Intravenous immunoglobulin for the treatment of Crohn's disease

Therapeutic approach to central nervous system involvement of Behçet's disease

BACKGROUND

Neurologic involvement in Behçet's disease (BD) represents a major cause of disease morbidity and mortality. Early recognition and timely treatment represent crucial aspects that aim at preventing long-term disability. The absence of robust and evidence-based studies further complicates the management of neuro-BD (NBD). In this review we aim at collecting the best available evidence and suggest a treatment algorithm for an optimal and personalized management of NBD.

EVIDENCE ACQUISITION

PubMed (NLM) database for papers written in English language was used to retrieve relevant articles for this review.

RESULTS AND CONCLUSIONS

Neurologic involvement in BD is one of the most serious and challenging aspects to manage, particularly in its chronic progressive form. It is important to distinguish between acute and chronic progressive NBD, as treatment may vary considerably. Currently, no standardized treatment guidelines support physicians in the decision-making process that therefore relies on low-level evidence. High dose corticosteroids remain the cornerstone for managing acute phase both in the parenchymal and non-parenchymal involvement. Prevention of relapses and control of disease progression represent crucial goals for acute and chronic progressive NBD respectively. In this regard, mycophenolate mofetil and azathioprine are valuable options in the acute NBD. On the other hand, low weekly dose methotrexate has been suggested for chronic progressive NBD. Refractory cases or intolerant patients to conventional therapies may benefit from biologic agents, particularly infliximab. First-line infliximab may be preferred in severe patients with high risk of damage. Other agents including tocilizumab, interleukin-1 inhibitors, B-cell depletion therapy and to a lesser extent, interferon-α and intravenous immunoglobulins are potential options in severe and multidrug resistant cases. Due to multiple organ involvement in BD, long-term treatment should be determined by a multidisciplinary approach. Therefore, multicenter collaborations in the context of international registry-based projects could promote data sharing, standardization of more clinical outcomes and knowledge diffusion that hopefully may optimize therapy and personalize the management of patients with such a complex syndrome.

Crohn's Disease-Like Features in a Patient With IgE and Selective IgG1 and IgG3 Deficiency

We report a 19-year-old male with congenital, combined deficiency of immunoglobulin (Ig) E and 2/4 subclasses of IgG (G1, G3) and chronic diarrhea. He presented at six years of age with chronic recurrent diarrhea responsive to immunoglobulin treatment. Initially, it was considered of infectious origin. However, at the age of 14 years, ileocolonoscopy and magnetic resonance enterography (MRE) were performed, and they showed a mild, limited, non-specific, terminal ileitis with increased eosinophil count on histology. A diagnosis of possible eosinophilic gastroenteritis was made, and budesonide was administered with temporary relief. However, at the age of 19 years, repeat ileocolonoscopy showed multiple ulcers in the terminal ileum and aphthous ulcers in the cecum, and repeat MRE demonstrated extensive ileal involvement. Esophagogastroduodenoscopy demonstrated the involvement of the upper GI tract with aphthous ulcers. Subsequently, gastric, ileal, and colonic biopsies revealed Ziehl-Neelsen-negative, non-caseating granulomas. We hereby report the first case of IgE and selective IgG1 and IgG3 deficiency complicated with Crohn's disease-like extensive GI involvement.

Sexual dimorphism in gut microbiota dictates therapeutic efficacy of intravenous immunoglobulin on radiotherapy complications

INTRODUCTION

With the mounting number of cancer survivors, the complications following cancer treatment become novel conundrums and starve for countermeasures. Intravenous immunoglobulin (IVIg) is a purified preparation for immune-deficient and autoimmune conditions.

OBJECTIVES

Here, we investigated whether IVIg could be employed to fight against radiation injuries and explored the underlying mechanism.

METHODS

Hematopoietic or gastrointestinal (GI) tract toxicity was induced by total body or abdominal local irradiation. High-throughput sequencing was performed to analyze the gut microbiota configurations and gene expression profile of small intestine. The untargeted metabolomics of gut microbiome was assessed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) analyses. Hydrodynamic-based gene delivery was used to knockdown the target genes in vivo.

RESULTS

Intravenous injection of IVIg protected against radiation-induced hematopoietic and GI tract toxicity in female mice but not in males. IVIg structured sex-characteristic gut microbiota configurations in abdominal irradiated mice. The irradiation enriched gut Lachnospiraceae in female mice but reduced those in males. IVIg injection combined with oral gavage of Lachnospiraceae or its metabolite hypoxanthine, alleviated radiation toxicity in male mice however, Lachnospiraceae or hypoxanthine alone failed to ameliorate the injuries. Abdominal local irradiation drove sex-distinct gene expression signatures in small intestine. Mechanistic investigation showed that replenishment of Lachnospiraceae or hypoxanthine offset abdominal radiation-reduced PLD1 expression in male mice. In females, irradiation elevated PLD1 expression. Deletion of PLD1 in GI tract of female mice erased the radioprotective effects of IVIg.

