Lymphocyte tubular structures in rheumatoid arthritis

Area of Science:

• Electron microscopy
• Immunology
• Rheumatology

Background:

• Lymphocyte tubular structures are cellular inclusions observed in various conditions.
• Tubulo-reticular structures (TRS) and parallel tubular arrays (PTA) are distinct types of lymphocyte inclusions.
• Understanding the prevalence and associations of these structures can provide insights into autoimmune diseases.

Purpose of the Study:

• To investigate the presence and characteristics of lymphocyte tubular structures in patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE).
• To compare the occurrence of TRS and PTA in RA, SLE, and healthy controls.
• To identify potential associations between TRS and clinical/laboratory parameters in RA patients.

Main Methods:

• Electron microscopy was used to examine lymphocyte samples.
• Eighty patients with RA, 15 with SLE, and 10 healthy individuals were included.
• Presence and cellular density of TRS and PTA were quantified.

Main Results:

• TRS were detected in 13/80 RA patients and 10/15 SLE patients, but not in healthy controls.
• In RA patients, TRS presence was significantly associated with antinuclear antibodies, LE cell phenomenon, and chlorambucil treatment, but not disease activity.
• The average number of cells with TRS was lower in RA patients compared to SLE patients.
• PTA were found in all RA, SLE, and healthy individuals, with similar cellular prevalence across groups.

Conclusions:

• TRS are specific to certain autoimmune conditions like RA and SLE, unlike PTA which are commonly found.
• TRS in RA are associated with specific serological markers and treatments, suggesting a link to immune dysregulation beyond general disease activity.
• The lower prevalence of TRS in RA compared to SLE warrants further investigation into the distinct pathobiology of these conditions.