Whipple's disease: A rare disease that can be spotted by many doctors

Whipple's disease, an extremely rare, chronic infection caused by Tropheryma whipplei, an actinobacterium ubiquitously present in the environment, is a multisystemic condition that can affect several organs. Therefore, Whipple's disease should always be considered by physicians working across various branches of medicine, including internal medicine, rheumatology, infectious diseases, gastroenterology, haematology, and neurology. Initially, Whipple's disease is challenging to diagnose due to both its rarity and non-specific clinical features, almost indistinguishable from rheumatological conditions. A few years later, the onset of gastrointestinal symptoms increases the specificity of its clinical picture and helps in reaching the correct diagnosis. Diagnosis is typically made by finding PAS-positive macrophages in the lamina propria at duodenal biopsy. PCR for Tropheryma whipplei is nowadays also increasingly available, and represents an undeniable help in diagnosing this condition. However, it may also be misleading as false positives can occur. If not promptly recognized and treated, central nervous system involvement may develop, which can be fatal. The therapeutic gold standard has not yet been fully established, particularly in cases of recurrent disease, neurological involvement, and an immune reconstitution inflammatory syndrome that may arise following the initiation of antibiotic therapy.

Clinical and laboratory predictors and prevalence of immune reconstitution inflammatory syndrome in patients with Whipple's disease

OBJECTIVES

Whipple's disease (WD) is a rare and potentially fatal infectious disease caused by Tropheryma whipplei. It is characterized by a long prodromal phase that mimics a rheumatological disease, often leading to immunosuppressant treatment. Immune reconstitution inflammatory syndrome (IRIS) is currently the most important complication of WD, requiring prompt recognition and treatment as it can be fatal. However, epidemiological data on IRIS are scarce. We aimed to identify the clinical and laboratory predictors of IRIS at WD diagnosis and to evaluate whether the prevalence of IRIS has changed over time.

METHODS

Forty-five patients with WD (mean age 52 ± 11 years; 10 females) were followed up between January 2000 and December 2021. Clinical and laboratory data at WD diagnosis were retrospectively collected and compared among patients who developed IRIS and those who did not.

RESULTS

Erythrocyte sedimentation rate (ESR; 33.4 ± 11.8 mm/h vs 67.1 ± 26.3 mm/h, P < 0.01), platelet (PLT; 234 × 109 /L vs 363 × 109 /L, P < 0.01), and body mass index (22.0 ± 2.0 kg/m2 vs 19.8 ± 3.0 kg/m2 , P = 0.04) differed significantly between patients who subsequently developed IRIS and those who did not. ROC analysis identified ESR ≤46 mm/h (AUROC 0.88, 95% CI 0.72-1.00) and PLT ≤ 327 × 109 /L (AUROC 0.85, 95% CI 0.70-1.00) as optimal cut-off values to discriminate WD patients at a high risk of developing IRIS. Prevalence of IRIS remained stable (22.2%) over time.

CONCLUSIONS

Low ESR and PLT count at diagnosis help identify WD patients at high risk of developing IRIS. Instead, a greater inflammatory response suggests a lower risk of IRIS. Prevalence of IRIS did not change over two decades.

Experience in the diagnosis and treatment of pneumonia caused by infection with Tropheryma whipplei: A case series

Tropheryma whipplei (TW) is the root cause of Whipple's disease (WD), a rare infectious illness leading to multi-organ impairment. A prominent feature of WD is acute pneumonia, which can be exceedingly challenging to diagnose clinically due to the pathogen's surreptitious nature. However and significantly, with the advent of metagenomic next-generation sequencing (mNGS) of bronchoalveolar lavage fluid (BALF), it offers clinicians a potent tool at their disposal to detect TW infections. The present study conducted a retrospective analysis of clinical data gleaned from five patients in Hunan Province in China. Findings in this study demonstrated the potential of BALF-mNGS in diagnosing pneumonia caused by TW infection.

