Whipple disease. Clinical review of 52 cases. The SNFMI Research Group on Whipple Disease. Société Nationale Française de Médecine Interne

[Bilateral panuveitis in Whipple's disease: Case report]

Whipple's disease is a rare disease linked to chronic infection with the intracellular gram-positive bacterium, Tropheryma whipplei. The clinical signs suggestive of this disease are the association of unexplained fever, lymphadenopathy, gastroenterological disorders (malabsorption) and inflammatory joint disorders (arthritis). However, isolated cardiological, neurological or ophthalmological forms have been described. We report the rare case of a 56-year-old patient complaining of floaters and recent visual loss, who presented with bilateral panuveitis in the absence of any systemic disorder. Clinical examination showed inflammation of the anterior segment, vitritis, inflammatory optic disc edema, focal retinitis, and venous vasculitis in both eyes. We describe the clinical characteristics and ancillary findings of the disease (fundus photos, visual field, auto-fluorescence, macular OCT, fluorescein and indocyanine green angiography). The diagnosis was made with the blood (T. whipplei) PCR test and with the help of accessory salivary gland biopsies. We describe the work-up leading to the diagnosis of Whipple's disease, the laboratory tests, and the recommended extended work-up. The patient's course was marked by complete resolution of the symptoms and clinical signs within a few months following corticosteroid therapy (1mg/kg/day) combined with hydroxychloroquine (600mg per day for 1 year) and life-long doxycycline therapy (200mg per day). In conclusion, this is a rare disease which should be discussed when dealing with steroid-resistant and/or steroid-dependent chronic uveitis with a negative work-up (especially in the presence of joint and/or digestive involvement).

Clinical, Laboratory, and Imaging Characteristics of Tropheryma Whipplei Detection in Bronchoalveolar Lavage Fluid Using Next-Generation Sequencing: A Case-Control Study

Objective

The aim of this study was to assess the prevalence of Tropheryma whipplei (TW) infection in the population and to investigate the clinical symptoms, as well as the laboratory and imaging characteristics of patients testing positive for TW using next-generation sequencing (NGS).

Methods

A retrospective review was conducted on 1346 bronchoalveolar lavage fluid (BALF) samples collected between January 2021 and September 2023. The case group comprised patients with TW detected using NGS while the control group included 65 randomly chosen Gram-positive bacterial infection patients without TW. Comparative analyses were carried out on the basic demographics, laboratory parameters, and imaging findings between the two groups. Additionally, the case group underwent an in-depth examination of underlying diseases, pathogens, final diagnoses, treatment strategies.

Results

The case group comprised of 51 patients with TW, constituting 3.8% of the total. There was no significant difference in gender and age between the case and control groups (P = 0.84, P = 0.07). Symptoms such as coughing, expectoration, wheezing, fever, and hemoptysis are less commonly detected in the case group with a higher incidence of chest pain when compared to the control group (P >0.05). The case group exhibited decreased albumin levels and increased C-reactive protein and D-dimer levels compared to normal levels. Imaging findings in the case group commonly included nodules, patchy images, and interstitial changes, the most common underlying disease is cardiovascular disease, and the most frequently co-occurring pathogen is the human herpesvirus. Among the case group, 27 patients received a final diagnosis of pneumonia, and 3 patients clinically diagnosed with Whipple's disease demonstrated improvement in both symptoms and imaging after treatment.

Conclusion

NGS revealed a relatively low overall detection rate of TW-positive patients using BALF. TW was more prevalent in middle-aged and elderly male patients characterized by symptoms such as cough, expectoration, shortness of breath, and fever. Chest imaging in these cases typically showed nodules and interstitial changes.

Pulmonary sarcomatoid carcinoma: A rare case report, diagnostic dilemma and review of literature

RATIONALE

Pulmonary sarcomatoid carcinoma (PSC), a rare tumor, comprises 0.1% to 0.4% of all malignant lung tumors. Given the rarity of PSC, its clinical course, therapeutic guidelines, and patient outcomes remain largely unknown. Therefore, it is imperative to alert clinicians to this extremely rare and instructive early-onset cancer.

