Systemic transsulfuration pathway thiol concentrations in chronic obstructive pulmonary disease patients

Area of Science:

• Biochemistry
• Pulmonology
• Cardiology

Background:

• Chronic obstructive pulmonary disease (COPD) patients face an elevated risk of cardiovascular disease (CVD).
• Elevated plasma homocysteine (Hcy) concentrations, a known CVD risk factor, are observed in COPD patients.
• Hcy is an analyte within the transsulfuration pathway.

Purpose of the Study:

• To investigate plasma concentrations of transsulfuration pathway analytes in COPD.
• To determine the relationship between these analytes, oxidative stress, and inflammation markers.
• To identify low molecular weight thiols implicated in the pathophysiology of both CVD and COPD.

Main Methods:

• Measured plasma concentrations of Hcy, cysteine (Cys), glutathione (GSH), cysteinylglycine (CysGly), glutamylcysteine (GluCys), taurine (Tau), oxidative stress markers (TBARS, protein-SH/PSH), and kynurenine/tryptophan (Kyn/Trp) ratio.
• Studied 54 COPD patients and 54 control subjects.
• Correlated thiol concentrations with lung function parameters, COPD severity, and oxidative/inflammatory markers.

Main Results:

• COPD patients exhibited significantly higher total Hcy and total CysGly concentrations compared to controls.
• Total Hcy and CysGly levels were significantly associated with impaired lung function and COPD severity.
• In COPD patients, total Hcy correlated with the Kyn/Trp ratio, while total CysGly correlated with PSH and the Kyn/Trp ratio.

Conclusions:

• Elevated total Hcy and CysGly concentrations are linked to COPD presence and severity.
• These thiols are associated with oxidative stress (CysGly) and inflammation (Hcy and CysGly) markers.
• Specific low molecular mass thiols may play a role in the inflammatory and oxidative stress pathways common to CVD and COPD.