Potential Role of Enhanced Cytokinemia and Endotoxemia on the Decreased Activity of Plasma ADAMTS13 in Patients with Alcoholic Hepatitis.

Background: Deficiency of ADAMTS13 results in an increase of the plasma unusually large von Willebrand factor multimer (UL-VWFM) and finally causes microcirculatory disturbance. We demonstrated that the imbalance of increased UL-VWFM over decreased ADAMTS13 activity may contribute to the development of multiorgan failure (MOF) in patients with alcoholic hepatitis (AH)(

Methods: Subjects studied were 28 patients with AH and 5 patients with SAH, who were admitted into our hospital between June 2001 and January 2006. All patients with AH survived, and 3 of 5 patients with SAH died of hepatic failure and MOF. Plasma ADAMTS13 activity and its inhibitor were determined by a sensitive chromogenic ELISA (ADAMTS13-act-ELISA: Kainos Inc.). Plasma VWF antigen (VWF:Ag), interleukin 6 (IL-6), interleukin 8 (IL-8), and tumor necrosis factor-α (TNF-α) were measured by ELISA. Plasma UL-VWFM was analyzed by SDS-0.9% agarose gel electrophoresis. Plasma endotoxin concentration was determined by a chromogenic substrate assay (Toxicolor LS-M Set, Seikagaku Kogyo Co.) with kinetic analysis after pretreatment with detergent, Triton X-100, and heating at 70 °C for 10 min.

Results: The concentrations of IL-6, IL-8, and TNF-α on admission were significantly higher in patients with SAH than in those with AH and healthy normal controls. The ADAMTS13 activity concomitantly decreased with increasing concentrations of cytokines on admission (IL-6 & IL-8; normal range (N) mean 68 % & 70 %, N ~ 100 pg/ml 37 % & 37 %, >100 pg/ml 13 % & 9%, TNFα; N 57 %, >N 22 %, respectively). In contrast, the VWF:Ag progressively elevated with increasing concentrations of these cytokines (IL-6 & IL-8; N 298 % & 309 %, N ~ 100 pg/ml 509 % & 425 %, >100 pg/ml 624 % & 880 %, TNFα; N 352 %, >N 609 %, respectively). Plasma endotoxin concentration was markedly higher in patients with SAH (means 52.3 pg/ml) and AH (21.7 pg/ml) than in controls (7.9 pg/ml). The endotoxin concentration inversely correlated with ADAMTS13 activity (r= − 0.474, p<0.01), and was higher in patients with UL-VWFM than those without (47.6 pg/ml vs. 18.5 pg/ml, p<0.001). The inhibitor was detected in 4 patients with SAH (0.9 ~ 2.1 BU/ml) and 6 patients with AH (0.5 ~ 1.6 BU/ml). Patients with the inhibitor showed lower serum albumin level (3.3 g/dl vs. 4.2 g/dl, p<0.05) and higher levels of serum total bilirubin (11.1 mg/dl vs. 2.5 mg/dl, p<0.01), polymorphonuclear neutrophil count (8762/mm³ vs. 4093/mm³, p<0.001), CRP (4.6 mg/dl vs. 1.1 mg/dl, p<0.05) and plasma endotoxin concentration (39.4 pg/ml vs. 17.3 pg/ml, p<0.01) than those without. At the recovery stage, the ADAMTS13 activity increased to normal range, the VWF:Ag decreased, and the UL-VWFM disappeared with the decrease in the concentrations of cytokines and endotoxin, and the disappearance of the inhibitor.

Conclusion: Decreased ADAMTS13 activity and increased VWF:Ag could be induced not only by enhanced cytokinemia including IL-6, IL-8, and TNFα, but also by the inhibitor against ADAMTS13:AC. Both cytokinemia and the inhibitor are closely related to enhanced endotoxemia, which may cause the imbalance of the enzyme to substrate leading to MOF especially in patients with SAH.