Abstract Background Autoimmune pulmonary alveolar proteinosis (aPAP) is a rare disease characterised by the presence of autoantibodies against Granulocyte-Macrophage Colony-Stimulating Factor (GM-CSF), resulting in defective surfactant clearance by alveolar macrophages and progressive hypoxemia. Understanding this pathophysiological mechanism is crucial, because conventional whole lung lavage only removes the accumulated surfactant but does not correct the actual defect. Inhaled GM-CSF can restore macrophage function, enhance oxygenation and provide a focused and less-invasive option. Therefore, we conducted this meta-analysis to assess the safety and efficacy of GM-CSF in treatment of aPAP. Methods We searched PubMed, Embase, Google Scholar, and Cochrane databases for RCT’s evaluating Efficacy and safety of inhaled GM-CSF in aPAP patients. Three randomized controlled trials met inclusion criteria. Data were pooled using inverse variance weighting method. Random-effects model was used and Forest plots were generated to illustrate pooled effect estimates. Analysis was done using R software (version 4.5.0). Results A total of 320 patients from three randomized controlled trials were included. Inhaled GM-CSF significantly improved oxygenation and lung function compared to placebo, as shown by greater reductions in A-aDO2 (MD: −5.25; 95% CI: −8.07 to − 2.42; p = 0.0003) and increases in DLCO (MD: 7.14; 95% CI: 4.27 to 10.01; p 0.0001). Quality of life also improved, reflected by lowerSGRQ scores (MD: −6.93; 95% CI: −10.61 to − 3.24; p = 0.0002). The 6-minute walk distance increased by 14.7 m (95%CI: -15.41 to 44.82; p = 0.3386), but did not reach statistical significance (p = 0.3386). Adverse events (RR: 1.02; 95% CI: 0.93-1.11; p = 0.6940) and serious adverse events (RR: 0.90; 95% CI: 0.56-1.44; p = 0.6526) were similar between the two groups. Conclusion Inhaled GM-CSF showed improvement in oxygenation, lung function and quality of life in aPAP patients. Also the adverse event profile is same as that of placebo. Future research should direct towards long term outcomes, optimal dosing duration and potential benefit as 1st line therapy over whole lung lavage. This abstract is funded by: None
Krishnamaneni et al. (Fri,) studied this question.