Sirolimus therapy for patients with adult polycystic kidney disease: a pilot study

A pilot study was performed on adult polycystic kidney disease (PCKD) patients to examine the effects of the anti-proliferative mammalian target of rapamycin inhibitor sirolimus on the growth of renal cysts. Eight consecutive PCKD patients were given sirolimus (1 mg/d PO) for 6 consecutive months, in addition to an angiotensin receptor blocker (ARB), namely telmisartan. Another 8 PCKD patients served as a control group given only telmisartan. All PCKD patients had a serum creatinine value <2 mg/dL with a negative urine culture before enrollment. All patients were diagnosed by renal magnetic resonance imaging (MRI) to measure renal volumes. After a 6-month follow-up, patients were rescanned to remeasure the MRI volumes. Renal function was stable in 5/8 subjects in the sirolimus group, improved in 2 cases, and worsened in 1 with an increase of serum creatinine to >2 mg/dL resulting in his withdrawal after 5 months of follow-up. In contrast, the serum creatinine value was stable in 3 control group subjects, worsen in 3, and improved in 2. Four patients in the sirolimus group experienced infectious complications, namely, urinary tract infections (UTI) in 2 which were treated with antibiotics, and monilial pharyngitis in 2, who were treated and cured with a topical antifungal. In the control group, only 2 developed and were treated for UTIs. Hematologic tests were normal in all patients. There was an insignificant rise in kidney volume as measured by MRI in the sirolimus group (2845 vs 3221 mL after 6 months; P = NS) compared with a significant increase in the control group (2667 vs 3590 mL after 6 months; P < .05). We concluded that sirolimus, in addition to an ARB, might be beneficial for PCKD patients who present early in their illness.