Cyst infection in autosomal dominant polycystic kidney disease: penetration of meropenem into infected cysts

Background: Cyst infection is a common and serious complication of autosomal dominant polycystic kidney disease (ADPKD) that is often refractory. Carbapenems are frequently needed to treat to patients with refractory cyst infection, but little is known about the penetration of newer water-soluble carbapenems into cysts. This study investigated the penetration of meropenem (MEPM) into infected cysts in patients with ADPKD. Methods: Between August 2013 and January 2014, 10 ADPKD patients (14 infected cysts) receiving MEPM at Toranomon Hospital underwent drainage of infected cysts and definite cyst infection was confirmed through detection of neutrophils by cyst fluid analysis. The serum concentration of MEPM was measured just after intravenous administration and was compared with that in fluid aspirated from infected cysts. Results: In the patients undergoing cyst drainage, the mean serum MEPM concentration was 35.2 +/- 12.2 mu g/mL (range: 19.7 to 59.2 mu g/mL, while the mean cyst fluid concentration of MEPM in the drained liver cysts (n = 12) or kidney cysts (n = 2) was 3.03 +/- 2.6 mu g/mL (range: 0 to 7.3 mu g/mL). In addition, the mean cyst fluid/serum MEPM concentration ratio was 9.46 +/- 7.19% (range: 0 to 18.8%). There was no relationship between the cyst fluid concentration of MEPM and the time until drainage after MEPM administration or between the cyst fluid/serum MEPM concentration ratio and the time until drainage. Conclusion: These findings suggest that MEPM shows poor penetration into infected cysts in ADPKD patients.