Tropheryma whipplei Increases Expression of Human Leukocyte Antigen-G on Monocytes to Reduce Tumor Necrosis Factor and Promote Bacterial Replication.

BACKGROUND & AIMS: Infection with Tropheryma whipplei has a range of effects-some patients can be chronic carriers without developing any symptoms, whereas others can develop systemic Whipple disease, characterized by a lack a protective inflammatory immune response. Alterations in HLA-G function have been associated with several diseases. We investigated the role of HLA-G during T whipplei infection. METHODS: Sera, total RNA, and genomic DNA were collected from peripheral blood from 22 patients with classic Whipple's disease, 19 patients with localized T whipplei infections, and 21 asymptomatic carriers. Levels of soluble HLA-G in sera were measured by enzyme-linked immuosorbent assay, and expressions of HLA-G and its isoforms were monitored by real-time polymerase chain reaction. HLA-G alleles were identified and compared with a population of voluntary bone marrow donors. Additionally, monocytes from healthy subjects were stimulated with T whipplei, and HLA-G expression was monitored by real-time polymerase chain reaction and flow cytometry. Bacterial replication was assessed by polymerase chain reaction in the presence of HLA-G or inhibitor of tumor necrosis factor (TNF) (etanercept). RESULTS: HLA-G mRNAs and levels of soluble HLA-G were significantly increased in sera from patients with chronic T whipplei infection compared with sera from asymptomatic carriers and control individuals. No specific HLA-G haplotypes were associated with disease or T whipplei infection. However, T whipplei infection of monocytes induced expression of HLA-G, which was associated with reduced secretion of TNF compared with noninfected monocytes. A neutralizing antibody against HLA-G increased TNF secretion by monocytes in response to T whipplei, and a TNF inhibitor promoted bacteria replication. CONCLUSIONS: Levels of HLA-G are increased in sera from patients with T whipplei tissue infections, associated with reduced production of TNF by monocytes. This might promote bacteria colonization in patients.

Gamma delta T cell expansion in Whipple's disease with muscular granulomatous vasculitis.

Whipple's disease usually presents as chronic joint pain followed by digestive manifestations. However, many different presentations have been described in the literature. We report here the first proven case of muscular vasculitis related to Whipple's disease, associated with an expansion of circulating activated γδ T lymphocytes.

Peripheral T-Cell Reactivity to Heat Shock Protein 70 and Its Cofactor GrpE from Tropheryma whipplei Is Reduced in Patients with Classical Whipple's Disease.

Classical Whipple's disease (CWD) is characterized by the lack of specific Th1 response toward Tropheryma whipplei in genetically predisposed individuals. The cofactor GrpE of heat shock protein 70 (Hsp70) from T. whipplei was previously identified as a B-cell antigen. We tested the capacity of Hsp70 and GrpE to elicit specific proinflammatory T-cell responses. Peripheral mononuclear cells from CWD patients and healthy donors were stimulated with T. whipplei lysate or recombinant GrpE or Hsp70 before levels of CD40L, CD69, perforin, granzyme B, CD107a, and gamma interferon (IFN-γ) were determined in T cells by flow cytometry. Upon stimulation with total bacterial lysate or recombinant GrpE or Hsp70 of T. whipplei, the proportions of activated effector CD4+ T cells, determined as CD40L+ IFN-γ+, were significantly lower in patients with CWD than in healthy controls; CD8+ T cells of untreated CWD patients revealed an enhanced activation toward unspecific stimulation and T. whipplei-specific degranulation, although CD69+ IFN-γ+ CD8+ T cells were reduced upon stimulation with T. whipplei lysate and recombinant T. whipplei-derived proteins. Hsp70 and its cofactor GrpE are immunogenic in healthy individuals, eliciting effective responses against T. whipplei to control bacterial spreading. The lack of specific T-cell responses against these T. whipplei-derived proteins may contribute to the pathogenesis of CWD.