CONCLUSION

IVIg battles against radiation injuries in a sex-specific, gut microbiome-dependent way through Lachnospiraceae/hypoxanthine/PLD1 axis. Our findings provide a sex-precise therapeutic avenue to improve the prognosis of cancer patients with radiotherapy in pre-clinical settings.

Transcriptomic landscape of persistent diarrhoea in rhesus macaques and comparison with humans and mouse models with inflammatory bowel disease

Diarrhoea is a widespread disease in captive rhesus macaques (Macaca mulatta) and a small proportion of individuals may experience persistent diarrhoea. Persistent diarrhoea can lead to a compromised immune system, intestinal inflammation and malnutrition. We analyzed the blood transcriptomes of 10 persistent diarrhoeal and 12 healthy rhesus macaques to investigate the gene expression differences between the two groups. We identified 330 DEGs between persistent diarrhoeal and healthy rhesus macaques. The 211 up-regulated DEGs in the diarrhoeal group were mainly enriched in immune-related and interleukin-related categories. Among them, three interleukin (IL) 18 related DEGs (IL18, IL18R1, and IL18BP) played important roles in actively regulating pro-inflammatory responses. Interestingly, the up- and down-regulated DEGs were both enriched in the same immune-related categories. Thus, we applied a new method to examine the distribution of DEGs in all child categories. We found that interleukin and T cell related categories were mainly occupied by up-regulated DEGs, while immunoglobulin production and B cell related categories were enriched by down-regulated DEGs. We also compared rhesus macaque DEGs with the DEGs of inflammatory bowel disease (IBD) humans and IBD mouse models and found that 30-40% of macaque DEGs were shared with IBD humans and mouse models. In conclusion, our results showed that there were significant immune differences between persistent diarrhoeal rhesus macaques and healthy macaques, which was similar to the expression differences in IBD patients and mouse models.

Effects of compaction and storage conditions on stability of intravenous immunoglobulin - Implication on developing oral tablets of biologics

Biological products, such as therapeutic proteins, vaccines and cell - based therapeutics have a rapidly growing global market. Monoclonal antibody represents a major portion of the biologics market. For biologics that target gastrointestinal tract, the oral delivery route offers many advantages, such as better patient compliance, easy administration and increased stability, over the parental route of administration. To lay the ground work for the oral delivery of biologics, we studied the solid state properties and effects of compaction pressure, particle size, and storage relative humidity on the stability of immunoglobulin G (IVIG). We employed complementary analytical and biophysical techniques, such as size exclusion chromatography and Dynamic light scattering to characterize the aggregates, circular dichroism and solid state Fourier-transform infrared spectroscopy to evaluate protein secondary structure and nano-DSC to probe thermal stability of protein conformations. Our results showed storage relative humidity could induce conformational changes and aggregation of IVIG. However, the IVIG binding activity did not significantly change with relative humidity. The commonly used compaction pressures did not promote protein aggregation, but noticeably reduced binding activity.

Intravenous immunoglobulin (IVIg) or IVIg-treated macrophages reduce DSS-induced colitis by inducing macrophage IL-10 production

Intravenous immunoglobulin (IVIg) is used to treat immune-mediated diseases but its mechanism of action is poorly understood. We have reported that co-treatment with IVIg and lipopolysaccharide activates macrophages to produce large amounts of anti-inflammatory IL-10 in vitro. Thus, we asked whether IVIg-treated macrophages or IVIg could reduce intestinal inflammation in mice during dextran sulfate sodium (DSS)-induced colitis by inducing macrophage IL-10 production in vivo. Adoptive transfer of IVIg-treated macrophages reduces intestinal inflammation in mice and collagen accumulation post-DSS. IVIg treatment also reduces DSS-induced intestinal inflammation and its activity is dependent on the Fc portion of the antibody. Ex vivo, IVIg induces IL-10 production and reduces IL-12/23p40 and IL-1β production in colon explant cultures. Co-staining tissues for mRNA, we demonstrate that macrophages are the source of IL-10 in IVIg-treated mice; and using IL-10-GFP reporter mice, we demonstrate that IVIg induces IL-10 production by intestinal macrophages. Finally, IVIg-mediated protection is lost in mice deficient in macrophage IL-10 production (LysMcre^+/- IL-10^fl/fl mice). Together, our data demonstrate a novel, in vivo mechanism of action for IVIg. IVIg-treated macrophages or IVIg could be used to treat people with intestinal inflammation and may be particularly useful for people with inflammatory bowel disease, who are refractory to therapy.

