Clinical, serologic, and genetic factors associated with pyoderma gangrenosum and erythema nodosum in inflammatory bowel disease patients

The causal impact of genetically predicted inflammatory bowel disease on extraintestinal manifestations: a mendelian randomization study

BACKGROUND

Extraintestinal manifestations (EIMs) significantly affect the life quality of people with inflammatory bowel disease (IBD) and are crucial factors impacting occurrence rates and mortality among IBD patients. This study performed a Mendelian randomization (MR) analysis to investigate the causal relationships between genetically predicted IBD and the development of EIMs, including erythema nodosum (EN), episcleritis, scleritis, uveitis, primary sclerosing cholangitis (PSC), and spondyloarthritis. To further investigate differences between subtypes, separate analyses were conducted for ulcerative colitis (UC) and Crohn's disease (CD).

METHODS

The study was conducted based on genome-wide association studies (GWAS) data. We carefully selected SNPs associated with both exposure and outcome by comparing and integrating data from GWAS and relevant literature, and prioritizing studies with large sample sizes, high quality, and as much population homogeneity as possible. The SNPs associated with IBD, UC and CD were extracted from the International Inflammatory Bowel Disease Genetics Consortium. And the SNPs associated with EIMs were extracted from the UK Biobank, the International PSC Study Group and the FinnGen study. A series of quality control steps were taken in our analysis to select eligible instrumental SNPs which were strongly associated with exposure. The causal effects were estimated using a primary analysis that employed inverse-variance weighting (IVW) and complementary analysis that utilized MR-Egger weighted by the median. A sensitivity analysis was conducted using the Cochran Q statistic, a funnel plot, the MR-Egger intercept, and a leave-one-out approach. Reverse causality analysis was also performed to ensure the robustness of the findings. Furthermore, a fixed-effects meta-analysis was employed to combine MR outcomes from various data origins, bolstering the strength and dependability of our findings.

RESULTS

Our findings indicated that genetically predicted IBD had a robust causal relationship with an increased risk of specific conditions, including EN (OR, 1.20; 95% CI, 1.09-1.32; p < 0.01), uveitis (OR, 1.15; 95% CI, 1.11-1.20; p < 0.01), PSC (OR, 1.21; 95% CI, 1.13-1.28; p < 0.01), and spondyloarthritis (OR, 1.19; 95% CI, 1.14-1.23; p < 0.01). In subgroup analyses, the causal effects of both UC and CD on EN, uveitis, PSC, and spondyloarthritis were also significant and robust. Additionally, no significant evidence of causality was observed between genetically predicted IBD, UC, and CD, and the occurrence of both episcleritis and scleritis. The results of reverse causality analysis indicated a robust causal association between genetically predicted PSC and the elevated risk of IBD (OR, 1.21; 95% CI, 1.15-1.29; p < 0.01), UC (OR, 1.27; 95% CI, 1.17-1.37; p < 0.01), and CD (OR, 1.10; 95% CI, 1.02-1.20; p < 0.01). Additionally, spondyloarthritis had a causal relationship with an increased risk of both IBD (OR, 1.03; 95% CI, 1.01-1.06; p < 0.01) and UC (OR, 1.05; 95% CI, 1.02-1.08; p < 0.01).

Effects of immune cells in mediating the relationship between inflammatory bowel disease and pyoderma gangrenosum: a two-sample, two-step mendelian randomization study

BACKGROUND

Although the precise cause of the co-occurrence of pyoderma gangrenosum (PG) and inflammatory bowel disease (IBD) is still unknown, prior research has shown that the two conditions coexist. Moreover, it is currently unknown how immune cells function in influencing the relationship between IBD and PG.

METHODS

In order to choose independent single nucleotide polymorphism (SNP) as instrumental variables, we were provided with genome-wide association study (GWAS) summary data of European populations from the IEU OpenGWAS project (for IBD) and a the FinnGen database (for PG) publically available. For the MR analysis, a range of analytical techniques were employed to peer into the possible causative relationship between PG and IBD. The two-step MR analysis was used to investigate the mediating role of immune cells between IBD and PG. The chief method utilized was the inverse variance weighted (IVW) approach. Using the Cochran's Q test and the MR-Egger intercept, respectively, heterogeneity or pleiotropy was evaluated to support the findings. MR-PRESSO (Mendelian Randomization Pleiotropy RESidual Sum and Outlier) were used to identify the outlier SNP.

RESULTS

IBD was found to raise the incidence of PG (IVW-FE: OR = 1.604, 95%CI = 1.308-1.966, p = 5.58 × 10- 6), according to MR findings. Moreover, UC or CD were strongly correlated with a greater risk of PG (OR = 1.339, 95%CI = 1.041-1.723, p = 0.023 for UC; OR = 1.339, 95%CI = 1.107-1.621, p = 0.003 for CD). The results of the reverse MR study did not suggest a connection between PG and IBD. CD4+ regulatory T cell is the mediator that particularly stood out in the interaction between UC and PG. There was evidence of neither heterogeneity nor horizontal pleiotropy. And the validity of these conclusions was verified.

CONCLUSION

In the European population, PG risk may be genetically elevated by IBD, including CD and UC, according to the current study. The effect of UC on PG may have been causally mediated by CD4+ regulatory T cells.

The association between erythema nodosum and pyoderma gangrenosum and pediatric inflammatory bowel disease

OBJECTIVES

The objectives of this study is to estimate rates and identify factors associated with erythema nodosum (EN) and pyoderma gangrenosum (PG) in pediatric patients with inflammatory bowel disease (IBD).

METHODS

This cohort study examined longitudinal visits of patients aged ≤ 21 years from the ImproveCareNow (ICN) registry. We evaluated the association of factors at the patient-level (demographics and IBD diagnosis age) and visit-level (IBD severity scores, markers and phenotypes, comorbidities, and treatment) with the presence of EN and PG, using longitudinal logistic regression models adjusted for time and within-patient clustering.

RESULTS

A total of 285,913 visits from 32,497 patients aged ≤ 21 years from the ICN registry were analyzed. The occurrence of EN was 1.57% (95% confidence interval [95% CI]: 1.43%-1.71%) and the occurrence of PG was 0.90% (95% CI: 0.80%-1.00%). Co-occurrence of EN and PG was reported in 0.30% (95% CI: 0.25%-0.37%) patients. Both EN and PG were associated (p < 0.0001) with worse intestinal disease, lower remission, higher inflammatory markers, and extraintestinal manifestations (EIMs) arthritis and uveitis.

CONCLUSIONS

EN and PG were associated with increased disease severity and other noncutaneous EIMs (arthritis and uveitis). A small subset of patients had developed both EN and PG.

Extraintestinal Manifestations in Inflammatory Bowel Disease: From Pathophysiology to Treatment

The inflammatory bowel diseases (IBDs) are systemic conditions that affect not only the gastrointestinal tract but also other parts of the body. The presence of extraintestinal manifestations can significantly impact the quality of life in IBD patients. Peripheral arthritis, episcleritis, and erythema nodosum are frequently associated with active intestinal inflammation and often improve with standard treatment targeting intestinal inflammation. In contrast, anterior uveitis, ankylosing spondylitis, and primary sclerosing cholangitis typically occur independently of disease flares. The incidence of these conditions in individuals with IBD can reach up to 50% of patients over the course of their lifetime. In addition, some advanced therapies utilized for the treatment of IBD potentially result in side effects that may resemble extraintestinal manifestations. This review provides a thorough analysis of the pathophysiology and treatment of extraintestinal manifestations associated with Crohn's disease and ulcerative colitis.

