A Study to Evaluate the Potential of Mesenchymal Stromal Cells to Treat Obliterative Bronchiolitis After Lung Transplantation

Inclusion Criteria: 1. Patients with single, bilateral or heart-lung allografts 2. Patients with bronchiolitis obliterans syndrome (BOS) grades 2 \& 3 (defined and graded according to international criteria (Appendix 1)), with evidence of deterioration in allograft function (i.e. deteriorating FEV1 or worsening BOS grade) within the last 12 months. 3. Patients with BOS grade 1 and evidence of deterioration in allograft function (i.e. deteriorating FEV1 or worsening BOS grade) within the last 12 months and at least one of the following additional risk factors for subsequent death: * Single lung transplant * Rapid deterioration (\>20% fall in FEV1 in the previous 12 months) * A pre-transplant diagnosis of usual interstitial pneumonia (pulmonary fibrosis) or pulmonary hypertension Exclusion Criteria: 1. Patients with active infection, acute allograft rejection, or airway anastomotic complications 2. Patients with \> 3 infective exacerbations of BOS in the last 12 months 3. Patients with a history of cytomegalovirus (CMV) pneumonitis 4. Patients with poor performance status and/or not expected to survive 3 months 5. Patients who are pregnant or breastfeeding 6. Patients with an allergy to beef products. 7. Any condition that in the opinion of the Investigator may interfere with the safety of the patient, his / her completion of required follow-up visits or evaluation of the study objectives.