A serological assay using Tropheryma whipplei antigens for the presumptive exclusion of Whipple disease.

Whipple disease (WD) is a rare infection in genetically susceptible people caused by the bacterium Tropheryma whipplei. An indirect immunofluorescence serological assay (IFA), detecting patient antibodies to the bacterium, was developed using T. whipplei as antigen. We hypothesised that this assay could be used to rule out WD in patients in whom the diagnosis was being considered, based on high immunoglobulin (Ig) G titres to T. whipplei. In this study, 16 confirmed WD patients and 156 age-matched controls from across Australia were compared serologically. WD patients mostly underproduced IgG antibody to T. whipplei, with titres of ≤1:32 being common. While at an antibody titre of <1:64 the assay sensitivity for WD was only 69% [95% confidence interval (CI) 41-89%], its specificity for excluding WD was 91% (95% CI 85-95%). This specificity increased to 95% (95% CI 90-98%) at an antibody titre of <1:16. Patients with antibody titres of >1:64 were unlikely to have WD. At this titre, the seroprevalence of T. whipplei IgG antibody was 92% (223/242) in Australian blood donors. Unlike other serological assays, which are used to confirm a specific infection, this novel assay is designed to rule out WD infection with a specificity in Australia of 91%. Further validation of this assay, by trialling in other countries, should now be undertaken, as its usefulness is dependent on there being a high background seropositivity to T. whipplei in the general population at the location in which the assay is being used.

Whipple Disease Misdiagnosed as Lymphoma by 18 F-FDG PET/CT: A Case Study.

ABSTRACT: Whipple disease is a rare disorder caused by infection with the gram-positive bacterium Tropheryma whipplei . It can invade various organs and systems of the whole body. This case report describes a patient with invasion of multiple lymph nodes throughout the body misdiagnosed as lymphoma by PET/CT.

Whipple's disease and Tropheryma whipplei infections: from bench to bedside.

Whipple's disease is a chronic and systemic disease caused by the Gram-positive bacterium Tropheryma whipplei that primarily affects the gastrointestinal tract. Data from the last two decades have substantially increased our knowledge of the spectrum and our understanding of T whipplei infections. Although T whipplei seems ubiquitously present in the environment, Whipple's disease itself is very rare. Remarkably, primary infections can be symptomatic, but most cases result in bacterial clearance and seroconversion. However, some individuals are unable to clear the bacterium leading to persistence and asymptomatic carriage. In very rare cases, which might be associated with a subtle immune defect, T whipplei replication is uncontrolled and manifests as classical Whipple's disease or T whipplei localised infections. In this review, we provide a comprehensive outline of T whipplei infection, including the epidemiology, clinical manifestations, diagnosis, and treatment. We also provide an up-to-date overview of our understanding of the host immune response and pathophysiology and discuss future research avenues to resolve the lacking pieces of the puzzle of T whipplei infections.

Rheumatological features of Whipple disease.

Whipple disease (WD) is a rare infectious systemic disease. Rheumatologists are at the frontline of WD diagnosis due to the early rheumatological manifestations. An early diagnosis is crucial, as usual anti-rheumatic drugs, especially TNF inhibitors, may worsen the disease course. We conducted a retrospective multicentre national study from January 2010 to April 2020 to better characterize the rheumatological features of WD. Classic WD (CWD) was defined by positive periodic acid-Schiff (PAS) staining of a small-bowel biopsy sample, and non-CWD (NCWD) was defined by negative PAS staining of a small-bowel biopsy sample but at least one positive Tropheryma whipplei (TW) polymerase chain reaction (PCR) for a digestive or extradigestive specimen. Sixty-eight patients were enrolled, including 11 CWD patients. Twenty patients (30%) received TNF inhibitors during the WD course, with inefficacy or symptom worsening. More digestive symptoms and systemic biological features were observed in CWD patients than in NCWD patients, but both patient groups had similar outcomes, especially concerning the response to antibiotics and relapse rate. Stool and saliva TW PCR sensitivity were both 100% for CWD and 75% for NCWD and 89% and 60% for small-bowel biopsy sample PCR, respectively. WD encountered in rheumatology units has many presentations, which might result from different pathophysiologies that are dependent on host immunity. Given the heterogeneous presentations and the presence of chronic carriage, multiple TW PCR tests on samples from specific rheumatological sites when possible should be performed, but samples from nonspecific digestive and extradigestive sites also have great value.