PATIENT CONCERNS

This report describes a 28-year-old woman with PSC, who was initially misdiagnosed with Whipple's disease. A conclusive diagnosis of PSC was made following careful clinical examination, imaging, and histopathological evaluation of the patient's biopsy sample. Radiological imaging revealed multiple nodules and mass formations in the left upper lobe of the patient's lung, with the largest measuring of 5.4 × 3.2 cm.

DIAGNOSIS

Histopathological examination indicated the presence of a malignant neoplasm associated with necrosis suggestive of sarcoma, which was pathologically staged as cT4N1M1.

INTERVENTIONS AND OUTCOMES

A regimen of doxorubicin and ifosfamide was administered therapeutically, resulting in a stable disease state.

LESSONS

The rarity and tumor origin challenge the diagnosis, which emphasizes the imperative role of histological examination, immunohistochemistry, and flow cytometry in achieving an accurate diagnosis. This report summarizes the existing publications to provide a comprehensive overview of PSC, including its clinical manifestations, radiographic imaging, pathologic features, diagnostic challenges, treatment strategies, and prognosis, and aims to improve the understanding of PSC.

Tropheryma whipplei infection in the lung of a patient with long COVID: a case report

BACKGROUND

Immune dysregulation in individuals with long COVID has been detected. Differential diagnosis of diffuse infiltration on chest CT in long COVID is challenging.

CASE PRESENTATION

A 62-year-old man presented with a 10-month history of dyspnea after COVID-19 infection. Dyspnea became worse in the one month preceding presentation. The chest CT showed multifocal, subpleural, bilateral opacities due to long-COVID, and infiltration around the bronchovascular bundle in the bilateral lower lung field. The pathology for the transbronchial cryobiopsy (TBCB) first reported chronic inflammation (mainly interstitial pneumonia). The patient had positive results on tests for the antibody, RO-52+, EJ+. The presumptive diagnosis of connective tissue disease-interstitial lung disease was made. Prednisone and cyclophosphamide were given. At follow-up one month later, the chest CT showed new diffuse ground-glass infiltration. The previous TBCB specimen was re-evaluated. Foamy macrophages were found in the alveolar air space. Periodic acid-Schiff (PAS) staining was performed. Numerous intracytoplasmic organisms were detected, with morphologic features consistent with those of Tropheryma whipplei. The patient recovered after intravenous ceftriaxone and oral trimethoprim-sulfamethoxazole. The final diagnosis was lung T. whipplei infection and long COVID-19.

CONCLUSION

This is the first case report of Tropheryma whipplei infection in the lung of a patient with long COVID-19. T. whipplei should be considered as a potential pathogen for diffuse lung infiltration in the post-COVID-19 era.

Diagnosis and treatment of Tropheryma whipplei infection in patients with inflammatory rheumatic disease: Data from the French Tw-IRD registry

OBJECTIVES

Tropheryma whipplei infection can manifest as inflammatory joint symptoms, which can lead to misdiagnosis of inflammatory rheumatic disease and the use of disease-modifying antirheumatic drugs. We investigated the impact of diagnosis and treatment of Tropheryma whipplei infection in patients with inflammatory rheumatic disease.

METHODS

We initiated a registry including patients with disease-modifying antirheumatic drugs-treated inflammatory rheumatic disease who were subsequently diagnosed with Tropheryma whipplei infection. We collected clinical, biological, treatment data of the inflammatory rheumatic disease, of Tropheryma whipplei infection, and impact of antibiotics on the evolution of inflammatory rheumatic disease.

RESULTS

Among 73 inflammatory rheumatic disease patients, disease-modifying antirheumatic drugs initiation triggered extra-articular manifestations in 27% and resulted in stabilisation (51%), worsening (34%), or improvement (15%) of inflammatory rheumatic disease. At the diagnosis of Tropheryma whipplei infection, all patients had rheumatological symptoms (mean age 58 years, median inflammatory rheumatic disease duration 79 months), 84% had extra-rheumatological manifestations, 93% had elevated C-reactive protein, and 86% had hypoalbuminemia. Treatment of Tropheryma whipplei infection consisted mainly of doxycycline plus hydroxychloroquine, leading to remission of Tropheryma whipplei infection in 79% of cases. Antibiotic treatment of Tropheryma whipplei infection was associated with remission of inflammatory rheumatic disease in 93% of cases and enabled disease-modifying antirheumatic drugs and glucocorticoid discontinuation in most cases.

