Infection of Cysts in Polycystic Kidney Disease

Today we were challenged by a case of a patient with PKD who had a urinary tract infection with a resistant E. Coli complicated by a presumed infected cyst.

In PKD, renal cyst infections are usually caused by E. Coli or other urinary organisms. They can be difficult to diagnose but often present with fever, abdominal pain, and elevated inflammatory markers. Cysts may enlarge or show evidence of complex septation or debris -- however, imaging is often not helpful in making the diagnosis.

Urine culture is positive in 40%, Blood in 25%, and cyst aspirates in another 12%. Medical therapy includes a relatively prolonged (3+ weeks) course of antibiotics. Usually fluoroquinolones or TMP/SMX are preferred because of cyst penetration. Beta-lactam and aminoglycoside penetration is relatively poor.

In failure of medical therapy (prolonged symptoms, fever, sepsis) or in cases where the presumed culprit cyst is greater than 5cm in diameter, percutaneous or surgical drainage is often required.

See the recently published case series here.

In our case today we elected to use high-dose ceftriaxone (since CIP/TMP-SMZ/AMP/CEF were resistant) to try and maximize intracyst concentration.