Bronchoalveolar Lavage Fluid D Dimer Levels Are Higher and More Prevalent in Black Patients with Pulmonary Sarcoidosis

Background: Abnormalities of lung coagulation and fibrinolysis in sarcoidosis are thought to play a role in the pathogenesis of this disease. Objective: We previously showed that bronchoalveolar lavage fluid (BALF) D dimer directly correlated with various measures of severity in sarcoidosis. Here, we analyze our observation that BALF D dimer was more frequently found at higher levels in African-American patients with pulmonary sarcoidosis. Methods: BALF D dimer was measured in 55 subjects with pulmonary sarcoidosis and 31 healthy volunteers by enzyme immunoassay. The healthy group established a normal range of BALF D dimer with 71 ng/ml as the highest measured level. This was the cut point for comparisons among the patients with sarcoidosis. Results: High BALF D dimer levels (>71 ng/ml) were found in younger patients with sarcoidosis and were associated with a significantly lower percent predicted forced expiratory volume in 1 s and greater numbers of BAL lymphocytes. Black patients with sarcoidosis had higher BALF D dimer levels (median 131, range 0–2,040 ng/ml) than white patients (median 18, range 0–605 ng/ml; p = 0.011). Higher than normal BALF D dimer levels were found in 61% of the black subjects with sarcoidosis, but in only 20% of the white individuals (χ 2 = 5.539, p = 0.019). BALF D dimer was the only disease measure that discriminated black from white individuals with sarcoidosis. Conclusion: BALF D dimer is an indicator of lung fibrin formation and degradation in sarcoidosis. The relationship of high D dimer levels with greater BAL lymphocytosis and worse lung function may be a marker of active sarcoidosis, especially in African-Americans who tend to suffer a more serious form of the disease.