Human galectin-1 and galectin-3 promote Tropheryma whipplei infection.

Tropheryma whipplei, is an actinobacterium that causes different infections in humans, including Whipple's disease. The bacterium infects and replicates in macrophages, leading to a Th2-biased immune response. Previous studies have shown that T. whipplei harbors complex surface glycoproteins with evidence of sialylation. However, the exact contribution of these glycoproteins for infection and survival remains obscure. To address this, we characterized the bacterial glycoprofile and evaluated the involvement of human ß-galactoside-binding lectins, Galectin-1 (Gal-1) and Galectin-3 (Gal-3) which are highly expressed by macrophages as receptors for bacterial glycans. Tropheryma whipplei glycoproteins harbor different sugars including glucose, mannose, fucose, ß-galactose and sialic acid. Mass spectrometry identification revealed that these glycoproteins were membrane- and virulence-associated glycoproteins. Most of these glycoproteins are highly sialylated and N-glycosylated while some of them are rich in poly-N-acetyllactosamine (Poly-LAcNAc) and bind Gal-1 and Gal-3. In vitro, T. whipplei modulates the expression and cellular distribution of Gal-1 and Gal-3. Although both galectins promote T. whipplei infection by enhancing bacterial cell entry, only Gal-3 is required for optimal bacterial uptake. Finally, we found that serum levels of Gal-1 and Gal-3 were altered in patients with T. whipplei infections as compared to healthy individuals, suggesting that galectins are also involved in vivo. Among T. whipplei membrane-associated proteins, poly-LacNAc rich-glycoproteins promote infection through interaction with galectins. T. whipplei modulates the expression of Gal-1 and Gal-3 both in vitro and in vivo. Drugs interfering with galectin-glycan interactions may provide new avenues for the treatment and diagnosis of T. whipplei infections.

Whipple disease: a 15-year retrospective study on 36 patients with positive polymerase chain reaction for Tropheryma whipplei.

Our institution has performed microbiological diagnosis of Tropheryma whipplei since 2001, initially with a PCR targeting 16S rRNA before the development of a quantitative PCR in 2012. Here we report the clinical characteristics of a cohort of patients suffering from Whipple disease (WD) and evaluate the impact of these molecular techniques. Patients with a positive PCR for T. whipplei between 2001 and 2016 were retrospectively collected from microbiological databases. Two infectious diseases specialists reviewed their medical records and classified them as definite WD, probable WD or carriage of T. whipplei without disease. A total of 1153 samples were tested for T. whipplei; 76 samples taken from 36 patients were positive. Fifteen were considered as presenting a definite WD, seven as a probable WD and 14 as carriers. Median age was 56.4 years (extremes, 6.6-76.1). Median time from symptoms to diagnosis was 3 years (2.5 months to 13.3 years). About 60% were immunosuppressed. The most frequent clinical presentations were joint pain (16/22), weight loss (15/22) and/or digestive tract disorder (15/22); 41% had neurological manifestations, 32% pulmonary involvement and 32% lymphadenopathies. Bacterial load in faeces or saliva were 88 425 copies/mL (IQR 6175-292 725) in definite and probable WD and 311 copies/mL (IQR 253-2090) in carriers, respectively. We observed a 90% PPV above 32 200 copies/mL in faeces. WD is a chronic multisystemic disease with frequent pulmonary involvement. Underlying immunodeficiency is commonly observed leading to more complex clinical presentation. Positive T. whipplei PCR in both stool and saliva has a high positive predictive value. Moreover, patients with WD present higher bacterial load in faeces with a threshold of >32 200 copies/mL predicting ongoing infection.

Case Report: Tropheryma whipplei Infection Presenting with Optic Disc Edema.