CONCLUSIONS

Tropheryma whipplei infection should be considered in inflammatory rheumatic disease patients with extra-articular manifestations, elevated C-reactive protein, and/or hypoalbuminemia before disease-modifying antirheumatic drugs initiation or in inflammatory rheumatic disease patients with an inadequate response to one or more disease-modifying antirheumatic drugs. Positive results of screening and diagnostic tests for Tropheryma whipplei infection involve antibiotic treatment, which is associated with complete recovery of Tropheryma whipplei infection and rapid remission of inflammatory rheumatic disease, allowing disease-modifying antirheumatic drugs and glucocorticoid discontinuation.

Whipple's Disease Presenting With a Chief Complaint of Dyspnea and Cough From Pulmonary Invasion Without Evidence of Gastrointestinal Involvement

A patient with immune thrombocytopenia, systemic lupus erythematosus on chronic corticosteroids, and interstitial lung disease was referred to the pulmonology clinic due to progressively worsening dyspnea. A bronchoscopy was done and a thorough workup was negative for any infectious pathology or malignancy. A lung biopsy with MicroGenDX test (MicroGen Diagnostics, Lubbock, TX) revealed Tropheryma whipplei, consistent with a Whipple disease diagnosis. Histopathology of biopsy specimens from an esophagogastroduodenoscopy showed moderate chronic active Helicobacter gastritis and unremarkable duodenal specimens without evidence of Tropheryma whipplei. For Helicobacter pylori gastritis, she was prescribed quadruple therapy with omeprazole, bismuth, metronidazole, and tetracycline. For pulmonary Whipple's disease, she completed two weeks of IV ceftriaxone, which led to improvement in dyspnea, and then was transitioned to 12 months of oral sulfamethoxazole-trimethoprim. In rare cases, Whipple's disease can present as isolated pulmonary disease without gastrointestinal involvement, especially in immunosuppressed patients with compromised lungs.

Ophthalmic manifestations of Whipple's disease

PURPOSE OF REVIEW

Whipple's disease is an infectious cause of uveitis that may present with nonspecific findings of intraocular inflammation, which can precede the development of neurologic symptoms and signs. Whipple's disease, then, may evade consideration in the differential diagnosis for uveitis.

RECENT FINDINGS

Molecular tests can be helpful in identifying the presence of Tropheryma whipplei from ocular specimens. The application of metagenomic sequencing for ocular specimens is promising, as it offers the opportunity to identify the pathogen when suspicion for an intraocular infection is high. Whipple's disease demonstrates the ability to abrogate the host immune response, which gives some insight into its pathogenesis.

SUMMARY

Whipple's disease should be suspected in patients who have uveitis refractory to anti-inflammatory therapy. Knowledge of this important pathogen can help direct the timely implementation of diagnostic testing.

Fever and Increased Gastrointestinal Uptake on Positron Emission Tomography after Anti-Tumour Necrosis Factor Therapy: A Case Report of Whipple's Disease

Introduction

Whipple's disease is a rare condition that can present with atypical and non-specific features requiring a high index of suspicion for diagnosis.

Case Presentation

We present a case of a man in his 40s with peripheral arthritis and bilateral sacro-ileitis for 4-5 years that was treated with an anti-tumour necrosis factor therapy, which led to worsening of his symptoms, elevation of the inflammatory markers, and the development of fever, night sweats, anorexia, and a significant weight loss. The patient had no abdominal pain, diarrhoea, or other gastrointestinal symptoms. An FDG-PET scan showed increased uptake in the stomach and caecum. Endoscopic examination showed inflammatory changes in the stomach and normal mucosa of the duodenum, jejunum, terminal ileum, caecum, and colon. Histopathology was inconclusive, but the diagnosis was confirmed with Tropheryma whipplei PCR testing. He had no neurological symptoms, but cerebrospinal fluid Tropheryma whipplei PCR was positive. He was treated with intravenous ceftriaxone 2 g daily for 4 weeks, followed by trimethoprim/sulfamethoxazole 160/800 mg twice daily for 1 year with close monitoring and follow-up.