Phenotypic diversity of Tropheryma whipplei clinical isolates

Tropheryma whipplei is a bacterial pathogen responsible for a wide range of infections in humans, covering asymptomatic carriage, acute infections, chronic isolated infections and classic Whipple's disease. Although the bacterium is commonly found in the environment, it very rarely causes disease. Genetic comparison of clinical isolates has revealed that main variations were found in region encoding T. whipplei surface glycoproteins called WiSP. However, no association has been made between the genetic diversity and the clinical manifestations of the infection. In this study we evaluated the phenotypic diversity of 26 clinical isolates from different origins and taken from patient with different infection outcomes. MRC5 and macrophages cells were infected, and bacterial uptake, survival and the pro-and anti-inflammatory potential of the different clinical isolates was assessed. No significant difference of phagocytosis was found between the different isolates; however, we found that bacterial replication was increased for bacteria expressing high molecular weight WiSP. In addition, we found that the expression of the genes coding for IL-1β and TGF-β was significantly higher when MRC5 cells were stimulated with isolates from chronic infections compared to isolates from localized infections while no significant differences were observed in macrophages. Overall, our study revealed that, as previously observed at the genetic level, phenotypic diversity of T. whipplei isolates is associated with the expression of different WiSP, which may result in subtle differences in host responses. Other host factors or genetic predisposition may explain the range of clinical manifestations of T. whipplei infections.

Potential Role for Urine Polymerase Chain Reaction in the Diagnosis of Whipple's Disease

BACKGROUND

Whipple's disease (WD) is a rare infection with Tropheryma whipplei that is fatal if untreated. Diagnosis is challenging and currently based on invasive sampling. In a case of WD diagnosed from a kidney biopsy, we observed morphologically-intact bacteria within the glomerular capsular space and tubular lumens. This raised the questions of whether renal filtration of bacteria is common in WD and whether polymerase chain reaction (PCR) testing of urine might serve as a diagnostic test for WD.

METHODS

We prospectively investigated urine samples of 12 newly-diagnosed and 31 treated WD patients by PCR. As controls, we investigated samples from 110 healthy volunteers and patients with excluded WD or acute gastroenteritis.

RESULTS

Out of 12 urine samples from independent, therapy-naive WD patients, 9 were positive for T. whipplei PCR. In 3 patients, fluorescence in situ hybridization visualized T. whipplei in urine. All control samples were negative, including those of 11 healthy carriers with T. whipplei-positive stool samples. In our study, the detection of T. whipplei in the urine of untreated patients correlated in all cases with WD.

CONCLUSIONS

T. whipplei is detectable by PCR in the urine of the majority of therapy-naive WD patients. With a low prevalence but far-reaching consequences upon diagnosis, invasive sampling for WD is mandatory and must be based on a strong suspicion. Urine testing could prevent patients from being undiagnosed for years. Urine may serve as a novel, easy-to-obtain specimen for guiding the initial diagnosis of WD, in particular in patients with extra-intestinal WD.

Tropheryma whipplei Infection (Whipple Disease) in the USA

BACKGROUND

Whipple disease (WD) is an infection caused by the bacterium Tropheryma whipplei (TW). Few cases have been reported in the USA.

AIMS

To report on the demographics, clinical manifestations, diagnostic findings, treatment, and outcomes of TW infection.

METHODS

Cases of TW infection diagnosed from 1995 to 2010 were identified in three US referral centers and from 1995 to 2015 in one. Definite classic WD was defined by positive periodic acid-Schiff (PAS) staining and probable WD by specific positive TW polymerase chain reaction (PCR) of intestinal specimens. Localized infections were defined by a positive TW PCR result from samples of other tissues/body fluids.

RESULTS

Among the 33 cases of TW infections, 27 (82%) were male. Median age at diagnosis was 53 years (range 11-75). Diagnosis was supported by a positive TW PCR in 29 (88%) and/or a positive PAS in 16 (48%) patients. Classic WD was the most frequent presentation (n = 18, 55%), with 14 definite and 4 probable cases. Localized infections (n = 15, 45%) affected the central nervous system (n = 7), joints (n = 4), heart (n = 2), eye (n = 1), and skeletal muscle (n = 1). Blood PCR was negative in 9 of 17 (53%) cases at diagnosis. Ceftriaxone intravenously followed by trimethoprim and sulfamethoxazole orally was the most common regimen (n = 23, 70%). Antibiotic therapy resulted in clinical response in 24 (73%).

CONCLUSIONS

TW infection can present as intestinal or localized disease. Negative small bowel PAS and PCR do not exclude the diagnosis of TW infection, and blood PCR is insensitive for active infection.

