Purpose of review: To describe the methods for derivation of clinical phenotypes in general and how they should be applied in sarcoidosis, taking into account the dimensions of the disease. The results from the small number of studies in this area are summarized.
Recent findings: Clinical phenotypes are determined by diverse ways. In sarcoidosis, some studies defined clinical phenotypes based on severity of disease and outcome after treatment of variable duration. A second approach to characterize clinical phenotypes is by using analytic or multivariate techniques. This approach considers several domains of disease and does not make assumptions a priori, with the hypothesis being developed after the results. A small study used factorial analysis for this purpose. Some well defined clinical phenotypes are described and future directions for research are given.
Summary: Clinical phenotypes, by examining relationships between several domains in sarcoidosis, are likely to better delineate the underlying processes and pathways. Larger studies with appropriate methods should be performed to better delineate clinical phenotypes in sarcoidosis.