Anatomical Variation in Mesenteric Macrophage Phenotypes in Crohn's Disease.

INTRODUCTION: Clinical trials are currently investigating whether an extended mesenteric resection for ileocecal resections could reduce postoperative recurrence in Crohn's disease. Resection of the mesorectum, which contains proinflammatory macrophages, during proct(ocol)ectomy, is associated with reduced recurrent inflammation and improved wound healing. We aimed to characterize the macrophages in the ileocecal mesentery, which were compared with those in the mesorectum, to provide a biological rationale for the ongoing trials. METHODS: In 13 patients with Crohn's disease and 4 control patients undergoing a proctectomy, tissue specimens were sampled at 3 locations from the mesorectum: distal (rectum), middle, and proximal (sigmoid). In 38 patients with Crohn's disease and 7 control patients undergoing ileocecal resections, tissue specimens also obtained from 3 locations: adjacent to the inflamed terminal ileum, adjacent to the noninflamed ileal resection margin, and centrally along the ileocolic artery. Immune cells from these tissue specimens were analyzed by flow cytometry for expression of CD206 to determine their inflammatory status. RESULTS: In the mesorectum, a gradient from proinflammatory to regulatory macrophages from distal to proximal was observed, corresponding to the adjacent inflammation of the intestine. By contrast, the ileocecal mesentery did not contain high amounts of proinflammatory macrophages adjacent to the inflamed tissue, and a gradient toward a more proinflammatory phenotype was seen in the central mesenteric area. DISCUSSION: Although the mesentery is a continuous structure, the mesorectum and the ileocecal mesentery show different immunological characteristics. Therefore, currently, there is no basis to perform an extended ileocecal resection in patients with Crohn's disease.

Treg and NK cells related cytokines are associated with deep rectosigmoid endometriosis and clinical symptoms related to the disease.

The aim of this study was to evaluate Treg and NK cells related cytokines in deep infiltrating endometriosis lesions and its relationship with clinical symptoms of the disease. mRNA expression of Transforming Growth Factor Beta (TGFB), Interleukin (IL)10, Interferon Gamma (IFNG), IL7, and IL15 was analyzed by Real-Time PCR in eutopic endometrium and rectosigmoid lesions from 11 women with deep infiltrating endometriosis and in eutopic endometrium from 11 healthy women. IL10, IFNG, and IL7 expression was significantly higher in endometriotic bowel lesions than in eutopic endometrium from women with endometriosis. IL10 and TGFB expression was significantly higher in endometriotic bowel lesions than in eutopic endometrium from healthy women. In addition, TGFB and IL15 levels correlated positively with deep dyspareunia and cyclic dyschezia, respectively, while IL7 levels correlated negatively with dysmenorrhea. Deep infiltrating rectosigmoid endometriosis displays alterations in Treg and NK cells related cytokine, and TGFB, IL7 and IL15 expression is related with dyspareunia, dysmenorrhea and cyclic dyschezia, respectively, in patients with the disease.

Global Cytokine Profiles and Association With Clinical Characteristics in Patients With Irritable Bowel Syndrome.

OBJECTIVES: Evidence suggests that patients with irritable bowel syndrome (IBS) have an altered cytokine profile, although it is unclear whether cytokines are linked with symptom severity. We aimed to determine whether global serum and mucosal cytokine profiles differ between IBS patients and healthy subjects and whether cytokines are associated with IBS symptoms. METHODS: Serum from 144 IBS patients and 42 healthy subjects was analyzed for cytokine levels of interleukin (IL)-5, IL-6, IL-8, IL-10, IL-12p70, IL-13, IL-17A, interferon (IFN)-γ, and tumor necrosis factor (TNF) by MSD MULTI-ARRAY. In total, 109 IBS and 36 healthy sigmoid colon biopsies were analyzed for mRNA expression of IL-8, IL-10, TNF, and FOXP3 by quantitative reverse transcription PCR. Multivariate discrimination analysis evaluated global cytokine profiles. Rectal sensitivity, oroanal transit time, and psychological and gastrointestinal symptom severity were also assessed. RESULTS: Global cytokine profiles of IBS patients and healthy subjects overlapped, but cytokine levels varied more in IBS patients. Serum levels of IL-6 and IL-8 tended to be increased and levels of IFN-γ tended to be decreased in IBS patients. Mucosal mRNA expression of IL-10 and FOXP3 tended to be decreased in IBS patients. Within both the full study cohort and IBS patients alone, serum level of TNF was associated with looser stool pattern, while subjects with more widespread somatic symptoms had increased serum levels of IL-6. Although neither IBS bowel habit subgroups nor patients with possible post-infectious IBS were associated with distinct cytokine profiles, a small cluster of IBS patients with comparatively elevated immune markers was identified. CONCLUSIONS: Global cytokine profiles did not discriminate IBS patients from healthy subjects, but cytokine profiles were more varied among IBS patients than among healthy subjects, and a small subgroup of patients with enhanced immune activity was identified. Also, association of inflammatory cytokines with some clinical symptoms suggests that immune activation may be of importance in a subset of IBS patients.

