|Year : 2022 | Volume
| Issue : 1 | Page : 46-48
Does the finding of horseshoe kidney in idiopathic nephrotic syndrome foresee prognosis or is it a co-incidental finding?
Walaa Abbas Alshammasi, Fakherah Alqahtani, Zainab Obaidi, Duaa Alsadeq, Abeer Bargawi, Ali Aldajani
Department of Pediatric Nephrology, Maternal and Children Hospital in Dammam, Dammam, Saudi Arabia
|Date of Submission||28-Dec-2021|
|Date of Decision||02-May-2022|
|Date of Acceptance||05-Jun-2022|
|Date of Web Publication||28-Jun-2022|
Walaa Abbas Alshammasi
Department of Pediatric, Nephrology Maternal and Children Hospital in Dammam, Dammam; Sick Kids Hospital, Toronto, Ontario
Source of Support: None, Conflict of Interest: None
A 6-year-old Yemini boy presented with nephrotic range proteinuria, hypoalbuminemia, edema, and hyperlipidemia, leading to a diagnosis of idiopathic nephrotic syndrome. Ultrasonography incidentally revealed a horseshoe kidney. While previous reports indicate the presence of congenital anomalies of the kidneys and urinary tract to be a poor predictor of remission in nephrotic syndrome, the present case responded to corticosteroids followed by sustained remission.
Keywords: Congenital anomalies of the kidney and urinary tract, horseshoe kidney, idiopathic nephrotic syndrome
|How to cite this article:|
Alshammasi WA, Alqahtani F, Obaidi Z, Alsadeq D, Bargawi A, Aldajani A. Does the finding of horseshoe kidney in idiopathic nephrotic syndrome foresee prognosis or is it a co-incidental finding?. Asian J Pediatr Nephrol 2022;5:46-8
|How to cite this URL:|
Alshammasi WA, Alqahtani F, Obaidi Z, Alsadeq D, Bargawi A, Aldajani A. Does the finding of horseshoe kidney in idiopathic nephrotic syndrome foresee prognosis or is it a co-incidental finding?. Asian J Pediatr Nephrol [serial online] 2022 [cited 2022 Aug 18];5:46-8. Available from: https://www.ajpn-online.org/text.asp?2022/5/1/46/348533
| Introduction|| |
The glomerular filtration barrier consists of podocytes, the glomerular basement membrane, and the fenestrated endothelium. Leaking of proteins through this barrier into the urinary space leads to the sequelae of nephrotic syndrome, regardless of the underlying pathogenesis. Although ultrasonography of the kidneys is essential in patients with nephrotic syndrome only when kidney biopsy is indicated, it is often performed to confirm the patient has two kidneys and to rule out anatomical anomalies that may be a relative contraindication to biopsy. However, one of the frequently asked questions among physicians is whether scanning the kidneys in the typical presentation of nephrotic syndrome is crucial. Congenital anomalies of the kidney and urinary tract (CAKUT) constitute a broad spectrum of defects such as ureteropelvic junction obstruction, posterior urethral valve, dysplastic kidney, and horseshoe kidneys. The coexistence of nephrotic syndrome and CAKUT is extremely rare.
The horseshoe kidney is the most common renal fusion anomaly, often detected incidentally on ultrasonography as patients are usually asymptomatic. Despite its association with various urological and nonurological anomalies, the horseshoe kidney is an uncommon finding in nephrotic syndrome. We present a case in which a patient with nephrotic syndrome coincidentally had horseshoe kidneys.
| Case Report|| |
A previously healthy 6-year-old Yemeni boy was admitted to the hospital with a history of puffiness over the face and lower limb swelling for 1 month, which gradually progressed to generalized edema involving the abdomen and scrotum. There was a history of frothy urine, but no history of decreased urine output or hematuria. Physical examination revealed a body temperature of 37°C, blood pressure of 112/68 mmHg, and pulse rate of 103 beats/min. Admission weight was 19.7 kg, just above the 25th percentile, and height was 110 cm, just above the 3rd percentile. There was moderate-to-severe edema with abdominal distension due to ascites. A diagnosis of nephrotic syndrome was presumed, and specific laboratory testing was performed to establish a diagnosis.
Urinalysis results showed 3+ proteinuria, with spot urine protein/creatinine ratio of 2800 mg/g and no hematuria. Serum albumin level was 1.57 g/dL and complement C3 and C4 were within the normal range at 1.48 g/L and 0.31 mg/dL, respectively. Antinuclear antibodies and antidouble-stranded antibodies were absent, and infection with hepatitis B or C was ruled out. Lipid profile showed high levels of cholesterol (15.6 mmol/L), triglycerides (2.9 mmol/L), and low-density lipoprotein (14.5 mmol/L). Blood urea was 11 mmol/L (reference range 3.6–17.9 mmol/L), serum creatinine 53 μmol/L (53.1–97.3 μmol/L), sodium 135 mmol/L, potassium 4.8 mmol/L, phosphate 1.5 mmol/L, and magnesium 0.9 mmol/L. Hemoglobin was 12 g/dL, white blood cell count 10.3 × 109/L, and platelet count 378 × 103/mm3. Ultrasonography of the kidneys showed that the kidneys were ectopic and fused anterior to the lumbar vertebra with anterior malrotation, with poor corticomedullary differentiation [Figure 1]. The imaging findings were suggestive of the horseshoe kidney.
|Figure 1: The kidneys were ectopic in location and fused anteriorly to the lumbar vertebra with anterior malrotation and poor corticomedullary differentiation, suggesting a horseshoe kidney. There were no stones, hydronephrosis, or masses. The image findings were suggestive of HSK|
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Following a diagnosis of nephrotic syndrome with an incidental finding of horseshoe kidney, the patient was initiated on therapy with prednisolone at 2 mg/kg daily to be given for 6 weeks and discharged 3 days after admission.
