Radiomic Imaging in Crohn’s Disease

X Li et al. Gastroenterol 2021; 160: 2303-2316. Development and Validation of a Novel Computed-Tomography Enterography Radiomic Approach for Characterization of Intestinal Fibrosis in Crohn’s Disease

Methods: This article describes the development a computed-tomography enterography (CTE)–based radiomic model (RM). This retrospective multicenter study included 167 CD patients who underwent preoperative CTE and bowel resection. 1454 radiomic features were extracted from venous-phase CTE and a machine learning–based RM was developed based on the reproducible features using logistic regression. The RM was validated in an independent external test cohort recruited from 3 centers.

Key findings:

  • In the training cohort, the area under the ROC curve (AUC) of RM for distinguishing moderate–severe from none–mild intestinal fibrosis was 0.888.
  • In the test cohort, the RM had an AUC of 0.816.
  • RM was more accurate than visual interpretations by either radiologist (radiologist 1, AUC = 0.554; radiologist 2, AUC = 0.598; both, P < .001) in the test cohort

My take: This CT approach with RM allowed for accurate characterization of intestinal fibrosis in CD. The images look pretty cool too.

SC Option for Infliximab

S Schreiber, S Ben-Horin et al. Gastroenterol 2021; 160 2340-2353. Full text: Randomized Controlled Trial: Subcutaneous vs Intravenous Infliximab CT-P13 Maintenance in Inflammatory Bowel Disease

Methods: Overall in this phase 1 randomized, open-label study in patients with either ulcerative colitis or Crohn’s disease, 66 and 65 patients were randomized to CT-P13 SC (every 2 weeks) and CT-P13 IV, respectively

Key findings: The pharmacokinetic noninferiority of CT-P13 SC to CT-P13 IV, and the comparable efficacy, safety, and immunogenicity profiles

These findings are in agreement with similar studies performed in patients with Rheumatoid Arthritis.

My take: If confirmed with additional studies, it is likely that SC infliximab treatment will be a useful alternative to intravenous infliximab. This is similar to data presented with vedolizumab which is currently administered intravenously.

Graphical Abstract

Review of Pyoderma Gangrenosum

K Vaidy et al. JPGN Reports 2020; Full text: Treatment of Pyoderma Gangrenosum in Pediatric Inflammatory Bowel Disease

This in-depth report reviews pyoderma gangrenosum including the differential diagnosis, the pathophysiology/genetics, presentation/diagnosis and treatment approaches. Anti-TNF therapy: “Currently available published data support using an anti-TNF-α biologic agent as first-line therapy for severe PG therapy in pediatric IBD, as well as for those cases that have not responded to local therapies.”

Related blog posts -PG:

What Can We Conclude from Five Patients Treated with a Combination of Infliximab and Tofacitinib?

Most often a letter to the editor would not grab my attention. A recent letter did: Full Text: Tofacitinib Is Safe and Effective When Used in Combination With Infliximab for the Management of Refractory Ulcerative Colitis (R Gilmore et al. Clin Gastroenterol Hepatol 2021; 1302-1303; reply 1303-1304 by JA Berinstein et al.)

This reported case series with 5 patients with severe ulcerative colitis (UC) who received a combination of tofacitinib and infliximab for at least 90 days were retrospectively reviewed. Tofacitinib dosing was de-escalated to 5 mg twice daily after 8 weeks. Thiopurine therapy was stopped with tofacitinib initiation.

Key findings:

  • Median duration of combination therapy was 9 months (range, 4–12 months). At 90 days, all patients had a reduction in Mayo score of ≥3. Four patients improved clinically and biochemically (Table 1), with 3 patients achieving steroid-free remission.
  • The only adverse event reported was one patient developing varicella zoster.

The authors letter title regarding tofacitinib being “safe and effective” is clearly overstated. The reply notes that in limited experience the group from the University of Michigan had a 50-year-old man develop severe pulmonary and CNS disease due to acquisition of legionnaires disease while on combination tofacitinib and infliximab.

My take: (borrowed from reply) “Efficacy and safety data obtained through rigorous randomized trials are needed…it is possible that long-term use of combination tofacitinib and infliximab will lead to an unacceptable risk of infection.”

