Leptin is a hormone produced by adipose tissue which is widely involved in several diseases, including chronic obstructive pulmonary diseases (COPD).

Based on this, Andreina Bruno (Istituto di Biomedicina e Immunologia Molecolare, Consiglio Nazionale delle Ricerche, Palermo, Italy) and her French and Italian colleagues studied the correlation between leptin and its receptor and the rate of inflammation in smoker subjects with and without COPD and in non-smoking healthy volunteers.

In this work, bronchial biopsies from the three different categories were examined by a specific colorimetric test that pointed out the presence of this hormone and its receptor in the pulmonary tissues. Besides, with the same method, the expression of specific inflammatory cells with and without the expression of leptin was studied.

What the authors found was a direct correlation between leptin presence in bronchial tissue and the progressive functional impairment in COPD. They also assessed the presence of leptin and its receptor in inflammatory cells and an higher expression of these cells in the patients with severe clinical conditions rather then in healthy volunteers.

These findings suggest that in patients with COPD the expression of leptin and its receptor can regulate proximal airway inflammation and leptin may act as a mediator able to perpetuate bronchial inflammation by increasing the survival of some inflammatory cells. Furthermore, it is well known that the adipose tissue is a multifunctional organ involved in inflammation by the production of different adipokines: in this context, leptin represents a pleiotropic molecule together with the others adipokines involved in the regulation of the immune system.

This evidence may support the hypothesis that leptin can be considered a marker of inflammation within the airways and mainly regulates the inflammatory cell infiltration in COPD with a potential impact on the severity of the disease.

The European Respiratory Journal is the peer-reviewed scientific publication of the European Respiratory Society (more than 7,000 specialists in lung diseases and respiratory medicine in Europe, the United States and Australia).

erj.ersjournals