Distinct clinical manifestations of sarcoidosis correlating with genetic factors
Sarcoidosis is a systemic granulomatous disease of unknown etiology. The lungs are engaged in more than 90 % of all cases but almost any organ such as the eyes, skin, heart and the nervous system can be involved.
In pulmonary sarcoidosis particularly CD4+ Th1 lymphocytes infiltrate the airways and an increased ratio of CD4+/CD8+ lymphocytes is commonly found in bronchoalveolar lavage (BAL) fluid. Sarcoidosis is influenced by a multitude of genes and the strongest associations are described within the HLA-region. Smoking is known to protect against disease. The first line of treatment is oral corticosteroids. Treatment is usually initiated in patients with progressive loss of lung function but also extra pulmonary manifestations such as involvement of the heart and nervous system are common indications.
The aim with this study is to find markers that could be used in clinical care to predict patients that have a high risk for chronic disease and/or a high risk for extra pulmonary manifestations in sarcoidosis. Such markers might also give us information about pathology.
We have more than 1000 patients registered in our data files. They are clinically well characterized, which enables studies of different subgroups. In the data files there are for example information about smoking, x-ray, treatment, extra-pulmonary manifestations, chronic/ non-chronic disease, BAL-data, lung function and HLA-type. We plan to study associations between specific HLA-DRB1* alleles and extra-pulmonary manifestations. Moreover, we will evaluate if the cells found in BAL fluid reflect the cells obtained from enlarged mediastinal lymph nodes. The patients included in this part of the study will undergo routine investigation with bronchoscopy and blood tests as well as investigation of mediastinal lymph nodes by endoscopic ultrasound fine needle aspiration via esophagus (EUS-FNA). We will also use flow cytometry for some of these analyses.
M.D. Ph D Pernilla Darlington