IgG and Fcγ Receptors in Intestinal Immunity and Inflammation

Fcγ receptors (FcγR) are cell surface glycoproteins that mediate cellular effector functions of immunoglobulin G (IgG) antibodies. Genetic variation in FcγR genes can influence susceptibility to a variety of antibody-mediated autoimmune and inflammatory disorders, including systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). More recently, however, genetic studies have implicated altered FcγR signaling in the pathogenesis of inflammatory bowel disease (IBD), a condition classically associated with dysregulated innate and T cell immunity. Specifically, a variant of the activating receptor, FcγRIIA, with low affinity for IgG, confers protection against the development of ulcerative colitis, a subset of IBD, leading to a re-evaluation of the role of IgG and FcγRs in gastrointestinal tract immunity, an organ system traditionally associated with IgA. In this review, we summarize our current understanding of IgG and FcγR function at this unique host-environment interface, from the pathogenesis of colitis and defense against enteropathogens, its contribution to maternal-fetal cross-talk and susceptibility to cancer. Finally, we discuss the therapeutic implications of this information, both in terms of how FcγR signaling pathways may be targeted for the treatment of IBD and how FcγR engagement may influence the efficacy of therapeutic monoclonal antibodies in IBD.

Intravenous Immunoglobulin Therapy Eliminates Candida albicans and Maintains Intestinal Homeostasis in a Murine Model of Dextran Sulfate Sodium-Induced Colitis

Intravenous immunoglobulin (IVIg) therapy has diverse anti-inflammatory and immunomodulatory effects and has been employed successfully in autoimmune and inflammatory diseases. The role of IVIg therapy in the modulation of intestinal inflammation and fungal elimination has not been yet investigated. We studied IVIg therapy in a murine model of dextran sulfate sodium (DSS)-induced colitis. Mice received a single oral inoculum of Candidaalbicans and were exposed to DSS treatment for 2 weeks to induce colitis. All mice received daily IVIg therapy starting on day 1 for 7 days. IVIg therapy not only prevented a loss of body weight caused by the development of colitis but also reduced the severity of intestinal inflammation, as determined by clinical and histological scores. IVIg treatment significantly reduced the Escherichiacoli,Enterococcusfaecalis, and C.albicans populations in mice. The beneficial effects of IVIg were associated with the suppression of inflammatory cytokine interleukin (IL)-6 and enhancement of IL-10 in the gut. IVIg therapy also led to an increased expression of peroxisome proliferator-activated receptor gamma (PPARγ), while toll-like receptor 4 (TLR-4) expression was reduced. IVIg treatment reduces intestinal inflammation in mice and eliminates C.albicans overgrowth from the gut in association with down-regulation of pro-inflammatory mediators combined with up-regulation of anti-inflammatory cytokines.

Efficacy and Factors Associated with Treatment Response of Intravenous Immunoglobulin in Inpatients with Refractory Inflammatory Bowel Diseases

BACKGROUND

The administration of intravenous immunoglobulin (IVIG) has demonstrated promise in the treatment of medically refractory inflammatory bowel diseases (IBD). We aimed to identify factors associated with IVIG failures in the treatment of refractory IBD.

METHODS

Our historical cohort included patients with refractory IBD admitted to our inpatient service with an exacerbation and treated with at least 1 dose of IVIG (0.4 g/kg). Detailed clinical variables were recorded for subjects. Examined outcomes included changes in disease-specific severity indices, the duration of surgery-free survival after IVIG, infusion reactions, subsequent IBD-related emergency department visits, hospital readmissions, and mortality.

RESULTS

Fifty-four subjects with refractory IBD (61% female, age 42 ± 16 yrs, 23 with Crohn's disease, 15 with ulcerative colitis, 16 with pouchitis) met the inclusion criteria. All disease severity scores were significantly improved after IVIG administration (Harvey-Bradshaw index P = 0.007, partial Mayo score P = 0.002, modified Pouchitis Disease Activity Index P = 0.008). Twenty-seven patients (50%) underwent surgery, with a mean surgery-free survival of 28.7 ± 3.7 months. In univariable analysis, patients with Clostridium difficile infection (CDI) had a 3-fold increased risk of bowel resection surgery after IVIG compared with those without (hazard ratio = 2.9, 95% confidence interval, 1.2-7.4; P = 0.023), and in subsequent multivariable analysis, CDI remained significant (hazard ratio = 3.0, 95% confidence interval, 1.2-7.6; P = 0.024). CDI was also associated with increased risk of hospital readmission (hazard ratio = 2.5, 95% confidence interval, 1.05-5.9; P = 0.038).