New Laboratory Tools for Emerging Bacterial Challenges

Since its creation, the Méditerranée-Infection foundation has aimed at optimizing the management of infectious diseases and surveying the local and global epidemiology. This pivotal role was permitted by the development of rational sampling, point-of-care tests, and extended automation as well as new technologies, including mass spectrometry for colony identification, real-time genomics for isolate characterization, and the development of versatile and permissive culture systems. By identifying and characterizing emerging microbial pathogens, these developments provided significant breakthroughs in infectious diseases.

IRF4 haploinsufficiency in a family with Whipple's disease

Most humans are exposed to Tropheryma whipplei (Tw). Whipple's disease (WD) strikes only a small minority of individuals infected with Tw (<0.01%), whereas asymptomatic chronic carriage is more common (<25%). We studied a multiplex kindred, containing four WD patients and five healthy Tw chronic carriers. We hypothesized that WD displays autosomal dominant (AD) inheritance, with age-dependent incomplete penetrance. We identified a single very rare non-synonymous mutation in the four patients: the private R98W variant of IRF4, a transcription factor involved in immunity. The five Tw carriers were younger, and also heterozygous for R98W. We found that R98W was loss-of-function, modified the transcriptome of heterozygous leukocytes following Tw stimulation, and was not dominant-negative. We also found that only six of the other 153 known non-synonymous IRF4 variants were loss-of-function. Finally, we found that IRF4 had evolved under purifying selection. AD IRF4 deficiency can underlie WD by haploinsufficiency, with age-dependent incomplete penetrance.

Tropheryma whipplei as a Cause of Epidemic Fever, Senegal, 2010-2012

Findings suggest that the bacterium has role in febrile episodes, is contagious, and has an epidemic character.

The bacterium Tropheryma whipplei, which causes Whipple disease in humans, is commonly detected in the feces of persons in Africa. It is also associated with acute infections. We investigated the role of T. whipplei in febrile patients from 2 rural villages in Senegal. During June 2010–March 2012, we collected whole-blood finger-prick samples from 786 febrile and 385 healthy villagers. T. whipplei was detected in blood specimens from 36 (4.6%) of the 786 febrile patients and in 1 (0.25%) of the 385 apparently healthy persons. Of the 37 T. whipplei cases, 26 (70.2%) were detected in August 2010. Familial cases and a potential new genotype were observed. The patients’ symptoms were mainly headache (68.9%) and cough (36.1%). Our findings suggest that T. whipplei is a cause of epidemic fever in Senegal.

Non-neoplastic histiocytic and dendritic cell disorders in lymph nodes

Benign and malignant proliferations of histiocytes and dendritic cells may be encountered in lymph nodes. Reactive histiocytic and dendritic cell infiltrates occur in response to diverse stimuli and in addition to causing lymphadenopathy, may be present unexpectedly in lymph nodes excised for other indications. This review summarizes the pathogenesis and histopathological features of the various non-neoplastic histiocytic and dendritic cell infiltrates that can occur in lymph nodes.

Clinical Manifestations, Treatment, and Diagnosis of Tropheryma whipplei Infections

Whipple's disease is a rare infectious disease that can be fatal if left untreated. The disease is caused by infection with Tropheryma whipplei, a bacterium that may be more common than was initially assumed. Most patients present with nonspecific symptoms, and as routine cultivation of the bacterium is not feasible, it is difficult to diagnose this infection. On the other hand, due to the generic symptoms, infection with this bacterium is actually quite often in the differential diagnosis. The gold standard for diagnosis used to be periodic acid-Schiff (PAS) staining of duodenal biopsy specimens, but PAS staining has a poor specificity and sensitivity. The development of molecular techniques has resulted in more convenient methods for detecting T. whipplei infections, and this has greatly improved the diagnosis of this often missed infection. In addition, the molecular detection of T. whipplei has resulted in an increase in knowledge about its pathogenicity, and this review gives an overview of the new insights in epidemiology, pathogenesis, clinical manifestations, diagnosis, and treatment of Tropheryma whipplei infections.

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.

Genotypic analysis of Tropheryma whipplei from patients with Whipple disease in the Americas

Tropheryma whipplei, the agent of Whipple disease, causes a rare bacterial disease that may be fatal if not treated. The classical form of the disease includes diarrhoea, weight loss, arthritis, endocarditis and neurological manifestations. Genotyping studies done in Europe, Africa and Asia showed high genetic diversity with no correlation between genotypes and clinical features, but contributed to a better understanding of the epidemiology of the disease. More than 70 genotypes have been described. No similar assessment of T. whipplei in the USA and the Caribbean has been performed. In this study, we describe genetic analysis of DNA from histopathological samples obtained from 30 patients from the Americas with Whipple disease and compare the genotypes with those previously identified. Complete genotypes were obtained from 18 patients (60%). Only 4 genotypes were previously described, and 14 were newly reported, confirming the diversity of T. whipplei strains.