At 2 weeks of follow-up, the child was in remission and there was no edema. The urinalysis result was negative for protein. The family was reassured, and it was planned that following completion of daily therapy for 6 weeks, the dose of prednisolone be reduced to 1.5 mg/kg every other day for 6 weeks. There were no relapses during 1 year of follow-up since the initial episode.
| Discussion|| |
Nephrotic syndrome, characterized by profound proteinuria, hypoalbuminemia, and edema, is described since 1830. Most patients with primary nephrotic syndrome have minimal change disease, and the vast majority of them respond to prednisolone treatment. He received therapy as per the International Study of Kidney Diseases in Children for the first episode, a 12-week steroid treatment regimen including 6-week prednisolone at 60 mg/m2 or 2 mg/kg daily for 6-week, followed by 40 mg/m2 or 1.5 mg/kg on alternative days for 6-week. More recently, in 2020, a Cochrane review confirmed what was previously studied in 2019; no variance in the primary outcome of time to first flare; there was a small difference in cost-effectiveness and quality of life supporting an extended regimen for 16 weeks (cumulative dose: 3150 mg/ m2) versus an 8-week course of prednisolone (cumulative dose: 2240 mg/m2) Our case did not necessitate biopsy because his laboratory investigation, in addition to his response to treatment, is characteristic of idiopathic nephrotic syndrome. He was an early responder. One of the frequently asked questions from families is about the expected disease course in their child based on available data. A physician's typical response is that it is very difficult to predict disease course at its onset. Patients who experience only a single episode of disease account for only one-third of the patients.
Mantan and Sethi stated that the presence of CAKUT is a predictor of difficult-to-control nephrotic syndrome. Of 10 cases of CAKUT and nephrotic syndrome reported by the authors, the majority had a difficult course of the disease. Whether this prediction is a matter of fact or not, can only be ascertained if an ultrasound of the kidneys is routinely performed to screen for CAKUT in all patients with nephrotic syndrome. [Table 1] lists the few reports in the literature in which an association between glomerular disease and horseshoe kidney has been reported.,,,, A total of five cases had a complete remission on the prednisolone course, whereas six other cases had partial responses and required second-line agents, two cases had remissions without steroids, and details of the disease course were lacking in four cases. Only five cases had disease onset in the pediatric age group. In our patient, we believe that the occurrence of idiopathic nephrotic syndrome in a patient with a horseshoe kidney was a mere coincidence. This case supports the idea that this renal malformation does not predispose to glomerular disease but may share risk factors for the disease in the general population.
|Table 1: Previous reports on the association of nephrotic syndrome with horseshoe kidneys|
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To conclude, lack of reporting and/or not performing renal ultrasound routinely in the presentation of nephrotic syndrome could make the combination of horseshoe kidney and nephrotic syndrome uncommon. The true significance of the association between CAKUT and nephrotic syndrome can only be determined if renal ultrasound is performed routinely in all patients with nephrotic syndrome in larger multicenter studies that also examine for genetic predisposition in such cases.
Consent for publication
Written informed consent was obtained from the patient for publication of this case report and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the parents have given their consent for the child's images and other clinical information to be reported in the journal. The parents understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Noone DG, Damien G et al
. Idiopathic nephrotic syndrome in children. Lancet 2018;392:61-74. doi:10.1016/S0140-6736(18)30536-1.
Mantan M, Sethi GR. Presence of CAKUT: A predictor of difficult-to-control nephrotic syndrome. Hong Kong J Nephrol 2013;15. doi:10.1016/j.hkjn.2013.03.006M.
Pal A, Kaskel F. History of nephrotic syndrome and evolution of its treatment. Front Pediatr 2016;4:56. doi:10.3389/fped.2016.00056.
Hahn D, Hodson EM, Willis NS, Craig JC. Corticosteroid therapy for nephrotic syndrome in children. Cochrane Database Syst Rev 2020:CD001533. doi:10.1002/14651858.CD001533.pub6.
Zotta F, Vivarelli M, Emma F. Update on the treatment of steroid-sensitive nephrotic syndrome. Pediatr Nephrol 2022;37:303-14. doi:10.1007/s00467-021-04983-3.
Chaabouni Y, Guesmi R, Hentati Y, Kammoun K, Hmida MB, Mnif Z, et al
. Minimal change disease in horseshoe kidney. Pan Afr Med J 2017;26:243. doi:10.11604/pamj.2017.26.243.11438.
Kayataş M, Urün Y. Two cases with horseshoe kidney in association with nephrotic syndrome: Is there a causal relationship between two conditions? Ren Fail 2007;29:517-8. doi:10.1080/08860220701278133.
Rivera F, Caparrós G, Vozmediano C, Bennouna M, Anaya S, Sánchez de la Nieta MD, et al.
[“Horseshoe kidney,” renal adenocarcinoma and nephrotic syndrome]. Nefrologia 2010;30:596-8.
Abson C, Jones M, Palmer A, Persey M, Gabriel R. Horseshoe kidney, focal and sclerosing glomerulonephritis and primary hypothyroidism. Nephron 1991;58:124. doi:10.3265/Nefrologia.pre2010.Jul.10550.
Shi SS, Yang XZ, Zhang XY, Guo HD, Wang WF, Zhang L, et al
. Horseshoe kidney with PLA2R-positive membranous nephropathy. BMC Nephrol 2021;22:277. doi:10.1186/s12882-021-02488-7.