Anaemia of chronic disease in rheumatoid arthritis. Raised serum interleukin-6 (IL-6) levels and effects of IL-6 and anti-IL-6 on in vitro erythropoiesis.
Serum and bone marrow from 21 patients with rheumatoid arthritis (RA) were studied in order to establish the pathogenetic role of interleukin-6 (IL-6) in anemia of chronic disease (ACD). Erythroid colony growth, using burst forming units of erythroblasts (BFUe) as a parameter, was impaired in ACD and not in nonanemic RA controls. Serum IL-6 was elevated in ACD and it correlated well with parameters of disease activity such as erythrocyte sedimentation rate and C-reactive protein. IL-6 addition to bone marrow cultures had inconsistent effects while anti-IL-6 addition resulted in impaired erythroid colony growth, suggesting stimulatory effects of IL-6 produced in the medium, which may be masked by simultaneous production of cytokines with suppressive effects. It was concluded that elevated serum IL-6 in ACD reflects disease activity. It probably plays no pathogenetic role in ACD. Its stimulatory effects on erythroid growth might counteract suppressive effects of other interleukins.
Vreugdenhil
G
G
Zuiderziekenhuis, Department of Internal Medicine, Rotterdam, The Netherlands.
Löwenberg
B
B
van Eijk
H G
HG
Swaak
A J
AJ
D000740:Anemia / Q000097:blood / Q000209:etiology* / Q000473:pathology; D000906:Antibodies / Q000502:physiology; D001172:Arthritis, Rheumatoid / Q000097:blood / Q000150:complications* / Q000473:pathology; D001853:Bone Marrow / Q000187:drug effects / Q000473:pathology; D002478:Cells, Cultured; D002908:Chronic Disease; D004920:Erythropoiesis / Q000187:drug effects; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000097:blood / Q000276:immunology / Q000502:physiology; D008297:Male; D008875:Middle Aged
D000906:Antibodies; D015850:Interleukin-6