-295 T-to-C promoter region IL-16 gene polymorphism is associated with Whipple's disease.

Whipple's disease (WD) is a rare systemic condition caused, in genetically predisposed subjects, by Tropheryma whipplei, a common bacterium widespread in the environment. The relevance of genetic predisposition in WD is shown by the association with HLA alleles DRB1*13 and DQB1*06 and by the demonstration that, in patients with WD, the cytokine genetic profile is skewed toward a Th2 and Treg response. Since IL-16 is involved in hampering the development of a protective macrophagic response against Tropheryma whipplei, we investigated whether the genetic background of IL-16 is different between patients with WD and controls. The -295 T-to-C polymorphism of the promoter region of the IL-16 gene was studied in 90 patients with WD and 152 healthy controls. Levels of serum IL-16 protein were also tested. The frequency of the wild type T allele was significantly higher in patients with WD compared to the controls (155/180 vs. 235/304; p = 0.02 for the Chi(2) test), odds ratio 1.82 [95 % confidence interval (CI) 1.07-3.10]. The TT genotype was found in 65/90 patients with WD and 88/152 controls (p = 0.026). No relationship was found between serum levels of IL-16 and genotypes. Although the functional consequences of this genetic background on levels of IL-16 and on the course of the disease are still unknown, we found, for the first time, that the wild type T allele and the TT genotype of the -295 polymorphism are associated with WD.

Systematic review: Whipple's disease (Tropheryma whipplei infection) and its unmasking by tumour necrosis factor inhibitors.

BACKGROUND: The classical form of Whipple's disease (WD), clinically characterised by arthropathy, diarrhoea and weight loss, is rare. Recently, other more frequent forms of Tropheryma whipplei infection have been recognised. The clinical spectrum includes an acute, self-limiting disease in children, localised forms affecting cardiac valves or the central nervous system without intestinal symptoms, and asymptomatic carriage of T. whipplei which is found in around 4% of Europeans. Genomic analysis has shown that T. whipplei represents a host-dependent or opportunistic bacterium. It has been reported that the clinical course of T. whipplei infection may be influenced by medical immunosuppression. AIM: To identify associations between immunomodulatory treatment and the clinical course of T. whipplei infection. METHODS: A PubMed literature search was performed and 19 studies reporting on immunosuppression, particularly therapy with tumour necrosis factor inhibitors (TNFI) prior to the diagnosis in 41 patients with Whipple?s disease, were evaluated. RESULTS: As arthritis may precede the diagnosis of WD by many years, a relevant percentage (up to 50% in some reports) of patients are treated with immunomodulatory drugs or with TNFI. Many publications report on a complicated Whipple?s disease course or T. whipplei endocarditis following medical immunosuppression, particularly after TNFI. Standard diagnostic tests such as periodic acid-Schiff stain used to diagnose Whipple?s disease often fail in patients who are pre-treated by TNFI. CONCLUSIONS: In cases of doubt, Whipple?s disease should be excluded before therapy with TNFI. The fact that immunosuppressive therapy contributes to the progression of T. whipplei infection expands our pathogenetic view of this clinical entity.

Non-alcoholic steatohepatitis occurs in celiac disease and is associated with cellular stress.

BACKGROUND AND AIMS: Liver and gut not only share alimentary but also immunological features. Major histocompatibility complex class I-related chains A and B (MIC A/B) function as indicators for cellular stress. These so called stress-induced ligands are suggested to play an important role in the progression of non-alcoholic fatty liver disease (NAFLD) and are a prominent feature of celiac disease (CD). PATIENTS AND METHODS: In the present study, 24 patients with celiac disease and 20 patients with non-alcoholic steatohepatitis (NASH) were included. Liver enzymes, serum cell death markers (M30, M65), MIC B and expression of adiponectin were determined. RESULTS: Mean patient age was 42 years (18 - 69) for CD and 49 years (33 - 68) for the NASH group. ALT and AST values were lower in CD compared to NASH patients. While serum cell death markers were higher in NASH, the predominant type of cell death in CD was apoptosis. Also, expression of MIC B was significantly up-regulated in CD patients as compared to NASH patients. Adiponectin values were significantly lower in NASH compared to CD patients. CONCLUSION: Stress-induced ligands and apoptosis are induced in CD. Prospective studies need to determine the exact role of cellular stress and apoptosis in the gut-liver axis and the clinical implications to screen for NAFLD in CD patients.