Conclusion

This case presents an atypical and challenging presentation of Whipple's disease and the importance of proactive testing for neurological involvement.

The spectrum of central nervous system involvement in Whipple's disease

BACKGROUND AND PURPOSE

To assess the clinical spectrum of central nervous system (CNS) involvement as well as cerebrospinal fluid (CSF) and neuroimaging findings in patients with Whipple's disease (WD) and to analyze the association of neurological symptoms with CSF and imaging findings.

METHODS

Neurological involvement was retrospectively analyzed in a series of 36 patients diagnosed with WD at a single center between 1992 and 2019. Findings of 81 comprehensive CSF examinations from 36 patients, including polymerase chain reaction (PCR) tests for Tropheryma whipplei (TW) in CSF from 35 patients, were systematically evaluated. The prevalence of ischemic stroke in patients with WD was compared to a matched control cohort.

RESULTS

Neurological symptoms occurred in 23 of 36 (63.9%) patients, with cognitive, motor, and oculomotor dysfunction being most frequent. TW was detected by PCR in CSF of 13 of 22 (59.1%) patients with and four of 13 (30.8%, p = 0.0496) patients without neurological symptoms. Total CSF protein (p = 0.044) and lactate (p = 0.035) were moderately elevated in WD with neurologic symptoms compared with WD without. No intrathecal immunoglobulin synthesis was observed. Three of 36 (8.3%) patients had hydrocephalus due to aqueductal stenosis. Patients with WD had an unexpectedly high prevalence of ischemic stroke (10/36, 27.7%) compared to matched controls (10/360, 3.2%).

CONCLUSIONS

Neurological involvement in patients with WD is common. Detection of TW DNA in CSF is only partly associated with neurological symptoms. Elevated CSF parameters suggest CNS parenchymal infection. Stroke is a hitherto underrecognized manifestation of WD. These findings suggest that mechanisms beyond CNS infection contribute to the spectrum of CNS involvement in WD.

Two consecutive cases of mycotic aneurysms resulting from Whipple disease

Whipple disease is a rare multisystemic infectious process caused by Tropheryma whipplei. Classical clinical manifestations include chronic diarrhea, malabsorption, weight loss, and arthralgias. Cases of endocarditis and isolated involvement of the central nervous system have also been reported. Isolated vascular complications are not common with this disease. Vascular manifestations are mainly described as systemic embolization from underlying endocarditis. We report two consecutive cases of mycotic pseudoaneurysms resulting from Whipple disease treated with successful vascular reconstruction using autologous vein grafting.

Whipple's Disease - delay of diagnosis by immunosuppressive therapy; a case-series report

BACKGROUND

Risk factors for the development of Whipple's disease (WD) are largely unknown. Case reports, case series, and reviews suggest immunosuppressive therapy as a potential triggering factor in WD. The low incidence of WD and non-specific symptoms at disease onset contribute to the frequent delay of diagnosis. We describe our centre´s experience on differences in the clinical presentation of patients with classic WD compared to patients with "masked" WD because of immunosuppressive therapy.

METHODS

In this retrospective case series, 8 patients were included. Diagnosis of WD was confirmed by histological staining of duodenal biopsies revealing T. whipplei within foamy macrophages or by PCR- based detection of specific T. whipplei DNA. Clinical manifestations, laboratory data, and medication have been recorded over a period of 19 years. Subgroup analyses for the two different variants of WD were performed.