Role of dendritic cells in the pathogenesis of Whipple's disease.

Accumulation of Tropheryma whipplei-stuffed macrophages in the duodenum, impaired T. whipplei-specific Th1 responses, and weak secretion of interleukin-12 (IL-12) are hallmarks of classical Whipple's disease (CWD). This study addresses dendritic cell (DC) functionality during CWD. We documented composition, distribution, and functionality of DC ex vivo or after in vitro maturation by fluorescence-activated cell sorting (FACS) and by immunohistochemistry in situ. A decrease in peripheral DC of untreated CWD patients compared to healthy donors was due to reduced CD11c(high) myeloid DC (M-DC). Decreased maturation markers CD83, CD86, and CCR7, as well as low IL-12 production in response to stimulation, disclosed an immature M-DC phenotype. In vitro-generated monocyte-derived DC from CWD patients showed normal maturation and T cell-stimulatory capacity under proinflammatory conditions but produced less IL-12 and failed to activate T. whipplei-specific Th1 cells. In duodenal and lymphoid tissues, T. whipplei was found within immature DC-SIGN(+) DC. DC and proliferating lymphocytes were reduced in lymph nodes of CWD patients compared to levels in controls. Our results indicate that dysfunctional IL-12 production by DC provides suboptimal conditions for priming of T. whipplei-specific T cells during CWD and that immature DC carrying T. whipplei contribute to the dissemination of the bacterium.

Chronic infections of the small intestine.

PURPOSE OF REVIEW: Chronic infections of the small intestine cause significant morbidity and mortality globally. This review focuses on the recent advances in the field of our understanding of selected intestinal infections. RECENT FINDINGS: Primary and secondary immunodeficiency increase the susceptibility to many chronic intestinal infections. Endoscopy and intestinal biopsies are central to establishing a diagnosis of these conditions. Tuberculosis (TB) remains a major global health challenge. Emerging therapeutic agents to counteract multidrug-resistant strains have shown clinical efficacy, but concerns regarding mortality remain. PCR-based diagnostic TB tests have the potential to reduce diagnostic delays, but remain to be validated for intestinal infections. Adjunctive diagnostic imaging modalities can differentiate infections from Crohn's disease with increasing accuracy. Whipple's disease remains rare, but there have been substantial advances in our understanding of the causative organism Tropheryma whipplei. Extended treatment with broad-spectrum antibiotics is effective in most cases. The narrow therapeutic window and limited armamentarium for treating invasive filamentous fungal infections contribute to their significant morbidity and high rates of mortality. SUMMARY: The speed and accuracy of diagnosing chronic intestinal infections have improved with recent imaging and laboratory methodologies. Significant research opportunities remain for clinicians and scientists to improve the diagnostic accuracy and clinical outcomes of chronic intestinal infections.

-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.

Tropheryma whipplei , Immunosuppression and Whipple's Disease: From a Low-Pathogenic, Environmental Infectious Organism to a Rare, Multifaceted Inflammatory Complex.

BACKGROUND: The actinobacterium Tropheryma whipplei was detected 20 years ago by molecular techniques, and following its culture has been characterized as the cause of a systemic infection known as Whipple's disease (WD). T. whipplei occurs in the environment, is prevalent only in humans, is believed to be transmitted via oral routes and to be host dependent. KEY MESSAGES: The classical form of T. whipplei infection, i.e. classical WD (CWD), is rare. It is well defined as slowly progressing chronic infection with arthralgia, diarrhea and weight loss, mostly in middle-aged men. However, current research revealed a much broader spectrum of clinical features associated with T. whipplei infection. Thus, T. whipplei may cause acute and transient infections (observed primarily in children) and the bacterium, which is found in soil and water, occurs in asymptomatic carriers as well as in CWD patients in clinical remission. In addition, T. whipplei affects isolated and localized body compartments such as heart valves or the central nervous system. Subtle immune defects and HLA associations have been described. New findings indicate that the progression of asymptomatic T. whipplei infection to clinical WD may be associated with medical immunosuppression and with immunomodulatory conditions. This explains that there is a discrepancy between the widespread occurrence of T. whipplei and the rareness of WD, and that T. whipplei infection triggered by immunosuppression presents with protean clinical manifestations. CONCLUSIONS: This review highlights recent findings and the clinical spectrum of infection with T. whipplei and WD, focusing specifically on the role of host immunity and immunosuppression. Current concepts of the pathogenesis, diagnosis and therapy are discussed.

