SP-A Recombinant Rabbit mAb (SDT-3520-21)

Surfactant protein A (SP-A) is a lung-specific collectin and a promising noninvasive biomarker for various pulmonary disorders.

In idiopathic pulmonary fibrosis (IPF), serum SP-A levels are significantly elevated and reflect disease activity. With an optimal cut-off of 51.21 ng/mL, SP-A demonstrates a diagnostic sensitivity of 81.8% and specificity of 76.7% (AUC 0.858). Combining SP-A with other markers like KL-6, SP-D, and MMP-7 can further improve diagnostic accuracy. A recent meta-analysis of 2,573 interstitial lung disease (ILD) patients confirmed that elevated serum SP-A is a pivotal biomarker for assessing disease occurrence, progression, acute exacerbation, and mortality. Specifically, SP-A levels were significantly higher in progressive versus stable ILD, in acute exacerbation versus non-acute exacerbation, and in non-survivors versus survivors. In community-acquired pneumonia (CAP), lower serum SP-A on admission is associated with increased risks of mechanical ventilation, ICU admission, and poor prognosis. SP-A also shows diagnostic value in pulmonary alveolar proteinosis (PAP), tuberculosis, and as a marker for lung adenocarcinoma.

Overall, SP-A is a valuable diagnostic and prognostic biomarker, though standardization of assays and cut-off values remains a challenge for broader clinical translation.