Cancer of the sigmoid colon and antibodies. A puzzle.

UNLABELLED: In this work we describe the case report of a woman affected by cancer of the sigmoid colon and with a positive direct antiglobulin test (DAT) and indirect antiglobulin test (IAT). Case report with results: A meticulous medical history showed that the woman had been suffering from recurrent fetal loss. Then she had cardiac and coagulative problems. These data suggested a phospholipid syndrome. CONCLUSION: The patient had a medical history positive for a phospholipid syndrome and we think that this disease could explain the onset of the autoantibody.

Influence of CD68+ macrophages and neutrophils on anastomotic healing following laparoscopic sigmoid resection due to diverticulitis.

BACKGROUND: The aim of this prospective study was to evaluate the predictive value of a potential preexisting low-grade inflammation regarding the incidence of anastomotic leakage in elective laparoscopic sigmoid resection due to diverticulitis. METHODS: Patients with either chronically recurrent diverticulitis or sigmoid stenosis caused by chronic diverticulitis were included in this study. All patients with acute local or systemic inflammation were excluded. Detailed patient information (e.g. American Society of Anesthesiologists (ASA) grade, comorbidities, duration of hospital stay, and anastomotic leakage) was prospectively recorded. CD68(+) macrophages, neutrophils, CD3(+) T-lymphocytes, CD11c(+) dendritic cells, MHCII, TNFR1, and NF-κB were evaluated by immunohistochemistry within the acquired sample of colonic bowel wall tissue. Clinical and immunohistochemical data was compared between groups (leakage vs. no leakage). Additionally, a matched-pair analysis was performed due to the widely heterogeneous groups concerning the number of patients and to minimize the effect of extraneous variables. RESULTS: A total of 83 patients were included in the study, of which 7 patients suffered an anastomotic leakage. Neither the clinical nor the immunohistochemical parameters were significantly different between the groups. The matched-pair analysis revealed a nonsignificant increase in mean duration of hospital stay for the group with anastomotic leakage and a significantly higher percentage of CD68(+) macrophages and neutrophils in the colonic wall obtained at the index operation in both the mucosal and submucosal layers for the leakage group. CONCLUSIONS: A preexisting low-grade inflammation represented by infiltrates of macrophages and neutrophils is a predictor for increased risk of developing colon anastomotic leakage.

Expression of membrane drug efflux transporters in the sigmoid colon of HIV-infected and uninfected men.

The use of antiretroviral therapy (ART) as pre-exposure prophylaxis (PrEP) has gained global attention as a promising HIV prevention strategy in men who have sex with men. Permeability of these agents in the rectal mucosa may be partially regulated by interactions with drug efflux transporters, P-glycoprotein (P-gp), multidrug resistance-associated proteins (MRPs) and/or breast cancer resistance protein (BCRP). The objective of this work was to investigate the expression of drug efflux transporters in recto-sigmoid colon tissues of HIV-infected and uninfected men, and evaluate the association of ART and/or HIV infection with drug transporter expression. MDR1/P-gp, MRPs (1-4) and BCRP mRNA and protein expression were detected in sigmoid colon biopsies of HIV-uninfected individuals. Biopsies from HIV-infected, ART-naïve participants revealed a significant downregulation of P-gp and MRP2 protein levels compared to HIV-uninfected individuals. Biopsies from HIV-infected ART-treated patients showed 1.9-fold higher P-gp protein expression and 1.5-fold higher MRP2 protein expression compared to the ones obtained from the HIV-infected ART-naïve patients. This is a first report demonstrating that HIV infection or ART could alter expression of drug efflux transporters in gut mucosa which in turn could affect the permeability of PrEP antiretroviral agents across this barrier, a highly vulnerable site of HIV transmission.

