Collagen Diseases

collagenoses, a group of diseases characterized by primary, usually progressive, affection of the connective tissue and vascular walls of various organs.

The term “collagen diseases” was suggested by the American scientist P. Klemperer in 1942 to describe a process manifested by swelling of the collagenous fibers (an element of connective tissue). Since collagen diseases are characterized by damage to all the structural components of connective tissue—the fibers, the cells, and the basic intracellular substances—the term “connective-tissue diseases” might be more suitable.

According to the majority of investigators, the collagen diseases include rheumatism, rheumatoid arthritis, systemic lupus erythematosus, systemic scleroderma, dermatomyositis, and periarteritis nodosa.

All collagen diseases take a progressive undulatory course. They are all accompanied by fever and affection of many of the body’s systems—the joints, skin, serous membranes, lungs, heart, kidneys, and nervous system. However, the course of each of the conditions has unique elements and individual manifestations.

The reasons for the onset of collagen diseases are varied; for some, they have not yet been established. Among the numerous theories of the developmental mechanisms of collagen diseases, the most widely accepted is that they are of infectious-allergic origin (in particular, autoimmune genesis). The discovery of various autoantibodies in all collagen diseases is of great diagnostic significance and is used widely in clinical practice. The general immunological disturbances include the elevation of the mucoprotein and gamma-globulin content of blood serum, the elevation of the amount of certain amino acids in serum proteins, an increase in the number of plasmocytes and reticular cells in the bone marrow and lymph nodes, the appearance of various antiorgan autoantibodies (to tissues of the heart, kidneys, synovial membrane, and joints), and the appearance of rheumatoid factor and antibodies to thrombocytes, leucocytes, and erythrocytes. In addition, each collagen disease has its own specific set of immunological phenomena, such as the lupus (Le) cells and antinuclear reactions characteristic of systemic lupus erythematosus and the rheumatoid factor in rheumatoid arthritis.

Corticosteroid hormones and various agents that suppress immunological reactions (immunodepressants) have a therapeutic effect in the majority of collagen diseases.