Immunopathology of immune reconstitution inflammatory syndrome in Whipple's disease.

During antimicrobial treatment of classic Whipple's disease (CWD), the chronic systemic infection with Tropheryma whipplei, immune reconstitution inflammatory syndrome (IRIS), is a serious complication. The aim of our study was to characterize the immunological processes underlying IRIS in CWD. Following the definition of IRIS, we describe histological features of IRIS and immunological parameters of 24 CWD IRIS patients, 189 CWD patients without IRIS, and 89 healthy individuals. T cell reconstitution, Th1 reactivity, and the phenotype of T cells were described in the peripheral blood, and infiltration of CD4(+) T cells and regulatory T cells in the duodenal mucosa was determined. During IRIS, tissues were heavily infiltrated by CD3(+), predominantly CD45RO(+)CD4(+) T cells. In the periphery, initial reduction of CD4(+) cell counts and their reconstitution on treatment was more pronounced in CWD patients with IRIS than in those without IRIS. The ratio of activated and regulatory CD4(+) T cells, nonspecific Th1 reactivity, and the proportion of naive among CD4(+) T cells was high, whereas serum IL-10 was low during IRIS. T. whipplei-specific Th1 reactivity remained suppressed before and after emergence of IRIS. The findings that IRIS in CWD mainly are mediated by nonspecific activation of CD4(+) T cells and that it is not sufficiently counterbalanced by regulatory T cells indicate that flare-up of pathogen-specific immunoreactivity is not instrumental in the pathogenesis of IRIS in CWD.

Whipple's disease.

Whipple's disease is a chronic, systemic infection caused by Tropheryma whipplei. Gene amplification, isolation and DNA sequencing of T whipplei have extended our knowledge of this pathogen, which is now recognised as a ubiquitous commensal bacterium. The spectrum of signs associated with T whipplei has now been extended beyond the classic form, which affects middle-aged men, and begins with recurrent arthritis followed several years later by digestive problems associated with other diverse clinical signs. Children may present an acute primary infection, but only a small number of people with a genetic predisposition subsequently develop authentic Whipple's disease. This bacterium may also cause localised chronic infections with no intestinal symptoms: endocarditis, central nervous system involvement, arthritis, uveitis and spondylodiscitis. An impaired TH1 immune response is seen. T whipplei replication in vitro is dependent on interleukin 16 and is accompanied by the apoptosis of host cells, facilitating dissemination of the bacterium. In patients with arthritis, PCR with samples of joint fluid, saliva and stools has become the preferred examination for diagnosis. Immunohistochemical staining is also widely used for diagnosis. Treatment is based on recent microbiological data, but an immune reconstitution syndrome and recurrence remain possible. The future development of serological tests for diagnosis and the generalisation of antigen detection by immunohistochemistry should make it possible to obtain a diagnosis earlier and thus to decrease the morbidity, and perhaps also the mortality, associated with this curable disease which may, nonetheless, be fatal if diagnosed late or in an extensive systemic form.

Constrictive pleuropericarditis: a dominant clinical manifestation in Whipple's disease.

