Sequential administration of MSCs obtained from adipose tissue is an effective and safe treatment for acute graft versus host disease refractory to first-line treatment. Furthermore the infusion of these cells produces a biological pattern in patients that relates to the clinical response.

Multicenter, open, non -controlled clinical trial. It is a phase I-II trial to assess the safety and efficacy of sequential infusion of allogeneic MSCs from adipose tissue, expanded "in vitro" platelet lysate in the treatment of patients undergoing hematopoietic stem cell trasplantation, who have developed a refractory graft versus host disease to first line of treatment.

This is a prospective, multicenter, open to patients undergoing allogeneic transplantation in Spanish hospitals, with one cohort of patients who receive four sequential doses of MSC.

Inclusion Criteria:

1. Diagnosis of ≥ grade II Graft Versus Host Disease refractory to first-line treatment.
2. Having been subjected to hematopoietic Stem Cell Transplantation as treatment for malignant blood disorder has been controlled by the transplantation. The source may have been bone marrow cells or peripheral blood (PB) and coming from a family member or unrelated donor.
3. Having been transplanted with myeloablative or non-myeloablative conditioning.
4. normal cardiac function (EF ≥ 40%) without evidence of uncontrolled hypertension, congestive heart failure, angina pectoris or myocardial infarction within 6 months prior to the process
5. Lung function without evidence of severe obstructive or restrictive lung disease.
6. Age between 18 and 65 years.
7. Women of childbearing age considered until one year after the last menstrual period and which have not undergone a surgical sterilization must obtain a negative pregnancy test at the time of inclusion in the study and commit to use a medically approved birth control while on study.
8. normal cardiac function (EF ≥ 40%) without evidence of uncontrolled hypertension, congestive heart failure, angina pectoris or myocardial infarction within 6 months prior to the process.
9. Signature of informed consent -

Exclusion Criteria:

1. uncontrolled blood disorder by transplantation or progression at the time of inclusion.
2. bacterial, viral, fungal or is not being controlled.
3. Any circumstance that the proposed trial dissuade medical treatment. Pregnancy, lactation or refusal to use safe contraceptive measures.
4. Patients who are currently participating or have completed their participation in a clinical trial in less than 3 months or who have participated in a clinical trial of Advanced Therapies at any previous time period.
5. Patients who are currently participating or have completed their participation in a clinical trial in a period shorter than 3 months or who have participated in a clinical trial of Advanced Therapies at any previous time.
6. positive serology for Hepatitis B , Hepatitis C and AIDS Virus. -