Somatostatin in Polycystic Kidney: a Long-term Three Year Follow up Study (ALADIN)

Autosomal Dominant Polycystic Kidney Disease (ADPKD) is the most common hereditary renal disease, responsible for 8% to 10% of the cases of end stage renal disease (ESRD) in Western countries. At comparable levels of blood pressure control and proteinuria, patients with ADPKD have faster decline in glomerular filtration rate than those with other renal diseases and do not seem to benefit to the same extent of ACE inhibitor therapy. A reasonable explanation for the above findings is that in ADPKD progression is largely dependent on the development and growth of cysts and secondary disruption of normal tissue. Thus, renoprotective interventions in ADPKD - in addition to achieve maximal reduction of arterial blood pressure and proteinuria and to limit the effects of additional potential promoters of disease progression such as dyslipidemia, chronic hyperglycemia or smoking - should also be specifically aimed to correct the dysregulation of epithelial cell growth, secretion, and matrix interactions characteristic of the disease.

Evidence that specific receptors for somatostatin are present in the kidney tissue, arises the possibility that somatostatin treatment in patients with ADPKD might inhibit fluid formation and eventually induce the shrinking of renal cysts.To evaluate the tolerability and the safety of long-acting somatostatin in ADPKD patients, a prospective cross-over controlled study has been recently performed. This pilot study demonstrated the safety of six month treatment of long-acting somatostatin in patients with ADPKD. Moreover, the percent increase of total kidney volume was significantly lower in patients on somatostatin than in placebo. Overall, these findings provide the basis for designing a long-term study in ADPKD patients aimed to document the efficacy of the somatostatin treatment in preventing further increase or even reducing the total kidney volume and the renal volume taken up by small cysts, eventually halting kidney disease progression.