Emphysema is a chronic lung condition in which alveoli, or air sacs, may be:

* destroyed
* narrowed
* collapsed
* stretched
* over-inflated
Chronic Obstructive Pulmonary Disease (COPD)

COPD is a term that refers to a large group of lung diseases which can interfere with normal breathing. It is estimated that 11 percent of the US population has COPD. The two most common conditions of COPD are chronic bronchitis and emphysema.

The causes of COPD are not fully understood. It is generally agreed that the most important cause of chronic bronchitis and emphysema is cigarette smoking. Causes such as air pollution and occupational exposures may play a role, especially when combined with cigarette smoking. Heredity also plays a contributing role in some patients' emphysema, and is especially important in a rare form -- due to alpha 1 anti-trypsin deficiency.

Symptoms
Patients with chronic bronchitis usually have a cough and sputum production for many years before they develop shortness of breath.

Patients with emphysema usually have shortness of breath and develop a cough and sputum during a respiratory infection, or in the later stages of the illness.

Over-inflation of the air-sacs is a result of a breakdown of the walls of the alveoli, and causes a decrease in respiratory function and breathlessness. Damage to the air sacs is irreversible and results in permanent "holes" in the tissues of the lower lungs.

Hepatocyte and keratinocyte growth factors are key growth factors in the process of alveolar repair. We hypothesized that excessive alveolar destruction observed in lung emphysema involves impaired expression of hepatocyte and keratinocyte growth factors or their respective receptors, c-met and keratinocyte growth factor receptor. The aim of our study was to compare the expression of hepatocyte and keratinocyte growth factors and their receptors in lung samples from 3 groups of patients: emphysema; smokers without emphysema and non-smokers without emphysema.