Cytokine genetic profile in Whipple's disease.

Whipple's disease (WD) is a very rare chronic systemic condition characterised by a Th2/T regulatory (Treg) dysregulated immune response versus Tropheryma whipplei, a bacterium widely diffuse in the environment. To investigate whether this Th2/Treg polarised response has a genetic background, we investigated the Th1, Th2, Th17 and Treg cytokine genetic profile of 133 patients with WD. Thanks to the European Consortium on WD (QLG1-CT-2002-01049), the polymorphism of 13 cytokine genes was analysed in 111 German and 22 Italian patients using the polymerase chain reaction with sequence-specific primers (PCR-SSP) technique. The frequencies of the genotypes, haplotypes and functional phenotypes were compared with those obtained in 201 German and 140 Italian controls. Clinical heterogeneity was also considered. Functionally, WD patients may be considered as low producers of TGF-ß1, having an increased frequency of the genotype TGF-ß1+869C/C,+915C/C [12.3 % vs. 3.81 %, odds ratio (OR) = 4.131, p = 0.0002] and high secretors of IL-4, carrying the genotype IL-4-590T/T (5.34 % vs. 1.17 %, OR = 5.09, p = 0.0096). No significant association was found between cytokine polymorphism and clinical variability. Analogously to the recent cellular findings of a Th2/Treg polarised response, we showed that the cytokine genetic profile of WD patients is skewed toward a Th2 and Treg response. This was similar in both German and Italian populations. However, the significant deviations versus the controls are poorer than that expected on the basis of these recent cellular findings.

Perioperative adjuvant therapy with infliximab in complicated anal Crohn's disease.

PURPOSE: Infliximab may represent an adjuvant to surgical therapy in patients with severe anal Crohn's disease as it has been shown to affect rapid remissions in a proportion of cases. PATIENTS AND METHODS: Nineteen patients underwent infliximab therapy 5 mg/kg perioperatively to scheduled anal reconstructive surgery for complicated fistulising anal Crohn's disease. RESULTS: One adverse event was recorded (generalised exanthema with subsequent resolution). Eight patients showed complete clinical remission refusing further surgery. One of the eight relapsed during follow-up and was continued on infliximab. Surgery consisted of advancement flaps. It was successful at first attempt in nine of the remaining 11 patients (82%). Operative fistula closure remained unsuccessful in two patients. Overall, 16 of 19 patients (84%) with advanced anal Crohn's disease had a favourable outcome. CONCLUSION: The use of infliximab as adjuvant to surgery in this series of patients with complicated anal Crohn's disease was safe. Although the data is uncontrolled a positive effect of infliximab on the outcome of surgery may be postulated since our results compare favourably with other studies.

Interleukin-18 is increased only in a minority of patients with active Crohn's disease.

