Systemic autoimmune disorders constitute a well-characterized and separate group of
diseases in the field of clinical immunology and rheumatology. Despite their shared
characteristics, these diseases have several distinctive features. The similarity
and the difference are manifested both in etiology (i.e. the importance and ratio
of genetic and environmental factors), in pathomechanism (i.e. the dominance of cellular
or humoral immune response), in the disease outcome (fluctuating or chronic progressive)
and in the diversity of clinical manifestations (i.e. multiple organ involvements
or some dominant target organs/tissues). In the present work the authors describe
the features of four prototypic autoimmune disorders - systemic lupus erythematosus,
Sjogren's disease, dermato-polymyositis and systemic sclerosis - and characterise
in general the common and particular specific points of systemic autoimmune disorders
focusing on the variability and subgroups which can be observed even within certain
diseases.