Whipple's disease

In recent years, it has become apparent that Tropheryma whipplei not only causes a chronic multisystemic infection which is often preceded by arthropathies for many years, well known as 'classical' Whipple's disease, but also clinically becomes manifest with localized organ affections and acute (transient) infections in children. T. whipplei is found ubiquitously in the environment and colonizes in some healthy carriers. In this review, we highlight new aspects of this enigmatic infectious disorder.

Tropheryma whipplei infection (Whipple's disease) in a patient after liver transplantation

Whipple's disease (WD) is a rare infection caused by the bacterium Tropheryma whipplei that can affect multiple organs and most commonly occurs in the immunocompetent host. Only 3 cases of WD have been reported in the setting of immunosuppression for organ transplantation. Here, we report the first case of WD, to our knowledge, in a patient after liver transplantation with comorbid graft-versus-host-disease. We discuss the diagnostic challenges in this setting and the value of electron microscopy and in situ hybridization methods for confirming the infection. WD may be under-diagnosed in immunosuppressed transplant patients because the disease can present with atypical clinical and histological features that suggest other conditions.

Tropheryma whipplei infection and Whipple's disease

Recent advances in medical microbiology, epidemiology, cellular biology, and the availability of an expanded set of diagnostic methods such as histopathology, immunohistochemistry, PCR, and bacterial culture have improved our understanding of the clinical range and natural course of Tropheryma whipplei infection and Whipple's disease. Interdisciplinary and transnational research activities have contributed to the clarification of the pathogenesis of the disorder and have enabled controlled trials of different treatment strategies. We summarise the current knowledge and new findings relating to T whipplei infection and Whipple's disease.

Tropheryma whipplei, a Potential Commensal Detected in Individuals Undergoing Routine Colonoscopy

Mucosal biopsy samples from individuals not suspected of having Whipple's disease were tested for the presence of Tropheryma whipplei. A sensitive and specific real-time PCR assay targeting a sequence present seven times in the T. whipplei genome was used. T. whipplei DNA was detected in 2.0 and 3.8% of the patients undergoing gastroduodenoscopy and colonoscopy, respectively, who were tested.

Whipple's Disease

Background

Whipple's disease (WD) is rarely the cause of a malabsorption syndrome. The disease is a chronic infection of the intestinal mucosa with the bacterium Tropheryma whipplei, which leads to a lymphostasis with an impaired absorption of the nutrition. Due to its low incidence (1:1,000,000) and the non-specific early symptoms, the disease is often diagnosed only after many years.

Methods

Based on a selective literature review and the clinical experience of the authors, the current knowledge of WD regarding pathogenesis, clinical presentation, diagnosis, and therapy are presented in this paper.

Results

Recent studies suggest that a host-specific dysfunction of the intestinal macrophages is responsible for the chronic infection with T. whipplei. Prior to patients reporting symptoms of a malabsorption syndrome (chronic diarrhea/steatorhea, weight loss), they often suffer from non-specific symptoms (polyarthralgia, fever, fatigue) for many years. Misdiagnoses such as seronegative polyarthritis are frequent. Furthermore, neurological, cardiac, ocular, or dermatological symptoms may occur. The standard method concerning diagnosis is the detection of PAS(periodic acid-Schiff)-positive macrophages in the affected tissues. Immunohistochemical staining and PCR(polymerase chain reaction)-based genetic analysis increase the sensitivity and specificity of conventional detection methods. Endoscopically, the intestinal mucosa appears edematous with lymphangiectasias, enlarged villi, and white-yellowish ring-like structures. The German treatment recommendations include a two-week intravenous induction therapy with ceftriaxone, which is followed by a three-month oral maintenance therapy with trimethoprim/sulfamethoxazole.

Conclusion

WD is rarely responsible for a malabsorption syndrome. However, if WD is not recognized, the disease can be lethal. New diagnostic methods and prospectively approved therapeutic concepts allow an adequate treatment of the patient. Due to the host-specific susceptibility to T. whipplei, a lifelong follow-up is necessary.

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.

