The purpose of this study is to take a population of lung transplant recipients who meet UCLA criteria for induction chemotherapy with thymoglobulin and prospectively study weather giving the first dose intraoperatively versus postoperatively makes a difference with how patients do during and after lung transplantation. In addition, these cohorts will be compared to patients who do not qualify for thymoglobulin and receive either an alternative agent or no agent. The primary endpoint is primary graft dysfunction. We will also evaluate several other early and late end points such as ventilator days, ICU/hospital days, acute/chronic rejection, infection, CT chest abnormalities, and survival.

We will also collect donor lung tissue and lavage fluid for measurement of various proteins and receptor expression at two time points: (1) prior to implementation and dosing of induction chemotherapy and (2) after transplantation (following a course of induction chemotherapy). This will allow us to possibly make a connection between the profiles of the various proteins and receptors and the clinical outcomes, depending on weather the patient has received induction chemotherapy, starting intraoperatively or postoperatively.

• Drug: rabbit antithymocyte globulin + placebo
• Drug: placebo + rabbit antithymocyte globulin

• Active Comparator: We plan to blindly randomize these 25 lung transplant patients to intraoperative dosing of thymoglobulin followed by 3 additional postoperative doses (the first of these 3 postoperative doses will be placebo)
• Experimental: We plan to blindly randomize these 25 lung transplant patients to 3 postoperative doses of thymoglobulin (the intraoperative dose will be placebo)

Inclusion Criteria:

• On a voluntary basis, all patients eligible for bilateral lung transplantation between the ages of 18-65 years (inclusive)

Exclusion Criteria:

• Have any known allergy to horse or rabbit antithymocyte polyclonal agents
• Have a preoperative platelet count less then 100,000/mm3
• Are recipients of multiple organ transplants (either simultaneous or sequential)
• Are recipients of a single lung transplantation
• Have a contraindication to rabbit antithymocyte globulin based on judgement of the investigators (i.e. bleeding diathesis or overwhelming risk of intense immunosuppression) including the following patients: greater than 65 years of age, prior diagnosis of malignancy (with the exception skin malignancies), underlying suppurative lung disease (i.e. bronchiectasis, cystic fibrosis, etc.).