Diabetes, Vol 46, Issue 6 1047-1053, Copyright © 1997 by American Diabetes Association
Modulatory effect of erythrocytes on the platelet reactivity to collagen in IDDM patients
J Valles, MT Santos, J Aznar, M Velert, G Barbera and R Carmena
Research Center and Department of Clinical Pathology, University Hospital La Fe, Valencia, Spain.
Platelets participate in the atherothrombotic complications of diabetes.
Recent data demonstrate that platelet reactivity can be modulated via
cell-cell interactions with erythrocytes and neutrophils. In this study,
platelet reactivity was evaluated in 30 IDDM patients. We used an
analytical procedure that permits an independent evaluation of platelet
activation (granule release, eicosanoid formation) and platelet recruitment
(pro-aggregatory activity of cell-free releasates) after platelet
stimulation with collagen in the presence or absence of other blood cells.
The interaction between platelets and erythrocytes (hematocrit 40%)
resulted in a marked enhancement of platelet activation (5HT, betaTG, TXA2
release) and recruitment in both patients and control subjects. The
erythrocyte enhancement of platelet TXA2 synthesis and recruitment was
significantly higher in the patients, while no differences were detected in
platelet granule release. The elevated platelet recruitment in the IDDM
patients was found to be due to 1) increased susceptibility of diabetic
platelets to the prothrombotic effect of erythrocytes and 2) the greater
response of diabetic platelets to their own cell-free releasate. Patients
with poor metabolic control (elevated HbA1c) or longer evolution time had
an even greater platelet recruitment. The presence of microalbuminuria is
not related to the platelet recruitment. Since platelet recruitment is an
essential step in thrombus growth, its enhancement may favor thrombotic
complications in IDDM.