Background: Asthma is a complex multifactorial disease that is not yet fully understood. Oxidative stress due to an imbalance between the oxidative forces and the antioxidant defense systems has been implicated in asthma pathogenesis. However, much debate still surrounds the key genetic factors involved in the development of this disease. Candidate genes include the glutathione S-transferases (GSTs). In particular, mu, pi, and theta classes of GSTs play an important role in regulating infl ammatory responses. However, few and contradictory data are available on the association between asthma development and GST gene polymorphisms (GSTM1, GSTP1, and GSTT1) .

Objectives: To investigate whether GSTM1, GSTT1, and GSTP1 polymorphisms are associated with asthma development.

Methods: We recruited 200 unrelated healthy individuals and 199 asthmatic patients from Rome in Central Italy. Genotyping of GSTM1 and GSTT1 genes was performed by a multiplex polymerase chain reaction (PCR) while the GSTP1 polymorphism (rs1695) was determined using PCR-restriction fragment length polymorphism analysis.

Results: Our results suggest that the GST polymorphisms analyzed are not associated with asthma, confi rming the uncertain role of GST
genes in the development of asthma.

Conclusions: Oxidative stress is certainly involved in the development of asthma, and GSTs may therefore infl uence asthma risk, although, as our results show, their role in pathogenesis remains to be elucidated. Future studies should focus on the interactions of GST genes with t he environment and other antioxidant genes to shed light on the role of GSTs in asthma.

Key words: Asthma. Glutathione S-transferases. Gene-candidate study. Adult patients. Oxidative stress.