Table 1.
Descriptive statistics for cases and controls used in the current study.
Figure 1.
Plasma IL-6 levels are significantly elevated in individuals with Opisthorchis-induced APF and Opisthorchis-induced CCA.
The distribution of plasma concentration of Interleukin (IL)-6) in picograms per milliliter is shown in boxplots by study group. The bottom and top of each box represent the 25th and 75th percentile (the lower and upper quartiles, respectively) of IL-6 concentration in plasma per group. The band near the middle of each box represents the median value of IL-6 concentration per group. The whiskers represent the minimum (bottom) and maximum (top) of IL-6 concentration per group.
Table 2.
Odds Ratios for plasma IL-6 levels for O. viverrini infected individuals with and without Advanced Periductal Fibrosis.
Table 3.
Odds Ratios for plasma IL-6 levels for O. viverrini infected individuals with1 and without Cholangiocarcinoma (CCA)2.
Figure 2.
Plasma IL-6 concentrations can be used to detect individuals with Opisthorchis-induced advanced periductal fibrosis.
A receiver-operating-characteristic (ROC) curve plots the True Positive Probability (sensitivity) against the False Negative Probability (1– specificity) for the full range of IL-6 cut-off points for the detection of Opisthorchis-induced Advanced Periductal Fibrosis (APF) as determined by ultrasound. The area under the ROC curve is interpreted as the probability of correctly identifying (accuracy) a randomly selected participant as either a case (APF positive) or a non-case (APF negative). The 45-degree line in the graph subsumes an area equal to 0.50 (50%), which is equivalent to using a coin toss procedure to classify participants as either cases or controls. As determined by this ROC curve, the optimal cutpoint is 11 pg/mL of plasma IL-6, which refers to the concentration that maximizes the “sensitivity” and the “specificity” of classifying an individual at APF positive. Based on this cutoff point, the Positive Predictive Value (PPV) and the Negative Predictive Value (NPV) of plasma IL-6 concentration to detect APF was also determined (see Table 4). All analyses were performed using Stata version 10 (College Station, TX). The ROC was derived from 210 O. viverrini infected individuals with Advanced Periductal Fibrosis as determined by ultrasound (gold standard) versus 210 age, sex, and nearest neighbor-matched controls (O. viverrini infected but negative for APF.)
Table 4.
The diagnostic utility of plasma Interleukin (IL)-6 levels for Opisthorchis-induced pathologies.
Figure 3.
Plasma IL-6 concentrations can be used to detect O. viverrini infected individuals with cholangiocarcinoma (CCA).
A receiver-operating-characteristic (ROC) curve plots the True Positive Probability (sensitivity) against the False Negative Probability (1– specificity) for the full range of IL-6 cut-off points for the determination of Opisthorchis-induced cholangiocarcinoma (CCA). The area under the ROC curve is interpreted as the probability of correctly identifying (accuracy) a randomly selected participant as either a case (APF positive) or a non-case (APF negative). The 45-degree line in the graph subsumes an area equal to 0.50 (50%), which is equivalent to using a coin toss procedure to classify participants as either cases or controls. As determined by this ROC curve, the optimal cutpoint is 11 pg/mL of plasma IL-6, which refers to the concentration that maximizes the “sensitivity” and the “specificity” of classifying an individual at APF positive. Based on this cutoff point, the Positive Predictive Value (PPV) and the Negative Predictive Value (NPV) of plasma IL-6 concentration to detect APF was also determined (see Table 4). All analyses were performed using Stata version 10 (College Station, TX). The ROC was derived from 121 cases of histologically proven, O. viverrini associated CCA cases from the biological repository of the Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Thailand and 210 individuals who are O. viverrini infected but negative for APF and CCA.