BACKGROUND AND AIMS: It has been suggested that Crohn's Disease (CD) is associated with an elevated T helper 1 response as manifested by increased production of interleukin-18 (IL-18). Local concentrations of neutralizing IL-18 binding proteins (IL-18 bp) may counteract biological functions of mature IL-18 in mucosal inflammation. Therefore, we investigated the IL-18/IL-18 bp system in a large group of patients with active inflammatory bowel disease (IBD) to identify patients that could respond theoretically to IL-18 neutralizing treatment strategies. PATIENT/METHODS: IL-18 and IL-18 bp messenger RNA (mRNA) expression in colonic mucosa from patients with active CD (n = 72), active ulcerative colitis (UC; n = 32), and non-IBD controls (infectious colitis or diverticulitis; n = 19) and normal, non-diseased controls (n = 20) were measured by reverse-transcribed real-time polymerase chain reaction. Mature IL-18 protein and IL-18 bp expression in inflamed mucosa were assessed by Western blotting. RESULTS/FINDINGS: Although IL-18 mRNA was increased in some patients with CD, the increase was not statistically significant. Densitometric evaluation of IL-18/alpha-actin ratio in patients with active CD (n = 20) and patients with UC (n = 10) demonstrated an increased ratio of IL-18 protein in CD when compared to UC (1.04 vs 0.72 [median]). On closer inspections, only 7/20 CD patients had an increased IL-18 protein expression in inflamed areas compared to noninflamed mucosa. INTERPRETATION/CONCLUSION: IL-18 expression in active CD is heterogeneous, only a minority of patients expresses elevated levels. Further treatment strategies targeting IL-18 expression in active CD should be concentrated on this subgroup of patients.

[Whipple's disease]. / Morbus Whipple.

Whipple's disease is a rare infectious disorder affecting mostly middle aged men. The causative organism, Tropheryma whipplei, recently has been cultivated and phylogenetically identified as an actinomycete. The rareness of the disease despite the ubiquitous occurence of T. whipplei presumably is related to a predisposing defect in cellular immunity. The diagnosis usually can be established by small bowel biopsy, but is frequently delayed due to protean clinical manifestations. The initiation of antibiotic treatment in most cases results in clinical remission, however, a significant number of patients is refractory to antimicrobial therapy or has a relapsing course.

Current concepts of immunopathogenesis, diagnosis and therapy in Whipple's disease.

Whipple's disease (WD) is a rare chronic infectious disorder caused by the rod- shaped bacterium Tropheryma whipplei. The disorder is characterized clinically by arthralgia, abdominal pain, diarrhea, malabsorbtion and progressive weight loss. Other important sites of infection include the heart (resulting in the clinical picture of endocarditis and heart failure) and the central nervous system (CNS) (manifestations include confusion, memory loss, focal cranial nerve signs, nystagmus and ophtalmoplegia). The bacterium is presumed to be ubiquitously present. A defect in cellular immune response may predispose patients for an infection with T. whipplei and this might explain the rarity of the disorder despite the ubiquitous bacterial presence. The presumed immunological defect is likely to be quite specific for T. whipplei, since patients are not generally affected by other infections. Decreased production of Interleukin(IL)-12, IL-2 and Interferon (IFN)-g accompanied by an increased secretion of IL-4 are the main features of this defective immunological response. The finding of periodic acid-Schiff (PAS)-positive macrophages in the lamina propria of tissue samples obtained by duodenal biopsy usually establishes the diagnosis. The PAS-positive inclusions represent the remnants of the bacteria. Attempts to isolate the causative agent were unsuccessful for nearby 100 years after the first recognition of the disease. In the year 2000, the bacterium was finally successfully grown on a human fibroblast cell line. Untreated WD patients suffer from a chronic progressive disorder which possibly leads to death. Most patients show a fast clinical improvement to antibiotic therapy, but clinical relapses are described frequently. There is a number of patients, unable to eradicate the bacterium even after several antibiotic treatments and patients with CNS disease, in both of whom alternative therapy strategies are necessary.

Decreased levels of interleukin-12p40 in the serum of patients with Whipple's disease.

