Systemic lupus erythematosus

Lupus (systemic lupus erythematosus) is an autoimmune disease in which the immune system attacks the body's own tissues, including skin, joints and kidneys. Neutrophils and their "traps" are part of the lupus story, so researchers ask whether alpha-1 antitrypsin (AAT) matters.

What we know

Neutrophils, a type of white blood cell, can throw out traps (NETs): web-like strands of DNA studded with proteins. In lupus, these traps can carry the body's own material to the immune system, which reacts as if it were foreign, helping switch on type I interferon, a signal running through much of lupus. In one study, people who cleared traps poorly more often had kidney involvement.

AAT is the body's "brake" for neutrophil enzymes such as elastase. In lupus-prone mice, AAT or AAT gene therapy reduced disease. No trial has tested AAT for lupus in people.

About this series: Mark Egly diagnosed his own alpha-1 antitrypsin deficiency at age 62. After learning he had emphysema and COPD despite never smoking, he connected the dots himself, and testing confirmed it. That discovery set the Foundation on the path of tracing AAT's possible links to conditions like this one.