The immunopathology of progressive systemic sclerosis (PSS)

Area of Science:

• Rheumatology
• Immunology
• Pathology

Background:

• Progressive systemic sclerosis (PSS) is an enigmatic rheumatic disease of unknown origin.
• It is characterized by fibrosis in the skin and internal organs.
• While occupational exposures exist, most PSS patients lack known predisposing factors, and a clear genetic basis is unproven.

Purpose of the Study:

• To explore the immunologic underpinnings of PSS.
• To investigate the relationship between cell-mediated immunity to collagen and scleroderma.
• To review the pathological features and mortality factors in PSS.

Main Methods:

• Review of existing literature on PSS etiology, immunology, and pathology.
• Analysis of lymphocyte transformation assays in patients with scleroderma.
• Examination of reported immunologic abnormalities and their diagnostic significance.

Main Results:

• PSS involves fibrosis and small vessel occlusion, affecting multiple organ systems.
• While various immunologic abnormalities are noted, they are often non-specific.
• Peripheral blood lymphocytes from scleroderma patients show transformation when exposed to collagen, suggesting a link to cell-mediated immunity.

Conclusions:

• Cell-mediated immunity to collagen is significantly associated with scleroderma development.
• Organ involvement, particularly heart, kidney, or lung, increases PSS mortality.
• A definitive experimental model for PSS remains elusive, though related conditions can be induced in animal models and humans.