Incidence, epidemiology and outcomes of acute allograft rejection following liver transplantation in Australia.

BACKGROUND: Acute allograft rejection is a well-known complication of liver transplantation (LT). The incidence, epidemiology and outcomes of acute rejection have not been well-described in Australia. METHODS: We retrospectively studied consecutive adults who underwent deceased-donor LT at a single centre between 2010-2020. Donor and recipient data at time of LT and recipient outcomes were collected from a prospective LT database. Liver biopsy reports were reviewed and only a graft's first instance of biopsy-proven acute rejection was analysed. RESULTS: During the study period, 796 liver transplants were performed in 770 patients. Biopsy-proven rejection occurred in 34.9% of transplants. There were no significant changes in the incidence of rejection over time (linear trend p=0.11). The median time to first episode of rejection was 71 days post-LT: 2.2% hyperacute, 50.4% early (≤90 d) and 47.5% late rejection (>90 d). Independent risk factors for rejection were younger recipient age at transplant (aHR 0.98 per year increase, 95% CI 0.97-1.00, p=0.01), and ABO-incompatible grafts (aHR 2.55 vs. ABO-compatible, 95% CI 1.27-5.09, p<0.01) while simultaneous multiorgan transplants were protective (aHR 0.21 vs. LT only, 95% CI 0.08-0.58, p<0.01). Development of acute rejection (both early and late) was independently associated with significantly reduced graft (aHR 3.13, 95% CI 2.21-4.42, p<0.001) and patient survival (aHR 3.42, 95% CI 2.35-4.98, p<0.001). CONCLUSION: In this 11-year Australian study, acute LT rejection occurred in 35%, with independent risk factors of younger recipient age and ABO-incompatible transplant while having a simultaneous multiorgan transplant was protective. Acute rejection was independently associated with reduced graft and patient survival after adjustment for other factors.

Bacterial infections in patients with COVID-19: the impact of procalcitonin testing on antibiotics prescription in the real world.

BACKGROUND: Bacterial infections are not prevalent among patients hospitalized with COVID-19, while unnecessary prescription of antibiotics was commonly observed. This study aimed to determine the impact of procalcitonin testing on antibiotics prescription in the real-world setting. METHODS: We performed a territory-wide retrospective cohort study involving all laboratory-confirmed patients hospitalized in public hospitals in Hong Kong in 2020 with COVID-19. We determined the prevalence of bacterial co-infections (documented infections within 72 h of admission) and secondary bacterial infections (infections after 72 h of admission) and antibiotics consumption, and the correlation between procalcitonin testing and antibiotics prescription. RESULTS: The cohort included 8666 patients, with mean age 45.3 ± 19.9 years, 48.5% male, and comorbidities in 26.9%. Among 2688 patients with bacterial cultures performed, 147 (5.5%) had bacterial co-infections, and 222 (8.3%) had secondary bacterial infections. Antibiotics were prescribed for 2773 (32.0%) patients during the hospital admission. Procalcitonin tests were performed for 2543 (29.3%) patients. More patients with procalcitonin testing received antibiotics (65.9% vs. 17.9%, p < 0.001). Procalcitonin testing was associated with 5-fold increased risk of antibiotics prescription after adjusting for confounding variables. At hospital level, procalcitonin testing correlated with antibiotics prescription. Patients with procalcitonin level < 0.5 ng/mL had a lower probability of antibiotics initiation and shorter duration of antibiotics therapy. CONCLUSIONS: Procalcitonin testing was not associated with lower prescription of antibiotics. Patients with low procalcitonin level had lower antibiotics exposure, supporting the use of procalcitonin to exclude bacterial infections aiding early stopping of antibiotics among patients hospitalized with COVID-19.

Thromboembolic Risks with Concurrent Direct Oral Anticoagulants and Antiseizure Medications: A Population-Based Analysis.

