Relationship Between Presentation of Sarcoidosis and T Lymphocyte Profile: Discussion

The results presented in this study confirm previous observations of signs of a T lymphocyte alveolitis and the influence of smoking on T lymphocyte subsets in patients with sarcoidosis. Most remarkably, we demonstrated that the BAL fluid T lymphocyte profiles are related to the differential clinical presentation of sarcoidosis patients. This relationship was found to be less pronounced in Sms. However, comparison between the different studied categories of sarcoidosis patients is rather difficult, whereas estimating the exact time of onset of the asymptomatic patients and those presenting with respiratory symptoms is much more difficult than assessing the time of onset of erythema nodosum. Although the influence of smoking on BAL fluid cell profile has been studied extensively, only a few reports concerning the influence of clinical presentation of sarcoidosis on the cell profile in BAL fluid samples have hitherto been published. Pleural Effusions
Costabel et al suggested earlier that cellular im-munoregulation may be disturbed in the lungs of cigarette smokers and as such, may influence pulmonary host defense. In the present study, we confirm the data previously reported by others, by showing that smoking results in increased total cell counts, less increased percentages of T lymphocytes, and less increased CD4/CD8 ratios in the BAL fluid samples in sarcoidosis patients. Thus, alveolitis, as determined by immunologic marker analysis, is less significant in smokers.
Although all sarcoidosis patient groups, both Sms and NSms, in our study appeared to have an increased CD4/CD8 ratio in BAL fluid samples, NSm asymptomatic patients (group A) had the lowest, less increased ratio (4.7) in comparison with that of NSm symptomatic patients with respiratory and general symptoms (group B). These latter patients had a mean CD4/CD8 ratio of 8.0, while NSm patients presenting with acute onset sarcoidosis (ie, Lofgren syndrome), had the highest ratio (10.7) in the BAL fluid samples. These significant changes in the CD4/CD8 ratio seem to be primarily due to an increased influx of CD4+ T lymphocytes to the alveoli, indicating an active immune response. The reported decreased influx of CD8+ T lymphocytes also determines the CD4/CD8 ratio in sarcoidosis, most prominently demonstrated in patients with Lofgrens syndrome, who showed significant lower percentages CD8+ T lymphocytes both in Sms and NSms. Interestingly, patients with pronounced alveolitis, as reflected in a high CD4/CD8 ratio in BAL fluid samples, who clinically present with acute onset such as Lofgrens syndrome, do not need corticosteroid or any other treatment and have a short recovery time period. In contrast, sarcoidosis patients with a relatively low CD4/CD8 ratio in BAL fluid samples more frequently develop permanent lesions, such as pulmonary fibrosis. These data confirm the previously suggested poor prognostic significance of “isolated” BAL fluid analysis results. The aforementioned best prognosis and spontaneous resolution of the lesions in almost all cases suffering from Lofgrens syndrome, compared with other subgroups, suggests the beneficial role of especially CD4+ T lymphocytes in the immune response in sarcoidosis and their essential function in defense.

This entry was posted in Sarcoidosis and tagged alveolitis, bronchoalveolar lavage, erythema, lofgrens syndrome, sarcoidosis, smoking.