, Yeong Chan Lee2,*
, Minjee Kim1
, Eun Ran Kim1
, Dong Kyung Chang1
, Young-Ho Kim1
, Sung Noh Hong1
1Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
2Department of Physiology, Ajou University School of Medicine, Suwon, Korea
© 2026 Korean Association for the Study of Intestinal Diseases.
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Funding Source
The authors received no financial support for the research, authorship, and/or publication of this article.
Conflict of Interest
Kim JE is an editorial board member of the journal but was not involved in the peer reviewer selection, evaluation, or decision process of this article. No other potential conflicts of interest relevant to this article were reported.
Data Availability Statement
The data underlying this article cannot be shared publicly, given the privacy expectations of the individuals who participated in the study. The data will be shared upon reasonable request to the corresponding author.
Author Contributions
Conceptualization: Kim JE, Hong SN. Data curation: Kim JE, Lee YC. Data interpretation: Kim JE. Formal analysis: Kim JE. Investigation: Hong SN. Methodology: Lee YC. Project administration: Hong SN. Resources: Kim JE. Software: Kim JE. Supervision: Hong SN. Validation: Kim M, Kim ER, Chang DK, Kim YH. Visualization: Lee YC. Writing–original draft: Kim JE. Writing–review & editing: Hong SN, Lee YC, Kim M, Kim ER, Kim YH, Chang DK. Approval of final manuscript: all authors.
| Characteristics | Total (n = 40) |
|---|---|
| Age (yr) | 33.5 (26.8–44.3) |
| Male sex | 32 (80.0) |
| Age at diagnosis (yr) | 22.5 (16.8–31.8) |
| Diagnosis | |
| CD | 28 (70.0) |
| UC | 12 (30.0) |
| Location (CD only) | |
| Terminal ileum (L1) | 3 (10.7) |
| Colon (L2) | 2 (7.1) |
| Ileocolon (L3) | 20 (71.4) |
| Ileocolon and upper GI (L3+L4) | 3 (10.7) |
| Behavior (CD only) | |
| Non-stricture, non-penetrating (B1) | 6 (21.4) |
| B1+p | 8 (28.6) |
| Stricture (B2) | 7 (25.0) |
| B2+p | 4 (14.3) |
| Penetrating (B3) | 1 (3.6) |
| B3+p | 2 (7.1) |
| Disease extent (UC only) | |
| E2 (left sided) | 5 (41.7) |
| E3 (extensive) | 7 (58.3) |
| Bio-experienced | |
| Naive | 2 (5.0) |
| Experienced | 38 (95.0) |
| Multi-biologic failure | |
| None | 2 (5.0) |
| 1 | 7 (17.5) |
| ≥ 2 | 31 (77.5) |
| MOA | 6.0 (3.0–7.0) |
| Anti-TNF | 6 (15.0) |
| VDZ | 0 |
| UST | 3 (7.5) |
| Small cell | 0 |
| Anti-TNF+VDZ | 4 (10.0) |
| Anti-TNF+UST | 14 (35.0) |
| Anti-TNF+VDZ+UST | 8 (20.0) |
| Anti-TNF+VDZ+UST+small cella | 1 (2.5) |
| Anti-TNF+UST+small cellb | 1 (2.5) |
| VDZ+UST+small cellc | 1 (2.5) |
| Baseline score (CD only) | |
| Loose stool (numbers/wk) | 12.0 (2.0–54.3) |
| Abdominal pain score | 2.0 (2.0–3.0) |
| PRO2¹ | 14.0 (3.8–57.3) |
| Baseline score (UC only) | |
| Stool frequency | 2.0 (2.0–3.0) |
| Rectal bleeding | 2.0 (1.8–3.0) |
| PRO2² | 5.0 (3.8–5.0) |
| Baseline CRP (mg/dL) | 0.82 (0.28–1.83) |
| Baseline fecal calprotectin (μg/g) (n = 29) | 395.0 (121.4–636.7) |
| Previous surgery | 12 (30.0) |
| CD | 11 |
| UC | 1 |
| Disease duration (yr) | 10.0 (4.75–14.0) |
Values are presented median (interquartile range) or number (%).
Small molecule agents:
a filgotinib (clinical trial),
b CCR9 antagonist+ozanimod (clinical trial),
c tofacitinib (clinical trial).