BACKGROUND AND OBJECTIVE: Drug-drug interactions between direct oral anticoagulants (DOAC) and antiseizure medications via the cytochrome P450 (CYP) or the P-glycoprotein (P-gp) systems may lead to under-anticoagulation. The clinical relevance of these interactions is unclear. We aimed to elucidate the risk of thromboembolism with concurrent DOAC and CYP/P-gp modulating antiseizure medications. METHODS: In this propensity score-weighted population-based retrospective cohort study, we used competing risk regression analyses to determine the risks of ischemic stroke, venous thromboembolism, and death in DOAC recipients taking CYP/P-gp-modulating antiseizure medications (phenytoin, valproate, levetiracetam, carbamazepine, or phenobarbital) versus those taking CYP/P-gp-neutral antiseizure medications (pregabalin, gabapentin, or clobazam). We also performed secondary analyses for the epilepsy and atrial fibrillation subgroups. RESULTS: Among DOAC users, CYP/P-gp-modulating antiseizure medications were collectively associated with an increased risk of ischemic stroke (adjusted hazard ratio 1.28, 95% confidence interval 1.05-1.57, p = 0.017). In addition, phenytoin (adjusted hazard ratio 1.34, 95% confidence interval 1.07-1.68, p = 0.011) and valproate (adjusted hazard ratio 1.38, 95% confidence interval 1.10-1.74, p = 0.006) were associated with increased mortality. In the epilepsy subgroup, the risk of ischemic stroke and venous thromboembolism did not differ between CYP/P-gp-modulating and CYP/P-gp-neutral antiseizure medications. CONCLUSIONS: Although CYP/P-gp-modulating antiseizure medications were associated with an increased risk of ischemic stroke when paired with DOAC in the primary analysis, such a phenomenon was not found among patients with epilepsy who took phenytoin, valproate, or levetiracetam with DOAC. Therefore, these antiseizure medication options among patients with epilepsy with concurrent DOAC should not be restricted solely based on their potential drug-drug interactions. Yet, the increased mortality during concurrent use of DOAC with phenytoin or valproate might call for caution.

Association of genetic variations with NAFLD in lean individuals.

BACKGROUND & AIMS: How adiposity influences the effect of genetic variants on non-alcoholic fatty liver disease (NAFLD) in the Asian population remains unclear. We aimed to study the association between genetic risk variants and susceptibility/severity of NAFLD in the lean, overweight and obese individuals. METHODS: Nine hundred and four community subjects underwent proton-magnetic resonance spectroscopy and transient elastography examination. Lean (<23 kg/m2 ), overweight (23-24.9 kg/m2 ) and obesity (≥25 kg/m2 ) were defined according to the body mass index cut-offs for Asians. NAFLD was defined as intrahepatic triglycerides ≥5%. PNPLA3, TM6SF2, MBOAT7 and 9 other gene polymorphisms were analysed by rhAMPTM SNP assays. RESULTS: Five hundred and twenty-nine (58.5%), 162 (17.9%) and 213 (23.6%) subjects were lean, overweight and obese, respectively. The prevalence of NAFLD was 12.4%, 41.4% and 59.1% in the three groups (P < .001). Amongst those with NAFLD, lean subjects (30.3%) were more likely to carry the PNPLA3 rs738409 GG genotype than overweight (17.9%) and obese subjects (17.4%) (P = .003). Compared with the CC genotype, the GG genotype was associated with the greatest increase in the risk of NAFLD in lean subjects (odds ratio [OR] 6.04), compared with overweight (OR 3.43, 95% CI [1.06, 11.14]) and obese subjects (OR 2.51, 95% CI [0.93, 6.78]). Additionally, the TM6SF2 rs58542926 TT genotype was associated with reduced serum triglycerides only in lean subjects. A gene-BMI effect was not observed for the other gene polymorphisms. CONCLUSIONS: The PNPLA3 rs738409 gene polymorphism has a greater effect on liver fat in Asian lean individuals than in overweight or obese ones.

Risks of post-colonoscopic polypectomy bleeding and thromboembolism with warfarin and direct oral anticoagulants: a population-based analysis.

