Low Dose ATG Plus Low Dose PTCy as GVHD Prophylaxis in Haplo-HSCT

Inclusion Criteria:

* Patients diagnosed with hematologic malignancies (AML, ALL, high-risk MDS, lymphoma, CML) were enrolled in this study. Diagnosis was according to the criteria of 2008 World Health Organization (WHO) classification of tumors of hematopoietic and lymphoid tissues.
* Family members selected as donors were typed at the HLA-A, -B, -DQB1, -C and -DRB1 locus at high-resolution level. Haplo was defined as recipient-donor number of HLA mismatches \> 2.(20)
* 14 to 70 years old.
* Performance status scores no more than 3 (ECOG criteria).
* Adequate organ function as defined by the following criteria: alanine transaminase （ALT）, aspartate transaminase（AST） and total serum bilirubin \<2×ULN (upper limit of normal). Serum creatinine and blood urea nitrogen (BUN) \<1.25×ULN.
* Adequate cardiac function without acute myocardial infarction, arrhythmia or atrioventricular block, heart failure, active rheumatic heart disease and cardiac dilatation(the patients has been improved after treatment of the disease and are not expected to affect transplant can include in the study).
* Absence of any other contraindications of stem cell transplantation. Willingness and ability to perform HSCT.
* Signed and dated informed consent document indicating that the patient (or legally acceptable representative) has been informed of all pertinent aspects of the trial prior to enrollment. Willingness and ability to comply with scheduled visits, treatment plans, laboratory tests, and other study procedures.

Exclusion Criteria:

* Presence of any condition inappropriate for HSCT.
* Life expectancy \< 3 months because of other severe diseases.
* Presence of any fatal disease, including respiratory failure, heart failure, liver or kidney function failure.
* Uncontrolled infection.
* Pregnancy or breastfeeding.
* Has enrolled in another clinical trials.
* Other severe acute or chronic medical or psychiatric condition or laboratory abnormality that may increase the risk associated with study participation or study drug administration, or may interfere with the interpretation of study results, and in the judgment of the investigator would make the patient inappropriate for entry into this study.