Positron emission tomography in the diagnosis of Whipple's endocarditis: a case report

BACKGROUND

Whipple's disease is a systemic infection that sometimes is associated with cardiac manifestations. The diagnosis of Tropheryma whipplei endocarditis is still the result of chance because there are no diagnostic criteria and clinical signs are often those of cardiac disease rather than infection.

CASE PRESENTATION

Culture-negative endocarditis was suspected in a non-febrile 77-year-old French woman from North France with a history of a graft replacement 4 years prior. Positron emission tomography revealed intense fluorodeoxyglucose uptake around the metal ring of the aortic graft. The valve was replaced, and T. whipplei was detected in a valve sample by molecular assays. Immunohistochemical staining of the valve for T. whipplei was also positive.

CONCLUSION

The localization of infectious foci by positron emission tomography and systematically testing valve specimens for T. whipplei are promising for diagnosing Whipple's disease.

High prevalence of Tropheryma whipplei in Lao kindergarten children

Background

Tropheryma whipplei is a bacterium commonly found in feces of young children in Africa, but with no data from Asia. We estimated the prevalence of T. whipplei carriage in feces of children in Lao PDR (Laos).

Methods/Principal Findings

Using specific quantitative real-time PCR, followed by genotyping for each positive specimen, we estimated the prevalence of T. whipplei in 113 feces from 106 children in Vientiane, the Lao PDR (Laos). T. whipplei was detected in 48% (51/106) of children. Those aged ≤4 years were significantly less frequently positive (17/52, 33%) than older children (34/54, 63%; p< 0.001). Positive samples were genotyped. Eight genotypes were detected including 7 specific to Laos. Genotype 2, previously detected in Europe, was circulating (21% of positive children) in 2 kindergartens (Chompet and Akad). Genotypes 136 and 138 were specific to Chompet (21% and 15.8%, respectively) whereas genotype 139 was specific to Akad (10.55%).

Conclusions/Significance

T. whipplei is a widely distributed bacterium, highly prevalent in feces of healthy children in Laos. Further research is needed to identify the public health significance of this finding.

Tropheryma whipplei is a common bacterium carried in feces of young children. Here, using specific PCR, we estimated the prevalence of T. whipplei in 113 feces from 106 children in Vientiane, the Lao PDR (Laos). T. whipplei was detected in 48% (51/106) of children. Eight genotypes were detected, including 7 specific to Laos. Genotype 2, previously detected in Europe, was circulating (21% of positive children) in 2 kindergartens (Chompet and Akad). Genotypes 136 and 138 were specific to Chompet (21% and 15.8%, respectively), whereas genotype 139 was specific to Akad (10.55%). Long regarded as a rare bacterium, now we can affirm that T. whipplei is a widely distributed bacterium, highly prevalent in feces including those from children in Vientiane.

Tropheryma whipplei endocarditis

Tropheryma whipplei endocarditis differs from classic Whipple disease, which primarily affects the gastrointestinal system. We diagnosed 28 cases of T. whipplei endocarditis in Marseille, France, and compared them with cases reported in the literature. Specimens were analyzed mostly by molecular and histologic techniques. Duke criteria were ineffective for diagnosis before heart valve analysis. The disease occurred in men 40-80 years of age, of whom 21 (75%) had arthralgia (75%); 9 (32%) had valvular disease and 11 (39%) had fever. Clinical manifestations were predominantly cardiologic. Treatment with doxycycline and hydroxychloroquine for at least 12 months was successful. The cases we diagnosed differed from those reported from Germany, in which arthralgias were less common and previous valve lesions more common. A strong geographic specificity for this disease is found mainly in eastern-central France, Switzerland, and Germany. T. whipplei endocarditis is an emerging clinical entity observed in middle-aged and older men with arthralgia.

Relationship between previous treatments and onset of symptoms in patients with Whipple's disease

The clinical features of Whipple's disease (WD) consist of arthropathy that precedes the involvement of other organs, such as the gastrointestinal tract, nervous system and heart. It has been shown that gastrointestinal manifestations can be precipitated by immunosuppressive therapy used to control the arthropathy. In the present study, we investigated the clinical features of the Italian population of patients affected by WD. The clinical histories of 22 patients with WD were reviewed. Relationship between previous treatments and onset of symptoms was analysed. 20/22 patients suffered from arthropathy that had started before gastrointestinal complaints; gastrointestinal symptoms were present in 18 patients and neurological involvement was found in 5. WD must always be taken into account in male patients with long-standing ill-defined arthropathy, and it should be ruled out before starting immunosuppressive or antibiotic treatment that can make correct diagnosis and management very difficult.