Colonic involvement in celiac disease and possible implications of the sigmoid mucosa organ culture in its diagnosis.

PURPOSE: Celiac disease (CD), a systemic autoimmune disorder that typically involves duodenal mucosa, can also affect other intestinal areas. Duodenal and oral mucosa organ culture has already been demonstrated as a reliable procedure to identify CD. The present study investigated gluten-dependent immunological activation of colonic mucosa in CD patients. We took advantage of the numerous colonoscopies performed for various clinical conditions or only for defensive medicine. METHODS: Forty-four patients with gastrointestinal symptoms or in need of colorectal cancer screening were divided into patients with serum anti-endomysium (EMA) and anti-tissue transglutaminase (anti-tTG) antibody positive results (Group A), patients with serum antibody negative results (Group B), and patients with inflammatory bowel disease (IBD) (Group C). The autoantibodies EMA and anti-tTG were evaluated in supernatants of cultured sigmoid and duodenal biopsies from patients on a gluten-containing diet. RESULTS: In Group A, EMA and anti-tTG resulted positive in all duodenal culture supernatants. In sigmoid culture supernatants, EMA and anti-tTG were detected in 12/16 (75 %) and 13/16 (81.3 %) patients, respectively. In Group B, none of the 17 patients showed EMA and anti-tTG positive results in both duodenal and sigmoid cultures. In Group C, all 11 patients presented EMA negative results in sigmoid cultures. Only in one patient, anti-tTG were detectable in the sigmoid culture supernatant, as expected in cases of IBD. CONCLUSIONS: Data confirm that the gluten-dependent immunological activation affects more intestinal tracts with different degrees of involvement, suggesting that the organ culture of colonic biopsies could represent a new tool to opportunistically detect CD.

A role for mucosal IL-22 production and Th22 cells in HIV-associated mucosal immunopathogenesis.

Interleukin-22 (IL-22) is a cytokine with epithelial reparative and regenerative properties that is produced by Th22 cells and by other immune cell subsets. Therefore, we explored the hypothesis that disruption of the gut barrier during HIV infection involves dysregulation of these cells in the gastrointestinal mucosa. Sigmoid IL-22-producing T cell and Th22 cells were dramatically depleted during chronic HIV infection, epithelial integrity was compromised, and microbial translocation was increased. These alterations were reversed after long-term antiretroviral therapy. While all mucosal IL-22-producing T-cell subsets were also depleted very early during HIV infection, at these early stages IL-22 production by non-T-cell populations (including NKp44+ cells) was increased and gut epithelial integrity was maintained. Circulating Th22 cells expressed a higher level of the HIV co-receptor/binding molecules CCR5 and α4ß7 than CD4+ T-cell subsets in HIV-uninfected participants, but this was not the case after HIV infection. Finally, recombinant IL-22 was protective against HIV and tumor necrosis factor-α-induced gut epithelial damage in a validated in vitro gut epithelial system. We conclude that reduced IL-22 production and Th22 depletion in the gut mucosa are important factors in HIV mucosal immunopathogenesis.

Regeneration of colorectal epithelium in diverticulosis.

Excessive poorly differentiated epitheliocytes were detected in the crypts and subepithelial regions of the colorectal mucosa during the regeneration process in the majority of patients with diverticular disease. The compensatory reaction of the sigmoid mucosa decreased, which was seen from rarely detected cryptic hyperplasia. Disorders in the epitheliocyte proliferation and differentiation were paralleled by changes in tissue levels of proinflammatory cytokines (elevation of TNF-α and IFN-γ and reduction of IL-1ß and IL-8) and increase of IL-4, regulating lymphocyte activation.

Sclerosing nodular lesions of the gastrointestinal tract containing large numbers of IgG4 plasma cells.