BACKGROUND: Whipple's disease is a rare, multisystemic, chronic infectious disease which classically presents as a wasting illness characterized by polyarthralgia, diarrhea, fever, and lymphadenopathy. Pleuropericardial involvement is a common pathologic finding in patients with Whipple's disease, but rarely causes clinical symptoms. We report the first case of severe fibrosing pleuropericarditis necessitating pleural decortication in a patient with Whipple's disease. CASE PRESENTATION: Our patient, an elderly gentleman, had a chronic inflammatory illness dominated by constrictive pericarditis and later severe fibrosing pleuritis associated with a mildly elevated serum IgG4 level. A pericardial biopsy showed dense fibrosis without IgG4 plasmacytic infiltration. The patient received immunosuppressive therapy for possible IgG4-related disease. His poor response to this therapy prompted a re-examination of the diagnosis, including a request for the pericardial biopsy tissue to be stained for Tropheryma whipplei. CONCLUSIONS: Despite a high prevalence of pleuropericardial involvement in Whipple's disease, constrictive pleuropericarditis is rare, particularly as the dominant disease manifestation. The diagnosis of Whipple's disease is often delayed in such atypical presentations since the etiologic agent, Tropheryma whipplei, is not routinely sought in histopathology specimens of pleura or pericardium. A diagnosis of Whipple's disease should be considered in middle-aged or elderly men with polyarthralgia and constrictive pericarditis, even in the absence of gastrointestinal symptoms. Although Tropheryma whipplei PCR has limited sensitivity and specificity, especially in the analysis of peripheral blood samples, it may have diagnostic value in inflammatory disorders of uncertain etiology, including cases of polyserositis. The optimal approach to managing constrictive pericarditis in patients with Whipple's disease is uncertain, but limited clinical experience suggests that a combination of pericardiectomy and antibiotic therapy is of benefit.

Regulatory T cells in patients with Whipple's disease.

Classical Whipple's disease (CWD) is caused by chronic infection with Tropheryma whipplei that seems to be associated with an underlying immune defect. The pathognomonic hallmark of CWD is a massive infiltration of the duodenal mucosa with T. whipplei-infected macrophages that disperse systemically to many other organ systems. An alleviated inflammatory reaction and the absence of T. whipplei-specific Th1 reactivity support persistence and systemic spread of the pathogen. In this article, we hypothesized that regulatory T cells (T(reg)) are involved in immunomodulation in CWD, and we asked for the distribution, activation, and regulatory capacity of T(reg) in CWD patients. Whereas in the lamina propria of CWD patients before treatment numbers of T(reg) were increased, percentages in the peripheral blood were similar in CWD patients and healthy controls. However, peripheral T(reg) of CWD patients were more activated than those of controls. Elevated secretion of IL-10 and TGF-ß in the duodenal mucosa of CWD patients indicated locally enhanced T(reg) activity. Enhanced CD95 expression on peripheral memory CD4(+) T cells combined with reduced expression of IFN-γ and IL-17A upon polyclonal stimulation by CD4(+) cells from untreated CWD patients further hinted to T(reg) activity-related exhaustion of effector CD4(+) T cells. In conclusion, increased numbers of T(reg) can be detected within the duodenal mucosa in untreated CWD, where huge numbers of T. whipplei-infected macrophages are present. Thus, T(reg) might contribute to the chronic infection and systemic spread of T. whipplei in CWD but in contrast prevent mucosal barrier defect by reducing local inflammation.

[Neurological complications of inflammatory bowel diseases]. / Neurologische Komplikationen entzündlicher Darmerkrankungen.

Inflammatory bowel diseases, such as Crohn's disease, ulcerative colitis, autoantibody driven celiac disease and infectious Whipple's disease can all be associated with neurological symptoms. The neurological manifestation may occur even before the gastrointestinal symptoms or the enteropathic symptoms can even be absent as in celiac disease. These diseases can be caused by malresorption and lack of vitamins due to enteral inflammation as well as (auto-)immunological mechanisms and drug-associated side effects. Thus, inflammatory bowel diseases have to be considered in the differential diagnosis. In this review the most common neurological manifestations of these diseases will be described as well as the diagnostic approach.

Type I interferon induction is detrimental during infection with the Whipple's disease bacterium, Tropheryma whipplei.

