Pathogenetic Role Of Arachidonic Acid Metabolism And Some Immunological Factors In Hemorrhagic Fever With Renal Syndrome

Hemorrhagic fever with renal syndrome(HFRS) is a severe infectious disease with high mortality in China. However, the pathogenesis of the disease remains unclear. So far most people are of the belief that the direct viral attack and immunopathogenesis are considered as the main mechanism of HFRS. It is the absence of clear evidence for virus cytopathology in fatal cases of HFRS and the coincidence of the humoral immune response with disease that have led to regarding immunopathogenesis as the main cause of this disease. But the data reported so far have not given a comprehensive explanation of the mechanism of the disease. Metabolic disorder of some inflammatory medium during the course of HFRS has also been regarded as a pathophysiological basis for this disease. It has been beleived that there are some obvious disorders of arachidonic acid(AA) metabolism, to which the pathologic course of HFRS correlated. Little is known, however, about the mechanism of this metabolism derangement, about the relation between arachidonic acid and about the pathologic damage in HFRS.The present study was undertaken to investigate the relationship between AA and its metabolic products to the pathogenesis of this disease and to explore the immunopathogenesis of HFRS.1. High levels of circulating PLA₂ have been implicated on the pathogenesis of profound systemic hypotension in infectious disease. In attempting to detect similar mechanisms in HFRS, the plasma samples form pateints were assayed by acidimetric for PLA₂ activity. The results showed that the activity of PLA₂ in the febrile phase of HFRS was slightly elevated, but there was no significant difference compared with that of normal control. However, in the oliguric stage the activity of PLA₂ became remarkably higher and it was the highest in the hypotensive stage in comparison with that of normal control. It restored to normal levels in the diuretic and convalescent stages. It was also found that these variations corresponded well with the serum BUN level, proteinuria contents, platelets counts, cAMP/cGMP level in platelets and plasma TXA₂, indicating that the elevated PLA₂ levels were related well with clinical manifestations. The results suggest that circulating PLA₂ was involved in the...