Evaluation of bronchoalveolar lavage fluid phospholipids and cytokine release by alveolar macrophages as prognostic markers in sarcoidosis.

BACKGROUND

The clinical course of sarcoidosis is unpredictable and reliable laboratory prognostic parameters are lacking.

OBJECTIVES

The aim of the present study was to estimate the prognostic value of bronchoalveolar lavage fluid (BALF) phospholipids and cytokine production by alveolar macrophages (AM) in pulmonary sarcoidosis.

METHODS

We investigated BALF parameters in 64 subjects (55 patients with sarcoidosis and 9 healthy volunteers as controls). After a period of 12 months, the total sarcoidosis study population was divided into three groups according to radiological, functional and laboratory dynamics: the group with a favorable (n = 15), the one with an unfavorable (n = 16) and the one with an intermediate clinical course of the disease (n = 24).

RESULTS

The group of patients with a poor clinical outcome was characterized by a lower percentage of lymphocytes in BALF [20% (4-56%)], rather small amounts of cytokines [TNF-alpha: 1.5 ng/ml/10(6 )(0.08-8.6), IL-6: 5.75 ng/ml/10(6) (1.7-22.5)] and a significant decrease in BALF phospholipids [total lipid phosphorus (TLP): 29.9 micromol/l (13.8-68.3) as compared to 67.5 micromol/l (33.2-127.2) in controls]. Patients with a favorable clinical outcome were shown to have higher lymphocytosis (40%, range 6-64, p < 0.05 versus poor outcome), intensive TNF-alpha and IL-6 release by AM, and close to normal phospholipid content in BALF.

CONCLUSIONS

The level of TNF-alpha secretion by AM <3.9 ng/ml/10(6) and total lipid phosphorus in BALF less than 30 micromol/l may serve as markers of poor prognosis in pulmonary sarcoidosis.