Am. J. Respir. Crit. Care Med., Vol 155, No. 1, Jan 1997, 249-253.
Lung alkaline phosphatase as a marker of fibrosis in chronic interstitial disorders
A Capelli, M Lusuardi, CG Cerutti and CF Donner
Salvatore Maugeri Foundation, IRCCS, Medical Center of Rehabilitation, Division of Pulmonary Disease, Veruno, Italy.
Alkaline phosphatase (ALP) in lung lavage fluids is a marker of tissue
damage and type II cell proliferation. Type II pneumocytes are extensively
involved in fibrosis. The aim of our study was to verify whether local ALP
activity can be held as a marker of fibrosis in chronic interstitial lung
disorders. ALP was determined in the bronchoalveolar lavage of 140
subjects: 25 control subjects, and 33 patients with silicosis, 38 with
idiopathic pulmonary fibrosis (IPF), and 18 with Stage I, 16 with Stage II,
and 10 with Stage III/IV sarcoidosis. We observed a significant
augmentation of ALP activity in patients with IPF, as well as in those with
Stages II and III/IV sarcoidosis. Albumin was higher in those with Stages I
and II sarcoidosis, but it was normal in the other groups. Therefore, a
significant increase in ALP:albumin ratio characterized IPF (median, 10.3;
range, 2.4 to 83.2) and Stage III/IV sarcoidosis, (8.9, 4.4 to 103.1) as
compared with Stage I (2, 1.1 to 18) and Stage II (4.7, 0.7 to 26.6)
sarcoidosis, silicosis (6.5, 0.5 to 42.7), and the nonsmoker (6.1, 2.9 to
12.9) and smoker (6.4, 2 to 15.2) control groups. We conclude that an
increase of the ALP: albumin ratio in bronchoalveolar lavage fluids from
patients with chronic interstitial disorders may reflect a fibrosing
progression.
