Contribution of Aflatoxin B1 Exposure to Liver Cirrhosis in Eastern Ethiopia: A Case-Control Study

Liver Cirrhosis of Unknown Etiology and Its Predictors in Eastern Ethiopia

Background

The global burden of liver cirrhosis is increasing, with 2.1 million incident cases and nearly 1.5 million deaths in 2019. Despite the enormous progress in our understanding of the etiology of liver cirrhosis, significant cases of the disease have been reported in Eastern Ethiopia due to unidentified causes. Hence, this study aimed to identify predictors of liver cirrhosis of unknown etiology in Eastern Ethiopia.

Methods

A score of 7 out of 11 possible points on the ultrasound-based cirrhosis scale was used as a diagnostic criterion to include 127 liver cirrhosis patients. The study participants' demographic, dietary, lifestyle, and clinical data were gathered using a structured questionnaire and standardized reporting forms. The associations between the outcome (known and unknown etiology) and independent variables were modeled using binary logistic regression analysis.

Results

The etiology of liver cirrhosis was known in only 23% of patients and attributed to hepatitis B virus (21%), hepatitis C virus (0.8%), and alcohol abuse (0.8%). Sorghum consumption as a staple food (adjusted odds ratio (AOR) =3.8; 95% CI: 1.2, 12.5), splenomegaly (AOR = 4.0; 95% CI: 1.1, 14.4), and a family history of liver disease (AOR = 0.24; 95% CI: 0.06, 0.91) were significantly associated with liver cirrhosis of unknown etiology.

Conclusion

Sorghum consumption was found to be the determinant factor of liver cirrhosis of unknown etiology, suggesting it as a possible source of exposure to aflatoxin B1.

Copy Number Variation in the GSTM1 and GSTT1 Genes and the Risk of Liver Cirrhosis in Eastern Ethiopia

Background

Polymorphisms in glutathione S-transferase M1 (GSTM1) and T1 (GSTT1) can cause an entire gene deletion. The current methodology can accurately identify GSTM1 and GSTT1 copy number variants (CNVs), which may shed light on the true contribution of each gene copy to the cellular detoxification process and disease risk. Because liver cirrhosis is becoming a critical worldwide health issue, this study determined the CNVs of GSTM1 and GSTT1 and their relationship to the risk of liver cirrhosis.

Methods

In this study, we compared 106 patients with liver cirrhosis to 104 healthy controls. Real-time PCR was used to identify the CNVs of GSTM1 and GSTT1. Logistic and linear regression models were used to estimate the relationship between liver cirrhosis and clinical chemistry variables with the CNVs, respectively.

Results

In 3.3% of the study participants, >2 copies of the GSTM1 or GSTT1 genes were detected. GSTT1 carriers had a significantly lower risk of liver cirrhosis (p<0.05) compared with individuals who had homozygous deletion (adjusted odds ratio (AOR) = 0.47; 95% CI: 0.25, 0.86). This risk reduction was significant (p<0.05) in patients with a single copy of the GSTT1 gene (AOR = 0.48; 95% CI: 0.25, 0.91). Those with ≥2 copies of combined GSTM1 and GSTT1 also had a significantly (p<0.05) lower risk of developing liver cirrhosis compared with double null genotypes (AOR = 0.38; 95% CI: 0.16, 0.91, p trend <0.001). Moreover, ≥2 copies of combined GSTM1 and GSTT1 genes were associated with a substantial decrease in alanine amino transferase (ALT) and aspartate aminotransferase (AST) levels, respectively.

Conclusion

A single copy number of GSTT1, and ≥2 copies of combined GSTM1 and GSTT1 genes were associated with a reduced risk of liver cirrhosis in Ethiopians. These findings underscore the importance of gene-environment interactions in the multifactorial development of liver cirrhosis.