Circulating monocytes are activated in newly diagnosed type 1 diabetes mellitus patients.
Investigations in the BB rat and the non-obese diabetic (NOD) mouse have provided substantial evidence for the involvement of the monocyte/macrophage system in the development of type 1 diabetes mellitus. However, it is not known whether monocytes play the same role in the pathogenesis of human type 1 diabetes. We investigated this problem in a longitudinal study of 29 recent-onset type 1 diabetes mellitus patients. Monocyte chemotaxis, phagocytosis and superoxide production as well as metabolic and haematological parameters were studied immediately after diagnosis and 6 months later. At diagnosis the patients had activated casein and C5a chemotaxis (casein 70 +/- 9 versus 150 +/- 5 (mean +/- s.e.m.), P < 0.001; C5a 137 +/- 10 versus 158 +/- 5, P < 0.05 (activation immobilizes monocytes, reducing the measured values)), and activated superoxide production (3.6 +/- 0.3 versus 3.0 +/- 0.3, P < 0.05). After 6 months casein chemotaxis (115 +/- 16 versus 150 +/- 5, P < 0.05) and Candida phagocytosis (3.3 +/- 0.1 versus 2.8 +/- 0.2, P < 0.001) were still activated. There was no correlation with other clinical or paraclinical parameters. We conclude that the circulating monocytes in newly diagnosed type 1 diabetes patients are activated. It is reasonable to expect that monocytes at the local site of inflammation in pancreas are even further activated. This could play a pathogenic role in beta cell destruction.
Josefsen
K
K
Bartholin Instituttet, Kommunehospitalet, Copenhagen K, Denmark.
Nielsen
H
H
Lorentzen
S
S
Damsbo
P
P
Buschard
K
K
D000328:Adult; D001772:Blood Cell Count; D002364:Caseins / Q000494:pharmacology; D002634:Chemotaxis, Leukocyte / Q000187:drug effects; D015936:Complement C5a / Q000494:pharmacology; D003922:Diabetes Mellitus, Type 1 / Q000097:blood* / Q000175:diagnosis / Q000209:etiology; D005260:Female; D006801:Humans; D008297:Male; D009000:Monocytes / Q000276:immunology* / Q000502:physiology; D016260:Monocytes, Activated Killer / Q000276:immunology* / Q000502:physiology; D010179:Pancreas / Q000473:pathology; D010587:Phagocytosis; D016897:Respiratory Burst; D013997:Time Factors
D002364:Caseins; D015936:Complement C5a