BACKGROUND: There were limited data on the risk of post-polypectomy bleeding (PPB) in patients on direct oral anticoagulants (DOAC). We aimed to evaluate the PPB and thromboembolic risks among DOAC and warfarin users in a population-based cohort. METHODS: We performed a territory-wide retrospective cohort study involving patients in Hong Kong from 2012 to 2020. Patients who received an oral anticoagulant and had undergone colonoscopy with polypectomy were identified. Propensity-score models with inverse probability of treatment weighting were developed for the warfarin-DOAC and between-DOAC comparisons. The primary outcome was clinically significant delayed PPB, defined as repeat colonoscopy requiring haemostasis within 30 days. The secondary outcomes were 30-day blood transfusion requirement and new thromboembolic event. RESULTS: Apixaban was associated with lower PPB risk than warfarin (adjusted HR (aHR) 0.39, 95% CI 0.24 to 0.63, p<0.001). Dabigatran (aHR 2.23, 95% CI 1.04 to 4.77, adjusted p (ap)=0.035) and rivaroxaban (aHR 2.72, 95% CI 1.35 to 5.48, ap=0.002) were associated with higher PPB risk than apixaban. In subgroup analysis, apixaban was associated with lower PPB risk in patients aged ≥70 years and patients with right-sided colonic polyps.For thromboembolic events, apixaban was associated with lower risk than warfarin (aHR 0.22, 95% CI 0.11 to 0.45, p<0.001). Dabigatran (aHR 2.60, 95% CI 1.06 to 6.41, ap=0.033) and rivaroxaban (aHR 2.96, 95% CI 1.19 to 7.37, ap =0.013) were associated with higher thromboembolic risk than apixaban. CONCLUSIONS: Apixaban was associated with a significantly lower risk of PPB and thromboembolism than warfarin, dabigatran and rivaroxaban, particularly in older patients with right-sided polyps.

Secular trend of treatment uptake in patients with chronic hepatitis B: A territory-wide study of 135 395 patients from 2000 to 2017.

BACKGROUND AND AIMS: The uptake of antiviral treatment for patients with chronic hepatitis B (CHB) has been suboptimal. We aimed to determine the secular trend of treatment uptake in the territory-wide CHB cohort in Hong Kong from 2000 to 2017 and the factors for no treatment despite fulfilling treatment criteria. METHODS: Chronic hepatitis B patients under public clinics and hospitals were identified through electronic medical records. The treatment indications were defined according to the Asian-Pacific guidelines published at the time of patients' first appearance in four periods: 2000-2004, 2005-2009, 2010-2013, and 2014-2017. RESULTS: There were 135 395 CHB patients were included; 1493/12472 (12.0%), 7416/43426 (17.1%), 10 129/46559 (21.8%), 8051/32 938 (24.4%) patients fulfilled treatment criteria in the four periods, respectively. The treatment uptake rate increased with time: 35.1%, 43.4%, 60.2%, and 68.6% respectively. High fibrosis indices (APRI, FIB-4, and Forns indices) appeared to be the main factors for treatment indication in non-cirrhotic patients, with over 90% fulfilling treatment criteria due to high fibrosis indices alone. Of those fulfilling treatment criteria by high fibrosis indices, less than 60% of patients (25.2%, 36.1%, 46.0%, and 58.9%, respectively) had antiviral treatment initiated. Normal platelet count (odds ratio 0.42, P < 0.001) was the independent factor associated with not initiating antiviral treatment in patients fulfilling treatment criteria. CONCLUSIONS: Treatment uptake rates have been increasing over time. Normal platelet count, which reflects less advanced liver disease, precludes patients from receiving antiviral treatment even if treatment indication is fulfilled. Hence, the importance to identify non-cirrhotic patients with significant liver fibrosis should be emphasized.

Gut microbiota composition reflects disease severity and dysfunctional immune responses in patients with COVID-19.

OBJECTIVE: Although COVID-19 is primarily a respiratory illness, there is mounting evidence suggesting that the GI tract is involved in this disease. We investigated whether the gut microbiome is linked to disease severity in patients with COVID-19, and whether perturbations in microbiome composition, if any, resolve with clearance of the SARS-CoV-2 virus. METHODS: In this two-hospital cohort study, we obtained blood, stool and patient records from 100 patients with laboratory-confirmed SARS-CoV-2 infection. Serial stool samples were collected from 27 of the 100 patients up to 30 days after clearance of SARS-CoV-2. Gut microbiome compositions were characterised by shotgun sequencing total DNA extracted from stools. Concentrations of inflammatory cytokines and blood markers were measured from plasma. RESULTS: Gut microbiome composition was significantly altered in patients with COVID-19 compared with non-COVID-19 individuals irrespective of whether patients had received medication (p<0.01). Several gut commensals with known immunomodulatory potential such as Faecalibacterium prausnitzii, Eubacterium rectale and bifidobacteria were underrepresented in patients and remained low in samples collected up to 30 days after disease resolution. Moreover, this perturbed composition exhibited stratification with disease severity concordant with elevated concentrations of inflammatory cytokines and blood markers such as C reactive protein, lactate dehydrogenase, aspartate aminotransferase and gamma-glutamyl transferase. CONCLUSION: Associations between gut microbiota composition, levels of cytokines and inflammatory markers in patients with COVID-19 suggest that the gut microbiome is involved in the magnitude of COVID-19 severity possibly via modulating host immune responses. Furthermore, the gut microbiota dysbiosis after disease resolution could contribute to persistent symptoms, highlighting a need to understand how gut microorganisms are involved in inflammation and COVID-19.