BACKGROUND: An impaired production of interleukin (IL)-12 and T cell interferon-gamma (IFN-gamma) of in vitro stimulated monocytes has been discussed as a pathogenic factor in Whipple's disease (WD). It is unclear whether this defect of cellular immunity is translated to the humoral immune system and to serum correlates. METHODS: We analyzed the serum of 40 patients with Whipple's disease in various degrees of disease activity by sandwich enzyme-linked immunosorbent assay for differences in cytokine and cell adhesion molecule concentrations compared with age- and sex-matched controls. RESULTS: We observed a highly significant reduction of IL-12p40 levels (patients, 0.18+/-0.05 ng/ml (mean+/-SEM); controls, 3.19+/-0.39 ng/ml; p<0.01) in all stages of disease activity, whereas the concentration of IL-12p70 was comparable with controls. Furthermore, we observed a slight decrease in tumour necrosis factor alpha (TNF-alpha) concentrations in the serum of patients (patients, 6.36+/-0.90 pg/ml; controls, 10.5+/-1.23 pg/ml; p<0,05). The levels of other cytokines such as IFN-gamma, IL-2, IL-13 and transforming growth factor beta, as well as soluble cell adhesion molecules lymphocyte function-associated antigen 3 and intercellular adhesion molecule 1, were not significantly different compared with controls. Levels of immunoglobulin G2 (IgG2) measured in the serum of WD patients were below normal in 24 of 29 patients and were even below the 95% confidence interval in 10 patients. CONCLUSION: Our data demonstrate a persistent defect of the cellular immune response with decreased serum concentrations of IL-12p40 and TNF-alpha and decreased IgG2 levels in a large group of WD patients. These data support as in vivo finding the results obtained in previous investigations with stimulated monocytes/lymphocytes. The isolated decrease in IL-12p40 may hint at possible defects in the IL-12/IFN-gamma promoter system.

Progress, problems, and perspectives in diagnosis and treatment of Whipple's disease.

Whipple's disease is a rare chronic infectious disorder first described in 1907 by G.H. Whipple. The disorder is caused by the newly identified bacterium Tropheryma whipplei and there is evidence that altered immune functions play a role in the manifestation of the disease. The organ systems mostly affected are the joints and the gut, and in the further course often also the heart, lung, brain, and eyes. The intestinal involvement occurs with abdominal pain and diarrhea, which leads to weight loss, malnutrition, and anemia. In some cases the infection spreads to the central nervous system, which may lead to loss of memory, confusion, or disturbances in gait. In the last few years, several steps towards an improved diagnosis of the disease and characterization of the causative bacterium have been made. While untreated disease may be lethal, treatment is often able to eradicate the organism. At present, therapy is based on observations in small patient groups and personal experience. There are different antibiotic therapy regimens often starting with intravenous application for 2 weeks followed by oral medication for 1 year. The first clinical therapy study is ongoing.

An interleukin 12 p40-IgG2b fusion protein abrogates T cell mediated inflammation: anti-inflammatory activity in Crohn's disease and experimental colitis in vivo.

BACKGROUND AND AIMS: Interleukin-12 (IL-12), a p35/p40 heterodimer, plays a pivotal role in the immune response in Crohn's disease (CD). Since IL-12 p40 dimers act as IL-12 antagonists, we assayed p40 dimer proteins to modulate chronic intestinal inflammation. METHODS: We generated a fusion protein consisting of the IL-12(p40) subunit fused to the constant region of IgG2b. IL-12(p40)-IgG2b was tested in a murine 2,4,6,-trinitrobenzene sulphonic acid (TNBS) colitis model and in lamina propria mononuclear cells (LPMNC) from patients with CD in vitro. RESULTS: Dimeric IL-12(p40)-IgG2b fusion protein bound specifically to the IL-12 receptor. In concentrations <10(-7) M, it acted as an IL-12 antagonist as it inhibited interferon gamma (IFN-gamma) secretion, suppressed proliferation, and increased apoptosis of LPMNC from patients with CD. However, in concentrations >10(-6) M, IL-12(p40)-IgG2b increased IFN-gamma secretion and lymphocyte proliferation thereby acting as an IL-12 agonist. In TNBS colitic mice, IL-12(p40)-IgG2b decreased mortality (10% v 68%), prevented body weight loss, reduced tumour necrosis factor alpha, and increased IL-10 secretion. CONCLUSIONS: The IL-12(p40)-IgG2b fusion protein has dichotomic properties as a specific IL-12 antagonist and selective repressor of mucosal inflammation at low concentration and as an IL-12 agonist at high concentration.

