Prediction of nonalcoholic fatty liver in prospective liver donors

Updated Reference Intervals for Alanine Aminotransferase in a Metabolically and Histologically Normal Population

BACKGROUND & AIMS

This study aims to reevaluate upper reference limit (URL) for alanine aminotransferase (ALT) by considering the changing epidemiology of major liver diseases. We employed histological and metabolic parameters in Asian living liver donors.

METHODS

We performed a retrospective analysis of 5455 potential living liver donors from 2005 to 2019. Participants were screened for hepatitis B, C, HIV, and alcohol use. Histologically and metabolically healthy participants were assessed using the Prati criteria (body mass index <23 kg/m2, triglyceride ≤200 mg/dL, fasting glucose ≤105 mg/dL, total cholesterol ≤220 mg/dL). The updated ALT-URL was determined as the 95th percentile among participants without hepatic steatosis and who met the Prati criteria.

RESULTS

The median age was 30 years, with a male predominance (66.2%). Among 5455 participants, 3162 (58.0%) showed no hepatic steatosis, with 1553 (49.1%) meeting both the criteria for no steatosis and the Prati criteria for metabolic health. The updated URL for ALT in these participants was 34 U/L for males and 22 U/L for females, which was significantly lower than conventionally accepted values. Using this revised ALT-URL, 72.8% of males with ALT levels ≥34 U/L and 55.0% of females with ALT levels ≥22 U/L showed signs of steatosis, whereas 32.7% of males and 22.2% of females met the criteria for metabolic syndrome.

CONCLUSIONS

Our study provided the newly established reference intervals for ALT levels in a metabolically and histologically verified Asian population. The proposed URL for ALT are 34 U/L and 22 U/L for males and females, respectively.

Geographic disparities in access to liver transplant for advanced cirrhosis: Time to ring the alarm!

Decompensated cirrhosis and hepatocellular cancer are major risk factors for mortality worldwide. Liver transplantation (LT), both live-donor LT or deceased-donor LT, are lifesaving, but there are several barriers toward equitable access. These barriers are exacerbated in the setting of critical illness or acute-on-chronic liver failure. Rates of LT vary widely worldwide but are lowest in lower-income countries owing to lack of resources, infrastructure, late disease presentation, and limited donor awareness. A recent experience by the Chronic Liver Disease Evolution and Registry for Events and Decompensation consortium defined these barriers toward LT as critical in determining overall survival in hospitalized cirrhosis patients. A major focus should be on appropriate, affordable, and early cirrhosis and hepatocellular cancer care to prevent the need for LT. Live-donor LT is predominant across Asian countries, whereas deceased-donor LT is more common in Western countries; both approaches have unique challenges that add to the access disparities. There are many challenges toward equitable access but uniform definitions of acute-on-chronic liver failure, improving transplant expertise, enhancing availability of resources and encouraging knowledge between centers, and preventing disease progression are critical to reduce LT disparities.

Relatively Poor Long-term Outcomes Following Liver Transplantation for NASH in the United States

BACKGROUND

Nonalcoholic steatohepatitis (NASH) continues to increase in frequency as an indication for liver transplantation (LT). Data on long-term outcomes for these patients are limited. We aimed to compare long-term patient and graft survival in patients undergoing LT for NASH in the United States to other indications.

METHODS

We analyzed data from the Scientific Registry of Transplant Recipients of adult patients who underwent primary deceased-donor LT from January 1, 2005, to December 31, 2019.

RESULTS

NASH has increased as an indication for LT by 4.5-fold, from 5.2% in 2005 to 23.4% in 2019. Patient (61.2%) and graft survival (59.2%) at 10 y are significantly poorer for NASH than for all other indications other than alcohol. Patients transplanted for NASH have higher body mass index (32.2 versus 27.6) and greater frequency of diabetes (13% versus 11.6%) than any other indication (P < 0.001). Portal vein thrombosis, location in intensive care unit, dialysis, and pre-LT diabetes (P < 0.001 for all) are independently predictive of patient death and graft loss. Body mass index is not predictive. NASH patients undergoing simultaneous liver kidney have markedly worse 10-y patient and graft survival than liver-only (52.3% versus 62.1%). Graft loss was attributed to recurrence of NASH in <1% of patients.

CONCLUSIONS

LT for NASH is associated with relatively poor long-term patient and graft survival when compared with patients transplanted for other indications, NASH patients undergoing simultaneous liver kidney have the worst long-term outcomes.

Prevalence of Non-alcoholic Fatty Liver Disease in India: A Systematic Review and Meta-analysis

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) contributes to a large proportion of liver disease burden in the world. Several groups have studied the prevalence of NAFLD in the Indian population.

AIM

A systematic review of the published literature and meta-analysis was carried out to estimate the prevalence of NAFLD in the Indian population.

