Many lung diseases have symptoms such as shortness of breath and dyspnea, what is the most important condition for a patient to consider? Dr. Xu Kaifeng: The most important diagnostic clue for this disease comes from a chest X-ray or CT. normal chest images show that the lungs are very clear and transparent, but in this type of patient, due to the accumulation of material in the alveoli, the imaging will show that the lungs are opaque and there is some thin sand-like material, which prompts the doctor to investigate further. The most suggestive test for this disease is a CT of the lungs, especially a high-resolution CT. The characteristics of CT findings in alveolar protein deposition are as follows: First, there are unclear shadows in both lungs at the same time, with a map-like distribution and a clear plate structure like a map of the world; second, there are paving-stone-like changes in the lungs, just like the broken bricks or small square tiles that pave the ground inside the yard. This is a typical feature in the radiology or respiratory department and is very suggestive. If there are respiratory symptoms, can the diagnosis be confirmed by blood tests? Dr. Xu Kaifeng: The diagnosis can be made by biochemical blood tests for anti-GM-CSF neutralizing antibodies. It is mainly an autoimmune alveolar protein deposition disease, and a positive blood biochemistry test for this antibody is part of the evidence to confirm the diagnosis. By checking the blood for this antibody, the diagnosis can be made in more than 90-95% of patients without the need for a pathological tissue biopsy. However, clinical testing for such antibodies is not yet commonly performed in China, and only in a few large general hospitals than. Is a tissue biopsy usually required? Dr. Xu Kaifeng: Currently, the main method to confirm the diagnosis of the disease in China is histopathological diagnosis, mainly through bronchoscopy to obtain pathological tissue. Bronchoscopy can serve two purposes. First, through bronchoscopy, saline is pumped into the alveoli for lavage, and then the lavage fluid is recovered. In normal people, the alveolar lavage fluid is very clear and transparent, but in patients with alveolar protein deposition, the alveolar lavage fluid can be cloudy, like rice soup or lime water, and this lavage fluid can precipitate after it has been left for some time. The doctor can make a preliminary judgment based on the basic state of the alveolar lavage fluid, and then send the lavage fluid to the pathology department for further examination and special staining to help with the diagnosis. Second, after bronchoscopy to take alveolar intra-alveolar tissue for pathological biopsy, only pathological tissue examination can finally confirm the diagnosis at present. When bronchoscopy is not convenient to take pathological tissue, open-heart surgery can also be performed. At present, most hospitals in China make a definite diagnosis through bronchoscopy or open-chest, but it will become more and more popular to confirm the diagnosis directly through blood biochemical examination to simplify the diagnostic procedure and reduce the pain of patients during the diagnosis. Will alveolar lavage through bronchoscopy affect the patient’s respiratory function? Dr. Xu Kaifeng: The diagnostic alveolar lavage instills about 75-100ml of fluid, which is not as uncomfortable as choking on a mouthful of water as the patient may think, and it is very safe and the patient will not feel any discomfort.