Abstract

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)(

Alcohol Clin Exp Res
,
2007
,
31
:
27S
–35S
). Endotoxemia has been considered to trigger the enhancement of pro-inflammatory cytokines, which may cause systemic inflammatory response syndrome together with microcirculatory disturbance leading to MOF in severe alcoholic hepatitis (SAH). The aim of this study was to determine the plasma cytokine levels, plasma endotoxin concentration and the inhibitor against the ADAMTS13, and tried to explore potential mechanism to reduce the activity of plasma ADAMTS13 in patients with AH and SAH.

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.

Disclosures: No relevant conflicts of interest to declare.

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