SIGNIFICANCE: Whipple disease is a rare chronic, systemic bacterial infection that predominantly affects the small intestine but also other organs of the body. When left untreated, it can be not only vision threatening but also life threatening because of its central nervous system involvement. Therefore, early detection and treatment are important. PURPOSE: We report a rare case of unilateral optic disc edema as a critical identifying sign of Whipple disease. CASE REPORT: An asymptomatic 49-year-old African American man presented for an eye examination and was found to have optic nerve edema of the right eye. His best-corrected visual acuity was 20/20 in the right and left eye. He denied symptoms of diplopia, amaurosis fugax, or eye pain. His medical history was significant for HIV with no recent detectable viral load at the time of his eye examination. The patient denied any other infectious risk factors or changes in medical status. Extensive ophthalmic, neuroimaging, and laboratory investigations were completed as a comprehensive approach to rule out more common etiologies for unilateral optic disc edema. This initial workup yielded no identifying etiology, and the patient was monitored closely with frequent examinations with a retina specialist. Soon after his diagnosis of optic nerve edema, the patient developed new symptoms of chronic diarrhea, weight loss, and fatigue requiring hospitalization. Evaluations by internal medicine and gastroenterology, including serological testing, stool analysis, histological and microbiological analysis, esophagogastroduodenoscopy, and gastrointestinal biopsy, confirmed a diagnosis of Whipple disease that was successfully treated with oral antibiotics. CONCLUSIONS: Whipple disease is a rare cause of infectious optic nerve edema that may present with other rheumatoid and gastrointestinal symptoms. A comprehensive medical approach for investigating unilateral optic nerve edema is paramount in diagnosing and treating Whipple disease.

Another Whipple's triad? Pericardial, myocardial and valvular disease in an unusual case presentation from a Canadian perspective.

BACKGROUND: Whipple's disease is a clinically relevant multi-system disorder that is often undiagnosed given its elusive nature. We present an atypical case of Whipple's disease involving pan-valvular endocarditis and constrictive pericarditis, requiring cardiac intervention. A literature review was also performed assessing the prevalence of atypical cases of Whipple's disease. CASE PRESENTATION: A previously healthy 56-year-old male presented with a four-year history of congestive heart failure with weight loss and fatigue. Notably, he had absent gastrointestinal symptoms. He went on to develop pan-valvular endocarditis and constrictive pericarditis requiring urgent cardiac surgery. A clinical diagnosis of Whipple's disease was suspected, prompting duodenal biopsy sampling which was unremarkable, Subsequently, Tropheryma whipplei was identified by 16S rDNA PCR on the cardiac valvular tissue. He underwent prolonged antibiotic therapy with recovery of symptoms. CONCLUSIONS: Our study reports the first known case of Whipple's disease involving pan-valvular endocarditis and constrictive pericarditis. A literature review also highlights this presentation of atypical Whipple's with limited gastrointestinal manifestations. Duodenal involvement was limited and the gold standard of biopsy was not contributory. We also highlight the Canadian epidemiology of the disease from 2012 to 2016 with an approximate 4% prevalence rate amongst submitted samples. Routine investigations for Whipple's disease, including duodenal biopsy, in this case may have missed the diagnosis. A high degree of suspicion was critical for diagnosis of unusual manifestations of Whipple's disease.

Whipple disease after bariatric surgery: from malabsorption to malnutrition status.

Introduction: Malabsorptive bariatric techniques are associated with nutritional deficiencies. However, when patients do not respond to supplemental intensive treatments they should be closely followed because they can hide other pathological conditions. We present the case of a 47-year-old man with morbid obesity (body mass index [BMI]: 48 kg/m2) who underwent bariatric surgery. In 2016, he presented severe pneumonia and hospitalization at the Intensive Unit Care was required. After this episode, his nutritional state impaired, presenting 6-7 diarrhea/steatorrhea events per-day and requiring several hospitalizations due to the persistence of severe hypoproteinemia. He was given parenteral high-protein associated with low-fat oral diet. He presented a temporary biochemical improvement, but the hypoproteinemia recurred. Finally, tests revealed the presence of Tropheryma whipplei as protein-losing enteropathy. Whipple's disease (WD) is a rare cause of diarrhea and malnutrition, and these symptoms can be confused with the postoperative status of malabsorptive bariatric techniques. WD requires early diagnosis with prolonged antibiotic treatment to avoid severe complications.

