Sphingomyelin and Medullary Sponge Kidney Disease: A Biological Link Identified by Omics Approach

Background: Molecular biology has recently added new insights into the comprehension of the physiopathology of the medullary sponge kidney disease (MSK), a rare kidney malformation featuring nephrocalcinosis and recurrent renal stones. Pathogenesis and metabolic alterations associated to this disorder have been only partially elucidated.Methods: Plasma and urine samples were collected from 15 MSK patients and 15 controls affected by idiopathic calcium nephrolithiasis (ICN). Plasma metabolomic profile of 7 MSK and 8 ICN patients was performed by liquid chromatography combined with electrospray ionization tandem mass spectrometry (UHPLC–ESI-MS/MS). Subsequently, we reinterrogated proteomic raw data previously obtained from urinary microvesicles of MSK and ICN focusing on proteins associated with sphingomyelin metabolism. Omics results were validated by ELISA in the entire patients' cohort.Results: Thirteen metabolites were able to discriminate MSK from ICN (7 increased and 6 decreased in MSK vs. ICN). Sphingomyelin reached the top level of discrimination between the two study groups (FC: −1.8, p < 0.001). Ectonucleotide pyrophophatase phosphodiesterase 6 (ENPP6) and osteopontin (SPP1) resulted the most significant deregulated urinary proteins in MSK vs. ICN (p < 0.001). ENPP6 resulted up-regulated also in plasma of MSK by ELISA.Conclusion: Our data revealed a specific high-throughput metabolomics signature of MSK and indicated a pivotal biological role of sphingomyelin in this disease.

Laparoscopic nephron-sparing surgery for a tumor near the isthmus of a horseshoe kidney with a complicated blood supply

A horseshoe kidney is a congenital kidney malformation commonly associated with complications such as hydronephrosis, renal calculi, and infections of the renal pelvis. Renal cell carcinoma is extremely rare in a horseshoe kidney; once it occurs, however, it is intractable because of vascular abnormalities. This is especially true in laparoscopic nephron-sparing surgery, even for tumors of <4 cm in diameter. We herein report a case involving an asymptomatic 65-year-old man with an incidental finding of a 4-cm solid mass near the isthmus of a horseshoe kidney on B-mode ultrasonography. Preoperative computed tomography of the renal artery revealed six arterial vessels supplying the affected kidney. Laparoscopic partial nephrectomy was performed. The outcome of this case suggests that laparoscopic nephron-sparing surgery might be a successful treatment method for a horseshoe kidney but that preoperative vessel evaluation and experienced laparoscopic skills are needed.

BARDET — BIEDL SYNDROME WITH CONGENITAL KIDNEY MALFORMATION IN A 14-YEAR-OLD GIRL

Aim. To show the variety and severity of the clinical symptoms of a rare hereditary disease — Вardet — Biedle syndrome — in a14-year-old girl. Materials and methods. We carried out a retrospective analysis of anamnestic data, the course of the disease, laboratory and instrumental data, as well as the therapy of a 14-year-old patient with Вardet-Вiedlе syndrome. Results. A 14-year-old patient with hereditary Вardet — Вiedlе syndrome (polydactyly, mental retardation, progressive obesity, pigment retinopathy) was found to have a congenital abnormality of kidney development — hypoplasia and dysplasia of the only right kidney complicated by chronic secondary pyelonephritis with the development of chronic kidney disease. Urine tests revealed leukocyturia, bacteriuria and proteinuria. The echo-signs of diffuse changes in the parenchyma of the right kidney were found during the ultrasound kidney examination. The left kidney was not determined. The conclusion of dynamic renal scintigraphy: the image of the left kidney is not reliably visualized (a sharp decrease in the function or absence of the kidney), the preserved filtration function and a moderate decrease in the excretory function of the right kidney. Intoxication syndrome, leukocyturia, bacteriuria and proteinuria were relieved against the background of antibacterial (Ceftriaxone) and symptomatic therapy. Conclusion. We have described a clinical case of the Вardet — Вiedlе syndrome with congenital kidney malformation (impaired function), but with the normal structure of the internal reproductive organs and sexual development. In the future, due to the development of chronic kidney disease, the patient should receive specialized nephrological care, as well as be observed by endocrinologist due to a high risk of developing type 2 diabetes mellitus.

Renal Cell Carcinoma in a Horseshoe Kidney: Radiology and Pathology Correlation

Renal cell carcinoma (RCC) is encountered in about 3% of all adult neoplasms. Presence of any kidney malformation can change the plan for surgical treatment of RCC with organ preserving surgery. We report a case of clear cell RCC in a horseshoe kidney. Computed tomography scan revealed a horseshoe kidney anomaly with a large mass in the left side. The diagnosis of RCC was confirmed by pathology and histology findings.