Evaluation of abnormal liver tests in the adult asymptomatic patient

Undiagnosed abnormal alanine transaminase levels in vulnerable populations: Impact of sex, race/ethnicity, and body mass

Background

Liver disease is a leading cause of death in the United States and is often initially detected incidentally on lab tests ordered by general practitioners. Alanine transaminase (ALT), a marker of liver inflammation, is commonly ordered and may be abnormal in the setting of elevated body mass index, diabetes and dyslipidemia. Data regarding ALT testing within vulnerable populations are limited. Therefore, the prevalence of ALT testing and abnormal ALT in the absence of known chronic liver disease (CLD) among a safety-net population were assessed and factors associated with these outcomes were identified.

Methods

In this retrospective longitudinal study of 92,997 patients seen between 01/2017-01/2019 within San Francisco's Safety-Net Healthcare System, electronic medical records were used to abstract data back to 04/1997. Descriptive analyses and multivariable modeling were performed.

Results

Overall, 59,323 (69%) without known CLD received an ALT test. Age, Black race, Latinx ethnicity, and metabolic factors were associated with higher odds of ALT testing, (p < 0.01). Among those with an abnormal ALT (44%) without known CLD: median age 53 years, 41% male, 19% White, 11% Black, 40% Latinx, 29% Asian/Pacific Islander (API), and 84% overweight/obese. On multivariable analysis, female sex (OR 2.7), Latinx ethnicity (OR 2.6), API race (OR 1.3), overweight/obesity (OR 1.8, OR 2.6), and dyslipidemia (OR 1.3) were associated with abnormal ALT, (p ≤ 0.001).

Conclusions

In the absence of known CLD, women, Latinx, API and persons with excess body weight were associated with greater odds of abnormal ALT. Future longitudinal studies are needed to confirm these differences and to determine if adequate work up for CLD is performed for abnormal ALT levels among at-risk populations.

Establishment of gender- and age-specific reference intervals for serum liver function tests among the elderly population in northeast China: a retrospective study

Introduction

Reference intervals (RIs) for younger population may not apply to the elderly population. The aim of this study was to establish gender- and age-specific RIs for serum liver function tests among the elderly population and to compare with younger population RIs currently used in China and other countries.

Materials and methods

This was a retrospective study, and subjects (≥ 18 year-old) were recruited from the laboratory information system (LIS) at the First Hospital of Jilin University between April 2020 and April 2021. The following parameters were collected: aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyltransferase (GGT), alkaline phosphatase (ALP), total protein (TP), albumin (ALB), total bilirubin (TBIL), and direct bilirubin (DBIL). The Tukey method was used to eliminate outliers. Reference intervals were established by the nonparametric method.

Results

A total of 23,597 healthy individuals were enrolled in the study. From all parameters AST, ALT, TP and ALB required no gender partition, while ALT, GGT, TP, ALB and DBIL required different partitions for age. Activities and concentrations of ALT, ALB, and TP showed a downward trend in the elderly aged 60-89. In contrast, DBIL showed a gradual upward trend.

Conclusion

The RIs for liver function tests among healthy elderly population were different from those among young population in China. There were apparent gender and age differences in the RIs of liver function for elderly and significant differences compared with national standards and RIs in other countries. Therefore, it is necessary to establish gender- and age-specific RIs for serum liver function tests among the elderly population.

Tobacco Smoke and CYP1A2 Activity in a US Population with Normal Liver Enzyme Levels

Non-alcoholic fatty liver disease (NAFLD) is common among 30% of American adults. Former and current smokers are at higher risk for NAFLD compared to never smokers. The ratio of urine caffeine metabolites to caffeine intake-namely, urine caffeine metabolite indices-has previously been used as a proxy for CYP1A2 activity, which is one of the main liver metabolizing enzymes. CYP1A2 activity is associated with NAFLD progression. No studies to our knowledge have examined the associations of liver enzymes, smoking intensity, and secondhand smoke (SES) with CYP1A2 activity (using caffeine metabolite indices) across smoking status. We analyzed national representative samples from the 2009-2010 National Health and Nutrition Examination Survey (NHANES). Interestingly, even within a normal range, several liver enzymes were associated with caffeine metabolite indices, and patterns of many of these associations varied by smoking status. For instance, within a normal range, aspartate aminotransferase (AST) in never smokers and bilirubin in current smokers were inversely associated with 1-methyluric acid and 5-acetylamino-6-amino-3-methyluracil (URXAMU). Furthermore, we observed a common pattern: across all smoking statuses, higher AST/alanine aminotransferase (AST/ALT) was associated with 1-methyluric acid and URXAMU. Moreover, in current smokers, increased lifelong smoking intensity was associated with reduced caffeine metabolite indices, but acute cigarette exposure as measured by SES levels was associated with increased caffeine metabolite indices among never smokers. In summary, commonly used liver enzyme tests can reflect the CYP1A2 activity even within a normal range, but the selection of these enzymes depends on the smoking status; the associations between smoking and the CYP1A2 activity not only depend on the intensity but also the duration of tobacco exposure.

Prolonged abnormal isolated aminotransferase levels in healthy children is a benign condition

AIM

Hypertransaminasaemia is a common incidental finding in children. It has been demonstrated that even prolonged elevation usually resolves spontaneously without clear aetiology. The aim of this study was to evaluate whether a longer follow-up period, on a larger group, supports the previous findings.