Introducción: Las técnicas bariátricas malabsortivas suelen asociarse a deficiencias nutricionales. Sin embargo, cuando los pacientes no responden a tratamientos intensivos suplementarios, deben valorarse otras condiciones patológicas. Presentamos el caso de un hombre de 47 años, obeso mórbido (índice de masa corporal [IMC]: 48 kg/m2) sometido a cirugía bariátrica, que dos años más tarde presentó neumonía severa, por lo que requirió ingreso en la Unidad de Cuidados Intensivos. Posteriormente, el estado nutricional se deterioró, presentando 6-7 episodios de diarrea-esteatorrea/día y requiriendo varias hospitalizaciones por hipoproteinemia severa. Recibió infusión parenteral rica en proteínas asociada con una dieta baja en grasas y presentó mejoría analítica temporal. Finalmente, las pruebas revelaron la presencia de Tropheryma whipplei, una bacteria que genera enteropatía pierde-proteínas. La enfermedad de Whipple (EW) es una causa poco común de diarrea y malnutrición. Estos síntomas pueden confundirse con el posoperatorio de técnicas bariátricas malabsortivas. La EW requiere un diagnóstico precoz con un tratamiento antibiótico prolongado para evitar complicaciones graves.

Tropheryma whipplei intestinal colonization in Italian and migrant population: a retrospective observational study.

AIM: To obtain the first molecular epidemiological survey of Tropheryma whipplei intestinal colonization in Italy. Materials & methods: Retrospective, observational study to assess the prevalence of T. whipplei, the causative agent of Whipple's disease, in stool samples (real-time PCR) of patients attending the Center for Tropical Diseases (Italy) and risk factors associated. RESULTS: Overall prevalence was 6.9% (85/1240). The younger age group showed a significantly higher rate than older age group (12.7 vs 5.9%, p = 0.002). The prevalence was 4.9% for Italians and 9.3% for migrants (p = 0.003). Among the latter, children less than 10 years had higher prevalence than older ones (17.3 vs 7.3%, p = 0.003). The young age, male gender and Giardia duodenalis and Entamoeba histolytica coinfection were risk factors. CONCLUSION: Our study confirms an increased risk of acquiring T. whipplei infection during childhood, under poor sanitary conditions.

Peripheral-blood b-cell subset disturbances in inflammatory joint diseases induced by Tropheryma whipplei.

OBJECTIVE: To look for abnormalities in circulating B-cell subsets in patients with rheumatic symptoms of Whipple's disease (WD). METHOD: Consecutive patients seen between 2010 and 2016 for suspected inflammatory joint disease were identified retrospectively. Results of standardized immunological and serological tests and of peripheral-blood B-cell and T-cell subset analysis by flow cytometry were collected. Patients with criteria suggesting WD underwent PCR testing for Tropheryma whipplei, and those with diagnosis of WD (cases) were compared to those without diagnosis (controls). We used ROC curve analysis to evaluate the diagnostic value of flow cytometry findings for WD. RESULTS: Among 2917 patients seen for suspected inflammatory joint disease, 121 had suspected WD, including 9 (9/121, 7.4%) confirmed WD. Proportions of T cells and NK cells were similar between suspected and confirmed WD, whereas cases had a lower proportion of circulating memory B cells (IgD-CD38low, 18.0%±9.7% vs. 26.0%±14.2%, P = 0.041) and higher ratio of activated B cells over memory B cells (4.4±2.0 vs. 2.9±2.2, P = 0.023). Among peripheral-blood B-cells, the proportion of IgD+CD27- naive B cells was higher (66.2%±18.2% vs. 54.6%±18.4%, P = 0.047) and that of IgD-CD27+ switched memory B cells lower (13.3%±5.7% vs. 21.4%±11.9%, P = 0.023), in cases vs. controls. The criterion with the best diagnostic performance was a proportion of IgD+CD27- naive B cells above 70.5%, which had 73% sensitivity and 80% specificity. CONCLUSION: Our study provides data on peripheral-blood B-cell disturbances that may have implications for the diagnosis and pathogenetic understanding of WD.

