Aspirin use is associated with reduced risk for recurrence of pyogenic liver abscess: a propensity score analysis.

Aspirin possesses anti-bacterial activity that may prevent recurrence of Klebsiella pneumoniae pyogenic liver abscess (KP-PLA). In ex-vivo study, aspirin was administered before bactericidal assay against serotype K1 K. pneumoniae. We identified 5,912 patients with PLA who had no known pre-existing hepatobiliary diseases or malignancy in Taiwan from 1999 to 2013 from nationwide cohort study. Multivariate Cox proportional hazards regression models was used to estimate the hazard ratios [HR] for the association between aspirin use and recurrent PLA. The PLA recurrence rate in patients taking aspirin daily for 30 or more days, from 90 days before to 90 days after the first PLA episode (aspirin users), and aspirin non-users was 42.5 and 74.6 per 1,000 person-years of follow-up, respectively. The population-based study showed a HR for PLA recurrence in aspirin users of 0.50 (95% confidence interval, 0.35-0.69), relative to that in non-users, after adjustments for confounders. An ex-vivo study indicated that aspirin was able to significantly enhance bacterial killing by leukocytes, whether collected from diabetic patients with KP-PLA recurrence or from healthy volunteers. Our results suggest that aspirin is associated with reduced risk for PLA recurrence among Taiwanese with PLA who had no preexisting hepatobiliary diseases or malignancy.

Statin Use Correlates with Reduced Risk of Pyogenic Liver Abscess: A Population-Based Case-Control Study.

Little research is available on the relationship between statin use and pyogenic liver abscess. The objective of the study was to determine whether prior use of statins is associated with pyogenic liver abscess. This case-control study was conducted to analyse the claim data of the Taiwan National Health Insurance Program. There were 1828 participants aged 20-84 years with first episode of pyogenic liver abscess from 2000 to 2013 as the cases and 1828 randomly selected participants without pyogenic liver abscess matched with sex, age and index year as the controls. Statin use was defined as 'current', 'recent' or 'past' if the statin prescription was filled ≤3 months, 3-6 months or >6 months before the date of pyogenic liver abscess diagnosis, respectively. Relative risk of pyogenic liver abscess associated with statin use was estimated by the odds ratio (OR) with 95% confidence interval (CI) using the multivariable logistic regression model. After controlling for potential confounders, the adjusted ORs of pyogenic liver abscess were 0.65 for participants with current use of statins (95% CI 0.50, 0.84), 0.74 for participants with recent use of statins (95% CI 0.49, 1.11), and 1.10 for participants with past use of statins (95% CI 0.90, 1.34), compared with participants with never use of statins. In the further analysis, the adjusted ORs of pyogenic liver abscess were 0.65 for participants with cumulative duration of statin use ≥12 months (95% CI 0.48, 0.88) and 0.68 for participants with cumulative duration of statin use <12 months (95% CI 0.43, 1.07), compared with participants with never use of statins. Our findings provide strong evidence that patients with current use of statins are associated with a 35% reduced odds of pyogenic liver abscess. The protective effect is stronger for longer duration of statin use.

Gastrointestinal stromal tumor as entry port for S. intermedius causing bacteremia and multiple liver abscesses. Case report and review of literature.

We report a case of a previously healthy 52-year-old man who presented with fever and liver lesions suspicious for metastatic disease, which proved subsequently to be abscesses. Further workup revealed a gastrointestinal stromal tumor (GIST) in the gastric corpus as entry port to Streptococcus intermedius-associated bacteremia and liver abscesses. After antibiotic treatment and surgical resection of the tumor, the patient recovered well. This unusual case indicates that gastrointestinal stromal tumors can remain undetected until they cause a life threatening infection. A review of recent literature pertaining to GIST and liver abscesses follows.

Lipopolysaccharide O1 antigen contributes to the virulence in Klebsiella pneumoniae causing pyogenic liver abscess.

Klebsiella pneumoniae is the common cause of a global emerging infectious disease, community-acquired pyogenic liver abscess (PLA). Capsular polysaccharide (CPS) and lipopolysaccharide (LPS) are critical for this microorganism's ability to spread through the blood and to cause sepsis. While CPS type K1 is an important virulence factor in K. pneumoniae causing PLA, the role of LPS in PLA is not clear. Here, we characterize the role of LPS O antigen in the pathogenesis of K. pneumoniae causing PLA. NTUH-K2044 is a LPS O1 clinical strain; the presence of the O antigen was shown via the presence of 1,3-galactan in the LPS, and of sequences that align with the wb gene cluster, known to produce O-antigen. Serologic analysis of K. pneumoniae clinical isolates demonstrated that the O1 serotype was more prevalent in PLA strains than that in non-tissue-invasive strains (38/42 vs. 9/32, P<0.0001). O1 serotype isolates had a higher frequency of serum resistance, and mutation of the O1 antigen changed serum resistance in K. pneumoniae. A PLA-causing strain of CPS capsular type K2 and LPS serotype O1 (i.e., O1:K2 PLA strain) deleted for the O1 synthesizing genes was profoundly attenuated in virulence, as demonstrated in separate mouse models of septicemia and liver abscess. Immunization of mice with the K2044 magA-mutant (K(1) (-) O(1)) against LPS O1 provided protection against infection with an O1:K2 PLA strain, but not against infection with an O1:K1 PLA strain. Our findings indicate that the O1 antigen of PLA-associated K. pneumoniae contributes to virulence by conveying resistance to serum killing, promoting bacterial dissemination to and colonization of internal organs after the onset of bacteremia, and could be a useful vaccine candidate against infection by an O1:K2 PLA strain.

Long-term outcome of pyogenic liver abscess: factors related with abscess recurrence.

BACKGROUND/AIMS: Long-term surveillance of pyogenic liver abscess remains unavailable. We thus aimed to identify the recurrence rates of pyogenic liver abscess among various etiologies and pathogens, and to elucidate the factors related with this recurrence. METHODS: Six-hundred and one patients with pyogenic liver abscess were prospectively enrolled to observe abscess recurrence during a mean follow-up period of up to 6.06 years. On the basis of the etiology of the initial abscess, patients were divided into different subgroups as follows: there were 152 (25.3%) patients classified as cryptogenic, 229 (38.1%) with diabetes mellitus, 144 (24%) with underlying biliary tract disease, and 76 (12.6%) with other organic diseases or mixed subgroups. RESULTS: The cumulative recurrence rates of pyogenic liver abscess were lower in both the cryptogenic (2.0%) and diabetic (4.4%) groups than in the underlying biliary tract disease (23.8%) group (log-rank test, P<0.001). The diabetic group had a higher rate of Klebsiella pneumoniae infection and a lower rate of Escherichia coli infection than the biliary tract group (P<0.001). For patients infected with K. pneumoniae, the recurrence rate of pyogenic liver abscess was as low as that of the diabetes and the cryptogenic groups (P>0.05). CONCLUSIONS: Pyogenic liver abscess is more commonly recurrent in patients with underlying biliary tract disease. Irrespective of diabetic status or cryptogenic etiology, the recurrence of K. pneumoniae-infected liver abscess is low in the long-term.