ADPKD is a systemic disease of polycystin dysfunction, not merely a renal condition. Intracranial berry aneurysms are the most clinically feared — screening MRA is recommended in those with a family history of SAH or high-risk occupations. Hepatic cysts are the commonest extrarenal finding but rarely cause portal hypertension.
The pentad of TTP (MAHA, thrombocytopenia, renal impairment, fever, neurological symptoms) is rarely complete — empirical plasma exchange should not wait for all five. ADAMTS13 activity <10% confirms TTP. In STEC-HUS, antibiotics are avoided as they trigger toxin release.