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.

Fetal multicystic kidney disease: Outcome and follow up

Introduction Congenital fetal anomalies are the great problem and one of the main causes of increased perinatal mortality and morbidity. The aim of this study is to determine the outcome of prenataly detected multicystic dysplastic kidney and to point to the necessity of postnatal diagnostic procedures. Material and methods The retrospective-prospective study encompasses 38 cases of the prenatally diagnosed unilateral fetal multicystic dysplastic kidney. The associated anomalies were revealed either by autopsy findings when the pregnancy was terminated, or when the pregnancy continued, by clinical and operative findings the newborns. Results The autopsy finding revealed bilateral multicystic displastic kidney or unilateral mylticystic displastic kidney and the agenesis of the contralateral kidney. The postnatal evaluation of the newborns with unilateral multicistic disease revealed that 84.3% of them had some concomitant anomaly of the urinary tract, most of them had an anomaly of the contralateral kidney (31.4%). The surgery was performed in 73.6% of children, in 17% of children the kidney function deteriorated after the surgery. Conclusion The findings of bilateral multicystic kidney disease and unilateral multicystic kidney disease and anamnion are the indication to terminate the pregnancy. The finding of an isolated unilateral multicystic dysplastic kidney require thorough examination, both prenatally and postnatally. We propose obligatory serial prenatal ultrasound examinations, followed by postnatal ultrasound, isotope scan, and urinary cystourethography.