[Histamine in rheumatic diseases].

Histamine, the decarboxylation product of histidine, was determined in serum, leucocytes, synovial fluid and synovial tissue rheumatic diseases. Histamine level was variable in most of the biological samples. In serum of patients with rheumatoid arthritis histamine was more frequent (50%) than in controls (10%). Leucocyte preparations containing basophile cells did not differ in their histamine concentration. Synovial fluid of rheumatoid arthritis patients showed histamine levels in the range of 1,0 to 23,4 ng/ml. The results were discussed by means of the pertinent literature.