Diagnostic investigation of the detection of granulocyte-macrophage colony stimulating factor antibody in serum for pulmonary alveolar proteinosis

Objective: To evaluate the diagnostic value of granulocyte-macrophage colony stimulating factor (GM-CSF) antibody in serum for pulmonary alveolar proteinosis (PAP).

Methods: Twelve PAP patients visiting Peking University People's Hospital or Fujian Provincial Hospital from January 1, 2002 to December 31, 2012, 25 patients with other pulmonary diseases (disease control), and 25 healthy volunteers (healthy control) were recruited in the study. The titer level of GM-CSF antibody in serum was determined with enzyme-linked immunosorbent assay (ELISA), and the clinical characteristics were collected in the PAP patients.

Results: The geometric mean titers of GM-CSF antibody in the PAP patients, the disease controls and the healthy controls were 1: 25 349, 1: 311 and 1: 256, respectively. The differences between the disease controls and the healthy controls were of no statistic significance (t = -1.14, P = 0.261) . With 3 times standard error (3s) above the mean value as the higher limit of X value(X = lgT, T standing for the reciprocal of the titer), the upper limit for T was 1698. With the T value ≥ 1698 as the diagnostic threshold for PAP, both the sensitivity and the specificity were 100%. The diagnostic value of GM-CSF antibody was similar to that of surgical lung biopsy and higher than that of transbronchial lung biopsy.

Conclusions: The detection of serum GM-CSF is non-invasive, convenient and efficient for the diagnosis of PAP with high sensitivity and specificity.