Increased expression of interleukin-12 receptor beta(2) on lamina propria mononuclear cells of patients with active Crohn's disease.

BACKGROUND AND AIMS: Since interleukin-12 is pathogenetically involved in Crohn's disease (CD) but not in ulcerative colitis (UC), expression and mechanisms of induction of interleukin-12 receptor (IL-12R) subunits beta(1) and beta(2) were analyzed in lamina propria mononuclear cells (LPMNC) of patients with CD and UC. PATIENTS AND METHODS: LPMNC from patients with CD ( n=17), UC ( n=14), and controls ( n=19) were isolated by standard techniques. IL-12R beta(1) and IL-12R beta(2) transcripts were semiquantified by RT-PCR, and expression of IL-12R beta(2) chain was characterized by flow cytometry. LPMNC were activated by cross-linking with anti-CD3 antibodies and B7-1 costimulation. RESULTS: IL-12R beta(1) and IL-12R beta(2) transcript concentrations were higher in inflamed specimens than in noninflamed segments of patients with CD but not in UC. Increased percentage of mucosal CD4(+)/IL-12R beta(2)(+) cells was observed in active CD, but not UC. In vitro stimulation of LPMNC with anti-CD3 antibodies resulted in an increase in IL-12R beta(1) transcripts irrespective of B7-1 mediated costimulation (84% and 95%, respectively). However, increased expression of IL-12R beta(2) mRNA (110%) was detected only after B7-1 costimulation. CONCLUSION: Our data indicate that increased mucosal expression of IL-12R beta(2) on LPMNC in CD but not in UC may be the result of B7-1 costimulation. Modulation or inhibition of IL-12R beta(2) expression on LPMNC could provide a selective therapeutic approach in CD.

The diagnosis and treatment of Whipple's disease.

Whipple's disease is a rare, chronic, and systemic infectious disease caused by the ubiquitously occurring bacterium Tropheryma whippelii. For two reasons, the disease represents a good example for documenting the input of modern molecular-based techniques into pathogenetic, diagnostic, and therapeutic concepts in clinical medicine. First, the unidentified and uncultivable causative organism has been characterized by novel molecular-genetic techniques. Second, in contrast to other chronic inflammatory disorders, clinical manifestations of T. whippelii infection seem to be based on reduced T-cell helper type 1 (TH1) activity. These findings have led to an improved pathophysiologic understanding of the disease and to new aspects in treatment strategies that are discussed in this paper.

Antigen-induced mucosal T cell activation is followed by Th1 T cell suppression in continuously fed ovalbumin TCR-transgenic mice.

We investigated kinetics and dose-dependent features of mucosal and peripheral immune responses following oral antigen application in a TCR-transgenic mouse model. Ovalbumin (OVA) TCR-transgenic mice were fed OVA at different doses (5-250 mg) and various frequencies (one to seven times, or continuous feeding). Low- and medium-dose (10, 100 mg) OVA feeding resulted in priming of immune responses, i.e. increased antigen-specific proliferation as well as IL-2, IL-4 and IFN-gamma secretion upon in vitro restimulation in Peyer's patches and spleen. Immune responses were suppressed with doses of one or three times 250 mg OVA feeding in the spleen. However, only the highest OVA feeding doses (7x250 mg OVA) or continuous feeding (5 mg daily in the drinking water over a 12-week period) actively suppressed immune responses and were associated with production of TGF-beta and IL-10 in the spleen and Peyer's patches. Thus, the cell population generated by continuous antigen feeding was characterized by production of suppressive cytokines and seems to be based on a counter-regulation with Th1 cytokines. These data further define the regulation of suppressive immune functions following antigen feeding in the periphery and the mucosal immune system.