Cytokine and autoantibody patterns in acute liver failure

Abstract

The mechanisms of idiosyncratic drug-induced liver injury (IDILI) are still a matter of dispute. Some of the characteristics of reactions that have been classed as metabolic idiosyncrasy could also be those of an immune-mediated reaction with an autoimmune component. Many auto-immune reactions appear to be mediated by T(H)17 cells, which are in part characterized by the production of interleukin (IL)-17. To test the involvement of T(H)17 cells in IDILI, we quantified a number of cytokines, chemokines, and autoantibodies in the serum of 39 patients with acute liver failure (ALF) due to IDILI and compared the values with those from 21 patients with acetaminophen-induced ALF and 10 patients with viral hepatitis-induced ALF. The IL-17 levels were elevated in 60% of patients with IDILI, but also in a similar number of patients with acetaminophen-induced ALF and occasionally in patients with viral hepatitis. Levels of other cytokines, such as IL-21, that are also produced by T(H)17 cells were higher in patients with IDILI, but again, there was overlap with acetaminophen DILI. Autoantibodies were more frequent in patients in the IDILI group but were absent in most patients. These data provide a picture of the cytokine/chemokine profile in patients with various types of ALF. The pattern varies from patient to patient and not specifically by etiology. This suggests that different underlying disease mechanisms may be at play in different individuals, even among those demonstrating injury from the same drug. Since cytokines may originate from more than one type of cell, interpretation of results of cytokine assays remains difficult in complex disease settings.

Figures

Figure 1. Biochemical parameters of liver failure patients

(A) Time from onset to hospitalization and serum levels of (B) AST and ALT, (C) bilirubin, and (D) alkaline phosphatase were compared between patients with acute liver failure of different etiologies. Statistical significance between IDILI patients (n = 39) and other patient groups (APAP, n = 21; Hepatitis A and B, n = 5 each) was determined by the t-test with Welch’s correction; levels of significance are indicated in the figure.

Figure 2. TH17-related cytokine/chemokine comparisons between patient groups

Serum concentrations of TH17-related cytokines/chemokines (e.g., IL-17, IL-21, IL-6, and IL-1α) were measured by Luminex using a human multiplex kit. The statistical significance of any differences between the APAP (n = 21) and IDILI (n = 39) patients’ values were determined by the t-test with Welch’s correction; levels of significance are indicated in the figure. Data from patients in the Hepatitis A, B, and C virus groups are shown for comparison (n = 5, 5, and 10, respectively).

Figure 3. Innate cytokine/chemokine comparisons between patient groups

Serum concentrations of innate cytokines/chemokines (e.g., MCP-1, IL-15, IP-10, and IFNγ) were measured by Luminex using a human multiplex kit. The statistical significance of any differences between the APAP (n = 21) and IDILI (n = 39) patients’ values were determined by the t-test with Welch’s correction; levels of significance are indicated in the figure. Data from patients in the Hepatitis A, B, and C virus groups are shown for comparison (n = 5, 5, and 10, respectively).

Figure 4. Serum levels of BAFF

Serum concentrations of BAFF were measured by ELISA. The statistical significance of any difference between the APAP (n = 21) and IDILI (n = 39) patients’ values was determined by the t-test with Welch’s correction by the t-test with Welch’s correction; level of significance is indicated in the figure.

Figure 5. Serum levels of ANA

Serum levels of ANA were measured using an ELISA kit that detects 9 different anti-nuclear antibodies. Serum samples were diluted in 1:100 and the manufacturer indicates that values greater than 10 should be considered positive. The statistical significance of any difference between the APAP (n = 21) and IDILI (n = 39) patients’ values was determined by the t-test with Welch’s correction; level of significance is indicated in the figure. Data from patients in the Hepatitis A, B, and C virus groups are shown for comparison (n = 5, 5, and 10, respectively).

Figure 6. Serum levels of anti-MPO antibodies

Serum anti-MPO levels were determined (semi-quantitation) by an ELISA kit. Serum samples were diluted in 1:100. The statistical significance of any difference between the APAP (n = 21) and IDILI (n = 39) patients’ values was determined by the t-test with Welch’s correction; level of significance is indicated in the figure. Data from patients in the Hepatitis A, B, and C virus groups are shown for comparison (n = 5, 5, and 10, respectively).