Another study of tofacitinib: GR Lichtenstein et al. Inflamm Bowel Dis 2021; 27: 816-825. Tofacitinib, an Oral Janus Kinase Inhibitor: Analysis of Malignancy (Excluding Nonmelanoma Skin Cancer) Events Across the Ulcerative Colitis Clinical Program Key finding: With an exposure of 2576.4 patient years & 124 overall cohort tofacitinib-treated patients, 20 developed a malignancy

Related blog post:

Key West, FL

Microscopic Disease Does Not Predict Relapse in Crohn’s Disease

AB Hu et al. Clin Gastroenterol Hepatol 2021; 19: 1226-1233. Full text: Ileal or Colonic Histologic Activity Is Not Associated With Clinical Relapse in Patients With Crohn’s Disease in Endoscopic Remission

In this retrospective study with 129 patients (mean age 25 yrs, mean disease duration 14.5 yrs) whose CD was in clinical/endoscopic remission, the authors examined factors associated with clinical relapse within 2 years; this included dose escalation, change in therapy, need for systemic steroids, or CD-related hospitalization or surgery.

Key findings:

  • Within 2 y of endoscopic evaluation, 42 patients (32.6%) had a clinical relapse.
  • There were no significant differences in proportions of patients with active ileal CD (23.8%), quiescent CD (28.6%), or normal histology (37%) between those who relapsed and those remaining in remission (P = .43). In addition, there was no no association between histologic features of active disease in ileal histology biopsies and symptom scores (Harvey Bradshaw index and simple inflammatory bowel disease questionnaire scores)
  • There were no significant differences in proportions of relapses among patients with active colonic disease (38.1%), quiescent disease (35.0%), or normal histology (27.9%, P = .73). 

My take: In terms of outcomes, clinical and endoscopic remission are important but whether histologic remission is needed is unclear (at this time).

Related blog posts:

Disclaimer: This blog, gutsandgrowth, assumes no responsibility for any use or operation of any method, product, instruction, concept or idea contained in the material herein or for any injury or damage to persons or property (whether products liability, negligence or otherwise) resulting from such use or operation. These blog posts are for educational purposes only. Specific dosing of medications (along with potential adverse effects) should be confirmed by prescribing physician.  Because of rapid advances in the medical sciences, the gutsandgrowth blog cautions that independent verification should be made of diagnosis and drug dosages. The reader is solely responsible for the conduct of any suggested test or procedure.  This content is not a substitute for medical advice, diagnosis or treatment provided by a qualified healthcare provider. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a condition.

Sacroiliitis, NAFLD, IMIDs -Concurring Problems with Inflammatory Bowel Disease

I Levine et al. Inflamm Bowel Dis 2021; 809-815. Prevalence, Predictors, and Disease Activity of Sacroiliitis Among Patients with Crohn’s Disease

Key findings in this cross-sectional retrospective study (n=258, median age 30 yrs):

  • Overall, 17% of patients had MRI evidence of sacroiliitis, of whom 73% demonstrated bone marrow edema.
  • Female gender, back pain, and later age of CD diagnosis were associated with sacroiliitis (P = 0.05, P < 0.001, P = 0.04, respectively).
  • Disease activity (clinical, endoscopic, and radiographic), disease location and CD therapy were not associated with sacroiliitis on MRE.
  • More than two-thirds with MRE evidence of sacroiliitis were never seen by a rheumatologist.

A Lin et al. Inflamm Bowel Dis 2021; 947-955. Prevalence of Nonalcoholic Fatty Liver Disease in Patients With Inflammatory Bowel Disease: A Systematic Review and Meta-analysis

Key finding:

  • Data pooled from 27 studies showed the prevalence of NAFLD among IBD patients was 32% (substantial heterogeneity); this is “statistically significantly higher than the prevalence of NAFLD in the general population (25.2%; P < 0.001)”

M Attauabi et al. Inflamm Bowel Dis 2021; 927-939. Systematic Review with Meta-analysis: The Impact of Co-occurring Immune-mediated Inflammatory Diseases on the Disease Course of Inflammatory Bowel Diseases

A total of 93 studies were identified, comprising 16,064 IBD patients with co-occurring IMIDs and 3,451,414 IBD patients without IMIDs. IMIDs included the following:

  • Unspecified autoimmune disease
  • Diabetes type 1
  • Asthma
  • Grave disease
  • Spondyloarthropathy
  • Ankylosing spondylitis
  • Iridocyclitis
  • Uveitis
  • Rheumatoid arthritis
  • Polymyalgia rheumatica
  • Psoriasis/psoriatic arthritis
  • Primary Sclerosing Cholangitis
  • Celiac disease
  • Pyoderma gangrenosum
  • Pernicious anemia
  • Autoimmune hepatitis
  • Sarcoidosis
  • Giant cell arteritis
  • Primary biliary cholangitis
  • Hashimoto thyroiditis
  • Episcleritis
  • Sjogren syndrome

