This study is for people with a specific condition called **dermatomyositis**. This is a disease that causes skin rashes and muscle weakness. Some of these people also have an issue with their lungs called **interstitial lung disease (ILD)**, which affects breathing. If you have a certain antibody, called **anti-MDA5**, you may also have a rapidly worsening form of this lung issue, known as **RPILD**. The study looks at how small living things inside the body (microbes) and the immune system, which helps fight illness, are related to these conditions.

Doctors will collect a sample from your lungs, using a procedure called **bronchoalveolar lavage**, to study these relationships. Participants need to be 18 or older and must agree to be part of the study by signing a consent form. You can't join if you have other diseases, are pregnant, or are in another study.

• Study involves a lung sample collection.
• Must be 18 or older to participate.
• Cannot participate if pregnant or in another trial.