Bacterial infections as a risk factor for non-neoplastic portal vein thrombosis development in cirrhotic patients

BACKGROUND

Portal vein thrombosis (PVT) and sepsis are common complications in patients with liver cirrhosis. Factors that lead to PVT are not completely understood. This study aimed to investigate the possible association between bacterial infections and the development of PVT in cirrhotic patients.

PATIENTS AND METHODS

202 consecutive cirrhotic patients without previous infections, followed at the Liver Unit in Verona Hospital, were enrolled from 2017 to 2021 (median follow-up 3.3 years). During the follow-up period, PVT was diagnosed by ultrasound, CT and/or MRI, and episodes of bacterial infections requiring hospitalization were recorded. Malignant PVT was an exclusion criterion.

RESULTS

Of the 202 patients enrolled (68.3 % males, mean age 63.8 ± 11 years), 22 (10.8 %) developed PVT during the follow up. In patients with PVT, the prevalence of previous bacterial infections was significantly higher compared to patients without PVT (63.6% vs 31.1 %; p = 0.02). Cox regression analysis revealed that a history of bacterial infection was the only variable that demonstrated a significant association with the risk of de novo PVT occurrence (HR 4.04, 95 % CI: 1.68-9.65).

CONCLUSION

in patients with liver cirrhosis bacterial infections are a predisposing factor for the following development of PVT. Further studies are needed to confirm this evidence.

Prevalence of portal vein thrombosis in non-alcoholic fatty liver disease: a meta-analysis of observational studies

Portal vein thrombosis (PVT) is a common complication of cirrhosis as a result of portal hypertension and modification in the hemostatic balance. Accumulating evidence now suggests that patients with non-alcoholic fatty liver disease (NAFLD), especially those with advanced forms, have an increased risk of PVT. Hence, we performed a meta-analysis of observational studies to estimate the overall prevalence of PVT in patients with NAFLD and its advanced forms compared with patients with advanced liver diseases from other etiologies. We systematically searched PubMed, Scopus and Web of Science databases from the inception date to December 30th 2022, using predefined keywords, to identify observational studies. Meta-analysis was performed using random-effects modeling. We included five observational studies for a total of 225,571 patients. Of these, 26,840 (11.9%) patients had NAFLD, whereas the PVT prevalence was 8.5% (n = 2,280). When compared with patients with advanced liver diseases from other etiologies, patients with NAFLD and its advanced forms had a higher risk of prevalent PVT (OR 1.34, 100% CI 1.07-1.67 p < 0,01). The between-study heterogeneity was substantial (I2 = 88%). This meta-analysis suggests that compared with patients with advanced liver diseases from other etiologies, patient with NAFLD and its advanced forms had a higher risk of prevalent PVT. Further research is required to understand the complex link between NAFLD/NASH and PVT development.

Spur cells in liver cirrhosis are predictive of acute-on-chronic liver failure and liver-related mortality regardless of severe anaemia

Chronic anaemia in advanced liver disease is a frequent finding. The aim was to explore the clinical impact of spur cell anaemia, a rare entity typically associated with end-stage of the disease. One-hundred and nineteen patients (73.9% males) with liver cirrhosis of any etiology were included. Patients with bone marrow diseases, nutrients deficiencies and hepatocellular carcinoma were excluded. In all patients, a blood sample was collected to check for the presence of spur cells on blood smear. A complete blood biochemical panel was recorded together with Child-Pugh (CP) score and Model for End-Stage Liver Disease (MELD) score. For each patients, clinically relevant events, such as acute-on-chronic liver failure (ACLF) and 1 year liver-related mortality, were registered. Patients were then grouped according to the percentage of spur cells at smear (> 5%, 1-5%, < 1%). Severe anaemia was defined as haemoglobin levels lower than 8 g/dL. 9.2% of subjects had > 5% spur cells, only 2 had evidence of haemolysis. In patients with > 5% spur cells, haemoglobin and albumin were lower compared with the other sub-group, while MELD score, CP score, International Normalized Ratio, ferritin, creatinine and unconjugated bilirubin were higher. Patients with more spur cells were more decompensated and developed more frequently ACLF. ACLF and liver-related mortality were significantly and independently associated with the presence of > 5% spur cells but not with baseline severe anaemia. Cirrhotic patients have a fairly high prevalence of spur cells, not always associated with severe haemolytic anaemia. The presence of spur red cells is per se associated with a worse prognosis and, therefore, should be always evaluated to prioritize patients for intensive management and eventually liver transplantation.

