Polycystic kidney disease in neonates and infants. Clinical diagnosis and histopathological correlation.

A significant cause of end-stage renal disease in infants (40% to 50% of cases) is represented by the group of renal cystic diseases. Actually, the fourth cause of renal failure in young adults is the autosomal dominant polycystic kidney disease (ADPKD). Moreover, the most common genetically inherited kidney disease was proved to be ADPKD, affecting 1-5 per 10 000 individuals. The study was conducted over a period of three years (July 26, 2015-October 30, 2018) on 22 patients aged between two days and 36 months, diagnosed with polycystic kidneys that presented multiple hospital admissions in the Department of Nephrology, "Maria Sklodowska Curie" Emergency Children's Hospital, Bucharest, Romania. The nephrectomy sections were obtained from the material of the Department of Pathology of the same Hospital. Prenatal ultrasonography results were correlated with positive family history of polycystic kidney disease (PKD), fetal enlarged kidneys and oligohydramnios. Neonatal diagnosis of PKD was considered when some of the neonates presented palpable flank masses that caused fetal dystocia. On the other hand, the pediatric clinical examination of older infants revealed abdominal distention secondary to renal masses. After surgical resection, the overall aspect of the kidneys showed that the normal parenchyma had been mostly replaced by cysts with thin, translucent walls that contained a clear fluid. Microscopy confirmed that the parenchyma was mostly replaced by dilated cysts delineated by simple cuboidal or simple flattened epithelium, with areas of remnant fetal kidney parenchyma separated by an enriched stroma. Immunohistochemistry for blood vessels (CD34) revealed normal fine walled blood vessel arcades in the control kidneys, while in most areas from polycystic disease, the blood vessels exhibited enlarged, thickened endothelium, and less collapsed lumens. Regarding the proliferative capacity of the tissues, our Ki67 immunostaining revealed that the less formed, younger tubules in the pathological state had a higher proliferative index compared to control tissue. There seemed to be less albumin immunostaining in the epithelia of the distal contort tubules but that distinction was present also in our pathology. The overall expression level was reduced in polycystic cases (p<0.05), and it could be that this expression decrease might be related to the reduced function of these kidneys. According to what literature states, we have emphasized in our study that aquaporin 1 (AQP1) showed overall decreased reactivity in PKD along with its expression in proximal tubule epithelia.

The Role of Early Diagnosis of Hepatorenal Cystic (HRC) Syndrome in Children-Clinical Trial.

The hepatorenal cystic (HRC) syndrome is a heterogeneous group of severe monogenic conditions that may be detected before birth. Effective programme evaluation of children with HRC syndrome is a systematic way to identify the renal and urinary tract malformations which represent the most common cause of end-stage renal disease (ESRD). We conducted a study involving 50 patients, who were between 3 months and 16 years of age, with multiple admissions in the Nephrology Department of "Maria Sklodowska Curie" Children Emergency Hospital from Bucharest, during 6 years (April 14th 2010-October 24th 2016), to evaluate the HRC syndrome. The admission symptomatology was mainly represented by the nephrology evaluation which was essential in the management of children's polycystic kidney disease. For example, a premature infant (gestational age=32 weeks) with positive heredo-collateral history (mother and grandmother were diagnosed with polycystic kidney disease), was tested positive for cystic renal disease after the fetal morphology was performed. It was also done a genetic determination for the presence of PKD1 and PKD2 mutations which are specific to autosomal dominant polycystic kidney disease-ADPKD. However, the genetic test was negative and a postnatal nephrological evaluation was performed using renal ultrasound. The image revealed autosomal recessive polycystic kidney disease-ARPKD. This study emphasizes the importance of an early diagnosis (prenatal, neontal, postnatal) correlated with the admission symptoms and also with the genetic diagnosis (mutations of PKD1 and PKD2).