RESULTS

Seven of eight patients were initially diagnosed with rheumatic disease (polyarthritis, polymyalgia rheumatica). One patient was correctly diagnosed at the beginning without any medication. Three patients were on immunosuppressive therapy and being treated with disease-modifying drugs (DMARDs), three patients were receiving low-dose cortisone in combination with non-steroidal anti- inflammatory drugs (NSAIDs), and one patient was receiving NSAIDs only. All patients presented with increased parameters of inflammation and with clinical and/or laboratory signs of a malabsorption. From the onset of first symptoms, diagnosis of WD took a median of 36 months (range: 6-120 months). The time between onset of joint complaints and onset of gastrointestinal symptoms was 36 months (range: 0-117 months). WD patients receiving immunosuppressive therapy, compared to those not receiving it, had a longer duration of gastrointestinal symptoms (12 months versus 6 months) and reported a greater weight loss (20,3 kg versus 7,8 kg) up to diagnosis of WD.

CONCLUSIONS

Immunosuppressive drugs may delay the diagnosis of WD and prolong the course of T. whipplei infection with deterioration of clinical symptoms. If a patient with rheumatic complaints develops gastrointestinal symptoms, diagnosis of WD should be considered and proper diagnostic investigation carried out.

Whipple's Disease: A Case Report

Whipple's disease (WD) is caused by Tropheryma whipplei, frequently found in lamina propria's macrophages in the small intestine. It is a rare and chronic systemic infection, and the principal clinical manifestations are diarrhea, weight loss, abdominal pain, and arthralgia. The diagnosis is difficult mainly because of its rarity and should be considered in patients with arthralgias, diarrhea, abdominal pain, and weight loss after more common conditions have been excluded. The laboratory diagnosis is established by a duodenal biopsy. The treatment involves 14 days of intravenous antibiotics with good penetration in the cerebrospinal fluid (i.e., ceftriaxone) and one-year treatment with oral co-trimoxazole. Early diagnosis and proper treatment are crucial because it improves the prognosis. We report the case of a 58-year-old female with skin hyperpigmentation, loss of appetite and weight (16% of body weight in three months), nausea, upper abdominal pain, and diarrhea. Esophagogastroduodenoscopy and colonoscopy were performed to obtain biopsy samples, which, together with laboratory tests and microbiological studies, led to a diagnosis of Whipple's disease.

Why Is Whipple's Disease Still a Challenging Diagnosis? A Case Report and Brief Review of Literature

Whipple's disease (WD) is a rare multisystemic infectious disease caused by Tropheryma whipplei. The pathogenesis of Whipple's disease remains unknown and clinical experience relies solely on various case reports published in the literature. The disease may occur at any age, with most studies describing patients in their fifth decade. Classic WD mainly affects the gastrointestinal tract, but extraintestinal commitment can occur, with the most common manifestations being arthralgias, lymphadenopathy, fever, and neurological symptoms. We present a case of a 69-year-old woman who presented with fever, macular rash, abdominal pain, lymphadenopathy, pleural and pericardial effusion, weight loss, and severely altered mental status over seven days. Initial workup tests only revealed leucopenia, thrombocytopenia, and hyperferritinemia. Since the fever persisted despite antibiotic treatment, an extensive workup was required until the final diagnosis of classic WD through histological examination of duodenal biopsies. Treatment with ceftriaxone was implemented for two weeks, followed by trimethoprim-sulfamethoxazole 160/800mg bid for 12 months. The patient presented full recovery and no recurrence after three years of follow-up. Even though WD was first described more than a century ago, WD is an elusive disease with a wide variety of clinical findings, leading to a still significant delay in diagnosis. WD should be considered in the differential diagnosis of rheumatologic disorders, chronic abdominal pain or diarrhea, neurological manifestations not suggestive of any other specific disease, non-caseating granulomatous diseases, and cases of lymphadenopathies. The authors aim to add additional clinical data and raise awareness for a rare condition that can be lethal if not timely treated. More studies and recommendations are needed concerning screening patients and treatment, with an urgent need to improve the delay in diagnosis.