CONCLUSIONS

Our study demonstrates that IVIG is beneficial in patients with medically refractory IBD, and that concomitant CDI is a risk factor for the treatment failure of IVIG for refractory disease.

Gastrointestinal Manifestations in X-linked Agammaglobulinemia

PURPOSE

X-linked agammaglobulinemia is a primary humoral immunodeficiency characterized by hypogammaglobulinemia and increased susceptibility to infection. Although there is increased awareness of autoimmune and inflammatory complications in X-linked agammaglobulinemia (XLA), the spectrum of gastrointestinal manifestations has not previously been fully explored.

METHODS

We present a case report of a family with two affected patients with XLA. Given the gastrointestinal involvement of the grandfather in this family, we performed a retrospective descriptive analysis of XLA patients with reported diagnoses of GI manifestations and inflammatory bowel disease (IBD) or enteritis registered at the United States Immunodeficiency Network, a national registry of primary immunodeficiencies.

RESULTS

In this cohort of patients with XLA, we found that up to 35% had concurrent gastrointestinal manifestations, and 10% had reported diagnoses of IBD or enteritis. The most commonly reported mutations were missense, which have been associated with a less severe XLA phenotype in the literature. The severity of symptoms were wide ranging, and management strategies were diverse and mainly experimental.

CONCLUSIONS

Patients with XLA may require close monitoring with particular attention for GI manifestations including IBD and infectious enteritis. Further studies are needed to improve diagnosis and management of GI conditions in XLA patients.

Impact of Low Immunoglobulin G Levels on Disease Outcomes in Patients with Inflammatory Bowel Diseases

BACKGROUND

Inflammatory bowel diseases (IBDs) are considered immune-mediated disorders with dysregulated innate and adaptive immunities. Secondary immunogloblin deficiency can occur in IBD and its impact on the disease course of IBD is not clear.

AIMS

We sought to determine associations between low IgG/G1 levels and poor clinical outcomes in IBD patients.

METHODS

This historic cohort study was performed on IBD patients with obtained IgG/IgG1 levels. The primary outcome was defined as any IBD-related bowel resection surgery and/or hospitalization. Subgroup analyses assessed particular surgical outcomes in Crohn's disease (CD), ulcerative colitis (UC) or indeterminate colitis (IC), and ileal pouch-anal anastomosis (IPAA). The secondary outcomes included IBD drug escalations and C. difficile or cytomegalovirus infections.

RESULTS

A total of 136 IBD patients had IgG/G1 levels checked and adequate follow-up, 58 (42.6 %) with normal IgG/G1 levels and 78 (57.4 %) having low levels. A total of 49 patients (62.8 %) with low immunoglobulin levels had IBD-related surgeries or hospitalizations, compared to 33 patients (56.9 %) with normal levels [odds ratio (OR) 1.28, 95 % confidence interval (CI) 0.64-2.56; p = 0.49]. Low IgG/G1 levels were associated with IBD-related surgery in CD in univariate analysis [hazard ratio (HR) 4.42, 95 % CI 1.02-19.23; p = 0.048] and in Kaplan-Meier survival curve analysis (p = 0.03), with a trend toward significance on multivariate analysis (HR 3.07, 95 % CI 0.67-14.31; p = 0.15). IBD patients with low IgG/G1 levels required more small bowel resections (12.8 vs. 1.7 %, p = 0.024) and 5-aminosalicylate initiations (28.2 vs. 13.8 %, p = 0.045).

CONCLUSIONS

Our study demonstrated a possible association between low IgG/G1 levels and poor outcomes in CD including surgery. Future implications include using immunoglobulin levels in IBD patients as a prognostic indicator or boosting humoral immunity as a treatment in this subset.

B-Cell Dysregulation in Crohn's Disease Is Partially Restored with Infliximab Therapy

BACKGROUND

B-cell depletion can improve a variety of chronic inflammatory diseases, but does not appear beneficial for patients with Crohn's disease.

OBJECTIVE

To elucidate the involvement of B cells in Crohn's disease, we here performed an 'in depth' analysis of intestinal and blood B-cells in this chronic inflammatory disease.

