Safety and Efficacy of Inhaled Alpha-1 Antitrypsin in Preventing Bronchiolitis Obliterable Syndrome in Lung Transplant Recipients

Inclusion Criteria:• Patients aged ≥18 years * Signature of informed consent * Lung transplant recipient in the past 6 months. * Stable concomitant therapy \>2 weeks prior to visit 1 * Non-tobacco user of any kind * No significant abnormalities in serum hematology, serum chemistry to the Principal Investigator's judgment((Hg\>8g/dL ,Creatinine\<2mg/dl,Liver enzymes\<3\*ULN) * Non-pregnant, non-lactating female subjects, whose screening pregnancy test is negative and who are using contraceptive methods deemed reliable by the investigator, or who are more than 5 years post-menopausal or surgically sterilized or whose way-of-life excludes sexual activity. * Sexually active female subjects of child-bearing potential, as well as male subjects, must use a medically acceptable effective contraceptive method (for male - method such us condoms; for female - methods such as oral contraceptive medication used for at least two weeks before study start, or a combination of any two of the following: diaphragm, cervical cap, condom or spermicide), before study start and throughout the entire duration of the study. Exclusion Criteria:• Diagnosis of BOS with according to Estenne M. et al. * Hospitalization within 1 month before study entry, not due to an airway disease * Severe liver cirrhosis with ascites * Hypersplenism * Grade III/IV esophageal varices; * Active pulmonary exacerbation within the 4 weeks prior to screening * History of massive hemoptysis: greater than 200 cc in a 24 hour period * Pregnancy or breastfeeding * Any serious or active medical or psychiatric illness which, in the opinion of the investigator, would interfere with patient treatment, assessment, or compliance with the protocol. * Fever at the time of the start of first (day #1) inhalation (oral temperature \>38ºC) * Evidence of uncontrolled hypertension * Pulse \>120/min (prior to study drug administration) * Any serious malignancy except for basal and squamous (scaly or plate-like) cell skin cancer within the previous 3 years prior to study start * Receipt of exogenous AAT within the last 6 months * Previous enrolment in this study (subject can not be enrolled twice into the study) * Evidence of congestive heart failure or other clinically significant cardiovascular conditions: myocardial infarction during the last year, arrhythmia requiring drug treatment during the last year, uncontrolled hypertension * Current smoker (someone who has smoked within 4 weeks prior to screening) * Subjects with an additional clinically significant inter-current illness (beside lung disease) (e.g., cardiac, hepatic, renal, endocrine, respiratory, neurological, hematological, neoplastic, immunological and skeletal) that the investigator determines that it could interfere with the safety or other assessments of this study * Any evidence of alcohol abuse or history of abuse of illegal and/or legally prescribed drugs such as barbiturates, benzodiazepines, amphetamines, cocaine, opioids, and cannabinoids * Being a sexually active female of child-bearing age without adequate contraception * Any other factor that, in the opinion of the investigator, would prevent the subject form complying with the requirements of the protocol