Patients’ demographic and clinical characteristics
A total of 458 DILI patients at Tianjin Second People’s Hospital were enrolled during the study period. The CONSORT diagram is shown in Table 1. The majority of the DILI patients had the hepatocellular type, accunting for 290 (63.32%) patients, 71 patients had the cholestatic type (15.5%), and 97 patients had the mixed type (21.18%). More female patients than male patients were affected by all three types of DILI injuries, 188 (64.83%) had the hepatocellular type, 52 (73.24%) had the cholestatic type, and 68 (70.10%) had the mixed type. The patient ages (mean ± SD) for the three types were 47.47±13.87, 51.82±12.77 and 50.71±12.03, respectively. The median (range) values of ALT, AST, GGT, ALP, TB, DB, Glu, TG and CHO are shown in Table 2. Except for Glu and TG, other biochemical data were statistically significant (P<0.05) among the different DILI types, using the Kruskal-Wallis H test, followed by a step-down pairwise comparison test. The results are shown in Figure 1.
Causative drugs involved in DILI patients
In this study, Chinese herbal medicines were the most commonly used drugs in 240 (52.41%) patients. Multiple herbal medicine use was the most common cause in 158 (34.50%) patients, and the top three medicines used individually were Polygonum multiflorum [46 (10.04%)], Alismae rhizome [7 (1.53%)] and Radix bupleuri [5 (1.09%)]. The second highest major category was chemotherapeutics used in 40 (8.73%) patients, followed by non-steroidal anti-inflammatory drugs (NSAIDs) used in 37 (8.08%) patients, antibiotics used in 29 (6.38%) patients and healthcare products used in 25 (5.46%) patients. Detailed results are shown in Table 3.
The diagnostic value of three clinical criteria
Among all 458 DILI patients, 340 were ultimately diagnosed with definite DILI, 118 were suspected DILI. For the three diagnosis scales of DILI, the scores (mean ± SD) of RUCAM, M&V and DDW-J were 8.04±1.66, 11.59±2.63 and 8.24±1.2, respectively. RUCAM confirmed DILI diagnosis with an AUROC of 0.730 (95% CI: 0.667–0.793), Z = 7.147, P<0.001, the optimal cut-off was 8, and the Youden Index were 0.3558 for “>8”, 0.3446 for “≥8”. M&V confirmed DILI diagnosis with an AUROC of 0.793 (95% CI: 0.740–0.847), Z = 10.753, P<0.001, the optimal cut-off was 11, and the Youden Index were 0.4084 for “>11”, 0.3907 for “≥11”. DDW-J confirmed DILI diagnosis with an AUROC of 0.764 (95% CI: 0.702–0.826), Z = 8.303, P<0.001, the optimal cut-off was 8, and the Youden Index were 0.3558 for “>8”, 0.4185 for “≥8”. The ROC curves are shown in Figure 2. The AUROCs, sensitivities, specificities, PPVs, NPVs and LR+, LR− values are shown in Table 4.
A sub-analysis of ROC and AUROC was performed according to the clinical injury type. In the hepatocellular type, the AUROCs of RUCAM, M&V and DDW-J were 0.688 (95% CI: 0.617–0.753), Z = 4.207, P<0.001, 0.741 (95% CI: 0.673–0.802), Z = 6.297, P<0.001 and 0.759 (95% CI: 0.692–0.818), Z = 6.552, P<0.001, respectively, In the cholestatic type, the AUROCs of RUCAM, M&V and DDW-J were 0.701 (95% CI: 0.534 –0.837), Z = 2.030, P = 0.042, 0.807 (95% CI: 0.649 –0.915), Z = 4.283, P<0.001 and 0.656 (95%CI: 0.487–0.800), Z = 1.606, P = 0.108 respectively. In the mixed type, the AUROCs of RUCAM, M&V and DDW-J were 0.765 (95% CI: 0.637 –0.865), Z = 4.173, P<0.001, 0.886 (95% CI: 0.777 –0.953), Z = 8.528, P<0.001 and 0.794 (95% CI: 0.670–0.888), Z = 4.444, P<0.001, respectively.
Histological findings and its diagnostic value combined with clinical criteria
We used immunohistochemistry HBsAg(-), HBcAg(-), preSI(-) to histologically confirming patients without hepatitis B virus infection and occult infection, CD68(+) were used to explain the pigmented macrophages. Among 458 DILI patients, 149 refused and 7 because of physical condition couldn’t perform liver biopsy. Finally, 302 DILI patients’ liver biopsies were included(Figure 1), 248 were diagnosed as definite DILI and 54 were suspected DILI. Although there were numerous histological manifestations in DILI(9, 20–22), we used rDILI-PSS to evaluate: steatosis in 204 cases (67.5%), 2 = 4.487, P = 0.106; cholestasis in 151 cases (50%), 2 = 3.886, P = 0.143; cell apoptosis in 139 cases (46%), 2 = 0.840, P = 0.657; eosinophil granulocyte infiltration in 131 cases (43.4%), 2 = 0.30, P = 0.985; central and/or portal phlebitis in 103 cases (34.1%), 2 = 25.948, P<0.001; iron deposition in 90 cases (29.8%), 2 = 5.737, P = 0.057; and pigmented macrophages in 92 cases (30.5%). 2 = 6.616, P = 0.037. Table 5 shows the results of the characteristics of histological findings according to injury type. The mean ± SD of the refined DILI-PSS score was 3.26±1.34. The new parameters: (pre1, pre2 and pre3) were DILI-PSS combined with RUCAM, M&V and DDW-J, respectively. The logistic regression formulas were expressed as pre1 = PSS+0.374*RUCAM, pre2 = PSS+0.338* M&V, and pre3 = PSS+0.578* DDW-J. The AUROCs of pre1, pre2 and pre3 were 0.843 (95% CI: 0.747–0.914), Z = 7.653, P<0.001, with a sensitivity of 77.94%, specificity of 85.71%; 0.907 (95% CI: 0.822–0.960), Z = 10.467, P<0.001, with a sensitivity of 77.94%, specificity of 92.86%; and 0.881 (95% CI: 0.790–0.942), Z = 9.352, P<0.001, with a sensitivity of 77.94%, specificity of 85.71%, respectively. The ROC curves are shown in Figure 2. and the diagnostic performance of pre1, pre2 and pre 3 are also shown in Table 4.
In the hepatocellular type, the AUROCs of pre1, pre2 and pre3 were 0.894 (95% CI: 0.787–0.959), Z = 9.086, P<0.001, 0.960 (95% CI: 0.857–0.994), Z = 19.015, P<0.001 and 0.940 (95% CI: 0.847–0.985), Z = 14.544, P<0.001, respectively; in the cholestatic type, the AUROCs were 0.750 (95% CI: 0.466 –0.931), Z = 2.000, P = 0.045, 0.500 (95% CI: 0.239 –0.761), Z = 0.000, P = 1.000,and 0.500 (95% CI: 0.239 –0.761), Z = 0.000, P = 1.000, respectively; in the mixed type, the AUROCs were 0.786 (95% CI: 0.524–0.943), Z = 2.146, P = 0.032, 0.869 (95% CI: 0.619–0.981), Z = 3.058, P = 0.002 and 0.762 (95% CI: 0.498 –0.930), Z = 2.052, P = 0.040, respectively.