Macrophages are the first line of defense against pathogens. Upon infection macrophages usually produce high levels of proinflammatory mediators. However, macrophages can undergo an alternate polarization leading to a permissive state. In assessing global macrophage responses to the bacterial agent of Whipple's disease, Tropheryma whipplei, we found that T. whipplei induced M2 macrophage polarization which was compatible with bacterial replication. Surprisingly, this M2 polarization of infected macrophages was associated with apoptosis induction and a functional type I interferon (IFN) response, through IRF3 activation and STAT1 phosphorylation. Using macrophages from mice deficient for the type I IFN receptor, we found that this type I IFN response was required for T. whipplei-induced macrophage apoptosis in a JNK-dependent manner and was associated with the intracellular replication of T. whipplei independently of JNK. This study underscores the role of macrophage polarization in host responses and highlights the detrimental role of type I IFN during T. whipplei infection.

Treated Whipple disease with erythema nodosum leprosum-like lesions: cutaneous PAS-positive macrophages slowly decrease with time and are associated with lymphangiectases: a case report.

Pathologically, Whipple disease (WD) is characterized by the accumulation of myriad macrophages parasitized by Tropheryma whipplei (TW) bacilli denoted by periodic acid-Schiff (PAS) positivity. These PAS+ macrophages are typically found in the duodenum associated with lymphangiectasia. Recently, we reported the presence of PAS+ macrophages and free TW in erythema nodosum leprosum (ENL)-like lesions and normal skin in a patient with WD who suffered from the immune reconstitution inflammatory syndrome (IRIS). We extend that report by describing the clinical and pathologic findings over 5 years of follow-up. First, the IRIS gradually diminished and abated over 18-month time. Second, at no point did WD recur, and all duodenal and skin biopsies tested by polymerase chain reaction were negative for TW DNA. Third, PAS+ macrophages were identified in 26 of 27 skin biopsies (96%) and decreased along with free TW over time. Fourth, ENL-like lesions had significantly greater numbers of PAS+ macrophages than normal skin. Moreover, normal abdominal skin (region of ENL-like lesions) had greater PAS+ counts than arm skin (not a site of IRIS). Last, lymphangiectases, a histologic sign of lymphostasis, was found in all skin biopsies. Overall, these findings implicate bacillary burden as a factor in the immune tolerance to live TW in active WD and the initiation of ENL-like nodules against dead/nonreplicative TW in treated WD. In addition, poor lymphatic drainage is likely responsible for the gradual clearance of TW from the skin and the impaired delayed-type hypersensitivity reaction (absence of activated macrophages) against TW found in WD, presumptively due to reduced/absent immune cell trafficking necessary for lymphocyte-macrophage interactions and induction of adaptive immunity.

Impaired immune functions of monocytes and macrophages in Whipple's disease.

BACKGROUND & AIMS: Whipple's disease is a chronic multisystemic infection caused by Tropheryma whipplei. Host factors likely predispose for the establishment of an infection, and macrophages seem to be involved in the pathogenesis of Whipple's disease. However, macrophage activation in Whipple's disease has not been studied systematically so far. METHODS: Samples from 145 Whipple's disease patients and 166 control subjects were investigated. We characterized duodenal macrophages and lymphocytes immunohistochemically and peripheral monocytes by flow cytometry and quantified mucosal and systemic cytokines and chemokines indicative for macrophage activation. In addition, we determined duodenal nitrite production and oxidative burst induced by T whipplei and by other bacteria. RESULTS: Reduced numbers of duodenal lymphocytes, increased numbers of CD163(+) and stabilin-1(+), reduced numbers of inducible nitric synthase+ duodenal macrophages, and increased percentages of CD163(+) peripheral monocytes indicated a lack of inflammation and a M2/alternatively activated macrophage phenotype in Whipple's disease. Incubation with T whipplei in vitro enhanced the expression of CD163 on monocytes from Whipple's disease patients but not from control subjects. Chemokines and cytokines associated with M2/alternative macrophage activation were elevated in the duodenum and the peripheral blood from Whipple's disease patients. Functionally, Whipple's disease patients showed a reduced duodenal nitrite production and reduced oxidative burst upon incubation with T whipplei compared with healthy subjects. CONCLUSIONS: The lack of excessive local inflammation and alternative activation of macrophages, triggered in part by the agent T whipplei itself, may explain the hallmark of Whipple's disease: invasion of the intestinal mucosa with macrophages incompetent to degrade T whipplei.

