Clinical and radiological features of invasive Klebsiella pneumoniae liver abscess syndrome

Abstract

Background: Recently, a striking new clinical manifestation of Klebsiella pneumoniae (KP) infection referred to as invasive KP liver abscess syndrome (IKPLAS), defined by liver abscess with contemporaneous metastatic KP infections at other body sites has been documented. Until now, however, there have been relatively few reports regarding its radiologic features. Purpose: To describe the clinical and radiological features of IKPLAS patients, and to compare them with those with KP liver abscess without metastatic infections to ascertain possible predictors of IKPLAS. Material and Methods: From January 2008 to May 2010, 35 patients (26 men and 9 women; mean age, 59.4 years) with both liver abscess and metastatic KP infections were diagnosed with IKPLAS. Their clinical and radiological features were retrospectively evaluated and compared with those of 25 contemporaneous non-metastatic patients to investigate predictive factors for metastatic infections. Results: The rate of intensive care unit admissions and overall mortality was 34.3% and 17.1% in IKPLAS patients, and was significantly higher than those of the non-metastatic group (8% and 0%, respectively). As for metastatic infections, the lung was the most common site and multiple nodules or masses (n = 9) were the most common manifestations. Univariate analysis revealed that liver abscess <= 5.8 cm, bilobar involvement of abscess and altered mentality were significantly related with IKPLAS. At multivariate analysis, liver abscess <= 5.8 cm was proven to be a significant independent predictor of IKPLAS (OR, 3.6; P = 0.038). In addition, altered mentality was present solely in IKPLAS (25.7% vs. 0%) although its P value (P = 0.052) did not reach a statistical significance at multivariate analysis. Conclusion: IKPLAS has significantly worse prognosis than non-metastatic KP abscess patients. In patients with KP liver abscess, liver abscess <= 5.8 cm can be used as an independent predictor of IKPLAS and altered mentality as a very specific feature in diagnosing IKPLAS.