Congenital Solitary Kidney from Birth to Adulthood

Acute kidney injury (AKI) and renal tubular damage (RTD), especially if complicated by acute tubular necrosis (ATN), could increase the risk of later chronic kidney disease. No prospective studies on AKI and RTD in children with type1diabetes mellitus (T1DM) onset are available. Objectives To evaluate the AKI and RTD prevalence and their rate and timing of recovery in children with T1DM onset. Design Prospective study. Settings and patients 185 children were followed up after 14 days from T1DM onset. The patients who did not recover from AKI/RTD were followed-up 30 and 60 days later. Main outcome measures AKI was defined according to the KDIGO criteria. RTD was defined by abnormal urinary beta-2-microglobulin and/or neutrophil gelatinase-associated lipocalin and/or tubular reabsorption of phosphate < 85% and/or fractional excretion of Na (FENa) > 2%. ATN was defined by RTD+AKI, prerenal (P)-AKI by AKI+FENa < 1%, and acute tubular damage (ATD) by RTD without AKI. Results Prevalence of diabetic ketoacidosis (DKA) and AKI were 51.4% and 43.8%, respectively. Prevalence of AKI in T1DM patients with and without DKA was 65.2% and 21.1%, respectively; 33.3% reached AKI stage 2, and 66.7% of patients reached AKI stage 1. RTD was evident in 136/185 (73.5%) patients (32.4% showed ATN; 11.4%, P-AKI; 29.7%, ATD). All patients with DKA or AKI presented with RTD. The physiological and biochemical parameters of AKI and RTD were normal again in all patients. The former within 14 days and the latter within 2months. Conclusions Most patients with T1DM onset may develop AKI and/or RTD, especially if presenting with DKA. Over time the physiological and biochemical parameters of AKI/RTD normalize in all patients. To evaluate the course of prenatally diagnosed and early-enrolled congenital solitary functioning kidney (CSFK) patients followed-up until adulthood and to identify risk factors for kidney injury. Material and Methods: Among all CSFK patients followed-up (period: 1993–2018), we recalled 56 patients with prenatal diagnosis and CSFK confirmation at 1-3 months of life reaching at least 18 years of age. Serum uric acid (SUA), heavy smoking (≥25 cigarettes/day) and overweight/obesity were clustered as modifiable risk factors (MRF). Kidney injury was defined by estimated glomerular filtration rate (eGFR) <90 ml/min/1.73m2 and/or 24h-ambulatory blood pressure monitoring confirmed hypertension and/or proteinuria. MRF and Congenital Anomalies of the Kidney and Urinary Tract (CAKUT) of CSFK were evaluated as risk factors for kidney injury. Results: The mean follow-up period was 21.1 years (range: 18-33 years). Mild kidney injury was found in 15 out of 56 patients (26.8%). The mean age at proteinuria, reduced eGFR and hypertension onset was 19.7 years (1.2 SDS), 20.7 years (2.7 SDS), and 22 years (5.6 SDS), respectively. Patients with CAKUT of CSFK and with both CAKUT of CSFK and MRF presented survival free from kidney injury of 0% at 22.2 and 24.2 years of age, respectively. Patients with MRF presented survival of 42.4% at 30 years. Patients without CAKUT of CSFK nor MRF presented 100% of survival at 30 years of age (p=0.002). The presence of CAKUT of CSFK was the only significant risk factor (Hazard Ratio=4.9; 95% Confidence Interval: 1.8–14.2; p=0.003). Conclusions: The outcomes of CSFK in early adulthood appear better than previously reported. Prompt diagnosis of CAKUT, healthy life-style promotion and monitoring of SUA may improve the prognosis of CSFK patients.