The causal relationship between inflammatory bowel diseases and erythema nodosum: a bidirectional two-sample mendelian randomization study

BACKGROUND

Individuals with inflammatory bowel disease (IBD) exhibit a heightened likelihood of developing erythema nodosum (EN), but the presence of causal link is unknown. The purpose of the present research was to investigate this connection using a bidirectional two-sample Mendelian randomization (MR) analysis.

METHODS

Summarized statistics for EN were sourced from the FinnGen consortium of European ancestry. The International Inflammatory Bowel Disease Genetic Consortium (IBDGC) was used to extract summary data for IBD. The inverse variance weighted (IVW) technique was the major method used to determine the causative link between them.

RESULTS

The study evaluated the reciprocal causal link between IBD and EN. The IVW technique confirmed a positive causal link between IBD and EN (OR = 1.237, 95% CI: 1.109-1.37, p = 1.43 × 10- 8), as well as a strong causality connection between Crohn's disease (CD) and EN (OR = 1.248, 95% CI: 1.156-1.348, p = 1.00 × 10- 4). Nevertheless, a causal connection between ulcerative colitis (UC) and EN could not be established by the data. The reverse MR research findings indicated that analysis indicated that an increase in EN risks decreased the likelihood of UC (OR = 0.927, 95% CI: 0.861-0.997, p = 0.041), but the causal association of EN to IBD and CD could not be established.

CONCLUSION

This investigation confirmed that IBD and CD had a causal connection with EN, whereas UC did not. In addition, EN may decrease the likelihood of UC. Further study must be performed to uncover the underlying pathophysiological mechanisms producing that connection.

Comprehensive Association Analyses of Extraintestinal Manifestations in Inflammatory Bowel Disease

BACKGROUND & AIMS

Patients with inflammatory bowel disease (IBD) frequently develop extraintestinal manifestations (EIMs) that contribute substantially to morbidity. We assembled the largest multicohort data set to date to investigate the clinical, serologic, and genetic factors associated with EIM complications in IBD.

METHODS

Data were available in 12,083 unrelated European ancestry IBD cases with presence or absence of EIMs (eg, ankylosing spondylitis [ankylosing spondylitis and sacroiliitis], primary sclerosing cholangitis [PSC], peripheral arthritis, and skin and ocular manifestations) across 4 cohorts (Cedars-Sinai Medical Center, National Institute for Diabetes and Digestive and Kidney Diseases IBD Genetics Consortium, Sinai Helmsley Alliance for Research Excellence Consortium, and Risk Stratification and Identification of Immunogenetic and Microbial Markers of Rapid Disease Progression in Children with Crohn's Disease cohort). Clinical and serologic parameters were analyzed by means of univariable and multivariable regression analyses using a mixed-effects model. Within-case logistic regression was performed to assess genetic associations.

RESULTS

Most EIMs occurred more commonly in female subjects (overall EIM: P = 9.0E-05, odds ratio [OR], 1.2; 95% CI, 1.1-1.4), with CD (especially colonic disease location; P = 9.8E-09, OR, 1.7; 95% CI, 1.4-2.0), and in subjects who required surgery (both CD and UC; P = 3.6E-19, OR, 1.7; 95% CI, 1.5-1.9). Smoking increased risk of EIMs except for PSC, where there was a "protective" effect. Multiple serologic associations were observed, including with PSC (anti-nuclear cytoplasmic antibody; IgG and IgA, anti-Saccharomyces cerevisiae antibodies; and anti-flagellin) and any EIM (anti-nuclear cytoplasmic antibody; IgG and IgA, anti-Saccharomyces cerevisiae antibodies; and anti-Pseudomonas fluorescens-associated sequence). We identified genome-wide significant associations within major histocompatibility complex (ankylosing spondylitis and sacroiliitis, P = 1.4E-15; OR, 2.5; 95% CI, 2.0-3.1; PSC, P = 2.7E-10; OR, 2.8; 95% CI, 2.0-3.8; ocular, P = 2E-08, OR, 3.6; 95% CI, 2.3-5.6; and overall EIM, P = 8.4E-09; OR, 2.2; 95% CI, 1.7-2.9) and CPEB4 (skin, P = 2.7E-08; OR, 1.5; 95% CI, 1.3-1.8). Genetic associations implicated tumor necrosis factor, JAK-STAT, and IL6 as potential targets for EIMs. Contrary to previous reports, only 2% of our subjects had multiple EIMs and most co-occurrences were negatively correlated.

CONCLUSIONS

We have identified demographic, clinical, and genetic associations with EIMs that revealed underlying mechanisms and implicated novel and existing drug targets-important steps toward a more personalized approach to IBD management.

Hippuric acid alleviates dextran sulfate sodium-induced colitis via suppressing inflammatory activity and modulating gut microbiota

Inflammatory bowel disease (IBD) is a chronic inflammatory disease associated with metabolic disorder and gut dysbiosis. Decreased abundance of hippuric acid (HA) was found in patients with IBD. HA, metabolized directly from benzoic acid in the intestine and indirectly from polyphenols, serves as a marker of polyphenol catabolism. While polyphenols and benzoic acid have been shown to alleviate intestinal inflammation, the role of HA in this context remains unknown. Herein, we investigated the effects and mechanism of HA on DSS-induced colitis mice. The results revealed that HA alleviated clinical activity and intestinal barrier damage, decreased pro-inflammatory cytokine production. Metagenomic sequencing suggested that HA treatment restored the gut microbiota, including an increase in beneficial gut bacteria such as Adlercreutzia, Eubacterium, Schaedlerella and Bifidobacterium_pseudolongum. Furthermore, we identified 113 candidate genes associated with IBD that are potentially under HA regulation through network pharmacological analyses. 10 hub genes including ALB, IL-6, HSP90AA1, and others were identified using PPI analysis and validated using molecular docking and mRNA expression analysis. Additionally, KEGG analysis suggested that the renin-angiotensin system (RAS), NF-κB signaling and Rap1 signaling pathways were important pathways in the response of HA to colitis. Thus, HA may provide novel biotherapy options for IBD.

Postoperative and Peristomal Pyoderma Gangrenosum: Subtypes of Pyoderma Gangrenosum

Postoperative pyoderma gangrenosum and peristomal pyoderma gangrenosum are 2 subtypes of pyoderma gangrenosum. The diagnosis is made as a clinicopathologic correlation when assessing a rapidly progressing ulcer with irregular and undermined borders following a surgical procedure, trauma, or the creation of a stoma. Familiarity with the associated risk factors and distinguishing features of these disorders can facilitate prompt recognition, proper diagnosis, and the initiation of treatment. Management usually involves the use of corticosteroids and steroid-sparing agents as immunomodulators to shift the inflammatory neutrophilic dermatoses to chronic noninflammatory wounds and eventual healing.