CD, Crohn’s disease; UC, ulcerative colitis; GI, gastrointestinal; B1, nonstricturing, non-penetrating; B2, stricturing; B3, penetrating; p, perianal modifier (perianal fistula); E2, left-sided colitis; E3, extensive colitis; MOA, mechanism of action; anti-TNF, tumor necrosis factor inhibitor; VDZ, vedolizumab; UST, ustekinumab; CRP, C-reactive protein; PRO21, composite of diarrhea episodes/week and abdominal pain episodes/week in CD; PRO22, composite of stool frequency and rectal bleeding in UC.
Diarrhea and abdominal pain reported as episodes/week. Stool frequency: 0, 0–2/day; 1, 1–2 more than normal; 2, 3–4 more than normal; 3, ≥5 more than normal. Rectal bleeding: 0, none; 1, streaks of blood; 2, obvious blood; 3, mostly blood.
| No. (%) | |
|---|---|
| Clinical remission | |
| CD (n = 17, PRO2¹) | 14 (82.4) |
| UC (n = 11, PRO2²) | 9 (81.8) |
| Clinical response | |
| CD (n = 17, PRO2¹) | 15 (88.2) |
| UC (n = 11, PRO2²) | 10 (90.9) |
Clinical remission: CD defined as ≤3 stools/day and abdominal pain score ≤1 (4 patients met criteria at baseline); UC defined as loose stool frequency ≤1 and rectal bleeding score=0. Clinical response: CD defined as a reduction in PRO2 components (stool frequency+abdominal pain) from baseline; UC defined as ≥50% reduction in PRO2 from baseline.
CD, Crohn’s disease; UC, ulcerative colitis; PRO2, composite index (PRO21 for CD: diarrhea+abdominal pain; PRO22 for UC: stool frequency+rectal bleeding).
| Total | No. (%) |
|---|---|
| None | 16 |
| Herpes zoster | 3 |
| Dermatitisa | 3 |
| Acne | 12 |
| Hyperlipidemia | 3 |
| Anemiab | 8 |
| Influenza | 1 |
| Characteristics | Total (n = 40) |
|---|---|
| Age (yr) | 33.5 (26.8–44.3) |
| Male sex | 32 (80.0) |
| Age at diagnosis (yr) | 22.5 (16.8–31.8) |
| Diagnosis | |
| CD | 28 (70.0) |
| UC | 12 (30.0) |
| Location (CD only) | |
| Terminal ileum (L1) | 3 (10.7) |
| Colon (L2) | 2 (7.1) |
| Ileocolon (L3) | 20 (71.4) |
| Ileocolon and upper GI (L3+L4) | 3 (10.7) |
| Behavior (CD only) | |
| Non-stricture, non-penetrating (B1) | 6 (21.4) |
| B1+p | 8 (28.6) |
| Stricture (B2) | 7 (25.0) |
| B2+p | 4 (14.3) |
| Penetrating (B3) | 1 (3.6) |
| B3+p | 2 (7.1) |
| Disease extent (UC only) | |
| E2 (left sided) | 5 (41.7) |
| E3 (extensive) | 7 (58.3) |
| Bio-experienced | |
| Naive | 2 (5.0) |
| Experienced | 38 (95.0) |
| Multi-biologic failure | |
| None | 2 (5.0) |
| 1 | 7 (17.5) |
| ≥ 2 | 31 (77.5) |
| MOA | 6.0 (3.0–7.0) |
| Anti-TNF | 6 (15.0) |
| VDZ | 0 |
| UST | 3 (7.5) |
| Small cell | 0 |
| Anti-TNF+VDZ | 4 (10.0) |
| Anti-TNF+UST | 14 (35.0) |
| Anti-TNF+VDZ+UST | 8 (20.0) |
| Anti-TNF+VDZ+UST+small cell |
1 (2.5) |
| Anti-TNF+UST+small cell |
1 (2.5) |
| VDZ+UST+small cell |
1 (2.5) |
| Baseline score (CD only) | |
| Loose stool (numbers/wk) | 12.0 (2.0–54.3) |
| Abdominal pain score | 2.0 (2.0–3.0) |
| PRO2¹ | 14.0 (3.8–57.3) |
| Baseline score (UC only) | |
| Stool frequency | 2.0 (2.0–3.0) |
| Rectal bleeding | 2.0 (1.8–3.0) |
| PRO2² | 5.0 (3.8–5.0) |
