Isomorphic skin reaction with DNCB in SLE and DLE

Area of Science:

• Immunology
• Dermatology
• Clinical Medicine

Background:

• Systemic and discoid lupus erythematosus (LE) are chronic autoimmune diseases with varying immune responses.
• Assessing cell-mediated immunity, such as DNCB sensitization, can provide insights into immune status in LE patients.

Purpose of the Study:

• To evaluate 2,3-dinitrochlorobenzene (DNCB) sensitization in patients with systemic and discoid lupus erythematosus (LE).
• To compare DNCB sensitization rates between LE patient groups and control populations.
• To investigate the occurrence of isomorphic reactions at DNCB exposure sites in LE patients.

Main Methods:

• DNCB sensitization testing was performed on patients with systemic LE (76), discoid LE (44), and various control groups (101 immunosuppressed/tumor patients, 40 eczematous patients, 115 unselected patients).
• Incidence of sensitization, age dependency, and isomorphic reactions were analyzed.
• Histological and immunofluorescence studies were conducted to support clinical findings.

Main Results:

• DNCB sensitization was comparable in discoid LE and mixed LE groups, but lower in systemic LE patients.
• The highest sensitization incidence was in polysensitized controls, and the lowest in immunosuppressed/tumor patients.
• Isomorphic reactions occurred in 43% of discoid LE and 25% of systemic LE patients, independent of reaction intensity.

Conclusions:

• DNCB sensitization capacity differs between systemic and discoid LE.
• Isomorphic reactions in LE patients are a distinct clinical finding not directly correlated with DNCB reaction intensity.
• Cell-mediated immunity assessment via DNCB sensitization offers valuable data for understanding LE immunopathology.