METHODS

English language literature published until April 2021 was searched from electronic databases. Original data published in any form which had reported NAFLD prevalence in the Indian population were included. The subgroup analysis of prevalence was done based on the age (adults or children) and risk category, i.e., average-risk group (community population, participants of control arm, unselected participants, hypothyroidic individuals, athletes, aviation crew, and army personnel) and high-risk group (obesity or overweight, diabetes mellitus, coronary artery disease, etc.). The prevalence estimates were pooled using the random-effects model. Heterogeneity was assessed with I².

RESULTS

Sixty-two datasets (children 8 and adults 54) from 50 studies were included. The pooled prevalence of NAFLD was estimated from 2903 children and 23,581 adult participants. Among adults, the estimated pooled prevalence was 38.6% (95% CI 32-45.5). The NAFLD prevalence in average-risk and high-risk subgroups was estimated to be 28.1% (95% CI 20.8-36) and 52.8% (95% CI 46.5-59.1), respectively. The estimated NAFLD prevalence was higher in hospital-based data (40.8% [95% CI 32.6-49.3%]) than community-based data (28.2% [95% CI 16.9-41%]). Among children, the estimated pooled prevalence was 35.4% (95% CI 18.2-54.7). The prevalence among non-obese and obese children was 12.4 (95% CI 4.4-23.5) and 63.4 (95% CI 59.4-67.3), respectively.

CONCLUSION

Available data suggest that approximately one in three adults or children have NAFLD in India.

Nonalcoholic Fatty Liver in Lean Individuals: Clinicobiochemical Correlates of Histopathology in 157 Liver Biopsies from Healthy Liver Donors

BACKGROUND

Generally diagnosis of non-alcoholic fatty disease is made on imaging, however, mild steatosis is difficult to diagnose on imaging. Liver biopsy is the procedure of choice but is not carried out as it is an invasive procedure. We describe our experience of 157 liver biopsies in living liver donors with normal body mass index (BMI) <23 kg/M² (lean).

MATERIALS AND METHODS

The study was conducted at a tertiary care center in north India. Data of lean living donors who underwent a liver biopsy before donation were analyzed. Data are presented as percentage, mean, or median (25-75 interquartile range).

RESULTS

Of 718 donors who had a liver biopsy before donation, 157 (21.8%) donors were lean (BMI < 23 kg/M²). Seventy-eight percent of lean donors had no or only one metabolic risk factor. Fifty-three (33.7%) of lean donors had nonalcoholic fatty liver (NAFL) in liver biopsy. When donors with NAFL were compared to donors with normal histology, donors with NAFL had significantly higher aspartate transaminase (26.6 ± 7.5 versus 23.7 ± 5.4, p = 0.007), alanine transaminase (33.4 ± 11.7 versus 27.8 ± 10.7, p = 0.003), and gamma glutamyl transpeptidase [25 (16-40.5) versus 18 (14-23), p = 0.003]. Only triglycerides (TGs) were statistically different among metabolic factors in lean NAFL and normal histology groups, 97 (70-161) versus 86 (62.5-114.7), p = 0.043. A total of 30% donors in the lean NAFL group had TGs >150 mg/dl as compared with 12.5% in the normal histology group, p = 0.009. Other metabolic risk factors were not statistically different.

CONCLUSION

One third of lean donors had NAFL. Among all metabolic risk factors, only higher TGs levels showed a significant association with NAFL.

Association between obesity after liver transplantation and steatosis, inflammation, and fibrosis of the graft

BACKGROUND

Nonalcoholic steatohepatitis has become one of the leading causes of liver transplantation. The development of steatosis, as well as the link to inflammation and fibrosis, after transplantation remain poorly understood. The aim of this analysis was to evaluate the influence of obesity on histopathological changes of the graft during long-term follow-up.

METHODS

A total of 1494 longitudinal liver biopsies of 271 recipients were evaluated during a follow-up period of 5 to 10 years. Clinical and laboratory parameters as well as histopathological categories of steatosis, inflammation, and fibrosis were explored by routine protocol biopsies.

RESULTS

The BMI and prevalence of diabetes mellitus significantly increased after transplantation (P < .01). Diabetes and de novo obesity were significantly associated with the degree of graft steatosis. There was no correlation between former steatosis and inflammation or fibrosis. Inflammation was a precursor of fibrosis, and fibrosis increased over the first 3 years (P < .01). No severe graft dysfunction was observed.

CONCLUSION

Obesity and diabetes mellitus correlated with higher grades of steatosis and de novo steatosis after transplantation. Metabolic syndrome must be considered as a serious post-transplant complication that can cause histopathological alteration. However, the progress from steatosis to steatohepatitis is not as common as expected.

