Study of Progression of Community Acquired Pneumonia in the Hospital in Patients With More Severe Preexisting Diseases and Immunosuppression

Inclusion Criteria: 1. Hospitalization with community acquired pneumonia (CAP) confirmed by pulmonary infiltrate in chest imaging 2. Valid informed consent form 3. Working diagnosis of CAP by enrolling physician 4. No hospitalization for any reason within 28 days prior to hospitalization for the current episode of CAP 5. At least 2 out of the five following clinical symptoms: * Fever * Cough * Purulent sputum * Shortness of breath or need for respiratory support * Crackling or rales on auscultation, dullness to percussion, or bronchial breathing 6. At least 1 of the following criteria * Known HIV infection or AIDS * Anti-tumor treatment within the past six months * Therapy with corticosteroids ≥ 20mg for ≥ 14 days before enrollment * Non-steroidal immunosuppressive therapy within the past six months * Cytostatic therapy within the past six months * Radiation therapy within the past six months * Bone marrow transplant received * Respiratory support at home via tracheostoma * Cystic fibrosis * Heart failure: New York Heart Association (NYHA) Stadium IV or HFrEF (defined as left ventricular ejection fraction \<40%). * Decompensated liver disease (Child-Pugh class C) * Diabetes mellitus with HbA1c ≥ 8,5 % * End-stage renal disease requiring dialysis * Pulmonary hypertension (all classes) with mPAP \> 20 mmHg (right heart catheter) Exclusion Criteria: 1. Participation in this study at an earlier time 2. More than 48 hours in the hospital before enrollment (for patients directly to intensive care: more than 7 days) 3. Pregnancy 4. Breastfeeding 5. Active tuberculosis 6. Acute lung injury or acute respiratory distress syndrome for extrapulmonary reasons 7. Massive aspiration 8. Sepsis with extrapulmonary focus 9. Acute pulmonary embolism