Cystic Kidney Diseases From the Adult Nephrologist’s Point of View

Abstract

Cystic kidney diseases affect patients of all age groups with the onset spanning from prenatal disease to late adulthood. Autosomal-dominant polycystic kidney disease (ADPKD) is by far the most common renal cystic disease. However, there are various cystic kidney diseases, the onset of which occurs at different times in life and depends on the type of the disease and the causative genes involved. When genetic kidney diseases are discussed in the adult setting this view is usually limited on autosomal-dominant kidney disease, the most frequent genetic disorder causing adult onset ESRD. Other diseases—such as autosomal-recessive polycystic kidney disease—are often being viewed as a disorder only important in pediatric nephrology. However, more recent data has revealed that, despite clear age peaks of onset for each disorder, all of them can also show highly variable phenotypes with classical adult onset genetic diseases being of importance in pediatrics and vice versa. Furthermore, the affected children need to be seen by adult nephrologists in the long term after transition, requiring knowledge on the underlying pediatric disease, potential extrarenal manifestations, and genetic counseling. Consequently, the view on these diseases should be widened on both ends. Close interaction between pediatric and adult nephrology is key to appropriate care of patients suffering from genetic kidney disease to profit from each other’s experience.

Exome sequencing of Saudi Arabian patients with ADPKD

“…Variable expressivity is common in ADPKD, with age at presentation and kidney disease severity greatly varying depending on the mutated gene, the mutation class, and the influence of other modifying genes [11]. Over 2,300 PKD1 and 300 PKD2 germline mutations have been identified in different populations, and the list is growing [12,30]. Clinical diagnosis of ADPKD is based upon the presence of kidney cysts on imaging in the context of a positive family history [31], typically with ultrasound, but also by CT or MRI.…”

Management of autosomal-dominant polycystic kidney disease—state-of-the-art

“…The position statement of the WGIKD and ERBP provides both a summary of available data on this point and a useful algorithm to help physicians in gauging progression [92]. Furthermore, patient selection—which is primarily based on past-time eGFR loss, TKV as adjusted by the Mayo classification and the PROPKD score (Table 3)—has recently been reviewed extensively [5, 97, 98] and shall not be the focus of this review. Importantly, REPRISE has added more data to patient selection by showing tolvaptan to also be effective in CKD Stage 4 as well as in patients above the age of 50 years [91].…”

“…These cell biological phenotypes are then the basis of cyst formation and progressive loss of kidney function. In the clinical setting, cystic kidney diseases can be separated into several groups of disorders based on age of onset, kidney morphology and extrarenal findings [4, 5]. Primarily, disorders of the nephronophthisis spectrum are distinguished from autosomal-recessive and autosomal-dominant polycystic kidney disease (ADPKD).…”

Evaluation of liver-type fatty acid binding protein (L-FABP) and interleukin 6 in children with renal cysts

“…6 The ADPKD is the most common genetically determined cause of end-stage renal failure in adults. 3,5,9 The reason for the development of ADPKD in 80-85% of cases is the mutation of the PKD1 gene, which encodes the polycystine-1 protein, while in the remaining 15-20% of patients it is the PKD2 gene encoding polycystin-2. 10 Incorrectly encoded proteins that arise as a result of mutations lead to the growth and proliferation of kidney tubules cells with the formation of cysts, then to their enlargement and secretion and collection of fluid inside them.…”