The goal of this clinical research study is to learn about the safety of giving mesenchymal stem cells (MSCs) to patients who have ARDS. Researchers also want to learn if these cells can help control ARDS when given with drugs that are routinely used to treat ARDS.

In this study, participants will receive 1 infusion of MSCs.

This is an investigational study. MSC infusions for the treatment of ARDS is investigational.

Up to 20 patients will take part in this study. All will be enrolled at MD Anderson.

The MSCs:

MSCs are a type of stem cell that can be removed from bone marrow and grown into many different cell types that can be used to treat cancer and other diseases. The MSCs used in this study were collected from healthy donors and are stored and grown in a laboratory at MD Anderson. The product you will receive is from a healthy donor that is not related to you.

MSC Administration:

If you are found to be eligible to take part in this study, you will receive MSCs by vein over about 1-2 hours 1 time on Day 1.

Study Visits:

On Days 1 and 3:

• Blood (about 2 tablespoons) will be drawn for routine tests, to check your heart, kidney, and liver function, and for biomarker testing.
• Blood (about ½ teaspoon) will be drawn to check the oxygen level in your blood.

On Days 14 and 30:

°Blood (about 2 tablespoons) will be drawn for routine tests, to check your heart, kidney, and liver function, and for biomarker testing.

On Days 30 and 60:

°You will be checked for possible reactions to your treatment, including graft-versus-host disease (GVHD - a reaction of the donor's immune cells against your body). This will be checked by physical exam, by the doctor reviewing your side effects, and blood from standard of care blood draws.

Length of Study:

Your participation on this study will end after the Day 60 study visit. You will be taken off study early if you are not able to receive the MSC infusion(s), if intolerable side effects occur, if the doctor thinks it is in your best interest, or if you are unable to follow study directions.

Inclusion Criteria:

1. ARDS characterized by hypoxemia and bilateral radiographic opacities not fully explained by cardiac failure or fluid overload as judged by the treating physician using all available data. Moderate ARDS includes patients with malignancies with the previous presentation and a P/F ratio </= 200 or SF ratio of </= 214. The duration of the hypoxemia criterion and the radiograph criterion must be within 10 days of the time of enrollment.
2. Patients age >/=18 years.
3. Treated with appropriate maximal medical therapy for pulmonary toxicity.
4. Negative pregnancy test in a woman with childbearing potential defined as not post-menopausal for 12 months or no previous surgical sterilization.
5. Patient or legally appropriate proxy must be able to understand study instructions and sign consent.

Exclusion Criteria:

1. Unstable ventricular tachycardia or fibrillation.
2. Moribund patients not expected to survive up to 48 hours.
3. Patients with ARDS resulting from trauma.
4. Patients with documented deep venous thrombosis or pulmonary embolism within the past 3 months.
5. Patients with severe chronic liver disease (Childs-Pugh score > 10).
6. Patients with previous solid organ transplant.
7. Pregnant and/or lactating women.