Screening for risk factors related to lung function impairment in patients who have recovered from AIDS with severe pneumonia, to provide clinical evidence for early identification and intervention of lung function damage in this population.

This is a prospective, single-center, non-randomized, clinical observational cohort study. It involves monitoring lung function at discharge (baseline, 0w), and at the 4th, 8th, 12th, 24th, and 48th weeks in patients recovering from severe pneumonia with AIDS. Basic demographic data, HIV RNA quantification, routine blood tests, blood biochemistry, arterial blood gas results, oxygenation index, immune function (CD3+, CD4+, CD8+ T cell counts), and imaging studies are also collected. Multifactorial logistic regression analysis is used to screen for clinical predictors of lung function decline in patients recovering from severe pneumonia

Inclusion Criteria:

1. Confirmed HIV infection;
2. Progression to the AIDS stage: CD4+ count <200 cells/µL and/or occurrence of opportunistic infections associated with AIDS;
3. Age between 18 to 65 years;
4. Meet the diagnostic criteria for severe pneumonia, with reference to the 2021 treatment guidelines for community-acquired pneumonia developed by the American Thoracic Society (ATS) and the Infectious Diseases Society of America (IDSA).

Exclusion Criteria:

1. Concurrent central nervous system lesions, severe liver disease, or cirrhosis;
2. Concurrent AIDS-related or non-related tumors;
3. Women who are pregnant or breastfeeding;
4. Presence of serious underlying diseases such as heart, lung, liver, kidney, etc.;
5. Alcohol abuse or drug use;
6. The researcher believes that the overall condition of the subject affects the evaluation and completion of the trial

All study participants come from the HIV/HBV co-infection cohort at the Guangzhou Eighth People's Hospital.