This is a prospective observational single center national study. Lung and heart transplant patients with a definite diagnosis of chronic lung allograft dysfunction (CLAD) or cardiac allograft vasculopathy (CAV) will be assigned for extracorporeal photopheresis (ECP) as per common clinical practice to a 6-month ECP cycle with the aim of limiting progression of organ dysfunction. The exact mechanisms of ECP in chronic rejection after lung and heart transplantation (CLAD and CAV) are elusive but it is thought to induce apoptosis of lymphocytes and to generate regulatory T cells, which modulate transplant immune rejection by a complex effect.

The primary objective of the present study is to identify the biomarkers associated to response to ECP after 6 months of treatment.

Lung transplanted patients will be enrolled according to current per center protocol at diagnosis of established CLAD grade 1-2 (diagnosis will be made according to published guidelines) . Rate of graft function decline will be classified as rapid (>/= 100 ml/month) or slow (< 100ml/month) during the 6 months preceding ECP treatment. All patients will be diagnosed as CLAD after a failure of a 3-month trial with azithromycin. They will be enrolled in ECP treatment at CLAD grade 1-2. ECP response will be assessed after 6 months of treatment and patients experiencing > 10% decline with respect to baseline value at ECP initiation in graft function will be classified as non-responders.Heart transplanted patients with demonstrated CAV in a recent angiography (<6 months) in absence of acute cellular or antibodies mediated rejection at myocardial biopsy, will be enrolled The diagnosis of CAV will require the presence of thickening of the arterial intima in any epicardial artery.

Heart and lung transplant patients who receive diagnosis of chronic lung allograft dysfunction (CLAD) or cardiac allograft vasculopathy (CAV)