METHODS

Patients with Crohn's disease were recruited to study B-cell infiltrates in intestinal biopsies (n = 5), serum immunoglobulin levels and the phenotype and molecular characteristics of blood B-cell subsets (n = 21). The effects of infliximab treatment were studied in 9 patients.

RESULTS

Granulomatous tissue showed infiltrates of B lymphocytes rather than Ig-secreting plasma cells. Circulating transitional B cells and CD21low B cells were elevated. IgM memory B cells were reduced and natural effector cells showed decreased replication histories and somatic hypermutation (SHM) levels. In contrast, IgG and IgA memory B cells were normally present and their Ig gene transcripts carried increased SHM levels. The numbers of transitional and natural effector cells were normal in patients who responded clinically well to infliximab.

CONCLUSIONS

B cells in patients with Crohn's disease showed signs of chronic stimulation with localization to granulomatous tissue and increased molecular maturation of IgA and IgG. Therapy with TNFα-blockers restored the defect in IgM memory B-cell generation and normalized transitional B-cell levels, making these subsets candidate markers for treatment monitoring. Together, these results suggest a chronic, aberrant B-cell response in patients with Crohn's disease, which could be targeted with new therapeutics that specifically regulate B-cell function.

Use of Intravenous Immunoglobulin for Patients with Inflammatory Bowel Disease with Contraindications or Who Are Unresponsive to Conventional Treatments

BACKGROUND

Managing patients with IBD who are refractory or have contraindications to standard therapies is challenging. Many will lose response, become intolerant to treatment, or develop infections with contraindication for immunosuppression. Therefore, alternative therapies, such as the use of intravenous immunoglobulin (IVIg), could be used to manage patients in these difficult cases.

METHODS

Data were extracted retrospectively from the electronic medical records at Vanderbilt University on patients with IBD who received IVIg (February 2011-June 2013). Patients were treated with IVIg 0.4 g·kg·d for 3 consecutive days and then 0.4 g/kg once monthly. The dose was increased to 0.4 g/kg biweekly for loss of response or partial response. Clinical response was defined as decreasing the Harvey-Bradshaw Index ≥3 points or improvement in C-reactive protein >25%. Clinical remission was defined as Harvey-Bradshaw Index score <5, no hospitalizations or surgeries after IVIg, or symptom resolution. Statistical analysis was performed using Wilcoxon signed-rank test.

RESULTS

Twenty-four patients with IBD received IVIg. Seventeen patients received IVIg for failure of standard treatment. Six patients received IVIg during active infection. Two patients had histoplasmosis, 1 patient had tuberculosis, and 2 patients had pulmonary fungal infections. One patient with ulcerative colitis was given IVIg for recurrent Clostridium difficile. Nine patients required dose escalation after median 153 days (30-360). Ninteen patients (79%) had a response or remission. Sixteen (67%) had a response and 3 (12.5%) obtained remission with IVIg. C-reactive protein decreased significantly after treatment (19 mg/dL [0.1-77] to 7.5 [0.2-20]), P < 0.05. Harvey-Bradshaw Index scores improved (8 [0-19] to 6 [0-17]), P = not significant. Of note, 62.5% had endoscopic improvement after treatment.

CONCLUSIONS

IVIg is safe and effective in the short-term management of patients with IBD when standard therapies are contraindicated.

Inflammatory bowel disease meta-evidence and its challenges: is it time to restructure surgical research?

AIM

The aim of this study was to compare the methodological quality and input paper characteristics of systematic reviews and meta-analyses reported in the medical and surgical literature by performing a systematic 'overview of reviews'. Ulcerative colitis (UC) and Crohn's disease (CD) were used as the framework for this comparison as they are relatively common serious conditions, with both medical and surgical options for therapy.

METHOD

Medline, Embase, CINHAL and the Cochrane Database were searched to November 2013. Eligible papers were systematic reviews or meta-analyses that considered a question of therapy in CD or UC. Two independent reviewers selected the papers, extracted the data and scored their methodology using the AMSTAR scoring system. The papers were categorized into medical therapy (M), surgical therapy (S) or medical and surgical therapy (MS) groups. Following retrieval of the sample of meta-evidence papers, the original input studies used in their creation were identified and a search of Medline, Embase, CINHAL and the Cochrane Database was performed. A team of researchers then examined the collection of papers for bibliographic and financial information.

