Renal manifestations of systemic and chronic disease

At a glance

• Systemic disease reaches the kidney through four compartments: glomeruli (proteinuria, haematuria), tubules and interstitium (sterile pyuria, electrolyte and acid-base disorders), vessels (hypertension, TMA, infarction) and the urinary tract (stones, obstruction).
• The urine is the quickest guide: dipstick, microscopy, ACR and PCR, plus complement, serology and free light chains.
• Kidney biopsy settles it when the cause is unclear, function is falling or treatment depends on the lesion.