METHODS

We retrospectively reviewed medical charts of children diagnosed with prolonged idiopathic hypertransaminasaemia, which spontaneously resolved over the follow-up period.

RESULTS

Of the 468 patients screened for elevated transaminases levels, 87 patients younger than 5 years of age were included in the study. An aetiology was found in half of the patients, and the most common aetiologies were fatty liver and cytomegalovirus (CMV) infection. Aminotransferase abnormality persisted for a median of 10 months, and alanine aminotransferase (ALT) levels ranged from 1.5 to 15.9-fold of the upper limit of normal (ULN). After normalisation of transaminase levels, the values remained normal for a documented mean period of 6.4 ± 3.0 years.

CONCLUSION

Although idiopathic asymptomatic aminotransferase elevation in healthy children resolves spontaneously in most children, the abnormality may be prolonged. Comprehensive workup finds aetiology only in half of the patients, and the most common aetiologies are fatty liver and CMV hepatitis, which can be diagnosed by non-invasive methods.

Fluorometric and colorimetric analysis of alkaline phosphatase activity based on a nucleotide coordinated copper ion mimicking polyphenol oxidase

In this work, a fluorometric and colorimetric analysis of alkaline phosphatase (ALP) activity was developed based on nanozymes. The nanozymes were composed of nucleotides (ATP, ADP and AMP) coordinated with copper ions. All three kinds of nanozymes (ATP-Cu, ADP-Cu and AMP-Cu) exhibited polyphenol oxidase (PPO)-mimic activity by catalyzing a chromogenic reaction of 2,4-dichlorophenol (2,4-DP) and 4-aminoantipyrine (4-AP). However, there were obvious differences in the PPO-like activity and the fluorescence of the three nanozymes produced from the same concentration of nucleotides (keeping the concentration of Cu²⁺ unchanged at 5 mM). The catalytic activities of produced ADP-Cu and AMP-Cu were obviously higher than that of ATP-Cu at a certain nucleotide concentration of 3 mM. In addition, when ATP was hydrolyzed into ADP and AMP by ALP, more nanozymes were produced and the catalytic activity of the system was enhanced, which resulted in an obvious increase of the colorimetric signal. The signal intensity was proportional to ALP concentration in the range of 0-30 U L^-1, and the detection limit for ALP was 0.3 U L^-1 from the colorimetric detection. Moreover, the fluorescence intensity of the produced nanozymes was also proportional to the ALP concentration in the range of 1-30 U L^-1 and the detection limit was 0.45 U L^-1 from the fluorescence detection. A fluorometric and colorimetric sensing ALP method was thus established. The method showed a high selectivity for ALP activity compared with proteins, amino acids and other interference components. Furthermore, the proposed method was also used to detect ALP activity in human serum samples, which showed great potential for diagnostic and practical purposes.

Overview of the Pathogenesis, Genetic, and Non-Invasive Clinical, Biochemical, and Scoring Methods in the Assessment of NAFLD

Nonalcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease worldwide. It represents a range of disorders, including simple steatosis, nonalcoholic steatohepatitis (NASH), and liver cirrhosis, and its prevalence continues to rise. In some cases, hepatocellular carcinoma (HCC) may develop. The develop;ment of non-invasive diagnostic and screening tools is needed, in order to reduce the frequency of liver biopsies. The most promising methods are those able to exclude advanced fibrosis and quantify steatosis. In this study, new perspective markers for inflammation, oxidative stress, apoptosis, and fibrogenesis; emerging scoring models for detecting hepatic steatosis and fibrosis; and new genetic, epigenetic, and multiomic studies are discussed. As isolated biochemical parameters are not specific or sensitive enough to predict the presence of NASH and fibrosis, there is a tendency to use various markers and combine them into mathematical algorithms. Several predictive models and scoring systems have been developed. Current data suggests that panels of markers (NAFLD fibrosis score, Fib-4 score, BARD score, and others) are useful diagnostic modalities to minimize the number of liver biopsies. The review unveils pathophysiological aspects related to new trends in current non-invasive biochemical, genetic, and scoring methods, and provides insight into their diagnostic accuracies and suitability in clinical practice.

When Do Clinicians Follow-up Abnormal Liver Tests in Primary Care?

BACKGROUND

Many guidelines addressing the approach to abnormal liver chemistries, including bilirubin, transaminases and alkaline phosphatase, recommend repeating the tests. However, when clinicians repeat testing is unknown.

MATERIAL AND METHODS

This retrospective study followed adult patients with abnormal liver chemistries in a patient-centered medical home (PCMH) from 2007 to 2016. All PCMH patients possessing at least 1 abnormal liver test (total bilirubin, aminotransferases and alkaline phosphatase) were included. Patients were followed from the index abnormal liver chemistry until the next liver test result, or the end of the study period. The primary predictor variable of interest was the number of abnormal chemistries (out of 4) on index testing. Demographic and clinical variables served as other potential predictors of outcome. A Cox proportional hazards model was applied to investigate associations between the predictor variables and the time to repeat liver chemistry testing.

RESULTS

Of 9,545 patients with at least 2 PCMH visits and 1 liver test abnormality, 6,489 (68%) obtained repeat testing within 1 year, and 80% of patients had follow-up tests within 2 years. Patients with multiple abnormal liver tests and those with higher degrees of abnormality were associated with shorter time to repeat testing.

CONCLUSIONS

A large proportion of patients with abnormal liver tests still lack repeat testing at 1 year. The number of liver abnormal liver tests and degree of elevation were inversely associated with the time to repeat testing.