BACKGROUND: Hyalinised fibrous nodules have been encountered within the gastrointestinal tract (GIT) and been labelled as reactive nodular fibrous tumours. Several have a history of abdominal surgery and/or sepsis that acts as a precipitating cause for the fibrosis. Recently, much attention has been focused on IgG4 related fibrosing lesions that are typically associated with a high population of IgG4 positive plasma cells and tissue fibrosis. There may be attendant elevated serum IgG4 levels and associated autoimmune disease. METHODS: We present four patients with well-circumscribed fibrous nodular lesions occurring in the GIT. Tissue was formalin fixed after microwave antigen retrieval and H&E stains and immunohistochemistry were performed. IgG4/IgG ratios were calculated from the three high power fields containing the densest concentration of positive plasma cells. RESULTS: The patients were two females (45 and 56 years) and two males (47 and 60 years) who presented with gastric (2 cases), caecal and sigmoid flexure involvement. One case had four lesions while the other three cases were solitary nodules. Two patients had coexistent autoimmune disease. All lesions were nodular and composed of paucicellular, hyalinised fibrous tissue associated with chronic inflammation. In all lesions the plasma cell population was strongly IgG4 positive. CONCLUSIONS: This paper describes unique, well-circumscribed sclerosing nodules containing IgG4 positive plasma cells within the bowel wall that may cause mucosal polypoid lesions. It is possible that these lesions may be related to the spectrum of IgG4 related sclerosing disease or belong to a separate subset of inflammatory reactive conditions that are rich in IgG4 plasma cells.

Tryptophan catabolism by indoleamine 2,3-dioxygenase 1 alters the balance of TH17 to regulatory T cells in HIV disease.

The pathogenesis of human and simian immunodeficiency viruses is characterized by CD4(+) T cell depletion and chronic T cell activation, leading ultimately to AIDS. CD4(+) T helper (T(H)) cells provide protective immunity and immune regulation through different immune cell functional subsets, including T(H)1, T(H)2, T regulatory (T(reg)), and interleukin-17 (IL-17)-secreting T(H)17 cells. Because IL-17 can enhance host defenses against microbial agents, thus maintaining the integrity of the mucosal barrier, loss of T(H)17 cells may foster microbial translocation and sustained inflammation. Here, we study HIV-seropositive subjects and find that progressive disease is associated with the loss of T(H)17 cells and a reciprocal increase in the fraction of the immunosuppressive T(reg) cells both in peripheral blood and in rectosigmoid biopsies. The loss of T(H)17/T(reg) balance is associated with induction of indoleamine 2,3-dioxygenase 1 (IDO1) by myeloid antigen-presenting dendritic cells and with increased plasma concentration of microbial products. In vitro, the loss of T(H)17/T(reg) balance is mediated directly by the proximal tryptophan catabolite from IDO metabolism, 3-hydroxyanthranilic acid. We postulate that induction of IDO may represent a critical initiating event that results in inversion of the T(H)17/T(reg) balance and in the consequent maintenance of a chronic inflammatory state in progressive HIV disease.

Decreased sigmoidal ABCB1 (P-glycoprotein) expression in ulcerative colitis is associated with disease activity.

AIMS: The modulation of the intestinal expression of detoxifying proteins by relevant transcription factors, intracellular receptors and cytokines in ulcerative colitis (UC) is poorly understood. Here, we compared the intestinal expression of drug transporters, metabolizing enzymes and putative regulatory genes between inflamed and noninflamed tissue and studied their modulation by disease activity. MATERIALS & METHODS: Sigmoidal biopsies of 18 UC patients and 18 healthy volunteers matched for age, gender and ABCB1 3435C>T genotype were investigated for mRNA expression levels of 43 systematically selected candidate genes by low-density array real-time PCR. Additionally, the ABCB1 gene product P-glycoprotein was visualized by immunohistochemistry and quantified by western blotting. Disease phenotype was categorized by clinical, endoscopic and histopathological examination. Disease activity was quantified by clinical activity index. RESULTS: In inflamed sigmoidal tissue from UC patients, 11 genes (NAT1, NR2B1, CEBPB, IFG, IL8, IL10, S100A12, SPP1, DEFA5, DEFA6 and HAMP) were overexpressed. By contrast, only the major human efflux transporter ABCB1 showed significantly lower expression levels, that were inversely correlated with those of certain antimicrobial peptides (DEFA5/6) and cytokines (IL1beta and IL8). Cell culture experiments revealed a time-dependent decrease of ABCB1 expression upon IL8 exposure. Disease activity profoundly modified ABCB1 expression, indicated by an inverse correlation of clinical activity index values with ABCB1 mRNA expression (r = -0.603; p = 0.017) and markedly reduced protein expression in UC patients with moderate and severe symptomology (p = 0.011). CONCLUSION: Cytokine-mediated downregulation of the major human efflux transporter ABCB1 in inflamed intestine of UC patients is presumably dependent on disease activity, with a possible contribution from IL8.

