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.

Keywords: Birt–Hogg–Dubé syndrome; autosomal dominant polycystic kidney disease; autosomal-recessive polycystic kidney disease; genetic kidney disease; nephronophthisis; polycystic kidney diseases; tuberous sclerosis complex; von Hippel–Lindau disease.

Figure 1

MRI imaging and volumetry of kidneys in autosomal-dominant polycystic kidney disease (ADPKD). These images reveal the classical features of ADPKD: strongly enlarged kidneys showing a ubiquitous distribution of cysts throughout the parenchyma. Kidney volume—an important prognostic feature now used in algorithm for making treatment decisions—can be obtained by planimetry (A,B) as done in the clinical trials. However, for everyday clinical decisions volumetry based on measuring the axes and using the ellipsoid formula has been shown to be sufficient (19) (C,D). From Müller et al. (27) (images kindly provided by Dr. Thorsten Persigehl, Institute of Radiology, University of Cologne).

Figure 2

Scheme of the diagnostic algorithm for polycystic kidney diseases combining clinical judgment with imaging modalities and molecular genetics. From Kurschat et al. (20). NPHP, nephronophthisis; MCKD, medullary cystic kidney disease (better to be termed now: autosomal-dominant tubulointerstitial disease); BBS, Bardet–Biedl syndrome; JBTS, Joubert syndrome; SLSN, Senior–Loken syndrome; MKS, Meckel–Gruber syndrome.