Changing paradigms in Whipple's disease and infection with Tropheryma whipplei.

More than a century after its first description through G.H. Whipple, the understanding of the chronic multisystemic infection called Whipple's disease is still limited. However, within recent years the knowledge about diagnosis and treatment, the pathogenesis, and the biology of the agent itself have been improved by molecular biological and immunological methods. Despite the ubiquitous presence of the causative bacterium Tropheryma whipplei, Whipple's disease is very rare, and immunogenetic host factors rather than the genotype of the agent influence the course of infection. Since the clinical features of classical Whipple's disease are non-specific and the spectrum of isolated organ-specific manifestations might be underestimated, diagnosis often still is a challenge. Moreover, besides classical Whipple's disease, there are newly recognized infections with T. whipplei, which do not fit in the concept of classical Whipple's disease, for example, acute self-limiting infection and isolated T. whipplei endocarditis. Antibiotic therapy is usually successful. However, several problems are still unresolved, of which the most important are the following: which antibiotic should be used; how long treatment should be continued; how the immunoreconstitution inflammatory syndrome, which may occur after initiation of treatment, should be managed; and which is the best treatment of severe neurological manifestations.

The immune reconstitution inflammatory syndrome in whipple disease: a cohort study.

BACKGROUND: Whipple disease, which is caused by infection with Tropheryma whipplei, can be treated effectively with antimicrobials. Occasionally, inflammation reappears after initial improvement; this is often interpreted as refractory or recurrent disease. However, polymerase chain reaction for T. whipplei in tissue is sometimes negative during reinflammation, indicating absence of vital bacteria, and this reinflammation does not respond to antimicrobials but does respond to steroids. OBJECTIVE: To demonstrate that the immune reconstitution inflammatory syndrome (IRIS) occurs in patients treated for Whipple disease. DESIGN: Cohort study. (International Standard Randomised Controlled Trial Number Register registration number: ISRCTN45658456) SETTING: 2 academic medical centers in Germany. METHODS: 142 patients treated for Whipple disease out of a cohort of 187 were observed for reappearance of inflammatory signs after effective antibiotic therapy. Definitions of IRIS in HIV infection, tuberculosis, and leprosy were adapted for application to Whipple disease. RESULTS: On the basis of study definitions, IRIS was diagnosed in 15 of 142 patients. Symptoms included fever, arthritis, pleurisy, erythema nodosum, inflammatory orbitopathy, small-bowel perforation, and a hypothalamic syndrome. Two patients died. There was a positive correlation with previous immunosuppressive treatment and a negative correlation with previous diarrhea and weight loss. LIMITATIONS: The study was observational and thus has inherent weaknesses, such as incomplete and potentially selective data recording. CONCLUSION: The immune reconstitution inflammatory syndrome was diagnosed in about 10% of patients with Whipple disease in the study cohort; the outcome varied from mild to fatal. Patients who had had previous immunosuppressive therapy were at particular risk. An immune reconstitution syndrome should be considered in patients with Whipple disease in whom inflammatory symptoms recur after effective treatment. Early diagnosis and treatment with steroids may be beneficial; prospective studies are needed. PRIMARY FUNDING SOURCE: European Commission and Deutsche Forschungsgemeinschaft.

Tumor Necrosis Factor Inhibitors Exacerbate Whipple's Disease by Reprogramming Macrophage and Inducing Apoptosis.

