Tuberous sclerosis complex-associated kidney angiomyolipoma: from contemplation to action
In a pioneering study published in 2008, Bissler et al. showed that sirolimus, an immunosuppressive drug that acts by inhibiting the mammalian target of rapamycin (mTORi) and is currently used in organ transplantation and cancer treatment, was able to decrease the volume of renal angiomyolipomas (AMLs) in patients with tuberous sclerosis complex (TSC) [1]. Over the last year, three other independent trials conducted by other teams in similar patients have confirmed and extended this remarkable step forward [2–4]. Together with other works demonstrating a comparable efficacy of sirolimus or everolimus on the neurological [5], pulmonary [6] and cutaneous [7] manifestations of TSC, these papers establish mTORi as the first medical treatment of this so far incurable disorder.
Since mTORi is, however, a treatment with a concerning safety profile and since not all patients with TSC-associated AMLs require intervention, the time has come for nephrologists to examine the pros and the cons of this new treatment and try to draw some insights into the current management of their patients.
Before scrutinizing the above-mentioned trials on the treatment of TSC-associated AMLs with sirolimus, the main clinical and genetic features of TSC are briefly reviewed and the rationale for treatment with mTORi is summarized. Then, after weighing the burden of mTORi side-effects, current indications are discussed mentioning the remaining uncertainties and unanswered questions.
http://ndt.oxfordjournals.org/content/early/2013/02/12/ndt.gft009.full