Natural History of Simple Steatosis or Nonalcoholic Fatty Liver

The histological spectrum of nonalcoholic fatty liver disease (NAFLD) ranges from simple steatosis or nonalcoholic fatty liver (NAFL) to nonalcoholic steatohepatitis (NASH), NASH-related cirrhosis and hepatocellular carcinoma. Ballooning degeneration of hepatocytes with or without fibrosis is the key feature that differentiates NASH from NAFL. Liver biopsy is the only reliable method for diagnosing NAFL and differentiating it from NASH. Although the epidemiology of NAFLD is well described, the need for invasive biopsy limits our knowledge of the community prevalence of NAFL. Recent data suggest that the biochemical composition of hepatic steatosis may have a bearing on the disease. Triglycerides, the most commonly accumulated lipid, have a cytoprotective role because of their inert nature. Several paired liver biopsy studies and longitudinal follow-up studies have shown that NAFL is not completely benign as previously envisaged. NAFL can indeed progress to NASH and severe fibrosis, with progression being influenced by presence of baseline or worsening metabolic risk factors. Overall, NAFL carries a low risk of liver-related and overall mortality although the risk of cardiovascular mortality is similar to that of NASH. Current concepts suggest the presence of a dynamic bidirectional cycling between NAFL and NASH with slow progression of fibrosis in majority of the patients. The fact that ultimately it is the onset of progressive fibrosis that dictates clinical outcomes brings into question the relevance of distinguishing NAFL from NASH.

Good Long-Term Outcomes in Patients With Primary Sclerosing Cholangitis Undergoing Living Donor Liver Transplantation

BACKGROUND

Primary sclerosing cholangitis (PSC) is a progressive cholestatic disorder with liver transplantation (LT) being the only definitive treatment in end-stage disease. Recurrence of PSC after LT is a significant concern which can lead to graft loss. The aim of this study is to find out the disease recurrence and long-term outcome after living donor liver transplantation (LDLT) in PSC.

METHODS

We conducted a retrospective review of all patients undergoing LDLT for PSC at our centre. Of 2268 adult LTs from August 2004 to July 2018, 32 (1.4%) patients underwent LDLT for PSC including 6 with PSC and autoimmune hepatitis overlap. The data were reviewed to look for PSC recurrence, complications, and overall survival. All patients received tacrolimus-based immunosuppression. Data are shown as number, percentage, median, and interquartile range (IQR).

RESULT

The mean age of 32 LDLT recipients was 44 ± 12 years (males 22, females 10). At the time of transplantation, the mean child's score was 9 ± 1.6 and model for end-stage liver disease score was 18.9 ± 6.4. Ulcerative colitis was seen in 7 patients and none had cholangiocarcinoma. Majority of patients (n = 29) received right lobe graft and all but 3 underwent hepaticojejunostomy for biliary reconstruction. PSC recurrence was seen in 6 (20%) patients during a median follow-up of 59 (29-101) months, after exclusion of 2 patients with early mortality. A total of five patients died during follow-up, and one of these deaths was due to PSC recurrence. There were 2 perioperative deaths due to sepsis and 3 deaths on follow-up (sepsis in 2 and PSC recurrence in 1).

CONCLUSION

LDLT can be performed in PSC with good overall long-term outcomes.

Body Mass Index and Unenhanced CT as a Predictor of Hepatic Steatosis in Potential Liver Donors

BACKGROUND

In living-donor liver transplantation, donor hepatic steatosis is crucial for both the donor and the recipient. Body mass index (BMI) and the unenhanced computed tomography liver attenuation index (CT LAI) are noninvasive methods to predict hepatic steatosis in living-donor liver candidates.

AIM

To analyze the diagnostic accuracy of CT LAI in conjunction with different BMI values for macrovesicular steatosis in living-donor liver candidates.

METHODS

A total of 264 potential liver donors were included. The diagnostic accuracy of 2 CT LAI cut-offs and 3 BMI cut-off values for the assessment of hepatic steatosis ≥15% and ≤5% was determined.

RESULTS

Using CT LAI, the area under the receiver operating characteristic curve was 0.97 (95% CI = 0.89-0.99) for hepatic steatosis ≥15% in donors with BMI <25 kg/m². For detecting hepatic steatosis ≥15%, a CT LAI ≤0 had specificities of 100%, 76.2%, and 55.6% and positive predictive values of 100%, 95.5%, and 93.5% for patients with BMI values <25 kg/m², 25 to 29.9 kg/m², and ≥30 kg/m², respectively. According to logistic regression analyses, only CT LAI ≤0 was found to be independently associated with hepatic steatosis ≥15%.

CONCLUSIONS

In donors with BMI <30 kg/m² and a CT LAI value >6, liver biopsy might be avoided. Biopsy may be reserved solely for donors with CT LAI value >0 and BMI ≥30 kg/m² as the diagnostic accuracy of computed tomography for predicting hepatic steatosis decreases with increasing BMI.