Key findings: Patients with IBD and co-occurring IMIDs were at increased risk of having extensive colitis or pancolitis (risk ratio, 1.38; 95% Cl, 1.25–1.52; < 0.01, I2 = 86%) and receiving IBD-related surgeries (risk ratio, 1.17; 95% Cl, 1.01–1.36; P = 0.03; I2 = 85%) compared with patients without IMIDs

Image below from Bahia Honda State Park (FL)

IBD-Like Microbiome in at-Risk Twins

Thus far, the relationship of the microbiome and inflammatory bowel disease has been a ‘chicken and the egg which came first’ conundrum. A new study (EC Brand, MAY Klaassen et al. Gastroenterol 2021; 160: 1970-1985. Full text pdf: Healthy Cotwins Share Gut Microbiome Signatures With Their Inflammatory Bowel Disease Twins and Unrelated Patients) offers some insight into this issue.

Methods: Fecal samples were obtained from 99 twins (belonging to 51 twin pairs), 495 healthy age-, sex-, and body mass index–matched controls, and 99 unrelated patients with IBD. Whole-genome metagenomic shotgun sequencing was performed.

Key findings:

  • No significant differences were observed in the relative abundance of species and pathways between healthy cotwins and their IBD-twins.
  • Compared with healthy controls, 13, 19, and 18 species, and 78, 105, and 153 pathways were found to be differentially abundant in healthy cotwins, IBD-twins, and unrelated patients with IBD, respectively.

Discussion: “The gut microbiome composition of individuals at increased risk of developing IBD (i.e. healthy cotwins from IBD-discordant twin pairs) displays IBD-like signatures on a species and pathway level…The overlap in gut microbial features between healthy cotwins at increased risk of developing IBD and related and unrelated IBD patients suggests that these IBD-like microbiome signatures might precede the onset of IBD. This potentially opens new avenues for diagnosis and therapy in individuals with pre-symptomatic IBD.”

My take This study indicates that the microbiome changes in persons with IBD are also found in their healthy twins. In many ways, this is similar to the frequent finding of abnormal serology in Crohn’s disease; ASCA antibodies were considered much less helpful as a diagnostic test after the realization that ~20% of healthy first degree relatives also have detectable levels.

Figure 4 (pg 1979) shows the relative abundance of a selection of IBD-associated species and highlights similarities between the healthy cotwins and IBD twins.

Related blog posts:

IBD Updates: Microbiome afer surgery, Anti-TNF agents NOT changing hospitalizations/surgeries, Biobanking Genetics

X Fang et al. Inflamm Bowel Dis 2021; 27: 603-616. Full Text: Gastrointestinal Surgery for Inflammatory Bowel Disease Persistently Lowers Microbiome and Metabolome Diversity

  • Methods: The UC San Diego IBD Biobank was used to prospectively collect 332 stool samples (every 6 months) from 129 subjects (50 ulcerative colitis; 79 Crohn’s disease). Of these, 21 with Crohn’s disease had ileocolonic resections, and 17 had colectomies.
  • Key finding: Intestinal surgeries in IBD patients seem to reduce the diversity of the gut microbiome and metabolome in IBD patients. Colectomy has a larger effect than ileocolonic resection.
  • Limitations: Confounding variables (eg. antibiotics) and selection bias (patients with more severe disease

C Verdon et al. Inflamm Bowel Dis 2021; 27: 655-661. No Change in Surgical and Hospitalization Trends Despite Higher Exposure to Anti-Tumor Necrosis Factor in Inflammatory Bowel Disease in the Québec Provincial Database From 1996 to 2015

Key findings:

  • 34,644 newly diagnosed patients with IBD (CD = 59.5%)
  • The probability of first and second hospitalizations remained unchanged in Québec and the probability of major surgery was low overall but did increase despite the higher and earlier use of anti-TNFs. However, the authors note that “in the present study, biologics use under the public reimbursement plan was 13% in patients with UC and 16% in patients with CD.”
  • My take: This study is provocative but probably misleading; it is quite likely that use of anti-TNF agents do lower the risk of hospitalization and surgery.