RESULTS

Five hundred papers were identified in the meta-evidence search, of which 118 were deemed eligible. There was a difference in the AMSTAR-rated average quality of the papers between the S and M group (S 7.36 vs M 8.75, P = 0.01). On average S papers were published in journals with a lower impact factor (S 3.26, M 5.04, MS 5.30, P < 0.001). S papers also showed more heterogeneity (I(2) ; S 37%, M 24%, MS 10%, P < 0.001). Some 25% of S meta-analyses used data-sets with significant heterogeneity (I(2) > 75%), compared with 8% of M meta-analyses and 3% of the MS meta-analyses. Some 5% of S papers were done on data sets that had I(2) values > 90%. There was no difference in the average number of papers assessed in each group, the average number of patients per meta-paper, the average time covered by the reviews, the average number of papers considered within each meta-analysis, or the average number of patients considered within each meta-analysis. Considering the conclusions of each meta-analysis, S meta-evidence was 50% more likely than M meta-evidence to be unable to make recommendations for practice. A total of 1499 original input papers were identified, of which 283 were used in more than one review. Within the non-repeated papers (n = 1023) the average impact factor within the S group was lower than that of the M and the MS groups (3.720 vs 11.230 vs 7.563, respectively; ANOVAP < 0.001). M papers had higher rates of pharmaceutical sponsorship than S papers (M 56% vs S 1%) and twice the level of government support (M 16% vs S 8%). Of note, 21% of M papers had corporate sponsorship but did not list any conflict of interest.

CONCLUSION

Compared with M meta-analyses, S meta-analyses in the UC and CD domain are more likely to be of poorer methodological quality, are of a greater degree of heterogeneity and less often offer a positive conclusion. The papers used to generate meta-evidence in M papers have a greater degree of corporate and government sponsorship, and are more likely to come from journals with higher impact factors.

Inflammatory bowel disease associates with proinflammatory potential of the immunoglobulin G glycome

BACKGROUND

Glycobiology is an underexplored research area in inflammatory bowel disease (IBD), and glycans are relevant to many etiological mechanisms described in IBD. Alterations in N-glycans attached to the immunoglobulin G (IgG) Fc fragment can affect molecular structure and immunological function. Recent genome-wide association studies reveal pleiotropy between IBD and IgG glycosylation. This study aims to explore IgG glycan changes in ulcerative colitis (UC) and Crohn's disease (CD).

METHODS

IgG glycome composition in patients with UC (n = 507), CD (n = 287), and controls (n = 320) was analyzed by ultra performance liquid chromatography.

RESULTS

Statistically significant differences in IgG glycome composition between patients with UC or CD, compared with controls, were observed. Both UC and CD were associated with significantly decreased IgG galactosylation (digalactosylation, UC: odds ratio [OR] = 0.71; 95% confidence interval [CI], 0.5-0.9; P = 0.01; CD: OR = 0.41; CI, 0.3-0.6; P = 1.4 × 10) and significant decrease in the proportion of sialylated structures in CD (OR = 0.46, CI, 0.3-0.6, P = 8.4 × 10). Logistic regression models incorporating measured IgG glycan traits were able to distinguish UC and CD from controls (UC: P = 2.13 × 10 and CD: P = 2.20 × 10), with receiver-operator characteristic curves demonstrating better performance of the CD model (area under curve [AUC] = 0.77) over the UC model (AUC = 0.72) (P = 0.026). The ratio of the presence to absence of bisecting GlcNAc in monogalactosylated structures was increased in patients with UC undergoing colectomy compared with no colectomy (FDR-adjusted, P = 0.05).

CONCLUSIONS

The observed differences indicate significantly increased inflammatory potential of IgG in IBD. Changes in IgG glycosylation may contribute to IBD pathogenesis and could alter monoclonal antibody therapeutic efficacy. IgG glycan profiles have translational potential as IBD biomarkers.

7th International Immunoglobulin Conference: Immunomodulation

Immunomodulation uses synthetic, natural and recombinant preparations to modify the immune response to a desired level, typically to treat specific autoimmune diseases, as will be discussed in this section. Rheumatoid arthritis (RA) is a common systemic autoimmune disease, affecting 1% of the population worldwide. Currently, a first-line disease-modifying therapy for RA is methotrexate; however, more than 40 monoclonal antibodies are in use or under investigation for the treatment of RA. This panoply of biological disease-modifying agents means that clinicians can make use of drugs with different mechanisms of action should one type become ineffective. In autoimmune pemphigus conditions, identification of pathogenic autoantibodies against intercellular cadherin desmoglein 1 and/or 3 antigens is one of the criteria for appropriate diagnosis. In pemphigoid conditions, autoantibodies are directed against bullous pemphigoid antigens BP230 and BP180, and in both types of immunobullous disease intravenous immunoglobulin (IVIg), as adjuvant therapy in combination with a cytotoxic drug, is effective in reducing autoantibody levels, disease severity and background steroid use. Further studies are required to establish the role of monoclonal antibodies in the treatment of autoimmune bullous disease. IVIg may also be effective in another at-risk population with autoimmune disease, namely secondary recurrent miscarriage (RM). However, the mechanism of action of IVIg in secondary RM is largely unknown, although levels of natural killer cell biomarkers, particularly CD56(+) , have been shown to decline after IVIg treatment. Data from meta-analyses of heterogeneous placebo-controlled trials indicate that IVIg may be effective in secondary RM, but most trials to date have used immunomodulatory doses lower than those considered to be efficient in autoimmune disease. The results of a recently completed study may help to address this question.