TIPE proteins control directed migration of human T cells by directing GPCR and lipid second messenger signaling

Tissue infiltration by circulating leukocytes via directed migration (also referred to as chemotaxis) is a common pathogenic mechanism of inflammatory diseases. G protein-coupled receptors (GPCRs) are essential for sensing chemokine gradients and directing the movement of leukocytes during immune responses. The tumor necrosis factor α-induced protein 8-like (TIPE or TNFAIP8L) family of proteins are newly described pilot proteins that control directed migration of murine leukocytes. However, how leukocytes integrate site-specific directional cues, such as chemokine gradients, and utilize GPCR and TIPE proteins to make directional decisions are not well understood. Using both gene knockdown and biochemical methods, we demonstrated here that 2 human TIPE family members, TNFAIP8 and TIPE2, were essential for directed migration of human CD4+ T cells. T cells deficient in both of these proteins completely lost their directionality. TNFAIP8 interacted with the Gαi subunit of heterotrimeric (α, β, γ) G proteins, whereas TIPE2 bound to PIP2 and PIP3 to spatiotemporally control immune cell migration. Using deletion and site-directed mutagenesis, we established that Gαi interacted with TNFAIP8 through its C-terminal amino acids, and that TIPE2 protein interacted with PIP2 and PIP3 through its positively charged amino acids on the α0 helix and at the grip-like entrance. We also discovered that TIPE protein membrane translocation (i.e. crucial for sensing chemokine gradients) was dependent on PIP2. Collectively, our work describes a new mechanistic paradigm for how human T cells integrate GPCR and phospholipid signaling pathways to control directed migration. These findings have implications for therapeutically targeting TIPE proteins in human inflammatory and autoimmune diseases.

Investigating the shared genetic architecture between primary sclerosing cholangitis and inflammatory bowel diseases: a Mendelian randomization study

BACKGROUND

Several studies have found that primary sclerosing cholangitis (PSC) and inflammatory bowel disease (IBD) are closely associated. However, the direction and causality of their interactions remain unclear. Thus, this study employs Mendelian Randomization to explore whether there are causal associations of genetically predicted PSC with IBD.

METHODS

Genetic variants associated with the genome-wide association study (GWAS) of PSC were used as instrumental variables. The statistics for IBD, including ulcerative colitis (UC), and Crohn's disease (CD) were derived from GWAS. Then, five methods were used to estimate the effects of genetically predicted PSC on IBD, including MR Egger, Weighted median (WM), Inverse variance weighted (IVW), Simple mode, and Weighted mode. Last, we also evaluated the pleiotropic effects, heterogeneity, and a leave-one-out sensitivity analysis that drives causal associations to confirm the validity of the analysis.

RESULTS

Genetically predicted PSC was significantly associated with an increased risk of UC, according to the study (odds ratio [OR] IVW= 1.0014, P<0.05). However, none of the MR methods found significant causal evidence of genetically predicted PSC in CD (All P>0.05). The sensitivity analysis results showed that the causal effect estimations of genetically predicted PSC on IBD were robust, and there was no horizontal pleiotropy or statistical heterogeneity.

CONCLUSIONS

Our study corroborated a causal association between genetically predicted PSC and UC but did not between genetically predicted PSC and CD. Then, we identification of shared SNPs for PSC and UC, including rs3184504, rs9858213, rs725613, rs10909839, and rs4147359. More animal experiments and clinical observational studies are required to further clarify the underlying mechanisms of PSC and IBD.

Causal relationship between inflammatory bowel disease and erythema nodosum: A two-sample bidirectional Mendelian randomization study

BACKGROUND

Previous studies have demonstrated the coexistence of erythema nodosum (EN) and inflammatory bowel disease (IBD), while the exact etiology of the co-occurrence of the two disorders remains uncertain.

METHODS

A bidirectional two-sample Mendelian randomization (MR) design was employed to determine the causal link between EN and IBD. Genetic variations associated with Crohn's disease (CD) and ulcerative colitis (UC) were derived from accessible genome-wide association studies pertaining to European ancestry. The FinnGen database was used to find the genetic variations containing EN. In the forward model, IBD was identified as the exposure, whereas in the reverse model, EN was identified as the exposure. The causal link between IBD and EN was examined using a range of different analysis techniques, the primary one being the inverse variance weighted (IVW) method, including inverse variance weighted-fixed effects (IVW-FE) and inverse-variance weighted-multiplicative random effects (IVW-MRE). To strengthen the results, assessments of sensitivity, heterogeneity, and pleiotropy were also conducted.

RESULTS

MR results showed that IBD increased the risk of EN (IVW-MRE: OR = 1.242, 95% CI = 1.068-1.443, p = 0.005). Furthermore, there was a strong correlation found between CD and a higher risk of EN (IVW-FE: OR = 1.250, 95% CI = 1.119-1.396, p = 8.036 × 10-5 ). However, UC did not appear to be linked to EN (IVW-FE: OR = 1.104, 95% CI = 0.868-1.405, p = 0.421). The reverse MR analysis findings did not imply that EN was linked to IBD. Horizontal pleiotropy did not appear to exist, and the robustness of these findings was confirmed.

CONCLUSION

The current investigation found that in European populations, IBD and its subtype CD could raise the incidence of EN.

Upadacitinib Plus Intensive Granulocyte and Monocyte Adsorptive Apheresis for Ulcerative Colitis Achieved Ulcer Healing for Pyoderma Gangrenosum

A 44-year-old woman who had been diagnosed with ulcerative colitis (UC) at 22 years old was diagnosed with severe flare-up of UC based on endoscopic findings associated with new-onset active pyoderma gangrenosum (PG) on both lower legs after she decided to discontinue UC treatment. Systemic treatment with intravenous prednisolone at 30 mg/day had achieved insufficient response to UC and PG, resulting in a diagnosis of corticosteroid-refractory UC and PG. Combination therapy with upadacitinib at 45 mg/day plus intensive granulocyte and monocyte adsorptive apheresis (GMA) was started to achieve clinical remission of UC. Ten weeks after starting this combination therapy, clinical improvement of UC was achieved with PG ulcer healing on both lower legs. A combination of upadacitinib plus intensive GMA may offer an effective therapeutic option for patients with active PG in addition to UC but has yet to be approved for induction or maintenance treatment of PG worldwide. PG is a dermatological involvement in UC patients that requires attention.

Clinical guidance of pyoderma gangrenosum 2022

Pyoderma gangrenosum (PG) is a rare, neutrophilic skin disease. For the purpose of accurate diagnosis and proper treatment of PG, the Japanese clinical practice guidance for PG developed by the Japanese Dermatological Association was published in 2022. In this guidance, clinical aspects, pathogenesis, current therapies, and clinical questions on PG are described from the viewpoints of current knowledge and evidence-based medicine. Here, the English version of the Japanese clinical practice guidelines for PG is presented and is intended to be widely referred to in the clinical examination and treatment of PG.

Supraphysiologic Vaginal Estrogen Therapy in Aged Mice Mitigates Age-Associated Bladder Inflammatory Response to Urinary Tract Infections

IMPORTANCE

Bladder diseases characterized by chronic inflammation are highly prevalent in older women, as are recurrent urinary tract infections (rUTIs). Recurrent urinary tract infections lead to chronic inflammation of the bladder mucosa and cause lower urinary tract symptoms that persist even after the infection is cleared. Vaginal estrogen therapy (VET) has long been used for the treatment of rUTIs; however, its mechanism of action remains unclear.

OBJECTIVES

The objective of this study was to examine the mechanism(s) by which VET affects bladder inflammation and response to rUTIs.

STUDY DESIGN

Here, we induced surgical menopause in aged (18 months old) mice followed by VET. Mice were then infected with uropathogenic Escherichia coli , and course of infection was investigated. Inflammatory cytokine response was assessed before and during infection using enzyme-linked immunosorbent assay. RNA sequencing analysis was used to compare the inflammatory status of the young versus aged bladder and principal changes confirmed via quantitative reverse transcriptase-polymerase chain reaction to determine the effects of VET on bladder inflammation. Impact on age-associated bladder tertiary lymphoid tissue formation was evaluated histologically.

RESULTS

In the ovariectomized aged model, VET not only mitigated uterine atrophy but was also associated with reduced rUTIs, number of bacterial reservoirs, dampened immune response, and promotion of terminal differentiation of urothelial cells. Bladder tertiary lymphoid tissue lesions were also reduced with VET, with an associated decrease in signals important for bladder tertiary lymphoid tissue formation. Finally, we determined that VET reverses age-associated upregulation of inflammatory genes and pathways.

CONCLUSIONS

Our data suggest that VET is effective by reducing age-associated hyperinflammatory conditions in bladder mucosa and in enhancing the host response to infection.

Extraintestinal Manifestations of Inflammatory Bowel Disease: Current Concepts, Treatment, and Implications for Disease Management

Inflammatory bowel diseases (IBDs) are systemic diseases that manifest not only in the gut and gastrointestinal tract, but also in the extraintestinal organs in many patients. The quality of life for patients with IBD can be substantially affected by these extraintestinal manifestations (EIMs). It is important to have knowledge of the prevalence, pathophysiology, and clinical presentation of EIMs in order to adapt therapeutic options to cover all aspects of IBD. EIMs can occur in up to 24% of patients with IBD before the onset of intestinal symptoms, and need to be recognized to initiate appropriate diagnostic procedures. EIMs most frequently affect joints, skin, or eyes, but can also affect other organs, such as the liver, lung, and pancreas. It is a frequent misconception that a successful therapy of the intestinal inflammation will be sufficient to treat EIMs satisfactorily in most patients with IBD. In general, peripheral arthritis, oral aphthous ulcers, episcleritis, or erythema nodosum can be associated with active intestinal inflammation and can improve on standard treatment of the intestinal inflammation. However, anterior uveitis, ankylosing spondylitis, and primary sclerosing cholangitis usually occur independent of disease flares. This review provides a comprehensive overview of epidemiology, pathophysiology, clinical presentation, and treatment of EIMs in IBD.

Systematic review and meta-analysis: the impact of co-occurring immune-mediated inflammatory diseases on the disease localization and behavior of Crohn's disease

BACKGROUND

Patients with Crohn's disease (CD) are at increased risk of co-occurring immune-mediated inflammatory diseases (IMIDs). As discrepancy exists regarding the phenotypic presentation of CD among patients with such co-occurring IMIDs, we aimed to conduct a systematic review with meta-analysis characterizing the phenotype of CD among this subgroup of patients.

METHODS

PubMed, Embase, and Scopus were searched from their earliest records to October 2019 for studies reporting the behavior and localization of CD according to the Vienna or Montreal Classifications and CD-related surgery in patients with co-occurring IMIDs. These studies were the subject of a random effect meta-analysis.

RESULTS

After reviewing 24,413 studies, we identified a total of 23 studies comprising 1572 and 35,043 CD patients with and without co-occurring IMIDs, respectively, that fulfilled our inclusion criteria. Overall, patients with co-occurring IMIDs were more likely to have upper gastrointestinal inflammation than were patients without co-occurring IMIDs [relative risk (RR) = 1.49 (95% confidence interval (CI) 1.09-2.04), p = 0.01, I 2 = 7%]. In addition, presence of primary sclerosing cholangitis (PSC) was associated with a lower occurrence of ileal affection [RR = 0.44 (95% CI 0.24-0.81), p < 0.01, I 2 = 32%], increased occurrence of colonic affection [RR = 1.78 (95% CI 1.33-2.38), p < 0.01, I 2 = 32%] and an increased likelihood of non-stricturing and non-penetrating behavior [RR = 1.43 (95% CI 0.97-2.11), p = 0.07, I 2 = 86%]. The latter reached significance when cumulating different IMIDs [RR = 1.30 (95% CI 1.09-1.55), p < 0.01, I 2 = 88%]. CD patients with PSC also underwent fewer CD-related surgeries [RR = 0.55 (95% CI 0.34-0.88), p = 0.01, I 2 = 0%], irrespective of CD location or behavior.

CONCLUSION

This study emphasizes that CD patients with co-existing PSC are likely to have a unique inflammatory distribution primarily confined to the colon, while patients with IMIDs in general have higher likelihood of affection of upper gastrointestinal tract and a non-stricturing and non-penetrating behavior. As such a phenotype of CD is typically associated with a milder disease course; future studies are needed to confirm these results.

Systematic Review with Meta-analysis: The Impact of Co-occurring Immune-mediated Inflammatory Diseases on the Disease Course of Inflammatory Bowel Diseases

BACKGROUND AND AIMS

Patients with inflammatory bowel diseases (IBDs) are at risk of developing a variety of other immune-mediated inflammatory diseases (IMIDs). The influence of co-occurring IMIDs on the disease course of IBD remains unknown. The aim of this study was therefore to conduct a systematic review and meta-analysis of the impact of IMIDs on phenotypic presentation and outcome in patients with IBD.

METHODS

PubMed and Embase were searched from their earliest records through December 2018 and updated in October 2019 for studies reporting proportions or ratios of IBD-related disease outcomes in patients with and without co-occurring IMIDs. Meta-analyses were performed to estimate summary proportions and risks of the main outcomes. PRISMA guidelines were used, and study quality was assessed according to the Newcastle-Ottawa Scale.

RESULTS

A total of 93 studies were identified, comprising 16,064 IBD patients with co-occurring IMIDs and 3,451,414 IBD patients without IMIDs. 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; P < 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. Co-occurrence of IMIDs other than primary sclerosing cholangitis in patients with IBD was associated with an increased risk of receiving immunomodulators (risk ratio, 1.15; 95% Cl, 1.06-1.24; P < 0.01; I2 = 60%) and biologic therapies (risk ratio, 1.19; 95% Cl, 1.08-1.32; P < 0.01; I2 = 53%).

CONCLUSION

This meta-analysis found that the presence of co-occurring IMIDs influences the disease course of IBD, including an increased risk of surgery and its phenotypical expression.

Vedolizumab and Extraintestinal Manifestations in Inflammatory Bowel Disease

In Crohn's disease and ulcerative colitis, inflammation is not limited to the digestive tract. Extraintestinal manifestations (EIMs), which affect up to 50% of patients, can substantially impair quality of life. EIMs may parallel luminal disease activity or have an independent course. They most commonly involve the musculoskeletal system (e.g., peripheral or axial arthritis) and skin (e.g., erythema nodosum and pyoderma gangrenosum). Less commonly, the hepatobiliary tract (e.g., primary sclerosing cholangitis [PSC]) and the eye (e.g., episcleritis, scleritis, and uveitis) are involved. Although the pathophysiology of EIMs is poorly understood, they are likely either manifestations of a primary systemic immune disease with variable expression amongst organs, or secondary phenomena to bowel inflammation. Additional pathophysiologic mechanisms may include aberrant lymphocyte homing mediated by ectopic expression of gut-specific chemokines and adhesion molecules, cross-reactivity between microbial and self-antigens, autoantibodies against epitopes shared by the intestine and extraintestinal tissues, elevated serum concentrations of cytokines, and alterations in innate immunity. Many EIMs independent of intestinal disease activity can be successfully treated with tumor necrosis factor (TNF) antagonists. The efficacy of vedolizumab-a monoclonal antibody targeting the α4β7 integrin-for the treatment of EIMs is uncertain, but data are emerging from post hoc analyses of randomized controlled trials, prospective and retrospective cohort studies, and case series. Vedolizumab may be effective in treating EIMs related to luminal disease activity (e.g., type 1 peripheral arthritis and erythema nodosum) but has not shown biochemical improvement in PSC. Its postulated role in the development of de novo EIMs is heavily confounded by the high proportion of patients previously exposed to TNF antagonists; new EIMs could result from TNF antagonist treatment cessation rather than being caused by vedolizumab. A common limitation of clinical studies is the lack of multidisciplinary involvement in the diagnosis and monitoring of EIMs, which may lead to misdiagnosis and overreporting. Future studies should rigorously measure EIMs in parallel with objective measures of luminal disease activity to provide more robust data on the relative efficacy of new drugs, especially as increasing numbers of gut-selective compounds enter clinical development.

A Wound Care Specialist's Approach to Pyoderma Gangrenosum

Significance: Pyoderma gangrenosum (PG) is a rare neutrophilic ulcerative dermatosis that poses a high burden of morbidity due to underdiagnosis, resistance to therapy, and limited therapeutic options. Optimization of wound care strategies and multimodal anti-inflammatory approaches are necessary to mitigate multiple converging pathways of inflammation leading to delayed healing, which is further complicated by additional factors such as pathergy. Recent Advances: PG treatment typically involves reducing inflammation, controlling pain, promoting wound healing, and treating the underlying etiology. Recent advances have been made with regard to targeted therapies for PG with topical, intralesional, and systemic medications. Wound management includes gentle cleansing without sharp debridement, limited topical antibacterial use, and maintenance of a moist environment to promote epithelial migration. Critical Issues: Wound dressings and compression therapy, in particular, introduce a wide variety of therapeutic options. Dressings should aim to target the specific PG wound type, depending on the depth and exudative nature of the wound, as well as local secondary factors. Superficial wounds, eschar, exudative wounds, granulating wounds, and colonized wounds are managed with variable approaches to the same underlying principles of pathergy avoidance, moisture balance, and reduction of immunogenic inflammatory stimuli. The importance of compression therapy to decrease edema and overgranulation fits within this treatment paradigm. Future Directions: As each of these treatment modalities offers a complex mixture of advantages and limitations, development of a systematic treatment algorithm in the future can help direct a more tailored path toward wound healing.

RETRACTED: Pyoderma gangrenosum in a cesarean section wound in a woman with myelodysplastic syndrome: A case report

Introduction

Pyoderma gangrenosum and myelodysplastic syndrome in pregnant women are both very rare, but can coexist. Here, we present a case of pyoderma gangrenosum in a cesarean section wound in a woman with myelodysplastic syndrome.

Case

A 34-year-old woman presented with thrombocytopenia and macrocytic anemia during pregnancy. The pregnancy was uneventful until 36 weeks of gestation, when premature rupture of membranes occurred and a cesarean section was performed for breech presentation. She presented four days later with redness and blisters at the wound site. Surgical site infection was diagnosed but did not improve with antibiotics, and multiple wound cultures were negative. Skin biopsy indicated pyoderma gangrenosum, and the redness and blisters responded to oral prednisolone. Post-partum bone marrow aspiration showed myelodysplastic syndrome. As the patient demonstrated no symptoms such as abnormal bleeding, no additional treatment was started, and she went on to receive regular follow-up for myelodysplastic disorder.

Discussion

This case shows the need for further assessment of hematological disorders diagnosed in pregnancy in women with pyoderma gangrenosum post-partum.

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Pyoderma gangrenosum and myelodysplastic syndrome in pregnant women are both very rare conditions.

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Myelodysplastic syndrome is the most frequent hematological disorder associated with pyoderma gangrenosum.

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We report the case of a woman diagnosed pyoderma gangrenosum with myelodysplastic syndrome.

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This case shows the need for bone marrow biopsy in women with hematological abnormalities and pyoderma gangrenosum.

Post-Operative Pyoderma Gangrenosum: A Long Journey for a Patient with Myelodysplastic Syndrome

Pyoderma gangrenosum (PG) is an inflammatory neutrophilic dermatosis, characterized by painful and erythematous papules, pustules or vesicles that rapidly become ulcerative and necrotic. These ulcers have multiple sub-types and can develop anywhere on the body. There are different postulations as to the mechanisms of development for each sub-type. More than half of patients with PG have an underlying disease, with the highest prevalence being inflammatory bowel disease (IBD), followed by inflammatory arthritis and hematological disorders. Post-operative PG should be considered in any patient undergoing surgery who subsequently develops characteristic necrotic lesions with delayed wound healing, fever and severe localized pain. The clinical manifestations and treatment may differ slightly depending on the type and cause of PG. Herein, we present a patient with myelodysplastic syndrome and arthritis, who underwent surgery for diverticulosis complicated by colovaginal fistula formation, and subsequently developed a very prolonged course of post-operative pyoderma gangrenosum. This report will address the types of PG, their various manifestations and pathogenesis, as well as the management specific to patients with myelodysplastic syndrome. It is our intent to better understand the sub-types in order to predict and prevent post-operative PG.

Assessment of extraintestinal manifestations in inflammatory bowel diseases: A systematic review and a proposed guide for clinical trials

BACKGROUND AND AIMS

Extraintestinal manifestations are common in inflammatory bowel disease patients, although there are few data available on their diagnosis, management and follow-up. We systematically reviewed the literature evidence to evaluate tools and investigations used for the diagnosis and for the assessment of the treatment response in inflammatory bowel disease patients with extraintestinal manifestations.

METHODS

We searched in PubMed, Embase and Web of Science from January 1999-December 2019 for all interventional and non-interventional studies published in English assessing diagnostic tools and investigations used in inflammatory bowel disease patients with extraintestinal manifestations.

RESULTS

Forty-five studies (16 interventional and 29 non-interventional) were included in our systematic review, enrolling 7994 inflammatory bowel disease patients. The diagnostic assessment of extraintestinal manifestations was performed by dedicated specialists in a percentage of cases ranging from 60-100% depending on the specific condition. The clinical examination was the most frequent diagnostic strategy, accounting for 35 studies (77.8%). In patients with primary sclerosing cholangitis or rheumatological symptoms, biochemical and imaging tests were also performed. Anti-TNF agents were the most used biological drugs for the treatment of extraintestinal manifestations (20 studies, 44.4%), and the treatment response varied from 59.1% in axial spondyloarthritis to 88.9% in ocular manifestations. No benefit was detected in primary sclerosing cholangitis patients after treatment with biologics.

CONCLUSIONS

In the clinical management of inflammatory bowel disease patients with extraintestinal manifestations the collaboration of dedicated specialists for diagnostic investigations and follow-up is key to ensure the best of care approach. However, international guidelines are needed to homogenise and standardise the assessment of extraintestinal manifestations.

The TIPE Molecular Pilot That Directs Lymphocyte Migration in Health and Inflammation

Lymphocytes are some of the most motile cells of vertebrates, constantly navigating through various organ systems. Their specific positioning in the body is delicately controlled by site-specific directional cues such as chemokines. While it has long been suspected that an intrinsic molecular pilot, akin to a ship's pilot, guides lymphocyte navigation, the nature of this pilot is unknown. Here we show that the TIPE (TNF-α-induced protein 8-like) family of proteins pilot lymphocytes by steering them toward chemokines. TIPE proteins are carriers of lipid second messengers. They mediate chemokine-induced local generation of phosphoinositide second messengers, but inhibit global activation of the small GTPase Rac. TIPE-deficient T lymphocytes are completely pilot-less: they are unable to migrate toward chemokines despite their normal ability to move randomly. As a consequence, TIPE-deficient mice have a marked defect in positioning their T lymphocytes to various tissues, both at the steady-state and during inflammation. Thus, TIPE proteins pilot lymphocytes during migration and may be targeted for the treatment of lymphocyte-related disorders.

Incisional pyoderma gangrenosum after caesarean section: Two case reports

Introduction

Pyoderma gangrenosum (PG) in pregnant women is rare and resembles surgical site infection (SSI). Here we present two cases of PG after caesarean section.

Case 1

A 29-year-old woman, who had a history of recurrent wound dehiscence after surgery, exhibited wound ulceration and exudate 6 days after caesarean section. Antibiotics were ineffective and multiple wound cultures were negative. Skin biopsy indicated PG and oral steroid administration resulted in wound improvement.

Case 2

A 27-year-old woman, who had a history of PG, exhibited wound ulceration and exudate 5 days after caesarean section. The lesion developed despite antibiotic administration, and multiple wound cultures were negative. Skin biopsy indicated PG and the wound improved after oral steroid administration.

Discussion

Definitive diagnosis of PG is essential because its treatment differs from that of SSI. PG after caesarean section can be misdiagnosed as SSI, even when there is a history of wound dehiscence or PG.

The Pathogenesis of Extraintestinal Manifestations: Implications for IBD Research, Diagnosis, and Therapy

This article reports on the sixth scientific workshop of the European Crohn's and Colitis Organisation [ECCO] on the pathogenesis of extraintestinal manifestations [EIMs] in inflammatory bowel disease [IBD]. This paper has been drafted by 15 ECCO members and 6 external experts [in rheumatology, dermatology, ophthalmology, and immunology] from 10 European countries and the USA. Within the workshop, contributors formed subgroups to address specific areas. Following a comprehensive literature search, the supporting text was finalized under the leadership of the heads of the working groups before being integrated by the group consensus leaders.

Current clinical issue of skin lesions in patients with inflammatory bowel disease

Inflammatory bowel disease (IBD) is associated with a number of extraintestinal complications, including skin lesions. Most reports have shown that skin lesions are found in 10-15% of IBD cases, although this depends on the definition of skin lesions. The representative skin lesions in patients with IBD are erythema nodosum, pyoderma gangrenosum, Sweet's syndrome, and so on. These lesions are often associated with IBD progression, and intestinal lesions in particular require appropriate treatment. Recently, another clinical issue regarding skin lesions in patients with IBD, a so-called paradoxical reaction, during the treatment with anti-tumor necrosis factor (TNF)-α agents has emerged. These reactions are termed paradoxical reactions because the skin lesions sometimes resemble psoriasis, although the anti-TNF-α agents have been historically used to treat psoriasis. Paradoxical reactions are reportedly found in approximately 5-10% of patients using anti-TNF-α agents and are no longer rare. Now that the use of biologics is at its culmination, reports regarding paradoxical reactions are predicted to increase in number; thus, we must recognize skin lesions with IBD patients including this type of adverse events and manage them appropriately while consulting with dermatologists.

Pyoderma Gangrenosum: A Review for the Gastroenterologist

Pyoderma gangrenosum (PG) is a rare ulcerative skin disease of unknown etiology often associated with systemic inflammatory conditions, most commonly inflammatory bowel disease (IBD). The most common presentation of PG is spontaneous rapid formation of an extremely painful ulcer on the extremities, associated with significant morbidity and mortality. Rarely, PG can also occur as a chronic peristomal complication or as an acute postoperative complication of a surgical wound. The clinical course is unpredictable; it may not correlate with IBD activity and may even precede a diagnosis of IBD. Pyoderma gangrenosum is a diagnosis of exclusion. Treatment is challenging, often involving a variety of immunosuppressive therapies. This review aims to provide an update for the gastroenterologist on the pathogenesis, presentation, diagnosis, and management of PG, a rare complication of IBD.

Low Rates of Dermatologic Care and Skin Cancer Screening Among Inflammatory Bowel Disease Patients

BACKGROUND

Dermatologic manifestations of inflammatory bowel disease (IBD) are common, and certain IBD medications increase the risk of skin cancer.

AIMS

To define the rates of care and factors associated with dermatologic utilization with a focus on skin cancer screening.

METHODS

We utilized a prospective, natural history IBD research registry to evaluate all outpatient healthcare encounters from 2010 to 2016. Gastrointestinal, dermatologic and primary care visits per individual were identified. We calculated the proportion of patients obtaining care, categorized primary indications for dermatologic visits, determined the incidence of melanoma and non-melanoma skin cancers, and used logistic regression to determine factors associated with dermatology utilization.

RESULTS

Of the 2127 IBD patients included, 452 (21.3%) utilized dermatology over the study period, and 55 (2.6%) had a total body skin examination at least once. The 452 patients incurred 1633 dermatology clinic visits, 278 dermatologic procedures, and 1108 dermatology telephone encounters. The most frequent indication was contact dermatitis or dermatitis. Factors associated with dermatology use were family history of skin cancer, employment, systemic steroids, longer disease duration, emergency room use, and the number of IBD-related clinic visits. Between 8.3 and 11% of IBD patients recommended for skin cancer screening visited dermatology each year, and the resulting incidence of non-melanoma skin cancer was 35.4/10,000 [95% CI 23.3-51.5] and melanoma was 6.56/10,000 [95% CI 2.1-15.3].

CONCLUSIONS

Less than one in ten IBD patients obtain dermatologic care. Given the increased risk of skin cancers among IBD patients, an emphasis on education, prevention, and screening merits attention.

Comparison of Clinical Features between Pyoderma Gangrenosum Concomitant by Inflammatory Bowel Disease and Idiopathic Pyoderma Gangrenosum

Background:

Pyoderma gangrenosum (PG) is a rare neutrophilic dermatosis that is highly associated with inflammatory bowel disease (IBD). Certain PG patients with no systemic disorders have been diagnosed with idiopathic PG. This study sought to clarify the difference between PG with IBD and idiopathic PG based on clinical features, laboratory tests, and medications.

Methods:

Twelve patients with PG and IBD and 24 patients with idiopathic PG, who were hospitalized in Peking Union Medical College Hospital from 2000 to 2017, were retrospectively categorized into the IBD group and control group, respectively. Data of clinical features, laboratory tests, and medications were collected and compared between the two groups.

Results:

Both groups were similar with respect to their clinical features. However, the IBD group had an increased occurrence of arthralgia or arthritis (58.3% vs. 12.5%, P = 0.007), anemia (83.3% and 29.2%, P = 0.004), and an increased percentage of antineutrophilic cytoplasmic antibody (ANCA)-positive patients (85.7% and 0.0%, P < 0.001), compared to the control group.

Conclusion:

PG patients with IBD had increased occurrence rates of arthralgia or arthritis, anemia, and ANCA-positive status compared to idiopathic PG patients.

Pyoderma gangrenosum: a review of pathogenesis and treatment

INTRODUCTION

Pyoderma gangrenosum (PG) is a complex neutrophilic dermatosis that can occur as an idiopathic disease, in association with systemic conditions such as inflammatory bowel disease, as part of an inherited inflammatory syndrome. It can be challenging to treat, as it occurs in a wide variety of clinical settings and there is a lack of a standardized treatment approach. The main limitations to treatment have been an incomplete understanding of the pathogenesis. However, recent advances have been made in understanding the pathogenesis of this condition, and PG is now considered an autoinflammatory disease process. Areas covered: This review discusses the newest studies that further define our understanding of this disease and the relevant literature on treatment options for pyoderma gangrenosum. Expert commentary: The presence of abnormal neutrophils and T-cells lead to immune dysregulation, leading to lesions of PG. Increased levels of inflammatory mediators including IL-1β, IL-8, IL-17, and TNF-α contribute to the development of the disease but there are still several unknown factors, including the trigger for immune dysregulation and additional contributory components of the immune system. We provide our approach to the management of PG lesions, which involves a multi-faceted approach including wound care, topical therapy, and systemic medications in most cases.

Drug management of neutrophilic dermatoses

INTRODUCTION

Neutrophilic dermatoses are a heterogenous group of chronic, cutaneous inflammatory conditions characterized by the accumulation of neutrophils in the skin and by systemic inflammation. Neutrophilic dermatoses can be idiopathic or associated with other inflammatory or systemic diseases, including the group of the hereditary, autoinflammatory syndromes. Clinical management is challenging, due to limited clinical evidence and lack of clinical practice guidelines. Areas covered: This review provides an overview of current therapeutic management of the three prototypical neutrophilic dermatoses, aseptic pustulosis of the folds, Sweet syndrome and pyoderma gangrenosum. In addition, we describe innovative, pathogenesis-oriented treatment approaches, which are based on recent advances in the pathophysiology of neutrophilic dermatoses and autoinflammatory syndromes. The increasing role of the IL-1 cytokine family in initiating neutrophilic inflammation in both idiopathic and syndromic disease opened the way for the use of targeted biological treatment. Another promising treatment strategy is aimed at blocking downstream effector cytokines, such as IL12/23 and IL-17, involved in the autoinflammatory immune cascade. Expert commentary: In chronic-recurrent and syndromic cases of neutrophilic dermatoses, there is an unmet clinical need for long-term, continuous disease control. Future controlled clinical studies will optimize the use of targeted-biological agents in sequential or combination treatment strategies.

Drug-induced pyoderma gangrenosum: a model to understand the pathogenesis of pyoderma gangrenosum

Pyoderma gangrenosum (PG) is a rare autoinflammatory condition in which the alteration of neutrophil function and the innate immune response play key roles in its pathogenesis. Cases of PG have been reported in patients being treated with certain medications, which may help us to understand some of the possible pathways involved in the aetiology of PG. The aim of this review is to review the cases of PG triggered by certain drugs and try to thoroughly understand the pathogenesis of the disease. To accomplish this, a PubMed search was completed using the following words: pyoderma gangrenosum, neutrophilic dermatosis, pathophysiology, drug-induced pyoderma gangrenosum. In total, we found 43 cases of drug-induced PG. Most of them were caused by colony-stimulating factors and small-molecule tyrosine kinase inhibitors. We propose that drugs induce PG through various mechanisms such as dysfunctional neutrophil migration and function, dysregulated inflammatory response, promotion of keratinocyte apoptosis and alteration of epigenetic mechanisms. PG is a rare condition with complex pathophysiology and drug-induced cases are even more scarce; this is the main limitation of this review. Understanding the possible mechanisms of drug-induced PG, via abnormal neutrophil migration and function, abnormal inflammation, keratinocyte apoptosis and alteration of epigenetic mechanisms would help to better understand the pathogenesis of PG and ultimately to optimize targeted therapy.

Pyoderma Gangrenosum: An Update on Pathophysiology, Diagnosis and Treatment

Pyoderma gangrenosum (PG) is a rare inflammatory neutrophilic disorder with prototypical clinical presentations. Its pathophysiology is complex and not fully explained. Recent information regarding the genetic basis of PG and the role of auto-inflammation provides a better understanding of the disease and new therapeutic targets. PG equally affects patients of both sexes and of any age. Uncontrolled cutaneous neutrophilic inflammation is the cornerstone in a genetically predisposed individual. Multimodality management is often required to reduce inflammation, optimize wound healing, and treat underlying disease. A gold standard for the management of PG does not exist and high-level evidence is limited. Multiple factors must be taken into account when deciding on the optimum treatment for individual patients: location, number and size of lesion/ulceration(s), extracutaneous involvement, presence of associated disease, cost, and side effects of treatment, as well as patient comorbidities and preferences. Refractory and rapidly progressive cases require early initiation of systemic therapy. Newer targeted therapies represent a promising pathway for the management of PG, and the main focus of this review is the management and evidence supporting the role of new targeted therapies in PG.

Pyoderma gangrenosum in a pregnant patient: A case report and literature review

Pyoderma gangrenosum (PG) is a rare ulcerative skin disease that usually starts as a pustular lesion and rapidly progresses to a painful ulcer with undermined violaceous borders. The occurrence of PG during pregnancy is uncommon. We describe a case of a pregnant patient with PG who was diagnosed as having ulcerative colitis after delivery. Obstetricians need to understand the pathogenesis of PG and its associated conditions because it is important to make a proper diagnosis and provide targeted therapy.

Genetics of inflammatory bowel disease: beyond NOD2

The study of the genetic underpinnings of inflammatory bowel disease has made great progress since the identification of NOD2 as a major susceptibility gene. Novel genotyping and sequencing technologies have led to the discovery of 242 common susceptibility loci, 45 of which have been fine-mapped to statistically conclusive causal variants; 50 genes associated with very-early-onset inflammatory disease have been identified. The evolving genetic architecture of inflammatory bowel disease has deepened our understanding of its pathogenesis through identification of major disease associated pathways-knowledge that has the potential to indicate novel drug targets or markers for personalised medicine. However, many causal variants have yet to be identified, and a large proportion of missing heritability still needs to be accounted for. In addition, the medical and scientific communities are probably not yet fully harnessing the power of these genetic discoveries.

Impaired skin barrier function in mice with colon carcinoma induced by azoxymethane and dextran sodium sulfate

We have previously reported that impaired skin barrier function was induced by small intestinal injury in mice. Therefore, we postulated that other intestinal diseases might also influence skin barrier function. In this study, we evaluated the skin barrier function of hairless mice with colon carcinoma that was induced by azoxymethane (AOM) and dextran sodium sulfate (DSS). In mice treated with these drugs, we observed elevated transepidermal water loss and reduced skin hydration levels, compared to those in the control mice. In addition, plasma nitrogen di/trioxide (NO2(-)/NO3(-)) levels were significantly elevated, and expression of type I collagen was significantly reduced in the treated mice, compared to those in control. These results suggest that impaired skin barrier function occurs in mice when colon carcinoma is present.

Cytokine and Chemokine Profile in Amicrobial Pustulosis of the Folds: Evidence for Autoinflammation

Autoinflammation has recently been suggested in the pathogenesis of neutrophilic dermatoses but systematic studies on their cytokine profile are lacking. Notably, amicrobial pustulosis of the folds (APF), classified among neutrophilic dermatoses, has been studied only in small case series. In our University Hospital, we conducted an observational study on 15 APF patients, analyzing their clinical and laboratory features with a follow-up of 9 months to 20 years. Skin cytokine pattern of 9 of them was compared to that of 6 normal controls. In all patients, primary lesions were pustules symmetrically involving the skin folds and anogenital region with a chronic-relapsing course and responding to corticosteroids. Dapsone, cyclosporine, and tumor necrosis factor blockers were effective in refractory cases. In skin samples, the expressions of interleukin (IL)-1β, pivotal cytokine in autoinflammation, and its receptors I and II were significantly higher in APF (P = 0.005, 0.018, and 0.034, respectively) than in controls. Chemokines responsible for neutrophil recruitment such as IL-8 (P = 0.003), CXCL 1/2/3 (C-X-C motif ligand 1/2/3) (P = 0.010), CXCL 16 (P = 0.045), and RANTES (regulated on activation, normal T cell expressed and secreted) (P = 0.034) were overexpressed. Molecules involved in tissue damage like matrix metalloproteinase-2 (MMP-2) (P = 0.010) and MMP-9 (P = 0.003) were increased. APF is a pustular neutrophilic dermatosis with a typical distribution in all patients. The disorder may coexist with an underlying autoimmune/dysimmune disease but is often associated only with a few autoantibodies without a clear autoimmunity. The overexpression of cytokines/chemokines and molecules amplifying the inflammatory network supports the view that APF has an important autoinflammatory component.

Genetics of Inflammatory Bowel Diseases

In this review, we provide an update on genome-wide association studies (GWAS) in inflammatory bowel disease (IBD). In addition, we summarize progress in defining the functional consequences of associated alleles for coding and noncoding genetic variation. In the small minority of loci where major association signals correspond to nonsynonymous variation, we summarize studies defining their functional effects and implications for therapeutic targeting. Importantly, the large majority of GWAS-associated loci involve noncoding variation, many of which modulate levels of gene expression. Recent expression quantitative trait loci (eQTL) studies have established that the expression of most human genes is regulated by noncoding genetic variations. Significant advances in defining the epigenetic landscape have demonstrated that IBD GWAS signals are highly enriched within cell-specific active enhancer marks. Studies in European ancestry populations have dominated the landscape of IBD genetics studies, but increasingly, studies in Asian and African-American populations are being reported. Common variation accounts for only a modest fraction of the predicted heritability and the role of rare genetic variation of higher effects (ie, odds ratios markedly deviating from 1) is increasingly being identified through sequencing efforts. These sequencing studies have been particularly productive in more severe very early onset cases. A major challenge in IBD genetics will be harnessing the vast array of genetic discovery for clinical utility through emerging precision medical initiatives. In this article, we discuss the rapidly evolving area of direct-to-consumer genetic testing and the current utility of clinical exome sequencing, especially in very early onset, severe IBD cases. We summarize recent progress in the pharmacogenetics of IBD with respect to partitioning patient responses to anti-TNF and thiopurine therapies. Highly collaborative studies across research centers and across subspecialties and disciplines will be required to fully realize the promise of genetic discovery in IBD.

Pathophysiology of pyoderma gangrenosum (PG): an updated review

Pyoderma gangrenosum is a challenging skin condition to identify and treat because of its multifactorial pathogenesis. It is a rare cutaneous manifestation diagnosed clinically by exclusion of infection, neoplasia, thrombophilia, and other inflammatory conditions. Pathogenetic and treatment studies are scarce. Abnormalities in the function of inflammatory cytokines, the immune system, and neutrophils combined with specific genetic mutations predispose patients to develop this complex disease process. Early recognition of patients at risk for pyoderma gangrenosum, the necessity to improve its early diagnosis, and the future outlook of targeted and personalized therapies relies on the improved comprehension of the complex pathogenesis of pyoderma gangrenosum.

Pyoderma gangrenosum: a commonly overlooked ulcerative condition

Background:

Pyoderma ga ngrenosum (PG) is a rare, inflammatory, destructive neutrophilic dermatosis, which mimics other ulcerative conditions.

Materials and Methods:

In a retrospective study based on patients diagnosed with PG over a 3-year period (2010–2013), we evaluated demographics, anatomical sites, number of lesions, subtypes, histopathology, associated conditions, treatment regimens, healing time, and recurrence.

Results:

Of our five patients, there were three males and two females, age ranging between 19 and 58 years (mean age 38 years). Four had single lesions localized to the lower limbs while one had multiple lesions (more than five) over bilateral hands and legs. Ulcerative subtype was observed in all the patients. One exhibited pathergy. Skin biopsies were done in four patients, revealing dense neutrophilic infiltrates in three cases and leukocytoclastic vasculitis in one. Associated systemic diseases were observed in all patients, four having inflammatory bowel disease and one having both systemic lupus erythematosus and anti-phospholipid syndrome. The patients were all treated with systemic corticosteroids either alone or in combination with immunosuppressants (e.g., azathioprine, mycophenolate mofetil, tacrolimus), and wound dressing. Split-thickness skin graft was done in one patient. Complete healing was achieved in all patients, ranging from one to 3 months after diagnosis. No recurrence was reported.

Conclusions:

Systemic corticosteroids, either alone or in combination with steroid-sparing agents are the mainstay of treatment. Should family physicians encounter a rapidly progressing ulcer that has poor response to usual wound management, timely referral to dermatology should be made.