K Gettler et al. Gastroenterol 2021; 160: 1546-1557. Full text PDF: Common and Rare Variant Prediction and Penetrance of IBD in a Large, Multi-ethnic, Health System-based Biobank Cohort

  • Methods: The authors used the Mount Sinai BioMe Biobank, which contains genetic data on
    32,595 patients. After rigorous phenotype validation, 19,541 individuals were retained, of whom 339 were IBD patients (273 CD, 28 UC, and 37 individuals who were classified as both) and 19,202 were controls
  • Key findings: In this study, the authors identified several rare VEO-IBD variants with high genetic penetrance using the biobank samples and then replicated results in large case control African American and European data sets.
  • One of the variants with the highest genetic penetrance located in the gene LRBA was predicted to result in a deleterious change to the amino acid structure. Reduced expression of CTLA-4 secondary to the variants we identified in LRBA may result in autoinflammation that contributes to IBD. “Targeting reduced CTLA-4 expression is an exciting treatment venue, because expression of CTLA-4 has been shown to be increased by chloroquine treatment in vitro.”
  • Enteropathy is present in 63% of all known individuals with LRBA deficiency, with 27% having chronic diarrhea as the presenting symptom

Mangroves in John Pennekamp State Park (Key Largo)

For the Next Insurance Appeal: Therapeutic Drug Monitoring in Adalimumab Treatment (Pediatrics) & Satire on Prior Authorizations

There is a lot of data supporting the use of therapeutic drug monitoring (TDM) for anti-TNF agents. A recent study (MJ Kim et al. JPGN 2021; 72: 870-876. Therapeutic Drug Monitoring of Adalimumab During Long-term Follow-up in Paediatric Patients With Crohn Disease) adds to this data and supports increased adalimumab (ADL) dosing if below target values.

In this prospective study of 31 pediatric patients with Crohn’s disease, the authors found correlations between ADL values and the endpoints of clinical remission (CR) and mucosal healing (MH). The authors checked TLs at 4 months, 1, 2, and 3 years. Key findings:

  • The median trough levels (TLs) of ADL were higher in patients in CR (7.6 ± 3.5 μg/mL) than in patients with active disease (5.1 ± 2.2 μg/mL).
  • ADL TLs were significantly higher in patients who achieved MH than in those who did not (14.2 ± 7.6 vs 7.8 ± 5.2 μg/mL). 
  • The optimal cut-point for predicting MH at 1 year of ADL treatment was 8.18 μg/mL
  • MH was noted in 42% at 4 months and 55% at 1 yr; CR was noted in 90% at 4 months and 84% at 1 yr. ADL treatment was associated with positive effects on growth indicators as well.

The authors discuss TDM for anti-TNF therapy, noting that for infliximab, the AGA recommends values >5 mcg/mL and the ACG >7.5 mcg/mL. There are fewer studies of ADL TDM -prior studies have indicated goals of >5.8, >7.1, >8, and >8.1; thus, this study is in agreement with these prior studies.

My take: This study further supports the value of TDM; better drug levels correlate with better outcomes.

Related blog posts:

Fort Jefferson, Dry Tortugas. The fort has reportedly 16 million bricks (I didn’t confirm this figure).

More satireOn Prior Authorizations:

Mediterranean Diet vs Specific Carbohydrate Diet for Crohn’s Disease

It appears that the Mediterranean diet works as well as the specific carbohydrate diet for adults with Crohn’s disease.

A Randomized Trial Comparing the Specific Carbohydrate Diet to a Mediterranean Diet in Adults with Crohn’s Disease (in press -thanks to Kipp Ellsworth for this reference) JD Lewis et al. Gastroenterol 2021; https://doi.org/10.1053/j.gastro.2021.05.047

Abstract:

Background & Aims

This study compared the effectiveness of the Specific Carbohydrate Diet (SCD) to the Mediterranean Diet (MD) as treatment for Crohn’s disease (CD) with mild to moderate symptoms.

Methods

Adult patients with CD and with mild-moderate symptoms were randomly assigned 1:1 to consume the MD or SCD for 12 weeks. For the first 6-weeks, participants received prepared meals and snacks according to their assigned diet. After 6-weeks, participants were instructed to follow the diet independently. The primary outcome was symptomatic remission at week 6. Key secondary outcomes at week 6 included: fecal calprotectin (FC) response (FC <250 μg/g and reduction by >50% among those with baseline FC >250 μg/g) and C-Reactive Protein (CRP) response (high-sensitivity CRP (hsCRP) <5 mg/L and >50% reduction from baseline among those with hsCRP >5mg/L).

Results

194 patients were randomized, and 191 were included in the efficacy analyses. The percentage of participants who achieved symptomatic remission at week 6 was not superior with SCD (SCD 46.5%, MD 43.5%; P = .77). FC response was achieved in 8/23 participants (34.8%) with SCD and 4/13 participants (30.8%) with MD (P = .83). CRP response was achieved in 2/37 participants (5.4%) with SCD and 1/28 participant (3.6%) with MD (P = .68).

Conclusions

SCD was not superior to MD to achieve symptomatic remission, FC response and CRP response. CRP response was uncommon. Given these results, the greater ease of following the MD, and other health benefits associated with MD, the MD may be preferred to the SCD for most patients with CD with mild to moderate symptoms.

Related blog post: