Infectious disease as aetiological factor in the pathogenesis of systemic sclerosis.

Systemic sclerosis is an autoimmune disease characterised by vascular obliteration, excessive extracellular matrix deposition and fibrosis of the connective tissues of the skin, lungs, gastrointestinal tract, heart, and kidneys. The pathogenesis of systemic sclerosis is extremely complex; at present, no single unifying hypothesis explains all aspects. Over the last 20 years increasing evidence has accumulated to implicate infectious agents in the aetiology of systemic sclerosis. Increased antibody titres, a preponderance of specific strains in patients with systemic sclerosis, and evidence of molecular mimicry inducing autoimmune responses suggest mechanisms by which infectious agents may contribute to the development and progression of systemic sclerosis. Here we review the current state of knowledge of infectious risk factors in systemic sclerosis and the possible mechanisms by which infectious exposures might induce pathologic processes.