Lupus and leprosy: beyond the coincidence

Area of Science:

• Immunology
• Infectious Diseases
• Rheumatology

Background:

• Systemic Lupus Erythematosus (SLE) is an autoimmune disease associated with increased infection susceptibility.
• Infections can trigger SLE flares, with known associations including parvovirus B19, cytomegalovirus, Epstein-Barr virus, and Mycobacterium tuberculosis.

Observation:

• Leprosy, caused by Mycobacterium leprae, can present symptoms mimicking lupus flares and induce autoantibody production.
• Molecular mimicry, where microbial antigens resemble self-antigens, is a potential mechanism linking infections to autoimmune diseases like SLE.

Findings:

• Three Brazilian patients with inactive SLE experienced disease flares concurrently with leprosy diagnosis.
• Shared epitopes between antibodies in lepromatous leprosy and SLE patients suggest M. leprae may trigger SLE reactivation.

Implications:

• Leprosy should be considered as a potential trigger for SLE flares, especially in endemic areas.
• Further research into molecular mimicry between M. leprae and SLE autoantigens is warranted.
• Understanding these triggers can improve patient management and diagnostic approaches for SLE.