MO052COL4A3/COL4A4 AS A CAUSE OF MULTICYSTIC KIDNEY DISEASE

Background and Aims Thin basement membrane nephropathy (TBMN), the most common cause of persistent microhaematuria (mH), is due to mutations in genes codifying alfa-3 and alfa-4 collagen IV chains (COL4A4/COL4A3). Initially considered as a benign condition, subsequent studies have shown that an important number of patients develop proteinuria and CKD. We reported in a previous small study the presence of multicystic kidney disease (MCD) in some TBMD patients. In this study we aimed to evaluate the presence of MCD in a larger cohort of TBMD patients and analyze its association with renal outcomes. Method We collected 50 patients with a diagnosis of TBMD based on the presence of persistent mH (>5 erythocytes per high power field in more than 90% of urinary sediments and radiological examinations to exclude other causes of mH) and at least one first-degree relative with persistent mH. TBMD diagnosis was confirmed by renal biopsy (glomerular basement membrane thickness less than 150nm) in 18 patients and by genetic test (pathogenic mutations in COL4A3/COL4A4) in 6 patients. MCD was diagnosed by the presence of uncountable cysts on renal ultrasonography. Results Mean age at diagnosis was 43.7 years, 34% were males and 18% had hypertension. At baseline, serum creatinine (SCr) was 0.9 mg/dL, proteinuria 0.48 gr/24h and 9 patients (18%) had CKD (estimated glomerular filtration rate -eGFR- lower than <60 mL/min/1.73m2). 7 patients (14%) had CKD G3 and 2 (4%) CKD G4. Kidney cysts were found in 34 patients (68%) and 19 (38%) met MCD criteria. After a mean follow-up of 14.7±11.5 years, 23 patients (46%) had CKD. Among them, 17 patients (34%) had CKD G3, 2 (4%) CKD G4, and 4 (8%) CKD G5. Hypertension was more frequent among CKD patients as compared with no-CKD patients (39 vs 0%, p 0.00), proteinuria was higher (0.58±0.68 vs 0.39±0.58 g/24h, p 0.05) and MCD more frequent (65.2% vs 14.8%, p 0.00). Patients with MCD had higher SCr (2.1 vs 1.1 mg/dL, p 0.004) and lower eGFR (41.7 vs 77.2 mL/min/1.73m2, p 0.00) at the end of follow-up, and MCD was the only risk factor for the occurrence of CKD (OR 6.49, 95% CI 1.3-31.6) by multivariable analysis that included age, hypertension and proteinuria. Conclusion MCD is frequently observed in TBMD patients and is a risk factor for the progression of CKD.

Posterior Urethral Valve and Prenataly Resolved Multicystic Dysplastic Kidney

Multicystic dysplastic kidney is a rare congenital anomaly of the kidney and urinary tract. The association with the posterior urethral valve is also very rare. Here we present a patient with both entities and prenatal resolution of the cysts. A 10-week old baby was referred for nephrourological work up due to prenatal diagnosis of the left multicystic kidney. He had serial US scans during the pregnancy. Immediately before delivery the cysts were not seen (prenatal resolution). There were no extrarenal anomalies. The first postnatal ultrasound scan revealed normal sized right kidney without dilatation of the pelvicalyceal system. The bladder had normal thickness of the wall. Technetium-99m dimercaptosuccinic acid scan showed no activity on the left side, and the right kidney appeared normal. At two months of age, a poor urinary steam was observed and additional urologic work up was indicated on clinical suspicion of PUV. Voiding urethrocystography revealed posterior urethral valve and the baby underwent cytoscopic valve resection. Conclusion: We present a rare association of two congenital anomalies of the kidney and urinary tract with prenatal involution of the multicystic dysplastic kidney that is extremely rare event as seen in our case. Presence of posterior urethral valve must be suspected in a male baby with a poor urinary stream even when his ultrasound scan of urinary system appears normal.

Prenatal presentation of Walker–Warburg syndrome with a POMT2 mutation: an extended fetal phenotype

Background Walker–Warburg syndrome (WWS) is a rare, lethal, genetically, and clinically heterogeneous congenital muscular dystrophy resulting from defective glycosylation of α-dystroglycan (α-DG) and is associated with both cranial and ocular malformations. Prenatal detection of posterior fossa anomalies in association with hydrocephalus are nonspecific, however, an additional finding of eye anomalies are typical for WWS. The purpose of this report is to elucidate the pattern of associated malformations in a fetus with WWS born to 3rd degree consanguineously married couple. Additionally, the fetal ultrasonography revealed congenital heart disease, clenched hands, and talipes equinovarus; these findings have not been previously reported and represent an expansion of prenatal spectrum associated with WWS. Case presentation We report on a specific sonographic pattern of congenital anomalies including hydrocephalus, agenesis of corpus callosum, and Dandy–Walker malformation. Ocular abnormalities include microphthalmia, cataract, and an echoic structure suggestive of persistent primary vitreous. Other features include congenital heart disease, unilateral multicystic kidney, and previously unreported findings of bilateral clenched hands and talipes equinovarus. The molecular analysis detected a homozygous splicing mutation, c.924-2A>C, in the POMT2 gene; this variant segregated with the phenotype. Conclusion WWS syndrome has characteristic prenatal ultrasound findings which can improve the prenatal identification of this condition and help in guiding the molecular diagnosis and counseling. The detection of bilateral clenched hands and talipes equinovarus is a novel finding that further expands the phenotypic spectrum of WWS.

EVALUATION OUTCOMES OF THE LAPAROSCOPIC RETROPERITONEAL NEPHRECTOMY FOR BENIGN NONFUNCTIONING KIDNEYS

Purpose: To assess results of retroperitoneoscopy nephrectomy for benign non-function kidneys from June 2013 to June 2017 at Quang Tri General Hospital. Materials and Methods: The study comprised 43 patients who underwent retroperitoneoscopic nephrectomy during a 4 years period beginning from June 2013. Results: Mean age of surgery was 52.6 years (28-72 years). 23 males and 20 females. 25 patients underwent left nephrectomy; 18 underwent right nephrectomy. Retroperitoneoscopic nephrectomy were completed successfully in 38 patients (88.4%). There was 5 patients required conversion to open surgery (11.6%), all cases by poor progression. The mean operating time was 112.7 minutes (range 70 to 210), mean blood loss was 45.7 ml (range 15 to 170 ml), and mean post-operation hospital stay was 4.3 days (range 3 to 9). A total of 21.1% complications (8/38 cases), no severe complications occurred. No re-intervention was needed. No case was mortality. The indications for surgery included hydronephrosis in 19/38 cases (50.0%), atrophic kidney in 13/38 cases (34.2%) and multicystic kidney in 6/38 cases (15.8%). Conclusions: Retroperitoneoscopic nephrectomy can be performed safely and successfully with obvious advantages for benign nonfunctioning kidneys regardless of the etiology or pathogenesis. Key words: nephrectomy, kidney, benign, retroperitoneoscopy