[THE EFFECT OF INFECTIOUS AND AUTOIMMUNE DISEASES ON PROCOAGULANT ACTIVITY OF FIBRINOGEN-LIKE PROTEIN 2 IN THE PERIPHERAL BLOOD].

Aims: In this article we address the effect of bacterial or viral infections as well as autoimmune diseases on FGL2 activity in the blood.

Background: Fibrinogen-like protein 2 (FGL2) is a novel prothrombinase capable of initiating thrombin generation independent of the classical coagulation pathway. FGL2 is involved in immune-coagulation response. Considering the tight relationship between coagulation and cancer, FGL2 had been suggested to be utilized as a potential biomarker for cancer. Recently, we have shown that FGL2 activity is increased in blood of B-cell lymphoma patients and decreased during remission. However, it is unclear whether FGL2 activity is simultaneously affected by the presence of conditions other than cancer.

Methods: FGL2 procoagulant activity levels were examined in peripheral blood cell samples of 93 patients with clinical diagnosis of various bacterial or viral infections or autoimmune diseases, and 39 healthy controls. Activity was determined according to clotting time measurements. Clinical and demographic data was collected.

Results: FGL2 activity in peripheral blood samples of healthy individuals and patients was rather similar. Moreover, no significant correlation was detected between measured FGL2 activity and clinical or demographic data of the patients. The range of activities was rather broad, indicating high variance (up to 2.5-fold from average) in the basal activity levels in the population.

Conclusions: The presence of infectious/autoimmune diseases does not significantly alter FGL2 activity in the peripheral blood.

Discussion: While FGL2 activity in the blood is affected by malignancies such as lymphomas, the presence of inflammatory/infectious diseases does not significantly influence basal FGL2 activity. The broad range of FGL2 activities in tested samples indicates that FGL2 is a better marker for follow up implications than diagnostic screening.