Sarcoidosis and its relation to other immune-mediated diseases: Epidemiological insights

Abstract

Several epidemiological studies show a co-occurrence of sarcoidosis with other immune-mediated diseases (IMD). There are many similarities between sarcoidosis and IMDs in their geographical distribution and risk factors. Understanding these similarities and identifying the differences can help us to better understand sarcoidosis and put it into context with other IMDs. In this review, we present the current knowledge about the overlap between sarcoidosis and other IMDs derived from epidemiological studies. Epidemiologic methods utilize study design and statistical analysis to describe the patterns in data and, ideally, identify causal relationships between an exposure and a health outcome. We discuss how study design and analysis may affect the interpretation of epidemiological studies on this topic and highlight some theories that attempt to explain the relation between sarcoidosis and other IMDs.