MIF- Thyroxine Interactions in the Pathogenesis of Pulmonary Arterial Hypertension

Inclusion Criteria: * Subject must be at least 18 years of age and have confirmed pulmonary hypertension (PH) and interstitial lung disease (ILD). * ILD was identified on high resolution computed tomography along with a total lung capacity (TLC) \<70% of predicted value on pulmonary function tests (PFTs) with no evidence of pulmonary hypertension on echocardiogram. * PAH group patients were defined as patients with a mean pulmonary artery pressure \>25 mmHg at rest and a wedge pressure of \<15 mmHg (millimeters of mercury), measured by right heart catheterization (WHO group I PAH). * PH+ILD group, subjects with evidence of ILD on high resolution CT Scan and mean pulmonary artery pressure \>25 mmHg on right heart catheterization. * Patient with evidence of Chronic thromboembolic disease on CT angiogram and mean pulmonary artery pressure \>25mmHg on right heart catheterization. (WHO group IV) * Patient with Pulmonary Hypertension due to other conditions, such as Sarcoidosis, Gauchers disease, Hemolytic Anemia and Myeloproliferative disorders. * Normal control group: Subjects without cardiopulmonary disease, with a normal PFT and ECG. Exclusion Criteria: * Failure to obtain informed consent; * Pregnancy * Subjects with cardiopulmonary disease other than PH and ILD; * Unexplained abnormal PFT, ECG, Routine blood/chemistries test * History or existing other sever organ/system diseases * Defined Acute pulmonary embolism * Age \< 18 years