Relationship Between Presentation of Sarcoidosis and T Lymphocyte Profile: Conclusion

Relationship Between Presentation of Sarcoidosis and T Lymphocyte Profile: ConclusionLymphocytic alveolitis is an early event in the evolution of pulmonary involvement in sarcoidosis. This inflammatory response precedes granuloma formation in the lung and may be latently present without clinical or physiologic impairment, while remaining undetected by radiologic investigation. It has been demonstrated by Valeyre et al that the alveolitis in sarcoidosis patients with erythema nodosum precedes the increase in serum angiotensin-converting enzyme. Furthermore, they showed that the serum IgG levels were correlated to the lymphocyte counts in BAL fluid samples. Increased levels of serum IgG are probably under the influence of T lymphocytes through the activation of В lymphocytes present in sarcoidosis lesions, as have been demonstrated by Rankin et al (1983) and recently by Fazel et al (1992).
Also, the existence of alveolitis in patients with extrapulmonary sarcoidosis with a normal chest x-ray film findings has been reported by others. Our findings that patients with Lofgrens syndrome show the most prominent alveolitis and the highest CD4/CD8 ratio in BAL fluid samples suggest the involvement of T lymphocytes activated by an unknown stimulus in the initiation of granulomatous inflammation in sarcoidosis. In addition, the characteristic findings of M. Lofgren, ie, erythema nodosum and arthralgia, early in the course of sarcoidosis, histologically resembling a nonspecific vasculitis, suggest a disseminated rather than a local immune response, probably antigen-driven. This speculated involvement of an antigen as a stimulus underlying the granulomatous response has been demonstrated by the so-called Kveim-Siltzbach test. Recently, du Bois et al provided evidence of recent stimulation of the T lymphocyte antigen receptor of T lymphocytes accumulating in the lung in sarcoidosis. Fazel et al found large numbers of В lymphocytes in sarcoidosis pulmonary lesions. The В lymphocytes at these sites were suggested to be the possible origin of some of the humoral changes in serum and lesions of sarcoidosis patients. They might also influence the pathogenesis of the disorder by presenting antigens and forming immune complexes at sites of disease activity. Therefore, analysis of the antigen specificity of these expanded populations is likely to provide insight into the pathogenesis of the disease.
In conclusion, patients with different clinical presentations of sarcoidosis have various T lymphocyte profiles in BAL fluid samples. Patients with erythema nodosum and/or arthralgia and hilar lymphadenopathy (ie, Lofgrens syndrome) show the most marked characteristics of alveolitis, including the highest CD4/ CD8 ratios in BAL fluid samples, suggesting a disseminated instead of a local immune response. Furthermore, cigarette smoking modifies the immunologic BAL fluid sample profile and in addition, alveolitis is found to be less pronounced in Sms. Therefore, disease presentation or activity at the time of onset and smoking status are crucial for interpretation of individual BAL fluid sample analysis results.

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