Treatment of classic Whipple's disease: from in vitro results to clinical outcome

OBJECTIVES

Patients with classic Whipple's disease have a lifetime defect in immunity to Tropheryma whipplei and frequently develop treatment failures, relapses or reinfections. Empirical treatments were tested before culture was possible, but the only in vitro bactericidal treatment consists of a combination of doxycycline and hydroxychloroquine.

METHODS

Our laboratory has been a reference centre since the first culturing of Tropheryma whipplei, and we have tested 27,000 samples by PCR and diagnosed 250 cases of classic Whipple's disease. We report here the clinical course of patients who were followed by one of our group.

RESULTS

Of 29 patients, 22 (76%) were previously treated with immunosuppressive drugs, 26 (90%) suffered from arthralgias and 22 (76%) exhibited weight loss. Intravenous initial treatment was paradoxically associated with an increased risk of failure (P = 0.0282). Treatment with doxycycline and hydroxychloroquine (± sulfadiazine or trimethoprim/sulfamethoxazole) was associated with a better outcome (0/13 failures), whereas all 14 patients who were first treated with trimethoprim/sulfamethoxazole and referred to us (P < 0.0001) experienced failure. Among the patients treated with doxycycline and hydroxychloroquine after previous antibiotic treatments, two presented with a reinfection caused by different T. whipplei strains. Finally, serum therapeutic drug monitoring allowed us to detect a lack of compliance in the only patient with failure among the 22 patients treated with lifetime doxycycline.

CONCLUSIONS

In vitro results were confirmed by clinical outcomes and trimethoprim/sulfamethoxazole was associated with failures. The recommended management is a combination of doxycycline and hydroxychloroquine for 1 year, followed by doxycycline for the patient's lifetime along with stringent therapeutic drug monitoring.

Widespread colonization of the lung by Tropheryma whipplei in HIV infection

RATIONALE

Lung infections caused by opportunistic or virulent pathogens are a principal cause of morbidity and mortality in HIV infection. It is unknown whether HIV infection leads to changes in basal lung microflora, which may contribute to chronic pulmonary complications that increasingly are being recognized in individuals infected with HIV.

OBJECTIVES

To determine whether the immunodeficiency associated with HIV infection resulted in alteration of the lung microbiota.

METHODS

We used 16S ribosomal RNA targeted pyrosequencing and shotgun metagenomic sequencing to analyze bacterial gene sequences in bronchoalveolar lavage (BAL) and mouths of 82 HIV-positive and 77 HIV-negative subjects.

MEASUREMENTS AND MAIN RESULTS

Sequences representing Tropheryma whipplei, the etiologic agent of Whipple's disease, were significantly more frequent in BAL of HIV-positive compared with HIV-negative individuals. T. whipplei dominated the community (>50% of sequence reads) in 11 HIV-positive subjects, but only 1 HIV-negative individual (13.4 versus 1.3%; P = 0.0018). In 30 HIV-positive individuals sampled longitudinally, antiretroviral therapy resulted in a significantly reduced relative abundance of T. whipplei in the lung. Shotgun metagenomic sequencing was performed on eight BAL samples dominated by T. whipplei 16S ribosomal RNA. Whole genome assembly of pooled reads showed that uncultured lung-derived T. whipplei had similar gene content to two isolates obtained from subjects with Whipple's disease.

CONCLUSIONS

Asymptomatic subjects with HIV infection have unexpected colonization of the lung by T. whipplei, which is reduced by effective antiretroviral therapy and merits further study for a potential pathogenic role in chronic pulmonary complications of HIV infection.

Tropheryma whipplei as a commensal bacterium

Tropheryma whipplei is the bacterial agent of the well-known and rare Whipple's disease, mainly observed among Caucasians. This bacterium has recently been involved in other chronic and acute infections. For a long time, the only known source of the bacterium was patients with Whipple's disease; however, thanks to the advent of molecular biology, T. whipplei has now been detected in specimens from healthy individuals, mainly in stool and saliva samples. The prevalence of carriage depends on several factors, such as age, exposure and geographical area, reaching 75% in stool specimens from children less than 4 years old in rural Africa. T. whipplei is a commensal bacterium that only causes Whipple's disease in a subset of individuals, probably those with a still-uncharacterized specific immunological defect.

