This study aims to explore a new therapeutic approach: the feasibility, safety and preliminary efficacy of directly spraying GM-CSF into the airway through bronchoscopy for the treatment of aPAP.

Inclusion Criteria:

1. Age: 18 to 60 years old;
2. A clear diagnosis of aPAP must meet at least one of the following diagnostic criteria:

1) BALF appears "milky white"; Or cytological examination reveals a large amount of PAS-positive protein deposition; 2) HRCT shows typical "paving stone-like changes"; 3) Positive for serum GM-CSF antibody. 3. There are more than one of the following treatment indications: Symptoms such as progressive breathing difficulties, coughing, and shortness of breath after activity occur; 2) Without oxygen inhalation, PaO2 > 65 mmHg 3) Pulmonary function DLCO accounts for % of the predicted value, ranging from 60% to 80%, including the critical value.

4. No other PAP specific treatments (such as WLL, inhaled GM-CSF, biological agents, etc.) have been received recently (for more than 4 weeks).

5. Agree to participate in this study and sign the informed consent form.

Exclusion Criteria:

1. Secondary PAP (such as secondary to blood diseases, etc.);
2. Patients with obvious pulmonary fibrosis, emphysema or irreversible lung function impairment;
3. Patients in the acute exacerbation stage;
4. Patients with other lung diseases (such as active pulmonary tuberculosis, bronchiectasis with purulent infection or other chronic infections; Have severe asthma, chronic bronchospasm, etc.
5. Have a history of allergy to GM-CSF antibodies or related drug components;
6. Patients who have participated in other clinical drug trials within the past three months;
7. Patients who have experienced severe complications related to bronchoscopy or are intolerant to bronchoscopy;
8. Concurrent with other serious cardiovascular and cerebrovascular diseases, hematological disorders, malignant tumors, etc.
9. Pregnant or lactating women.