Why Lupus Can Increase Infection Risk Despite an Overactive Immune System

Lupus is an autoimmune disease in which the immune system mistakenly attacks the body's own tissues. At the same time, people living with lupus can also be more vulnerable to serious infections. This may seem confusing; how can an immune system that is overactive still have trouble fighting bacteria?

Recent research provides some insight into this lupus and infection risk paradox.

An Overactive but Misdirected Immune Response

Researchers focused on neutrophils, a type of white blood cell that acts as one of the body's first defences against bacterial infections. Neutrophils can release structures called neutrophil extracellular traps (NETs), which contain DNA and antimicrobial proteins that can trap and help destroy harmful microorganisms.

However, not all NETs work in the same way.

Research suggests that chronic inflammation associated with lupus can interfere with the way neutrophils respond to bacteria. Instead of producing a NET response that is highly effective at killing bacteria, inflammatory signals may push neutrophils toward another type of response that is produced more quickly but may be less effective against infection.

This could mean that the immune system is highly active but not responding most effectively.

Why This Matters for People With Lupus

Infections are an important concern for people with lupus. Some of the increased risk can come from medications that suppress immune activity, while lupus itself may also affect how immune cells function.

The research suggests that simply having more inflammation does not necessarily provide better protection against infection. The type, timing, and effectiveness of the immune response are also important.

Researchers also found in lupus-prone mice that some existing lupus treatments could correct certain defects in neutrophil pathways. However, this research does not prove that these treatments reduce infections in people with lupus.

What Researchers Still Need to Understand

The immune system involves many different cells and processes, so neutrophils and NETs are only part of the picture. More research is needed to understand how different types of NETs influence both autoimmune inflammation and infection.

The findings also highlight that NETs should not necessarily be viewed as either completely helpful or harmful. Their effects may depend on the type of NET produced and the situation in which it occurs.

For a more detailed explanation of this research, read the original article on The Conversation: Why an overactive immune system can leave people with lupus vulnerable to infection.

Key Takeaway

Lupus does not simply involve a "weak" or "strong" immune system. The immune response can be overactive yet poorly directed, which may contribute to inflammation while still making it harder to control certain infections.Understanding these changes can help improve lupus awareness and support better patient education. An Arthritis Support Network can also provide people living with autoimmune and rheumatic conditions with useful information, awareness resources and community support.