Tropheryma whipplei is the agent of Whipple's disease, a rare systemic disease characterized by macrophage infiltration of the intestinal mucosa. The disease first manifests as arthralgia and/or arthropathy that usually precede the diagnosis by years, and which may push clinicians to prescribe Tumor necrosis factor inhibitors (TNFI) to treat unexplained arthralgia. However, such therapies have been associated with exacerbation of subclinical undiagnosed Whipple's disease. The objective of this study was to delineate the biological basis of disease exacerbation. We found that etanercept, adalimumab or certolizumab treatment of monocyte-derived macrophages from healthy subjects significantly increased bacterial replication in vitro without affecting uptake. Interestingly, this effect was associated with macrophage repolarization and increased rate of apoptosis. Further analysis revealed that in patients for whom Whipple's disease diagnosis was made while under TNFI therapy, apoptosis was increased in duodenal tissue specimens as compared with control Whipple's disease patients who never received TNFI prior diagnosis. In addition, IFN-γ expression was increased in duodenal biopsy specimen and circulating levels of IFN-γ were higher in patients for whom Whipple's disease diagnosis was made while under TNFI therapy. Taken together, our findings establish that TNFI aggravate/exacerbate latent or subclinical undiagnosed Whipple's disease by promoting a strong inflammatory response and apoptosis and confirm that patients may be screened for T. whipplei prior to introduction of TNFI therapy.

Specific and nonspecific B-cell function in the small intestines of patients with Whipple's disease.

Whipple's disease is a chronic multisystemic infection caused by Tropheryma whipplei that is characterized by arthritis, weight loss, and diarrhea. The immunological defects in the duodenal mucosa, the site of major replication of the agent underlying the pathogenesis of Whipple's disease, are poorly understood. Mucosal immunoglobulins are essential for the defense against intestinal pathogens; therefore, we analyzed the B-cell response in duodenal specimens and sera of Whipple's disease patients. Whereas systemic immunoglobulin production was affected only marginally, duodenal biopsy specimens of Whipple's disease patients contained reduced numbers of immunoglobulin-positive plasma cells and secreted less immunoglobulin compared to healthy controls but showed a weak secretory IgA response toward T. whipplei. This T. whipplei-specific intestinal immune response was not observed in controls. Thus, we were able to demonstrate that general mucosal immunoglobulin production in Whipple's disease patients is impaired. However, this deficiency does not completely abolish T. whipplei-specific secretory IgA production that nonetheless does not protect from chronic infection.

A paradoxical Tropheryma whipplei western blot differentiates patients with whipple disease from asymptomatic carriers.

BACKGROUND: Tropheryma whipplei is a bacterium that causes Whipple disease. However, T. whipplei can be carried in the gut of asymptomatic people, which may lead to difficulty in the interpretation of positive stool sample test results. METHODS: This study included 60 patients with classic Whipple disease at the time of diagnosis and 26 T. whipplei carriers. Western blots testing for total immunoglobulin (Ig), IgG, IgM, and IgA were performed using glycosylated and deglycosylated T. whipplei. A blind test involving 10 patients and 10 carriers was performed. Sera samples from 32 treated patients were tested for total immunoglobulin. RESULTS: Total immunoglobulin from patients with classic Whipple disease exhibited either a lack of reaction (23 [38%] of 60 patients) or a decrease in reaction (33 [55%] of 60 patients) with a T. whipplei glycoprotein of 110 kDa after deglycosylation. Only 4 patients exhibited a stronger immune response than that which was observed for carriers (21 [81%] of 26 carriers). Five carriers presented a response profile similar to that for the patients. IgM (4 [7%] of 60 patients) or IgA (1 [2%] of 60 patients) responses were rarely observed but were exclusive to patients. Overall, results were consistent and reproducible. Antibiotic therapy had no effect on the serological profiles of the patients. CONCLUSIONS: Western blot serology is useful to distinguish between carriers and patients; paradoxical responses of the antibodies were investigated.