Serum KL-6 as a Candidate Predictor of Outcome in Patients with SARS-CoV-2 Pneumonia.

Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2)-infection is associated with an extremely variable disease course. When interstitial pneumonia (IP) occurs, it can lead to acute respiratory distress syndrome and death. Serum Krebs von den Lungen-6 (KL-6) is an established marker of IP, but its role as a marker of SARS-CoV-2 pneumonia is debated. This bicentric study included 157 patients with SARS-CoV-2 pneumonia. The WHO Ordinal Scale for Clinical Improvement (0-10 points) was used to classify the clinical course. Serum samples were collected at admission, and on days 3 and 7 of hospitalization. KL-6 was measured by using automated chemiluminescence immunoassay. A total of 68 patients developed a severe SARS-CoV-2 pneumonia, 135 of them required oxygen, and 15 died during hospitalization. The patients requiring non-invasive ventilation, invasive ventilation, or extracorporeal membrane oxygenation had significantly higher serum KL-6 levels at admission. The serum KL-6 levels were tendentially higher in patients who died than in those who survived. Logistic regression identified serum KL-6 at a cut-off of 335 U/mL at admission as a significant predictor of severe SARS-CoV-2 pneumonia outcome. Serum KL-6 seems to be a candidate biomarker for the clinical routine to stratify patients with SARS-CoV-2 pneumonia for the risk of a severe disease outcome or death.

Pulmonary alveolar proteinosis - current and future therapeutical strategies.

PURPOSE OF REVIEW: We discuss the most recent advances in the treatment of pulmonary alveolar proteinosis (PAP), an ultra-rare syndrome. RECENT FINDINGS: Whole lung lavage (WLL) remains the gold standard of treatment for PAP syndrome. For the autoimmune form, recent trials with recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF) confirmed the efficacy in up to 70% of cases, especially under continuous administration. In patients with hereditary PAP with underlying GM-CSF receptor mutations, ex vivo autologous hematopoietic stem-cell gene therapy and transplantation of autologous ex vivo gene-corrected macrophages directly into the lungs are promising approaches. SUMMARY: There are no drugs approved for PAP at present, but cause-based treatments such as GM-CSF augmentation and pulmonary macrophage transplantation are paving the way for targeted therapy for this complex syndrome.