An unusual presentation of Whipple’s disease: adenopathies, polyarthralgia and dermatomyositis-like symptoms

Whipple’s disease (WD) is a rare systemic disease caused by gram-positive bacillus bacteria that invades multiple organs mainly the intestinal epithelium. Its manifestation is not only limited to the gastrointestinal tract but it also affects the joints, muscle and skin. This is a case of a 54-year-old male patient with a medical history of chronic arthritis presenting with bilateral progressive calves pain, anterior tibial hyperpigmentation, joints pain, anemia and weight loss. He was misdiagnosed as rheumatoid arthritis, for which he was treated by immunosuppressors for several years with no amelioration. After advanced investigations, he was found to have multiple retroperitoneal and mesenteric adenopathies, with an incidental finding of a mesojejunal mass during laparoscopy, from which the biopsies revealed the presence of histiocytosis and numerous intra-cytoplasmic particles with positive periodic acid–Schiff (PAS) suggesting the diagnosis of WD. Endoscopy was done and intestinal histology with polymerase chain reaction (PCR) test confirmed the diagnosis of WD. The patient was then treated with antibiotics (ceftriaxone and trimethoprim-sulfamethoxazole) with a remarkable clinical amelioration. To be aware of WD as a potential etiology behind malabsorption, musculoskeletal and skin abnormalities, is the first step in order to establish the diagnosis and provide adequate treatment, thus, improving the patient’s quality of life. WD is a rare, without antibiotic treatment deadly systemic infectious disease caused by the ubiquitary Gram-positive bacterium Tropheryma whipplei. This article aims to report a case marked with dermatomyositis like presentation that had a missed and delayed diagnosis.

Isolated central nervous system Whipple disease

Background:

Whipple disease (WD) is an infection caused by Tropheryma whipplei, which might present in three different forms: classical, localized, and isolated in the central nervous system (CNS).

Methods:

We report the result of a systematic review of the literature on WD unusually presenting with exclusively neurological symptoms, including two previously unpublished cases. A description of two cases with isolated CNS WD was performed, as well as a literature search in Cochrane, Scielo, and PubMed.

Results:

Two male adult patients presented with exclusively neurological symptomatology. Both magnetic resonance imaging (MRI) showed an intracranial mass suggestive of brain tumor. The histopathological examination was consistent with WD, with no systemic involvement. In the review of the literature, 35 cases of isolated CNS WD were retrieved. The median age at diagnosis was 43.5 (IQR 31.5–51.5). In 13 patients, the MRI showed a brain mass consistent with a brain tumor. The most common finding in the biopsy was the periodic-acid Schiff-stained foamy macrophages. Only five cases presented the pathognomonic sign of oculomasticatory myorhythmia. Thirteen cases had an adverse outcome that resulted in death during follow-up, whereas another 13 improved. The other nine patients remained stable or presented moderate improvement.

Conclusion:

Isolated CNS WD is a rare disease that should be considered among the differential diagnosis of CNS mass lesions. Brain biopsy is necessary to establish the diagnosis. It is stressed in the literature that an extended antibiotic course is required to prevent relapses and to control the disease.

Genomic characterization of two metagenome-assembled genomes of Tropheryma whipplei from China

Whipple’s disease is a rare chronic systemic disease that affects almost any organ system of the body caused by the intracellular bacterium Tropheryma whipplei, which is found ubiquitously in the environment. Sequencing of the T. whipplei genome has revealed that it has a reduced genome (0.93 Mbp), a characteristic shared with other intracellular bacteria. Until our research started, 19 T. whipplei strains had been sequenced from cultures originated in France, Canada, and Germany. The genome of T. whipplei bacterium has not been studied in Asia yet. Here, two metagenome-assembled genomes (MAGs) of T. whipplei from China were reconstructed through metagenomic next-generation sequencing (mNGS) and genome binning. We also provided genomic insights into the geographical role and genomic features by analyzing the whole genome. The whole-genome phylogenetic tree was constructed based on single-nucleotide polymorphism (SNP) distance calculations and then grouped by distance similarity. The phylogenetic tree shows inconsistencies with geographic origins, thus suggesting that the variations in geographical origins cannot explain the phylogenetic relationships among the 21 T. whipplei strains. The two Chinese strains were closely related to each other, and also found to be related to strains from Germany (T. whipplei TW08/27) and France (T. whipplei Bcu26 and T. whipplei Neuro1). Furthermore, the Average Nucleotide Identity (ANI) matrix also showed no association between geographic origins and genomic similarities. The pan-genome analysis revealed that T. whipplei has a closed pan-genome composed of big core-genomes and small accessory genomes, like other intracellular bacteria. By examining the genotypes of the sequenced strains, all 21 T. whipplei strains were found to be resistant to fluoroquinolones, due to the genetic mutations in genes gyrA, gyrB, parC, and parE. The 21 T. Whipplei strains shared the same virulence factors, except for the alpC gene, which existed in 7 out of the 21 T. whipplei strains. When comparing 21 entire T. whipplei pan-genomes from various nations, it was discovered that the bacterium also possessed a closed genome, which was a trait shared by intracellular pathogens.