Looking for Tropheryma whipplei source and reservoir in rural Senegal

Tropheryma whipplei, the bacterium linked to Whipple's disease, is involved in acute infections and asymptomatic carriage. In rural Senegal, the prevalence of T. whipplei is generally high but is not homogeneous throughout households in the same village. We studied environmental samples collected in two Senegalese villages and conducted the survey to investigate the difference between households. Overall, the comparison between five households with very high T. whipplei prevalence and three households without any registered cases showed that the only difference was the presence of toilets in the latter (1/5 versus 3/3; P = 0.01423). Among the 1,002 environmental specimens (including domestic and synanthropic animals and dust sampled in households) tested for T. whipplei DNA, only four specimens were slightly positive. Humans are currently the predominant identified reservoir and source of T. whipplei in these populations. Limited access to toilets and exposure to human feces facilitate the fecal-oral transmission of T. whipplei.

Whipple's disease

Whipple's disease is a chronic multisystemic infection, due to Tropheryma whipplei, a bacterium ubiquitously present in the environment. Although it is very rare, its clinical features are non-specific and can affect several different districts. Whipple's disease is therefore a condition that should always be kept in mind by doctors working in several branches of medicine, such as internal medicine, gastroenterology, rheumatology, neurology, and cardiology. The condition is fatal if not promptly recognized and treated, but the best treatment is still not completely defined, especially in relapsing disease, neurological manifestations, and in cases of immunoreconstitution after initiation of antibiotic treatment.

Previous immunosuppressive therapy is a risk factor for immune reconstitution inflammatory syndrome in Whipple's disease

INTRODUCTION

Whipple's disease is a rare chronic infection caused by Tropheryma whipplei. Although most patients respond to antibiotics, in some of them the start of the treatment is followed by recurrence of inflammation. Since polymerase chain reaction is negative for Tropheryma whipplei, this reinflammation cannot be a relapse of Whipple's disease itself. Very recently, it has been recognised as a complication of Whipple's disease and defined immune reconstitution inflammatory syndrome (IRIS). Our aim is to study the prevalence and the clinical features of IRIS in Italian patients with Whipple's disease.

METHODS

Evidence of IRIS was retrospectively revaluated in the clinical notes of 22 patients with Whipple's disease. Patients with no evidence of IRIS served as controls for the clinical findings.

RESULTS

Recurrence of arthralgia and/or fever allowed a diagnosis of IRIS in 5/22 patients. One patient died. Previous immunosuppressive therapy was found in all patients with IRIS but only in 7/17 controls (Fisher test, p=0.039). Age at diagnosis and diagnostic delay were higher in patients with IRIS compared to controls. However, statistical significance was not reached.

CONCLUSIONS

IRIS is a frequent complication of Whipple's disease and it can be fatal. The risk of IRIS is greatly increased in patients previously treated with immunosuppressive therapy.

Intrafamilial circulation of Tropheryma whipplei, France

Tropheryma whipplei, which causes Whipple disease, has been detected in 4% of fecal samples from the general adult population of France. To identify T. whipplei within families, we conducted serologic and molecular studies, including genotyping, on saliva, feces, and serum from 74 relatives of 13 patients with classic Whipple disease, 5 with localized chronic T. whipplei infection, and 3 carriers. Seroprevalence was determined by Western blot and compared with 300 persons from the general population. We detected T. whipplei in 24 (38%) of 64 fecal samples and 7 (10%) of 70 saliva samples from relatives but found no difference between persons related by genetics and marriage. The same circulating genotype occurred significantly more often in families than in other persons. Seroprevalence was higher among relatives (23 [77%] of 30) than in the general population (143 [48%] of 300). The high prevalence of T. whipplei within families suggests intrafamilial circulation.

Tropheryma whipplei: a common bacterium in rural Senegal

BACKGROUND

Tropheryma whipplei is known as the cause of Whipple's disease, but it is also an emerging pathogen, detected in stool, that causes various chronic localized infections without histological digestive involvement and is associated with acute infections, including gastroenteritis and bacteremia.

