EFFICACY AND SAFETY OF SIROLIMUS IN REDUCING CYST VOLUME IN PATIENTS WITH AUTOSOMAL DOMINANT POLYCYSTIC KIDNEY DISEASE

Abstract

Sreelatha Melemadathil1, Jayakumar Edathedathe Krishnan2, Noushad Thekke Puthiyottil3

BACKGROUND Autosomal-Dominant Polycystic Kidney Disease is by far the most frequent inherited kidney disease. In White populations, its prevalence ranges from one in 400 to one in 1000 (Gabow 1993). Though the corresponding figure in Blacks is not yet available, the incidence of ESRD due to ADPKD is similar in American Blacks and Whites (Yium et al, 1994). Renoprotective interventions in ADPKD are maximal reduction of blood pressure and proteinuria and limit the effects of additional potential promoters of disease progression such as dyslipidaemia, chronic hyperglycaemia or smoking. At present, there is no definitive treatment for reducing cyst volume and hence disease progression. Sirolimus (Rapamycin) is an immunosuppressant mostly used for the management of kidney transplant recipients. This drug by specifically and effectively inhibiting mTOR, exerts antiproliferative and growth inhibiting effects and could be important for the inhibition of cyst progression in ADPKD. MATERIALS AND METHODS
It is an interventional randomised open label, active control study for six months. ADPKD type 1 patients between the age of 18 to 60 years with a GFR > 40 mL/min/1.73 m2 were included in the study. RESULTS Total number of subjects enrolled – 60. Patients enrolled in sirolimus arm – 40. Patients enrolled in conventional treatment arm - 20. Patients dropped out due to sirolimus side effects - 5. Patients lost to followup - 1. Patients completed treatment in conventional treatment arm - 20. CONCLUSION
Treatment with mTOR inhibitor sirolimus for 6 months was effective in reducing total kidney volume, total renal cyst volume and volume of the largest cyst in patients with ADPKD. There was a small, but significant increase in renal parenchymal volume on treatment with sirolimus. Extending the duration of treatment to one year caused further significant reduction in total kidney volume and cyst volume. Major side effect of sirolimus in our patients was mucositis, which could be managed with topical measures. Sirolimus caused clinically significant anaemia and dyslipidaemia in treated patients.

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