Treatable Ataxias: How to Find the Needle in the Haystack?

Treatable ataxias are a group of ataxic disorders with specific treatments. These disorders include genetic and metabolic disorders, immune-mediated ataxic disorders, and ataxic disorders associated with infectious and parainfectious etiology, vascular causes, toxins and chemicals, and endocrinopathies. This review provides a comprehensive overview of different treatable ataxias. The major metabolic and genetic treatable ataxic disorders include ataxia with vitamin E deficiency, abetalipoproteinemia, cerebrotendinous xanthomatosis, Niemann-Pick disease type C, autosomal recessive cerebellar ataxia due to coenzyme Q10 deficiency, glucose transporter type 1 deficiency, and episodic ataxia type 2. The treatment of these disorders includes the replacement of deficient cofactors and vitamins, dietary modifications, and other specific treatments. Treatable ataxias with immune-mediated etiologies include gluten ataxia, anti-glutamic acid decarboxylase antibody-associated ataxia, steroid-responsive encephalopathy associated with autoimmune thyroiditis, Miller-Fisher syndrome, multiple sclerosis, and paraneoplastic cerebellar degeneration. Although dietary modification with a gluten-free diet is adequate in gluten ataxia, other autoimmune ataxias are managed by short-course steroids, plasma exchange, or immunomodulation. For autoimmune ataxias secondary to malignancy, treatment of tumor can reduce ataxic symptoms. Chronic alcohol consumption, antiepileptics, anticancer drugs, exposure to insecticides, heavy metals, and recreational drugs are potentially avoidable and treatable causes of ataxia. Infective and parainfectious causes of cerebellar ataxias include acute cerebellitis, postinfectious ataxia, Whipple's disease, meningoencephalitis, and progressive multifocal leukoencephalopathy. These disorders are treated with steroids and antibiotics. Recognizing treatable disorders is of paramount importance when dealing with ataxias given that early treatment can prevent permanent neurological sequelae.

Whipple's disease with normal duodenal histology diagnosed by ileal biopsy using balloon endoscopy

A 34 year-old previously healthy Japanese woman presented with a 4 year history of migratory arthralgia, chronic diarrhea, mild fever, and 10 kg weight loss. She was initially misdiagnosed with seronegative arthritis, followed by eosinophilic gastroenteritis. Oral prednisolone was found to be ineffective. Upper endoscopy revealed normal duodenal mucosa. Duodenal biopsy specimen indicated no abnormalities. However, balloon endoscopy revealed white shaggy villi in the ileum, and a biopsy specimen from which revealed diffuse infiltration of foamy macrophages in the lamina propria. These macrophages contained diastase-periodic acid-Schiff positive granules, consistent with Whipple's disease. Polymerase chain reaction analysis of DNA extracted from the ileum was compatible with Whipple's disease. In most previously reported cases of Whipple's disease, the duodenum was affected and duodenal biopsy specimens led to a diagnosis of Whipple's disease. Whipple's disease with normal duodenal histology is extremely rare and balloon endoscopy might be a useful diagnostic tool in such a case. The patient was treated with intravenous ceftriaxone and oral trimethoprim-sulfamethoxazole, and her symptoms improved one month after treatment. Balloon endoscopy performed 32 months later revealed complete improvement in lesions of the ileum.

