Recent advances in the clinical management of autosomal-dominant polycystic kidney disease.
Autosomal-dominant polycystic kidney disease (ADPKD) is an inherited disorder usually manifest in adulthood. It is characterized by the development of multiple renal cysts variably associated with extrarenal (mainly hepatic and cardiovascular) abnormalities. 1 With a prevalence rate ranging from 1 :400 to 1 :1000 in White populations, ADPKD is one of the most common genetic diseases and by far the most frequent inherited nephropathy. 1 ' 2 ADPKD currently accounts for 3-10% of all patients admitted for maintenance dialysis in Western countries. 1 Over the past decade, major progresses have been achieved in the understanding of the molecular basis of the disease. The gene incriminated in about 85% of cases, PKD1, has been located on chromosome 16 in 1985 3 and identified in 1994. 4 A second gene, PKD2, accounting for the vast majority of the other cases, has been mapped on chromosome 4 in 1993 5 ' 6 and was cloned this year. 7. The existence of a third gene is suggested by recent reports. 8 ' 9 Using various strategies, a number of researchers have competed to unravel the complete sequence of the PKD1 gene and predict the structure of the corresponding protein, called polycystin. 10 " 12 Polycystin appears to be an integral membrane glycoprotein probably involved in cell-cell and/or cell-matrix interaction. 10 Preliminary evidence suggests that the PKD2 protein functions as an ion channel or pore. 7 Polycystin could act as the regulator of the PKD2 channel activity. 7 How mutations in PKD1 and PKD2 lead to cyst development and other clinical abnormalities remains to be understood. Elucidation of this mechanism should pave the way to pharmacological intervention with the hope to prevent or, more realistically, arrest or slow the manifestations of the disease. Meanwhile, patients with ADPKD already benefit from various recent progresses in the clinical management of the condition. This editorial attempts to provide a concise update of the advances in the management of renal, hepatic and cerebral complications of ADPKD. For the few patients suffering from chronic renal pain resistant to common analgesics, Elzinga et al. (1992) 13 reexamined the role of cyst decompression, a technique abandoned in the 1960s because of its reportedly detrimental effect on renal function. They reported on surgical decompression (100-200 cysts unroofed per kidney) in 30 patients, with sustained pain relief (up to 4 years later) in 62%. Laparoscopic cyst decortication now appears as a promising, minimally invasive …