Early initiation of highly active antiretroviral therapy fails to reverse immunovirological abnormalities in gut-associated lymphoid tissue induced by acute HIV infection.

BACKGROUND: During the acute phase of HIV infection, large CD4+ T-cell depletion occurs in the gastrointestinal tract. The kinetics of CD4+ T-cell decrease and highly active antiretroviral therapy (HAART)-mediated immune reconstitution were evaluated. METHODS: Rectosigmoid colonic (RSC) biopsies and blood samples of nine patients with acute HIV infection were collected. CD4+ T-cell count, HIV RNA, intracellular HIV DNA and messenger RNA cytokine expression were evaluated before and after 6 months of HAART. RESULTS: All nine patients presented symptomatic retroviral infection. Early HAART was associated with a sustained and comparable reduction of HIV RNA in plasma, peripheral blood mononuclear cells (PBMCs) and RSC biopsies. HIV DNA decreased in PBMCs, but was only marginally reduced in RSC biopsies. Comparisons between reduction rates of HIV DNA in these two compartments confirmed that HIV DNA clearance was less efficient in RSC biopsies compared with PBMCs. Assessment of immunological profiles in PBMCs and RSC biopsies showed that the T-helper (Th)1-like/Th2-like ratio was sharply decreased in RSC biopsies and increased in PBMCs throughout the study period. A persistent Th2-like profile was detected in RSC biopsies. Efficient clearing of HIV DNA observed in PBMCs correlated with the establishment of a more favourable Th1-like profile. CONCLUSIONS: A less efficient clearance of intracellular HIV DNA following early introduction of HAART is associated with persistent immunological impairment in gut-associated lymphoid tissue (GALT), which is reflected by the skewed expression of cytokines in this reservoir. The present study shows that early initiation of HAART, in the short-term, is not effective in containing the establishment of HIV infection and in reversing associated immunological GALT abnormalities.

Involvement of central immunity in uncomplicated diverticular disease.

OBJECTIVE: The pathogenesis of symptoms of uncomplicated diverticular disease (UDD) is unclear, but changes in gut microflora and physiologic inflammation may be implicated. The objective of the study was to investigate the distribution of gut homing lymphocytes in peripheral blood and intestinal mucosa of UDD patients, and the effects of luminal antibiotic treatment. MATERIAL AND METHODS: Ten UDD patients and 10 age- and gender-matched healthy subjects underwent peripheral blood sampling, and colonoscopy with biopsies taken from the transverse and sigmoid colon. Treatment consisted of a 2-month course of rifaximin 1.2 g/day for 15 days/month. Blood sample and mucosal biopsies were repeated in UDD patients at the end of treatment. Flow cytometry was performed using monoclonal antibodies (CD3, CD4, CD8, CD25, CD19, CD45, CD62L, CD103). RESULTS: In peripheral blood, both CD4+ and CD8+/CD103+ were significantly higher in patients at baseline than in controls (0.95% versus 0.36%, and 0.5% versus 0.09%, respectively). After treatment, peripheral CD4+/CD103+ decreased (0.27%), while CD8+/CD103+ did not change (0.35%); on the contrary, peripheral CD25+ increased, the CD4+ subpopulation showing significantly higher levels than those in controls. No difference was found between lymphocytes in the diverticular sigmoid mucosa of patients at baseline and those in controls, but there was a significant decrease in CD8+/CD62L+ after treatment. In the normal transverse colon, CD4+/CD62L+ of patient at baseline were significantly lower than in controls. After treatment, CD4+/CD103+ levels significantly increased, while CD8+/CD62L+ levels significantly decreased. CONCLUSIONS: Both central and mucosal immunity may be modified in UDD patients, with an increased recruitment of CD103+ lymphocytes. A 2-month course of rifaximin appears to reduce CD103+ levels, suggesting a decrease in mobilization of mucosal homing.

