Elevated Soluble Platelet Glycoprotein VI Levels in Patients After Living Donor Liver Transplantation

Elevated plasma levels of soluble C-type lectin-like receptor 2 (CLEC2) in patients with thrombotic microangiopathy

BACKGROUND

Thrombotic microangiopathy (TMA) is caused by activated platelets. The plasma C-type lectin-like receptor 2 (CLEC2) levels in 58 patients with TMA were examined and compared with those in healthy volunteers and other diseases.

MATERIALS AND METHODS

The plasma levels of soluble platelet surface glycoprotein VI (GPVI) and CLEC2 were measured in patients with TMA.

RESULTS

Plasma CLEC2 levels in patients with DIC and TMA were significantly higher (p < 0.001) than those in thrombocytopenic patients with other hematological diseases, but no significant differences in the plasma CLEC2 levels were observed among patients with thrombotic thrombocytopenic purpura, hemolytic uremic syndrome (HUS), atypical HUS and other TMA. The plasma CLEC2 levels after the remission were significantly lower than those before treatment (p < 0.001). The plasma CLEC2 levels were poorly correlated with the levels of soluble GPVI in the plasma of patients with TMA. The plasma CLEC2 levels were not significantly differ between survivor and non-survivor in TMA patients, but were significantly higher in non-survivor in overall population (p < 0.001).

CONCLUSION

The measurement of the plasma CLEC2 level is considered to be important for the diagnosis and evaluation of TMA.

Platelet Activation Assessed by Glycoprotein VI/Platelet Ratio Is Associated With Portal Vein Thrombosis After Hepatectomy and Splenectomy in Patients With Liver Cirrhosis

Portal vein thrombosis (PVT) is a serious complication after hepatobiliary-pancreatic surgery. Portal vein thrombosis often develops in patients with liver cirrhosis (LC) postoperatively, although they have low platelet counts. Platelet activation is one of the causes of thrombosis formation, and soluble form of glycoprotein VI (sGPVI) has received attention as a platelet activation marker. We had prospectively enrolled the 81 consecutive patients who underwent splenectomy (Sx) and/or hepatectomy: these patients were divided as Sx (n = 38) and hepatectomy (Hx, n = 46) groups. The 3 patients who underwent both procedures were added to both groups. Each group was subdivided into patients with non-LC and LC: non-LC-Sx (n = 22) and LC-Sx (n = 16), non-LC-Hx (n = 40) and LC-Hx (n = 6). The presence of PVT was diagnosed by using enhanced computed tomography (CT) scan. Platelet counts were significantly lower in LC-Sx than in non-LC-Sx, and incidence of PVT was significantly higher in LC-Sx than in non-LC-Sx (68.8% vs 31.8%, P = .024). Soluble form of glycoprotein VI /platelet ratios on preoperative day and postoperative day 1 were significantly higher in LC-Sx than in non-LC-Sx. Incidence of PVT was significantly higher in LC-Hx than in non-LC-Hx (50.0% vs 7.5%, P < .01). Soluble form of glycoprotein VI /platelet ratios were significantly higher in LC-Hx before and after Hx, compared to non-LC-Hx. Patients with LC stay in hypercoagulable state together with platelet activation before and after surgery. Under this circumstance, alteration of portal venous blood flow after Sx or Hx is likely to cause PVT in patients with LC.