Autosomal dominant polycystic kidney disease (ADPKD) is the most common monogenic cause of end-stage renal failure in humans and results from germline mutations in PKD1 or PKD2 . Despite the recent approval of tolvaptan, safer and more effective alternative drugs are clearly needed to slow disease progression. As a first step in drug discovery, we conducted an unbiased chemical screen on zebrafish pkd2 mutant embryos using two publicly available compound libraries (Spectrum, PKIS) totalling 2,367 compounds to identify novel treatments for ADPKD. Using dorsal tail curvature as the assay readout, three major chemical classes (steroids, coumarins, flavonoids) were identified from the Spectrum library as the most promising candidates to be tested on human PKD1 cystic cells. Amongst these were an androgen, 5α−androstane 3,17-dione, detected as the strongest enhancer of the pkd2 phenotype but whose effect was found to be independent of the canonical androgen receptor pathway. From the PKIS library, we identified several ALK5 kinase inhibitors as strong suppressors of the pkd2 tail phenotype and in vitro cyst expansion. In summary, our results identify ALK5 and non-canonical androgen receptors as potential therapeutic targets for further evaluation in drug development for ADPKD.

ObjectivesA number of randomised control trials (RCTs) investigating the effects of long-acting somatostatin analogues in autosomal dominant polycystic kidney disease (ADPKD) and polycystic liver disease (PLD) have been recently reported. We sought to evaluate all available RCTs investigating the efficacy of somatostatin analogues treatment in ADPKD and PLD.Data sourcesElectronic databases; Pubmed, Clincaltrials.gov and Cochrane Central Register of Controlled TrialsEligibility criteria for selecting studiesRCTs and randomised cross-over trials comparing the effects of somatostatin analogue treatment with controls in patients with ADPKD or PLD.Data extraction and synthesisData extraction and bias assessments were performed by two independent reviewers between January and May 2019. Outcomes assessed included estimated glomerular filtration rate (eGFR), total kidney volume (TKV), total liver volume (TLV), progression to end stage renal failure (ESRF) and adverse effects. Data were pooled using a random-effects model and reported as relative risk or mean difference with 95% CIs.ResultsMeta-analysis was performed of six RCTs or randomised cross-over trials and three secondary analyses. A total of 592 patients were included. Compared with controls, somatostatin analogue treatment significantly reduced TLV (mean difference −0.15 L, 95% CI −0.26 to −0.03, p=0.01). There was no significant effect on TKV (mean difference −0.19 L, 95% CI −0.50 to 0.12, p=0.23) or eGFR (mean difference 0.27 mL/min/1.73 m2, 95% CI −2.03 to 2.57, p=0.82). There was no effect on progression to ESRF. Somatostatin analogues were associated with known adverse effects such as gastrointestinal symptoms.ConclusionsThe available RCT data show improvement in TLV with somatostatin analogue treatment. There was no benefit to TKV or eGFR in patients with ADPKD, while being associated with various side effects. Further studies are needed to assess potential benefit in reducing cyst burden in patients with PLD.

Introduction Subpubic cartilaginous cysts (SCCs) are rare. Aim This is the first reported case of a male patient presenting with neurological and sexual symptoms due to an SCC. Method We describe the clinical history of a patient who reported neuralgic pain, numbness in the groin and base of his penis, and loss of sexual function. Results A magnetic resonance imaging revealed the presence of an SCC with associated mass effect. A conservative approach was adopted and within 12 months, the cyst had decreased in size and his symptoms had improved. Conclusions Men who present with erectile dysfunction and neurological symptoms merit a thorough assessment including appropriate investigation to exclude organic pathology.