Fecal calprotectin in systemic sclerosis and review of the literature

Fecal calprotectin (FC) is a simple, non-invasive and reproducible test, which has been described to be highly elevated in patients with active inflammatory bowel diseases. Recently, few authors have reported increased levels of FC in SSc patients, although the relationship between FC levels and the degree of gastrointestinal involvement has not yet been determined in patients with SSc. Thus, this prospective study aimed to: 1) determine the prevalence of increased fecal calprotectin (FC) levels in unselected patients with systemic sclerosis (SSc); 2) make prediction about which SSc patients exhibit increased levels of FC; and 3) evaluate the correlation between increased levels of FC and digestive symptoms, and gastrointestinal involvement, including the presence of small intestinal bacterial overgrowth (SIBO) using glucose H2/CH4 breath test. 125 consecutive patients with SSc underwent FC levels and glucose H2/CH4 breath test. All of the patients with SSc also completed a questionnaire on digestive symptoms, and a global symptom score (GSS) was calculated. 93 (74.4%) patients had abnormal levels of FC (>50 μg/g); 68 patients (54.4%) exhibited highly elevated levels of FC (>200 μg/g). A marked correlation was found between abnormal FC levels and GSS score of digestive symptoms, esophageal involvement and delayed gastric emptying. Moreover, we found a strong association between abnormal levels of FC and the presence of SIBO on glucose H2/CH4 breath test, with the higher correlation between the presence of SIBO and the level of FC ≥275 μg/g with an area under the receiver operating characteristic curve of 0.97 ± 0.001 (CI: 0.93-0.99; p<10(-6)); the sensitivity of FC level ≥275 μg/g for predicting SIBO was as high as 0.93, while the specificity was 0.95. Finally, eradication of SIBO was obtained in 52.4% of the SSc patients with a significant improvement of intestinal symptoms. Finally, after 3 months of rotating courses of alternative antibiotic therapy, eradication of SIBO was associated with significant decrease of FC levels in SSc patients. The current study underscores that abnormal FC levels were correlated with gastrointestinal impairment, especially SIBO. Because FC levels ≥275 μg/g were markedly associated with the presence of SIBO, our findings suggest that FC may be a helpful test in identifying the group of SSc patients at high risk for SIBO requiring glucose breath test to detect SIBO. Finally, we also suggest that FC levels may be helpful in SSc patients to assess SIBO eradication, as long-term antibiotic therapy is costly and carries risks such as the onset of pseudo-membranous colitis and SIBO-related antibiotic resistance.

Frequency and risk factors of low immunoglobulin levels in patients with inflammatory bowel disease

Background and aims: Inflammatory bowel diseases (IBD) are considered to be dysregulated, immune-mediated disorders; and immunosuppressive medications are the mainstay of their treatment. Clinically, we have often observed low serum immunoglobulin (Ig) levels in these patients. The aim of this study was to assess the frequency and risk factors of secondary humoral immunodeficiency in IBD patients.

Methods: We conducted a cross-sectional study of eligible IBD patients with Crohn’s disease (CD), ulcerative colitis (UC), indeterminate colitis (IC) or restorative proctocolectomy with ileal pouch, who having serum Ig measured. Demographic and clinical variables were measured. Univariate and multivariate analyses were performed.

Results: A total of 324 patients was included, with a mean age of 38.8 years and 158 (48.8%) being male. Low IgG, IgG1, IgA, and IgM were found in 22.7%, 23.4%, 7.9%, and 10.9% of patients, respectively. The shared risk factors for a low IgG or IgM level were increasing age [odds ratio (OR) = 1.13; 95% confidence interval (CI) 1.03–1.23 for low IgG level and OR = 1.33; 95% CI 1.15–1.56 for low IgM level] and hypoalbuminemia (OR = 1.83; 95% CI 1.01–3.33 for low IgG level and OR = 3.17; 95% CI 1.23–8.15 for low IgM level). In addition, thioprine use was associated with low IgA level (OR = 2.76; 95% CI 1.03–7.39). IBD disease duration was a risk factor for low IgG1 level (OR = 1.40; 95% CI 1.12–1.76). The presence of concurrent primary sclerosing cholangitis (OR = 0.064; 95% CI 0.007–0.60) and the use of biologics (OR = 0.16; 95% CI 0.033–0.79) were associated with normal IgG1 level. IgG level was lower in CD patients than that in UC/IC and ileal pouch patients (P = 0.042). IgG and IgA levels were elevated in patients with inflammatory conditions of the pouch (P = 0.01; P = 0.003, respectively).

