Case report: Alanine aminotransferase deficiency detected in a patient with chronic hepatitis C

Abnormally Low Alanine Aminotransferase Ameliorated by a Living Donor Liver Transplantation: A Case Report

Alanine aminotransferase (ALT) is an enzyme that catalyzes the transfer of amino groups from alanine to ketoglutaric acid. ALT is an established marker of liver diseases. Occasionally, ALT levels may be abnormally low due to various factors, making accurate assessment difficult. To date, no studies have documented ALT alterations following Living donor liver transplantation (LDLT) in patients with low ALT levels. Here, we present a case of abnormally low ALT levels that were ameliorated by LDLT. A 27-year-old woman underwent LDLT for refractory cholangitis with biliary atresia. The patient's preoperative ALT level was 1 IU/L. Following graft reperfusion, ALT levels increased (peak value, 456 IU/L), primarily attributed to the donor liver. After LDLT, ALT levels consistently surpassed the lower limit. The differential diagnosis of abnormally low ALT levels suggested a genetic mutation as the most probable underlying cause. Even after LDLT, ALT levels in organs other than the transplanted liver would remain abnormally low. Therefore, to prevent underestimating liver damage, the standard ALT range for such cases should be set lower than the typical range.

Association of low alanine aminotransferase with loss of independence or death: A 5-year population-based cohort study

BACKGROUND AND AIM

Alanine aminotransferase (ALT) is an important enzyme for amino acid metabolism and gluconeogenesis, and low ALT is an indicator of vitamin B6 deficiency. However, it is unknown whether individuals with low ALT are likely to develop loss of independence (LOI) or death. We investigated the association of low ALT with LOI or death in the elderly.

METHODS

Between 2008 and 2010, 2,484 elderly individuals (≥ 65 years old) without functional dependency from the Locomotive Syndrome and Health Outcomes in the Aizu Cohort Study were enrolled. Based on baseline ALT values, the participants were divided into the following groups: ALT < 10 (n = 73), 10-20 (n = 1,372), 20-30 (reference, n = 734), 30-40 (n = 201), and ≥ 40 (n = 104) U/L groups. LOI was defined as requiring complete support for basic activities of daily living, which is care levels 3-5 in Japanese long-term care insurance certifications. The hazard ratios of LOI or death were estimated by Cox proportional hazard models adjusted for potential confounders.

RESULTS

During the median follow-up period of 5.75 (interquartile range 4.85-5.83) years, LOI or death occurred in 195 participants (7.85%). Compared with ALT 20-30 U/L, low ALT was associated with LOI or death (multivariable adjusted hazard ratios [95% confidence intervals]: 3.02 [1.57-5.81] and 1.55 [1.07-2.24] in ALT < 10 and 10-20 U/L groups, respectively), while high ALT was not (1.29 [0.72-2.31] and 1.49 [0.68-3.25] in ALT 30-40 and ≥ 40 U/L groups, respectively).

CONCLUSIONS

Clinicians should be aware of not only high ALT, indicating liver injury, but also low ALT associated with LOI or death.

Regulation of pyruvate metabolism and human disease

Pyruvate is a keystone molecule critical for numerous aspects of eukaryotic and human metabolism. Pyruvate is the end-product of glycolysis, is derived from additional sources in the cellular cytoplasm, and is ultimately destined for transport into mitochondria as a master fuel input undergirding citric acid cycle carbon flux. In mitochondria, pyruvate drives ATP production by oxidative phosphorylation and multiple biosynthetic pathways intersecting the citric acid cycle. Mitochondrial pyruvate metabolism is regulated by many enzymes, including the recently discovered mitochondria pyruvate carrier, pyruvate dehydrogenase, and pyruvate carboxylase, to modulate overall pyruvate carbon flux. Mutations in any of the genes encoding for proteins regulating pyruvate metabolism may lead to disease. Numerous cases have been described. Aberrant pyruvate metabolism plays an especially prominent role in cancer, heart failure, and neurodegeneration. Because most major diseases involve aberrant metabolism, understanding and exploiting pyruvate carbon flux may yield novel treatments that enhance human health.