuria.References1. Lang ME, Gowrishankar M (2003) Renal artery stenosis andnephrotic syndrome: a rare combination in an infant. PediatrNephrol 18:276–2792. Versmold HT, Kitterman JA, Phibbs RH, Gregory GA, TooleyWH (1981) Aortic blood pressure during the first 12 hours oflife in infants with birth weight 610 to 4220 grams. Pediatrics67:607–6133. Guignard JP, Gouyon JB, Adelman RD (1989) Arterial hyper-tension in the newborn infant. Biol Neonate 55:77–834. Cohn LH, Lee JL, Hopper J, Najarian JS (1968) The treatmentof bilateral renal vein thrombosis and nephrotic syndrome.Surgery 64:387–3965. Janower ML (1965) Nephrotic syndrome secondary to renalvein thrombosis. The value of inferior vena cavography. Am JRoentgenol Radium Ther Nucl Med 95:330–3346. Rossignol P, Chatellier G, Azizi M, Plouin PF (2002) Protein-uria in renal artery occlusion is related to active reninconcentration and contralateral kidney size. J Hypertens20:139–1447. Pasternack A, Eklund J, Krohn K (1967) Renal artery stenosisand the nephrotic syndrome. Acta Med Scand 181:265–2688. Ubara Y, Hara S, Katori H, Yamada A, Morii H (1997)Renovascular hypertension may cause nephrotic range protein-uria and focal glomerulosclerosis in contralateral kidney. ClinNephrol 48:220–2239. Lapinski R, Perico N, Remuzzi A, Sangalli F, Benigni A,Remuzzi G (1996) Angiotensin II modulates glomerular cap-illary permselectivity in rat isolated perfused kidneys. J Am SocNephrol 7:653–66010. Blanc F, Bensman A, Baudon JJ (1991) Renovascular hyper-tension: a rare cause of neonatal salt loss. Pediatr Nephrol5:304–30611. Barraclough MA (1966) Sodium and water depletion with theacute malignant hypertension. Am J Med 40:265–272546

Severe hypertension and massive proteinuria in a newborn with renal artery stenosis

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Severe hypertension and massive proteinuria in a newborn with renal artery stenosis

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