Study of Human Bone Marrow Mesenchymal Stem Cells in APAP

Inclusion Criteria: * Male or female aged 18 years or older * Patients diagnosed with aPAP by both CT and biopsy (TBLB, TBCB, or surgical lung biopsy) or bronchoalveolar perfusion (BAL) as well as GM-CSF autoantibodies in serum positive * No remission was demonstrated by CT, pulmonary function test results,or blood gas analysis at least 2 times (at least 3 months apart) before enrollment * At rest PaO2≤70 mmHg * Fertile participants must receive effective medical contraception (for both male and female participants, up to one year after the last study dosing) * Voluntary signed informed consent Exclusion Criteria: * Diagnosed with hereditary PAP, secondary PAP, or another type of PAP * Received whole lung lavage（WLL） therapy within 6 months before enrollment * Received previous GM-CSF therapy within 6 months before enrollment * Received other clinical trial treatment within 3 months before enrollment * Participated in other stem cell studies within 1 year before enrollment * Inflammatory disease or autoimmune disorder requiring treatment associated with significant immunosuppression (e.g. more than 10 mg/day systemic prednisolone) * Active infection (viral, bacterial, fungal or mycobacterial), which may affect the assessment of efficacy in the trial * History of malignant tumors * Known allergic reactions to any of the ingredients in the study drug * Participants who, in the opinion of the investigator, would aggravate any other serious pre-existing medical condition are not suitable for this trial * Women who are known to be pregnant, breastfeeding, have a positive pregnancy test (which will be detected during the screening process), or plan to become pregnant during the trial