The aim of this study is to determine whether mesenchymal stromal cell (MSC) treatment contribute to the good prognosis in patients with transplant-related complication, pneumonia post hematopoietic stem cell transplantation (HSCT).

Hematopoietic stem cell transplantation (HSCT) is a standard therapy strategy for most hematologic disorders and malignancies. Despite the improved survival attributed to advances in HSCT including transplantation techniques and supportive care, transplant-related pneumonia (severe pneumonia in particular) remains the leading cause of death for most HSCT patients and a major challenge for clinicians.

Mesenchymal stromal cells (MSCs), a form of multipotent cells, have been applied in therapy for various intractable disorders. MSC exerts its therapeutic effect through various biological functions including immunoregulation, tissue repairing, self-renew and differentiating into various cell lines. The American Thoracic Society has also suggested MSCs as a cell therapy agent for lung diseases. However, MSC therapy for pneumonia following HSCT has not been well investigated.

By investigating the efficacy of MSC treatment for HSCT-related pneumonia via comparing the outcomes in patients with and without MSC treatment, this study will provide a promising therapy for HSCT-related pneumonia.

Inclusion Criteria:

• patients with pneumonia after HSCT;
• patients under the age of 18 years;
• patients with normal pulmonary function before HSCT.

Exclusion Criteria:

• patients with other severe complications in progress when pneumonia occurred.

Patients who underwent hematopoietic stem cell transplantation (HSCT) in Guangzhou Women and Children's Medical Center and got pneumonia after HSCT.