Circulating D-dimers as a marker of disease activity in pulmonary sarcoidosis.

BACKGROUND AND AIMS: The search is on to find an easily measurable marker of disease activity in sarcoidosis. The present study was carried out to evaluate the utility of plasma D-dimer as a marker of disease activity in sarcoidosis. METHODS: Thirty newly diagnosed cases of sarcoidosis with clinical indications for treatment and an equal number of matched healthy controls were studied for the presence of D-dimers (DD) in the plasma before starting treatment with oral prednisolone and after clinical remission. Semi-quantitative estimations of DD were done using the latex agglutination slide test method (Commercial Kit - Diagnostica Stago, France) as per the manufacturer's recommendations. RESULTS: The mean age of cases and controls were 45.43 +/- 8.5 (range 34-60) and 46.16 +/- 8.07 (range 32-61) years, respectively. Of the 30 patients, nine (30%) were DD positive at baseline. The DD positive patients presented more often with dyspnoea, had radiological stage III (7 out of 9) disease and abnormal spirometry compared to patients with no detectable DD in their plasma. Of the 16 patients re-evaluated after clinical remission, eight (50%) were D-dimer positive. Two of the five patients initially DD positive had become negative and five additional patients who were negative at baseline had become positive. CONCLUSIONS: Plasma D-dimers, which were positive in 30% of untreated patients of sarcoidosis, indicate patients with significant pulmonary parenchymal involvement; but have no correlation with clinical disease remission.