The safety of stopping nucleos(t)ide analogue treatment in patients with HBeAg-negative chronic hepatitis B.

BACKGROUND: The rates of hepatitis B surface antigen (HBsAg) seroclearance after stopping nucleos(t)ide analogues (NA) in European (19% in 2 years) and Asian (13% in 6 years) patients with chronic hepatitis B (CHB) vary dramatically. We evaluated the incidence of hepatitis flare and HBsAg seroclearance in hepatitis B e antigen (HBeAg)-negative Chinese CHB patients who had stopped NA. METHODS: This was a territory-wide retrospective study in Hong Kong. We identified HBeAg-negative CHB patients from January 2000 to December 2017 who had stopped NA treatment for more than 3 months. Hepatitis flare was defined as ALT >2×ULN. RESULTS: The 1076 patients were predominantly middle-aged men (mean age 52 years, male 74.8%) when starting NA; they stopped NA after 82 ± 35 months of treatment. At 44.3 ± 24.6 months after stopping NA, 147 (13.6%) patients had hepatitis flare, which led to resumption of NA; whereas 77 (7.2%) patients had flare but did not resume NA. Decompensation occurred in 7/914 (0.8%) patients. A total of 695 (64.6%) patients remained on NA treatment at the last visit. Eleven patients had achieved HBsAg seroclearance (6 of them had hepatitis flare and 1 of these 6 patients achieved HBsAg seroclearance after NA was restarted). Hepatic events developed in 75/695 (10.8%) patients who had NA resumed vs 43/381 (11.3%) patients who did not resume NA (P = .677). CONCLUSIONS: Hepatitis flare and retreatment were common in HBeAg-negative CHB patients who stopped NA treatment; whereas HBsAg seroclearance rarely occurred. Stopping NA to achieve functional cure should not be recommended at this moment.

Development and validation of a model for hepatitis B e antigen seroconversion in entecavir-treated patients with chronic hepatitis B.

Achieving hepatitis B e antigen (HBeAg) seroconversion is a satisfactory endpoint during antiviral treatment for chronic hepatitis B (CHB). This study aimed to develop and validate a novel scoring system to predict HBeAg seroconversion during entecavir (ETV) treatment. A total of 526 patients with HBeAg-positive CHB treated with ETV for at least 1 year were randomly assigned to the training and validation cohorts. Baseline parameters including hepatitis B virus DNA, hepatitis B surface antigen (HBsAg), hepatitis B core antibody (HBcAb), and alanine aminotransferase level were quantified. Patients who achieved HBeAg seroconversion were compared with those without HBeAg seroconversion. A prediction model was established to predict HBeAg seroconversion during ETV treatment. After a median follow up of 2.67 years, 93 (36.0%) and 87 (32.5%) patients in the training and validation cohorts developed HBeAg seroconversion. A prediction score composed of age, HBsAg and HBcAb quantification was derived. Areas under receiver operating characteristic curve at 5 years of this prediction score were 0.70 and 0.72 in the training and validation cohorts. By using the dual cutoff values of 0.28 and 0.58, the model was endowed with high sensitivity and specificity to exclude or identify patients developing HBeAg seroconversion (90.3% sensitivity and 90.2% specificity in the training cohort as well as 92.8% sensitivity and 84.4% specificity in the validation cohort, respectively). A novel prediction score that uses baseline clinical variables was developed and validated. The score accurately estimates the probabilities of developing HBeAg seroconversion at 5-years ETV therapy in patients with CHB.