| Baseline CRP (mg/dL) | 0.82 (0.28–1.83) |
| Baseline fecal calprotectin (μg/g) (n = 29) | 395.0 (121.4–636.7) |
| Previous surgery | 12 (30.0) |
| CD | 11 |
| UC | 1 |
| Disease duration (yr) | 10.0 (4.75–14.0) |
| No. (%) | |
|---|---|
| Clinical remission | |
| CD (n = 17, PRO2¹) | 14 (82.4) |
| UC (n = 11, PRO2²) | 9 (81.8) |
| Clinical response | |
| CD (n = 17, PRO2¹) | 15 (88.2) |
| UC (n = 11, PRO2²) | 10 (90.9) |
| Variable | Non-remission | Remission | P-value |
|---|---|---|---|
| No. | 5 | 23 | |
| Sex | 1.00 | ||
| Male | 4 (80.0) | 17 (73.9) | |
| Female | 1 (20.0) | 6 (26.1) | |
| Age (yr) | 30.0 (29.0–33.0) | 38.0 (27.5–46.5) | 0.70 |
| Age at diagnosis (yr) | 18.0 (15.0–24.0) | 27.0 (17.0–35.0) | 0.07 |
| Smoking | 0.91 | ||
| Missing | 0 | 3 (13.0) | |
| Non-smoker | 3 (60.0) | 14 (70.0) | |
| Ex-smoker | 1 (20.0) | 3 (13.0) | |
| Current-smoker | 1 (20.0) | 3 (13.0) | |
| Multi-biologic failure | 0.52 | ||
| None | 0 | 2 (8.7) | |
| 1 | 0 | 3 (13.0) | |
| ≥ 2 | 5 (100.0) | 18 (78.3) | |
| MOA | 7.0 (5.0–7.0) | 6.0 (4.0–6.0) | 0.50 |
| CRP baseline (mg/dL) | 0.8 (0.1–0.8) | 0.6 (0.3–1.8) | 0.52 |
| Previous surgery | 4 (80.0) | 6 (26.1) | 0.08 |
| Total | No. (%) |
|---|---|
| None | 16 |
| Herpes zoster | 3 |
| Dermatitis |
3 |
| Acne | 12 |
| Hyperlipidemia | 3 |
| Anemia |
8 |
| Influenza | 1 |
Values are presented median (interquartile range) or number (%). Small molecule agents: filgotinib (clinical trial), CCR9 antagonist+ozanimod (clinical trial), tofacitinib (clinical trial). CD, Crohn’s disease; UC, ulcerative colitis; GI, gastrointestinal; B1, nonstricturing, non-penetrating; B2, stricturing; B3, penetrating; p, perianal modifier (perianal fistula); E2, left-sided colitis; E3, extensive colitis; MOA, mechanism of action; anti-TNF, tumor necrosis factor inhibitor; VDZ, vedolizumab; UST, ustekinumab; CRP, C-reactive protein; PRO21, composite of diarrhea episodes/week and abdominal pain episodes/week in CD; PRO22, composite of stool frequency and rectal bleeding in UC. Diarrhea and abdominal pain reported as episodes/week. Stool frequency: 0, 0–2/day; 1, 1–2 more than normal; 2, 3–4 more than normal; 3, ≥5 more than normal. Rectal bleeding: 0, none; 1, streaks of blood; 2, obvious blood; 3, mostly blood.
Clinical remission: CD defined as ≤3 stools/day and abdominal pain score ≤1 (4 patients met criteria at baseline); UC defined as loose stool frequency ≤1 and rectal bleeding score=0. Clinical response: CD defined as a reduction in PRO2 components (stool frequency+abdominal pain) from baseline; UC defined as ≥50% reduction in PRO2 from baseline. CD, Crohn’s disease; UC, ulcerative colitis; PRO2, composite index (PRO21 for CD: diarrhea+abdominal pain; PRO22 for UC: stool frequency+rectal bleeding).
Values are presented as number (%) or median (interquartile range). MOA, mechanism of action; CRP, C-reactive protein.
Dermatitis: erythema and pruritus requiring dermatologic consultation. Anemia: requiring iron supplementation or transfusion of red blood cells.
