Acute liver injury in two workers exposed to chloroform in cleanrooms: a case report

Cytotoxicity and genotoxicity evaluation of chloroform using Vicia faba roots

Chloroform is a widely used industrial chemical that can also pollute the environment. The aims of this study were to examine the potential cytotoxicity and genotoxicity of chloroform on plant cells, using the Vicia faba bioassay. Chloroform was evaluated at concentrations of 0.1, 0.5, 1, 2, and 5 mg·L-1. The following parameters were analyzed: the mitotic index (MI), micronucleus (MN) frequency, chromosomal aberration (CA) frequency, and malondialdehyde (MDA) content. The results showed that exposure to increasing concentrations of chloroform caused a decrease in MI and an increase in the frequency of MN in Vicia faba root tip cells, relative to their controls. Moreover, various types of CA, including C-mitosis, fragments, bridges, laggard chromosomes, and multipolar mitosis, were observed in the treated cells. The frequency of MN was positively correlated with the frequency of CA in exposure to 0.1-1 mg·L-1 chloroform. Furthermore, chloroform exposure induced membrane lipid peroxidation damage in the Vicia faba radicle, and a linear correlation was observed between the MDA content and the frequency of MN or CA. These findings indicated that chloroform exposure can result in oxidative stress, cytotoxicity, and genotoxicity in plant cells.

Acute liver injury in a non-alcoholic fatty liver disease patient with chloroform exposure: a case report

We report a rare case of acute liver injury by daily exposure to small amounts of chloroform in non-alcoholic fatty liver disease (NAFLD) patient. The patient had been followed up in our hospital every 3 months. Although his alanine aminotransferase (ALT) levels were steady around 30 ~ 60 U/L until August 2014, ALT level was spontaneously increased to more than 1,000 U/L at the follow-up point in late August 2014. As he was diagnosed as acute liver injury by chloroform exposure, we withdrew him from the exposure of chloroform and treated him with 600 mg/day of ursodeoxycholic acid. Afterwards, his ALT level rapidly improved and normalized within 1 month. To verify the influences of chloroform exposure, we measured plasma chloroform levels by gas chromatography. Although plasma chloroform concentration was 7.1 ng/ml (normal range: < 0.2 ng/ml) at the time of liver injury, the concentration had decreased to 0.7 ng/ml by 1 month later. Despite the fact that he had put on a face mask to protect from aspiration of chloroform, liver injury still occurred in the present case. Chloroform has a high solubility for lipids and accumulation of lipids in the liver might become a risk factor for liver injury by chloroform.

A case report of toxic hepatitis caused by chloroform in automotive parts manufacturer coating process

Background

Several cases of chloroform-induced hepatotoxicity have been reported worldwide, but only 2 cases have been reported in Korea. We encountered a case of toxic hepatitis due to chloroform exposure in February 2022 and report the diagnosis process and clinical findings.

Case presentation

A 38-year-old employee in charge of the coating after washing (degreasing) at an automotive parts manufacturer complained of jaundice and was diagnosed with acute toxic hepatitis. After the initial diagnosis, he continued to work, his symptoms worsened, and he was hospitalized for 8 days. Liver ultrasonography (elastography) revealed acute hepatitis. The washing agent contained chloroform, which was not listed on the materials safety data sheet, and the concentrations of chloroform in the workplace were up to 4.7 times the time-weighted average.

Conclusions

This patient showed typical toxic hepatitis with chloroform; further follow-up studies are required. Both employers and workers should be aware of information on toxic substances and take precautions to avoid exposure.

Exposure to organic solvents and hepatotoxicity

The purpose of this study was to identify the long-term effect of chemical exposure on the liver. Laboratory tests included alanine aminotransferase (ALT) dosage and oxidative stress tests, such as thiobarbituric acid reactive substances in plasma and superoxide dismutase (SOD) and glutathione S-transferase analysis in erythrocytes. The cross-sectional study comprised 70 workers, 30 of them exposed to organic solvents and 40 not exposed. All those exposed presented at least 5 years of exposure to solvents. Hepatitis B and C, known hepatic disease, comorbidities, use of alcohol, illicit drugs or hepatotoxic medications, smoking, body mass index >30, female sex and age (<18 or >65) were excluded from the sample. Results indicated that elevated ALT was more frequent in the exposed group compared to controls: 33% vs. 10.5%, with a statistical significance (p < 0.05). Thiobarbituric acid reactive substances were significantly elevated (p < 0.01) in the exposed group in comparison to controls. Antioxidant enzymes were more elevated in the exposed group compared to controls: SOD 7.29 (4.30-8.91) USOD/mg of protein vs. 3.48 (2.98-5.28) USOD/mg of protein and GST 2.57 µmol/min/mg of protein (1.80-4.78) vs. 1.81 µmol/min/mg of protein (1.45- 2.30) µM/min/mg of protein. The results suggest an association between exposure to organic solvents and hepatotoxicity.

Chronic, Recreational Chloroform-Induced Liver Injury

Historically used as an anesthetic, chloroform is a halogenated hydrocarbon that is associated with central nervous system depression, arrhythmias, and hepatotoxicity. It is no longer used clinically, but accidental and intentional poisonings still occur. We report a case of chronic chloroform abuse leading to severe hepatotoxicity in a 26-year-old male graduate student. The patient presented to the emergency department with a three-day history of abdominal pain, dehydration, and scleral icterus. He drank several beers the night before the onset of symptoms, but denied taking acetaminophen, ibuprofen, or other drugs. An extensive work-up revealed an aspartate aminotransferase (AST) of 13,527 U/L and alanine aminotransferase (ALT) of 8,745 U/L, but the cause of his liver injury could not be determined. It was not until many months later that the patient admitted to inhaling chloroform in the weeks leading up to his illness.

3-methyadenine attenuates chloroform-induced hepatotoxicity via autophagy activation

Chloroform is a common contaminant in the drinking water. Exposure of human to chloroform leads to severe hepatotoxicity. In the present study, chloroform-induced acute liver injury was investigated in mice using 3-methyadenine (3-MA), a common autophagy inhibitor. At 24 h after intraperitoneal injection of 0.5 mL/kg chloroform, serum alanine aminotransferase (ALT) levels were increased significantly; extensive necrosis and inflammation occurred as identified by histological examinations. Moreover, chloroform induced an increase in lipid peroxidation as demonstrated by increased formation of malondialdehyde (MDA) in the liver tissues. Hepatic antioxidants including glutathione (GSH) and superoxide dismutase (SOD) were decreased by chloroform treatment. All these changes were significantly inhibited by 3-MA treatment. Further mechanistic insights demonstrated that chloroform up-regulated pro-inflammatory cytokine, IL-1β, in the livers and blood, which was suppressed by 3-MA. Surprisingly, Western blots results showed that after 24-hours of chloroform treatment 3-MA activated autophagy as indicated by decreased levels of LC3B II and p62 protein. Co-treatment of chloroquine with 3-MA to inhibit autophagy would abrogate the hepatoprotection of 3-MA in chloroform hepatotoxicity. Taken together, findings in the present study suggested that a widely-used autophagy inhibitor, 3-MA, significantly reduced chloroform hepatotoxicity in mice via autophagy activation. Findings in this study also suggested that caution should be exercised when using 3-MA to modulate autophagy in vivo.