Immune reconstitution in the sigmoid colon after long-term HIV therapy.

Early and profound CD4+ T-cell depletion in gut-associated lymphoid tissue (GALT) may drive Human Immunodeficiency Virus (HIV) immunopathogenesis, and GALT immune reconstitution on highly active antiretroviral therapy (HAART) may be suboptimal. Blood and sigmoid colon biopsies were collected from HAART-treated individuals with undetectable blood HIV RNA for > or =4 years and from uninfected controls. HIV proviral levels and T-cell phenotype/function were examined in both compartments. CD4+ T-cell reconstitution in the sigmoid, including CD4+ T cells expressing CCR5, exceeded that in blood and did not differ from uninfected controls. Sigmoid HIV proviral load was not correlated with CD4+ reconsitution, but was correlated with the degree of mucosal CD8+ T-cell immune activation. Colonic Gag-specific T-cell responses were common, but were not associated with proviral load or immune activation. In this select study population, long-term HAART was associated with complete CD4+ T-cell reconstitution in sigmoid colon. However, colonic immune activation may drive ongoing HIV replication.

Parallel human immunodeficiency virus type 1-specific CD8+ T-lymphocyte responses in blood and mucosa during chronic infection.

Gut-associated lymphoid tissue is the major reservoir of lymphocytes and human immunodeficiency virus type 1 (HIV-1) replication in vivo, yet little is known about HIV-1-specific CD8+ T-lymphocyte (CTL) responses in this compartment. Here we assessed the breadth and magnitude of HIV-1-specific CTL in the peripheral blood and sigmoid colon mucosa of infected subjects not on antiretroviral therapy by enzyme-linked immunospot analysis with 53 peptide pools spanning all viral proteins. Comparisons of blood and mucosal CTL revealed that the magnitude of pool-specific responses is correlated within each individual (mean r2 = 0.82 +/- 0.04) and across all individuals (r2 = 0.75; P < 0.001). Overall, 85.1% of screened peptide pools yielded concordant negative or positive results between compartments. CTL targeting was also closely related between blood and mucosa, with Nef being the most highly targeted (mean of 2.4 spot-forming cells [SFC[/10(6) CD8+ T lymphocytes/amino acid [SFC/CD8/aa]), followed by Gag (1.5 SFC/CD8/aa). Finally, comparisons of peptide pool responses seen in both blood and mucosa (concordant positives) versus those seen only in one but not the other (discordant positives) showed that most discordant results were likely an artifact of responses being near the limit of detection. Overall, these results indicate that HIV-1-specific CTL responses in the blood mirror those seen in the mucosal compartment in natural chronic infection. For protective or immunotherapeutic vaccination, it will be important to determine whether immunity is elicited in the mucosa, which is a key site of initial infection and subsequent HIV-1 replication in vivo.

[The colonization resistance of the mucous membrane of the large intestine in patients with rheumatoid arthritis in a period of exacerbation]. / Kolonizatsiina rezystentnist' slyzovoï obolonky tovstoï kyshky u khvorykh na revmatoïdnyi artryt u period zahostrennia.

Specific and quantitative compositions of the colon mucous microflora in 36 patients with rheumatic arthritis (RA) in the remission period were studied. The mucous membrane of healthy people is colonized by bifidobacteria, lactobacilli, Bacteroides, Escherichia and enterococci. The mucous membrane in such people is mainly colonized by aerobic opportunistic conventionally pathogenic enterobacteria (enteropathogenic Escherichia, Citrobacter [correction of cytobacter], Enterobacter, Klebsiella, etc.), staphylococci, enterococci and anaerobic bacteria (Bacteroides, peptococci, peptostreptococci, etc.). Taking into account significant changes of colonization resistance in the colon mucous membrane in remission period of RA, it is necessary to apply bacteriotherapy, using bacterial drugs containing bifidobacteria and lactobacteria.