Acute kidney injury and post-reperfusion syndrome in liver transplantation

In the past decades liver transplantation(LT) has become the treatment of choice for patients with end stage liver disease(ESLD). The chronic shortage of cadaveric organs for transplantation led to the utilization of a greater number of marginal donors such as older donors or donors after circulatory death(DCD). The improved survival of transplanted patients has increased the frequency of long-term complications, in particular chronic kidney disease(CKD). Acute kidney injury(AKI) post-LT has been recently recognized as an important risk factor for the occurrence of denovo CKD in the long-term outcome. The onset of AKI post-LT is multifactorial, with pre-LT risk factors involved, including higher Model for End-stage Liver Disease score, more sever ESLD and pre-existing renal dysfunction, either with intra-operative conditions, in particular ischaemia reperfusion injury responsible for post-reperfusion syndrome(PRS) that can influence recipient's morbidity and mortality. Post-reperfusion syndrome-induced AKI is an important complication post-LT that characterizes kidney involvement caused by PRS with mechanisms not clearly understood and implication on graft and patient survival. Since preLT risk factors may influence intra-operative events responsible for PRS-induced AKI, we aim to consider all the relevant aspects involved in PRS-induced AKI in the setting of LT and to identify all studies that better clarified the specific mechanisms linking PRS and AKI. A Pub Med search was conducted using the terms liver transplantation AND acute kidney injury; liver transplantation AND post-reperfusion syndrome; acute kidney injury AND post-reperfusion syndrome; acute kidney injury AND DCD AND liver transplantation. Five hundred seventy four articles were retrieved on Pub Med search. Results were limited to title/abstract of English-language articles published between 2000 and 2015. Twenty-three studies were identified that specifically evaluated incidence, risk factors and outcome for patients developing PRS-induced AKI in liver transplantation. In order to identify intra-operative risk factors/mechanisms specifically involved in PRSinduced AKI, avoiding confounding factors, we have limited our study to "acute kidney injury AND DCD AND liver transplantation". Accordingly, three out of five studies were selected for our purpose.

Association between non-alcoholic fatty liver disease and obstructive sleep apnea

BACKGROUND Non-alcoholic fatty liver disease(NAFLD)is an emerging liver disease and currently the most common cause of incidental abnormal liver tests.The pathogenesis of NAFLD is multifactorial and many mechanisms that cause fatty liver infiltration,inflammation,oxidative stress and progressive fibrosis have been proposed.Obstructive sleep apnea(OSA)may be linked with the pathogenesis and the severity of NAFLD.AIM To study the association between NAFLD and OSA considering also the efficacy of continuous positive airway pressure(CPAP)treatment.METHODS A Pub Med search was conducted using the terms"non-alcoholic fatty liver disease AND(obstructive sleep apnea OR obstructive sleep disorders OR sleep apnea)".Research was limited to title/abstract of articles published in English in the last 5 years;animal and child studies,case reports,commentaries,letters,editorials and meeting abstracts were not considered.Data were extracted on a standardized data collection table which included:First author,publication year,country,study design,number of patients involved,diagnosis and severity of OSA,diagnosis of NAFLD,patient characteristics,results of the study.RESULTSIn total,132 articles were initially retrieved on Pub Med search and 77 in the last five years.After removal of irrelevant studies,13 articles were included in the qualitative analysis.There was a total of 2753 participants across all the studies with a mean age between 42 and 58 years.The proportion of males ranged from21%to 87.9%and the mean body mass index ranged from 24.0 to 49.9 kg/m2.The results of this review showed an increased prevalence of NAFLD in patients with diagnosis of OSA,even in the absence of coexisting comorbidities such as obesity or metabolic syndrome.Furthermore,the severity of NAFLD is associated with the increase in OSA severity.Effective CPAP treatment,although not always decisive,may stabilize or slow NAFLD progression with benefits on metabolic and cardiovascular functions.CONCLUSION In NAFLD patients,although asymptomatic,it is recommended to systematically perform polysomnography in order to early and better treat them before the development of potentially life threatening systemic dysfunctions.

Different behaviour of BK-virus infection in liver transplantrecipients

Polyomavirus BK(BKV) infects up to 90% of the general population. After primary infection, occurring early during childhood, a state of non-replicative infection is established in the reno-urinary tract, without complications for immunocompetent hosts. In immunocompromised individuals, particularly transplanted patients, asymptomatic BKV viremia and/or viruria can be observed. Renal grafts may also be sources of infection as BKV prefers kidneys rather than other solid organs for transplantation such as the liver. The mechanism behind the higher incidence of BKV infection in kidney transplant patients, compared to liver or heart transplantation, is unclear and the prevalence of BKV infection in non-renal solid organ transplants has not been yet thoroughly investigated. We evaluated the prevalence of Polyomavirus BK infection among liver transplant recipients. A Pub Med search was conducted using the terms BKV infection AND liver transplant recipients; BKV AND non-renal solid organ transplant*; BKV infection AND immunosuppression; the search was limited to title/abstract and English-language articles published from 2000, to March 2015. Eleven relevant studies suggest that the prevalence of BKV viruria and/or viremia among liver transplant recipients is less than that reported in kidney or heart transplant recipients, except when chronic kidney disease(CKD) is present at the same time. Data also suggest that viruric and viremic patients have higher levels of serum creatinine than BKV negative patients. Moreover, no specific immunosuppressive drugs are associated with the onset of BKV nephropathy. The comorbidity of transplantation and CKD could play a major role in promoting BKV replication.