Von willebrand factor levels in patients with diabetic retinopathy.

Plasma levels of von Willebrand factor (vWF), an indicator for endothelial injury, were measured in type II diabetic patients with or without retinopathy and 20 normal control subjects. Patients were grouped according to their degree of retinopathy, 12 patients with no evidence of retinopathy, 19 patients with background retinopathy and 23 patients with proliferative retinopathy. All groups of diabetic patients had significantly higher vWF levels when compared to normal controls. But the levels of vWF did not correlate with the severity of retinopathy. The data suggested that diabetic patients had some degree of endothelial injury that might not relate to the development of retinopathy.

Fibrinolytic activity in patients with diabetic retinopathy.

Tissue plasminogen activator (t-PA), plasminogen activator inhibitor (PAI-1) and plasminogen concentrations were measured in 62 patients with non-insulin dependent (type II) diabetes mellitus. Patients were grouped according to their degree of retinopathy; 13 patients with no evidence of retionpathy (BDR) and 26 patients with proliferative retinopathy (PDR). Twenty healthy individuals served as normal controls. PAI-1 levels of all diabetic groups were found to be lower than control group. But the difference was statistically significant only between PDR and controls. Plasminogen levels in diabetic groups were higher than in the control group, especially in the PDR group. There was no difference in t-PA levels between diabetics and the control group. It is concludedthat PAI is closely related with the development of retinopathy in diabetic patients.

Prothrombin fragment 1+2 and fibrinogen in Thai type 2 diabetic patients.

Since the evidence for the hypercoagulable state in terms of prothrombin fragment 1+2 (F1+2) in Thai diabetic patients has never been reported, we studied plasma F1+2 levels in 68 type 2 diabetic patients and in 20 normal age-matched volunteers. Fibrinogen, D- dimer, glucose, HbA1C, cholesteroi, triglyceride, HDL-cholesterol and creatinine were also determined. It was found that the levels of F1+2 and fibrinogen in the diabetic patients were significantly higher than in the controls (p<0.001 and p<0.01 respectively), while D-dimer was detected positively in 17 out of 64 patients whereas none could be detected in the 20 healthy volunteers. A total of 23 out of 68 patients had higher levels of F1+2 than the normal range. When we compared the clinical characteristics, blood chemistry analysis and hypercoagulable markers of the diabetic patients between the groups of high F1+2 and normal F1+2, there were significantly higher numbers of positive D-dimer cases in the high F1+2 group compared with the normal F1+2 group (p=1.01). The correlation between F1+2 vs diabetic duration was 0.29 with p value less than 0.05. This study suggests that there are hypercogulable states in Thai diabetic patients.

Effect of endothelial cells from babies born to pre-eclamptic mothers on tissue factor activity of normal endothelial cells.

A technique to measure the tissue factor activity of endothelial cells was developed and the tissue factor activity of the endothelial cells was studied after stimulation with cultured media from the endothelial cells of babies born to severe per-eclampsia patients and from normal pregnancies. The results show no statistical differences. Media from the endothelial cells of the babies of pre-eclampsia patients induced the tissue factor activity to a mean level of 0.08 mU/ml, whereas that from the normal pregnancies stimulated the tissue factor synthesis to a mean level of 0.14 mU/ml. It may be concluded that there are no injurious substances released from the endothelial cells of babies that cause increased tissue factor synthesis from endothelial cells.

Assessment of the coagulation activation in normal pregnancy and severe pre-eclampsia using D-dimer levels.

D-dimer was measured in 20 normal non-pregnant women, 20 normal pregnant women and 20 severe pre-eclampsia patients. D-dimer was found to be 182 + 63 ng/ml (mean+ SD) in non-pregnant women, significantly higher at 1,355+ 279 ng/ml in normal pregnant women and 1,928+ 625 ng/ml in severe pre-eclampsia. No abnormalities were detected in a screening coagulogram. It is concluded that D-dimer may-be more useful than a screening coagulogram. For the early detection of the activation of the coagulation system that occurs in normal pregnancy and becomes elevated in severe pre-eclampsia.