[Changes in the pulmonary artery in collagen diseases].

Morphological changes in the pulmonary artery and its major branches were studied histologically and histochemically on autopsy cases of polyarteritis nodosa (23), systemic lupus erythematosus (10), systemic scleroderma (12), and rheumatoid arthritis (5). The ages of the fatalities ranged from 9 months to 77 years. An identical type of lesions was revealed: disorders of the connective tissue, destruction of elastic fibers, alterations of vasa vasorum, with cellular reactions typical of each nosological form reflecting the peculiarities of the immunological processes. The initial stage in the genesis of lesions in the vascular walls of the major pulmonary arteries is the involvement of vasa vasorum as a regular disorder of the microcirculatory ways in all collagen diseases.