Conclusions: Low Ig level appears to be common in IBD patients. Increasing age, disease duration and hypoalbuminemia appeared to be risk factors. The findings may provide rationale for targeted therapy to boost humoral immunity in selected patients with IBD.

A comprehensive review and update on the biologic treatment of adult noninfectious uveitis: part II

INTRODUCTION

Treatment of adult, noninfectious uveitis remains a major challenge for ophthalmologists around the world, especially in regard to recalcitrant cases. It is reported to comprise approximately 10% of preventable blindness in the USA. The cause of uveitis can be idiopathic or associated with infectious and systemic disorders. The era of biologic medical therapies provides new options for patients with otherwise treatment-resistant inflammatory eye disease.

AREAS COVERED

This two-part review gives a comprehensive overview of the existing medical treatment options for patients with adult, noninfectious uveitis, as well as important advances for the treatment ocular inflammation. Part I covers classic immunomodulation and latest information on corticosteroid therapy. In part II, emerging therapies are discussed, including biologic response modifiers, experimental treatments and ongoing clinical studies for uveitis.

EXPERT OPINION

The hazard of chronic corticosteroid use in the treatment of adult, noninfectious uveitis is well documented. Corticosteroid-sparing therapies, which offer a very favorable risk-benefit profile when administered properly, should be substituted. Although nothing is currently approved for on-label use in this indication, many therapies, through either translation or novel basic science research, have the potential to fill the currently exposed gaps.

The complement system in inflammatory bowel disease

Complement is well appreciated to be a potent innate immune defense against microbes and is important in the housekeeping act of removal of apoptotic and effete cells. It is also understood that hyperactivation of complement, or the lack of regulators, may underlie chronic inflammatory diseases. A pipeline of products to intervene in complement activation, some already in clinical use, is being studied in various chronic inflammatory diseases. To date, the role of complement in inflammatory bowel disease has not received a lot of research interest. Novel genetically modified laboratory animals and experiments using antagonists to complement effector molecules have kindled important research observations implicating the complement system in inflammatory bowel disease pathogenesis. We review the evidence base for the role and potential therapeutic manipulation of the complement cascade in inflammatory bowel disease.

Impact of treatment on survival in polymyositis and dermatomyositis. A single-centre long-term follow-up study

OBJECTIVE

To assess the long-term outcome in polymyositis (PM) and dermatomyositis (DM), with a particular emphasis on mortality and influence of treatment.

METHODS

Diagnosis was based according to the Bohan and Peter's criteria. Patients have been followed up by a standardised protocol. Deaths were registered and causes of death were ascertained. Survival probability at 5 and 10years was estimated according to the Kaplan-Meier method, in the overall series and by a diagnostic group and an initial treatment. Mortality hazard ratios (95% CI) for major clinical and demographic features were estimated through univariate and multivariate Cox proportional hazard models.

RESULTS

91 patients (43 PM and 48 DM) were available for the study. Baseline characteristics were not different from those previously reported. Twenty-two patients (24%) died after a median follow-up of 8.7years. As for idiopathic myositis, the survival probabilities at 5 and 10years from the diagnosis were 96.2% and 88.8% for PM respectively; and 93.9% for DM, whereas a higher mortality was documented for cancer-associated myositis and overlap myositis. Male sex [HR=2.4, 95% CI 1.0 to 5.6], heart involvement (HR=1.8), interstitial lung disease (HR=2.3) and arthritis (HR=1.8) increased the risk of mortality, these risk excesses were confirmed in the multivariate analysis. Independent of these features, a higher mortality was documented for patients treated with glucocorticoids (HR=2.3) or immunosuppressants (HR=2.1) when compared to patients treated with immunoglobulins.

CONCLUSION

Our study, with longitudinal and statistical analyses, suggests that survival has considerably increased in patients with PM/DM. Prognostic factors for mortality are male sex, and heart and lung involvement. Immunoglobulin treatment, intravenously or subcutaneously, is associated with a better survival.