Specific variants in the GST genes seem to play a role in greater susceptibility to lung problems and possibly be a cause of asthma for some teenagers.
According to new research presented at the European Respiratory Society International Congress, a possible cause of asthma could be children taking paracetamol during their first two years of life. These individuals may be at a higher risk of developing phara by the age of 18.
The association between paracetamol and asthma
Ms Xin Dai, nurse and PhD candidate at the allergy and lung health unit at the University of Melbourne, Australia, told the meeting that the link between paracetamol use and asthma seemed strongest in those who had a particular variant of the glutathione S-transferase (GST) gene, GSTP1.
GST genes contain the instructions for making enzymes that use an antioxidant called glutathione to mop up the effects of exposure to toxins in the body and the lungs. This mechanism helps to prevent damage to cells and inflammation.
Dai explains: “paracetamol, on the other hand, consumes glutathione, reducing the body’s capacity to deal with toxic exposure.”
“We hypothesised that people who did not have full GST enzyme activity because of common genetic variations or deletions may be more susceptible to adverse effects on the lungs from paracetamol use.”
One variant of the GSTP1 gene, GSTP1 Ile/Ile, whereby the amino acid Isoleucine (Ile) is inherited from both parents, was found to be associated with a higher risk of developing asthma.
“We found that children with the GSTP1 Ile/Ile variant had 1.8 times higher risk of developing asthma by the age of 18 years for each doubling of the days of paracetamol exposure when compared to children who were less exposed.”
“In contrast, increasing paracetamol exposure in children who had other types of GSTP1 did not alter the risk of asthma.”
However, she warned that the research only showed that there was an association between paracetamol and asthma, not that paracetamol caused the condition.
Further research was needed to confirm her findings and fully understand the link. She also found that another GST gene variant, GSTM1, was linked with reduced lung function.
Adverse effect of using paracetamol during infancy
Dai concluded: “our findings provide more evidence that paracetamol use in infancy may have an adverse effect on respiratory health for children with particular genetic profiles and could be a possible cause of asthma.”
“There is mounting evidence that the GST superfamily of genes, including three major classes -GSTM1, GSTT1 and GSTP1 – are associated with various diseases, including cancers, asthma, atherosclerosis, allergies, Alzheimer’s and Parkinson’s disease.
“Our study adds to this body of evidence.”
Other factors to consider
This study essentially suggests that some people with particular variants of the GST genes may be more susceptible to adverse effects on their lungs from paracetamol use in infancy. This is intriguing and needs to be investigated further.
Nevertheless, it is important to understand that the observed association between paracetamol use in infancy and the increased risk of asthma in adolescents, especially in subjects with dysfunctional GST genetic variants, does not necessarily provide concrete proof of a relationship.
The association could be due to many factors, such as lower respiratory tract infections caused by viruses in infancy, which are treated with paracetamol and have been linked to asthma.