Inclusion Criteria:

• - Adults over 18 years of age and less than 80 years of age.

• - Both female and male.

• - Patients with new diagnosis of interstitial lung disease associated with connective tissue disorders, Antineutrophil cytoplasmic antibodies (ANCA) associated vasculitis or idiopathic pneumonia with autoimmune features (IPAF) or established diagnosis of ILD associated with CTD under conventional therapy for at least 6 months but less than 24 months, with no evidence of improvement.

• - Competent and able to provide written informed consent, and ability to comply with protocol.

Exclusion Criteria:

• - Patients with interstitial lung disease without evidence of a concomitant rheumatologic autoimmune disorder.

• - Exposure to rituximab or cyclophosphamide on the previous 2 months.

• - Severe interstitial lung disease defined by the presence of severe hypoxemia at rest (SO2 < 88% at rest) - Clinical assessment that indicates active chronic infections such as osteomyelitis or active tuberculosis (TB), or acute infections such as pneumonia, active bronchitis, cellulitis, etc. or active solid tumors or hematologic malignancies.

• - Previous treatment with mesenchymal stem cells.

• - Clinically significant medical conditions within the six months before administration of BMD-MSCs: e.g. myocardial infarction, active angina, congestive heart failure or other conditions that would, in the opinion of the investigators, compromise the safety of the patient.

• - Medical history of human immunodeficiency virus (HIV), Hepatitis B or C.

• - Abnormal complete blood count (CBC), creatinine, Aspartate aminotransferase (AST) or Alanine aminotransferase (ALT) at screening.

• - Pregnant or breast feeding.

• - Unwilling to agree to use acceptable contraception methods during participation in the trial.

- Inability to provide informed consent

Arms

Experimental: Interstitial Lung Disease with Connective Tissue Disorder

Subjects with Interstitial Lung Disease (ILD) associated with Connective Tissue Disorder (CTD) will receive a new treatment called Allogeneic (coming from a healthy donor) Bone Marrow Derived Mesenchymal Stem Cells (BMD-MSCs)

Interventions

Biological: - Allogeneic Bone Marrow Derived Mesenchymal Stem Cells (BMD-MSCs)

Subjects will be treated with regular standard of care plus 0.5-1 million MSC/Kg intravenously.