The multi-drug resistant organisms infections decrease during the antimicrobial stewardship era in cirrhotic patients: An Italian cohort study

BACKGROUND AND PURPOSE

Bacterial infections represent a major cause of morbidity and mortality in cirrhotic patients. Our aim was to assess the incidence of bacterial infections, in particular due to multidrug-resistant organisms (MDROs) before and after the introduction of the antimicrobial stewardship program, "Stewardship Antimicrobial in VErona" (SAVE). In addition, we also analysed the liver complications and the crude mortality during the whole follow up.

METHODS

We analysed 229 cirrhotic subjects without previous hospitalization for infections enrolled at the University Verona Hospital from 2017 to 2019 and followed up until December 2021 (mean follow-up 42.7 months).

RESULTS

101 infections were recorded and 31.7% were recurrent. The most frequent were sepsis (24.7%), pneumonia (19.8%), spontaneous bacterial peritonitis (17.8%). 14.9% of infections were sustained by MDROs. Liver complications occurred more frequently in infected patients, and in case of MDROs infections with a significantly higher MELD and Child-Pugh score. In Cox regression analysis, mortality was associated with age, diabetes and bacterial infections episodes (OR 3.30, CI 95%: (1.63-6.70). Despite an increase in total infections over the past three years, a decrease in the incidence rate in MDROs infections was documented concurrently with the introduction of SAVE (IRD 28.6; 95% CI: 4.6-52.5, p = 0.02).

CONCLUSIONS

Our study confirms the burden of bacterial infections in cirrhotic patients, especially MDROs, and the strong interconnection with liver complications. The introduction of SAVE decreased MDROs infections. Cirrhotic patients require a closer clinical surveillance to identify colonized patients and avoid the horizontal spread of MDROs in this setting.

Characterization of the initial alpha-thrombin interaction with glycoprotein Ib alpha in relation to platelet activation

We have evaluated the properties of alpha-thrombin interaction with platelets within 1 min from exposure to the agonist, a time frame during which most induced activation responses are initiated and completed. Binding at 37 degrees C was rapidly reversible and completely blocked by a monoclonal antibody, LJ-Ib10, previously shown to be directed against the alpha-thrombin interaction site on glycoprotein (GP) Ib alpha. By 2-5 min, however, binding was no longer fully reversible and was only partially inhibited by the anti-GP Ib alpha antibody. Results were similar at room temperature (22-25 degrees C), whereas the initial characteristics of alpha-thrombin interaction with platelets were preserved for at least 20 min at 4 degrees C. Equilibrium binding isotherms obtained at the latter temperature were compatible with a two-site model, but the component ascribed to GP Ib alpha, completely inhibited by LJ-Ib10, had "moderate" affinity (kd on the order of 10(-8) M) and relatively high capacity, rather than "high" affinity (kd on the order of 10(-10) M) and low capacity as currently thought. The parameters of alpha-thrombin binding to intact GP Ib alpha on platelets at 4 degrees C corresponded closely to those measured with isolated GP Ib alpha fragments regardless of temperature. Blocking the alpha-thrombin-GP Ib alpha interaction caused partial inhibition of ATP release and prevented the association with platelets of measurable proteolytic activity. These results support the concept that GP Ib alpha contributes to the thrombogenic potential of alpha-thrombin.