Title Page

Contents

ABSTRACT 7

Ⅰ. Introduction 9

Ⅱ. Methods 10

1. Study design and patient selection 10

2. Data collection and definition 11

3. Statistical Analysis 11

Ⅲ. Results 13

1. Patient characteristics 13

2. Clinical factors associated with fistula closure 13

3. Optimal IFX trough level cut-off required to achieve fistula closure 14

4. Clinical factors associated with fistula recurrence 14

Ⅳ. Discussion 16

Ⅴ. Conclusion 20

References 21

논문요약 33

Table 1. Baseline characteristics of the patients 24

Table 2. Clinical outcomes of the patients 25

Table 3. Comparative analysis of factors associated with fistula closure 26

Table 4. Logistic regression analysis of factors associated with fistula closure 27

Table 5. Logistic regression analysis of factors associated with fistula recurrence 28

Table 6. Previous literatures describing the association between trough level of IFX and fistula response in PFCD 29

Figure 1. Flow chart of study (Patient inclusion) 30

Figure 2. Box plot of infliximab trough levels in patients with and without fistula closure. (A) Trough levels during induction, (B) Trough levels during maintenance. 31

Figure 3. Receiver operating characteristic curve showing the association between infliximab trough level and fistula closure; (A) Trough levels during induction, (B) Trough levels during maintenance. 32