METHODS/PRINCIPAL FINDINGS

We conducted a study in 2008 and 2009 using 497 non-diarrheic and diarrheic stool samples, 370 saliva samples, 454 sera samples and 105 samples obtained from water samples in two rural Sine-Saloum villages (Dielmo and Ndiop) in Senegal. The presence of T. whipplei was investigated by using specific quantitative PCR. Genotyping was performed on positive samples. A serological analysis by western blotting was performed to determine the seroprevalence and to detect seroconversion. Overall, T. whipplei was identified in 31.2% of the stool samples (139/446) and 3.5% of the saliva samples (13/370) obtained from healthy subjects. The carriage in the stool specimens was significantly (p<10(-3)) higher in children who were between 0 and 4 years old (60/80, 75%) compared to samples obtained from individuals who were between 5 to 10 years old (36/119, 30.2%) or between 11 and 99 years old (43/247, 17.4%). The carriage in the stool was also significantly more common (p = 0.015) in subjects with diarrhea (25/51, 49%). We identified 22 genotypes, 16 of which were new. Only one genotype (#53) was common to both villages. Among the specific genotypes, one (#52) was epidemic in Dielmo (15/28, 53.4%, p<10(-3)) and another (#49) in Ndiop (27.6%, p = 0.002). The overall seroprevalence was estimated at 72.8% (291/400). Seroconversion was detected in 66.7% (18/27) of children for whom PCR became positive in stools between 2008 and 2009.

CONCLUSIONS/SIGNIFICANCE

T. whipplei is a common bacterium in the Sine-Saloum area of rural Senegal that is contracted early in childhood. Epidemic genotypes suggest a human transmission of the bacterium.

Systemic Tropheryma whipplei: clinical presentation of 142 patients with infections diagnosed or confirmed in a reference center

Culture of Tropheryma whipplei, the agent of Whipple disease (WD), was achieved in our laboratory in 2000, allowing new perspectives for the diagnosis of this disease and for the description of other potential clinical manifestations caused by this microorganism. Since 2000, we have developed new tools in our center in Marseille, France, to optimize the diagnosis of T whipplei infections. Classic WD was characterized by positive periodic acid-Schiff performed on duodenal biopsy. In the absence of duodenal histologic involvement, localized infections were defined by specific positive T whipplei polymerase chain reaction (PCR) results obtained using samples of other tissues and body fluids. The physicians in charge of patients were asked to complete a questionnaire. A total of 215 diagnoses were performed or confirmed and, among these, 142 patients with sufficient clinical data were included.Herein, we report epidemiologic data, clinical manifestations, and diagnostic tools of T whipplei infections. In the 113 patients with classic WD, the main symptom was arthralgia (88/113, 78%), which explains the many cases misdiagnosed as inflammatory rheumatoid disease (56/113, 50%). Frequently immunosuppressive treatments, more recently including tumor necrosis factor inhibitor, had been previously prescribed (50%) and were often responsible for more rapid clinical progression (43%). Sometimes a short course of antibiotics improved the clinical status.Endocarditis was the second most frequent manifestation of T whipplei, with 16 cases. The clinical picture of this entity corresponds to cardiovascular involvement with acute heart failure (50%) occurring without fever (75%) or previous valvular disease (69%). Neurologic symptoms were the third major manifestation. Other localized infections such as adenopathy, uveitis, pulmonary involvement, or joint involvement were sporadic. Infection with T whipplei resulted in multifaceted conditions. Some localized infections due to this agent have recently been reported and may correspond to emerging entities. Patients with inflammatory rheumatoid disease must be systematically interviewed to determine the efficacy of previous immunosuppressive and antibiotic therapies.

Tropheryma whipplei in children with gastroenteritis

This bacterium may be an etiologic agent of gastroenteritis.

Tropheryma whipplei, which causes Whipple disease, is found in human feces and may cause gastroenteritis. To show that T. whipplei causes gastroenteritis, PCRs for T. whipplei were conducted with feces from children 2–4 years of age. Western blotting was performed for samples from children with diarrhea who had positive or negative results for T. whipplei. T. whipplei was found in samples from 36 (15%) of 241 children with gastroenteritis and associated with other diarrheal pathogens in 13 (33%) of 36. No positive specimen was detected for controls of the same age (0/47; p = 0.008). Bacterial loads in case-patients were as high as those in patients with Whipple disease and significantly higher than those in adult asymptomatic carriers (p = 0.002). High incidence in patients and evidence of clonal circulation suggests that some cases of gastroenteritis are caused or exacerbated by T. whipplei, which may be co-transmitted with other intestinal pathogens.