Whipple disease after bariatric surgery: from malabsorption to malnutrition status / La enfermedad de Whipple después de cirugía bariátrica: de la malabsorción a la malnutrición

Malabsorptive bariatric techniques are associated with nutritional deficiencies. However, when patients do not respond to supplemental intensive treatments they should be closely followed because they can hide other pathological conditions. We present the case of a 47-year-old man with morbid obesity (body mass index [BMI]: 48 kg/m2) who underwent bariatric surgery. In 2016, he presented severe pneumonia and hospitalization at the Intensive Unit Care was required. After this episode, his nutritional state impaired, presenting 6-7 diarrhea/steatorrhea events per-day and requiring several hospitalizations due to the persistence of severe hypoproteinemia. He was given parenteral high-protein associated with low-fat oral diet. He presented a temporary biochemical improvement, but the hypoproteinemia recurred. Finally, tests revealed the presence of Tropheryma whipplei as protein-losing enteropathy. Whipple's disease (WD) is a rare cause of diarrhea and malnutrition, and these symptoms can be confused with the postoperative status of malabsorptive bariatric techniques. WD requires early diagnosis with prolonged antibiotic treatment to avoid severe complications

Las técnicas bariátricas malabsortivas suelen asociarse a deficiencias nutricionales. Sin embargo, cuando los pacientes no responden a tratamientos intensivos suplementarios, deben valorarse otras condiciones patológicas. Presentamos el caso de un hombre de 47 años, obeso mórbido (índice de masa corporal [IMC]: 48 kg/m2) sometido a cirugía bariátrica, que dos años más tarde presentó neumonía severa, por lo que requirió ingreso en la Unidad de Cuidados Intensivos. Posteriormente, el estado nutricional se deterioró, presentando 6-7 episodios de diarrea-esteatorrea/día y requiriendo varias hospitalizaciones por hipoproteinemia severa. Recibió infusión parenteral rica en proteínas asociada con una dieta baja en grasas y presentó mejoría analítica temporal. Finalmente, las pruebas revelaron la presencia de Tropheryma whipplei, una bacteria que genera enteropatía pierde-proteínas. La enfermedad de Whipple (EW) es una causa poco común de diarrea y malnutrición. Estos síntomas pueden confundirse con el posoperatorio de técnicas bariátricas malabsortivas. La EW requiere un diagnóstico precoz con un tratamiento antibiótico prolongado para evitar complicaciones graves

A rare presentation of hypovolemic shock secondary to Whipple's disease.

Whipple's disease is a rare, multisystem infection caused by the Gram-positive Tropheryma whippelii organism. In addition to neurological and rheumatological manifestations, this disease can result in significant gastrointestinal symptoms such as malabsorption, diarrhea, and weight loss. Given the diagnostic challenge and rare occurrence, a high index of suspicion is critical to prevent morbidity and mortality from this otherwise highly infectious disease transmitted via the fecal-oral route. We present a very rare but near-fatal case of hypovolemic shock secondary to protein-losing enteropathy and gastrointestinal bleeding from small bowel T. whippelii infection. Furthermore, the epidemiology, clinical presentation, diagnosis, and management of Whipple's disease is reviewed.

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.

Detection of Tropheryma whipplei in stool samples by one commercial and two in-house real-time PCR assays.

OBJECTIVE: Tropheryma whipplei, the causative agent of Whipple's disease, can also be identified in stool samples of humans without systemic disease. It is much more frequently detected in human stool samples in tropical environments than in industrialized countries. PCR-screening has been applied for point prevalence studies and environmental assessments in tropical settings, but results depend on the applied assay. We compared one commercial qPCR kit with two well-described in-house assays for detection of T. whipplei from stool. METHODS: Residual materials from nucleic acid extractions of stool samples from two groups with presumably different prevalences and increased likelihood of being colonized or infected by T. whipplei were tested. One group comprised 300 samples from study participants from western Africa (group 1); the second group was of 300 returnees from tropical deployments (group 2). Each sample was assessed with all three qPCR assays. Cycle threshold (Ct ) values were descriptively compared. RESULTS: Based solely on mathematical modeling, the three PCR assays showed considerably different detection rates of T. whipplei DNA in stool samples (kappa 0.67 (95% confidence interval [0.60, 0.73])). Considering the calculated test characteristics, prevalence of 28.3% for group 1 and 5.0% for group 2 was estimated. Discordant test results were associated with later Ct values. The study did not validate the assays for the detection of T. whipplei in Whipple's disease and for diagnostic purposes since clinical specificity and sensitivity were not investigated. CONCLUSIONS: In spite of the observed diagnostic uncertainty, PCR-based screening approaches can be used for epidemiological purposes and environmental samples to define the source and reservoir in resource-limited tropical settings if prevalence is calculated using diagnostic accuracy-adjusted methods.