PURPOSE: African-American race has been associated with a higher disease incidence of Sarcoidosis, more severe disease at diagnosis, more extrathoracic manifestations, and chronic course. Our hypothesis is that the lung granuloma counts are higher in African-Americans compared to Caucasians.
METHODS: Retrospective, cross-sectional study at a local referral center for sarcoidosis. Histopathologic evaluation of bronchoscopic lung biopsy specimens at diagnosis. The specimen slice represented that with the most intense granulomatous inflammation on 4X inspection and counts of granuloma made with 10X view. Granuloma were counted as bronchial or alveolar. Poisson log-linear modeling was utilized to control for potential confounding by stage of chest-ray, biopsy technique, gender, and number of pieces.
RESULTS: The subject population (n=189) was predominantly African-American (75%) and female (67%). African-American race (65% increase; 95% CI, 49% to 89%), female gender (32% increase, 95% CI, 22% to 43%), presence of necrosis (57% decrease, 95% CI, 53% to 61%), chest x-ray stage II relative to I (62% increase, 95% CI, 47% to 78%), and stage III relative to I (136% increase, 95% CI, 114% to 161%) were associated with lung granuloma counts. In a multivariate Poisson log-linear model, African-American race was significantly associated with increased granuloma counts, after adjustment for chest x-ray stage, age, gender, necrosis, biopsy type, and biopsy number (27% increase, 95% CI, 15% to 40%). When restricted to bronchial granuloma, the influence of race was more pronounced (55% increase, 95% CI, 38% to 75%), adjusted for chest x-ray stage, gender, biopsy type, biopsy number, and necrosis.
CONCLUSION: The intensity of pulmonary granuloma intensity is significantly higher among African-Americans compared to Caucasians at the time of diagnosis. We provide a partial histopathologic explanation for the differences in disease severity at diagnosis and bronchoscopic lung biopsy differences by race.
CLINICAL IMPLICATIONS: We provide a partial explanation for the differences by race seen in bronchoscopic biopsy yield studies. Future lung bronchoscopic lung biopsy studies need to control for the influence of race in design or analysis.
DISCLOSURE: Robert Burke, No Financial Disclosure Information; No Product/Research Disclosure Information