Increased surfactant protein-A levels in patients with newly diagnosed idiopathic pulmonary fibrosis.
OBJECTIVE
To measure surfactant protein-A (SP-A) in the BAL of patients with idiopathic pulmonary fibrosis (IPF).


METHODS
We examined SP-A in BAL and lung tissue of patients with IPF who met the stricter recommended criteria for IPF at the time of diagnosis and prior to the beginning of treatment.


METHODS
Twenty-six patients with IPF confirmed at biopsy and 22 patients with hypersensitivity pneumonitis (HP) were compared with 9 normal volunteers.


METHODS
All patients were subjected to pulmonary function testing, BAL, and lung biopsy prior to the beginning of treatment.


RESULTS
We measured SP-A in BAL fluids and performed SP-A immunohistochemistry on lung specimens. Lung tissues of patients with IPF showed extensive type II cell hyperplasia, usually containing greatly increased levels of immunoreactive SP-A. By enzyme-linked immunosorbent assay, we found a twofold increase over normal values in BAL SP-A without changes in total phospholipids. These data were in agreement with semiquantitative assessments of SP-A by protein immunoblotting and by Western blotting of sodium dodecyl sulfate gels. Patients with HP exhibited a threefold increase of BAL SP-A.


CONCLUSIONS
The reasons for the difference between our results and previously published reports describing decreased SP-A levels in IPF is not clear. It may relate to the stricter criteria for diagnosis, the absence of treatment prior to BAL, differences in the patient population, or to other methodologic differences.
Phelps
David S
DS
Department of Pediatrics, Penn State College of Medicine, PO Box 850, Hershey, PA 17033, USA. dsp4@psu.edu
Umstead
Todd M
TM
Mejia
Mayra
M
Carrillo
Guillermo
G
Pardo
Annie
A
Selman
Moises
M
D000328:Adult; D000368:Aged; D000542:Alveolitis, Extrinsic Allergic / Q000175:diagnosis* / Q000378:metabolism; D015415:Biomarkers / Q000032:analysis; D001707:Biopsy, Needle; D015153:Blotting, Western; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry* / Q000166:cytology; D016022:Case-Control Studies; D015331:Cohort Studies; D004587:Electrophoresis, Agar Gel; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D011336:Probability; D011379:Prognosis; D011658:Pulmonary Fibrosis / Q000175:diagnosis* / Q000378:metabolism; D037662:Pulmonary Surfactant-Associated Protein A / Q000032:analysis / Q000378:metabolism*; D012016:Reference Values; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric
D015415:Biomarkers; D037662:Pulmonary Surfactant-Associated Protein A