Central Nervous System Whipple Disease Presenting as Hypersomnolence

Whipple disease (WD) is a rare systemic infection caused by Tropheryma whipplei (T. whipplei). Its clinical features are broad, and atypical clinical patterns such as the involvement of the heart, lungs, or the central nervous system (CNS) can occur. We report a case of a 58-year-old man who had been previously diagnosed with classic WD; he was evaluated for functional decline, extreme somnolence, and recurrent admissions for hydrocephalus. The patient was diagnosed with a neurologic relapse of WD after a positive T. whipplei polymerase chain reaction (PCR) from a cerebral spinal fluid (CSF) sample. He was successfully treated with IV ceftriaxone followed by oral trimethoprim-sulfamethoxazole (TMP-SMX). In classic WD, the CNS symptoms usually present in the late phase of the disease or in the form of relapse, especially after an inadequate treatment course. This case highlights the importance of considering CNS involvement in WD when a patient with a previous history of classic WD presents with hypersomnolence, hydrocephalus, or other neurologic symptoms.

Gut dysbiosis is associated with acceleration of lupus nephritis

The gut microbiota (GM) exerts a strong influence over the host immune system and dysbiosis of this microbial community can affect the clinical phenotype in chronic inflammatory conditions. To explore the role of the GM in lupus nephritis, we colonized NZM2410 mice with Segmented Filamentous Bacteria (SFB). Gut colonization with SFB was associated with worsening glomerulonephritis, glomerular and tubular immune complex deposition and interstitial inflammation compared to NZM2410 mice free of SFB. With SFB colonization mice experienced an increase in small intestinal lamina propria Th17 cells and group 3 innate lymphoid cells (ILC3s). However, although serum IL-17A expression was elevated in these mice, Th17 cells and ILC3s were not detected in the inflammatory infiltrate in the kidney. In contrast, serum and kidney tissue expression of the macrophage chemoattractants MCP-1 and CXCL1 were significantly elevated in SFB colonized mice. Furthermore, kidney infiltrating F4/80+CD206+M2-like macrophages were significantly increased in these mice. Evidence of increased gut permeability or "leakiness" was also detected in SFB colonized mice. Finally, the intestinal microbiome of SFB colonized mice at 15 and 30 weeks of age exhibited dysbiosis when compared to uncolonized mice at the same time points. Both microbial relative abundance as well as biodiversity of colonized mice was found to be altered. Collectively, SFB gut colonization in the NZM2410 mouse exacerbates kidney disease, promotes kidney M2-like macrophage infiltration and overall intestinal microbiota dysbiosis.

Whipple's disease? A case report and discussion

Background

Whipple's disease (WD) is a rare chronic systemic disease caused by the Gram-positive bacillus Tropheryma whipplei. Despite over 100 years of observation and study history of this disease, it still remains a difficult diagnostic and therapeutic challenge.

Clinical case presentation

Authors report the case of a 38-year-old man with long-time PPIs treatment because of GERD and no other clinical and paraclinical symptoms. Endoscopic slightly enlarged villi, accumulation of whitish matter at the tip of the villi of distal duodenal mucosa and periodic acid-Schiff staining positive inclusions in the stromal tissue may be typical signs of Whipple's disease. In discussion the possible explication of this case are presented.

Conclusions

It is still a challenge to diagnose Whipple's disease. Histological findings may confirm the diagnosis in patients with a combination of typical clinical manifestations, but histological signs alone are not pathognomic, and are not enough for a definitive diagnosis.

Endocarditis and systemic embolization from Whipple's disease

Whipple’s disease (WD), caused by infection with the organism Tropheryma whipplei, is a rare disease that classically presents with diarrhea, weight loss, and polyarthralgia. Less commonly, Whipple’s Disease can presentation with endocarditis or neurologic infections. The authors report a patient with Whipple’s Disease endocarditis whose initial presentation was acute lower extremity arterial occlusion, and review current literature regarding the epidemiology, diagnosis, treatment, and prognosis of Whipple’s Disease endocarditis.

Small and Large Intestine (I): Malabsorption of Nutrients

Numerous disorders can alter the physiological mechanisms that guarantee proper digestion and absorption of nutrients (macro- and micronutrients), leading to a wide variety of symptoms and nutritional consequences. Malabsorption can be caused by many diseases of the small intestine, as well as by diseases of the pancreas, liver, biliary tract, and stomach. This article provides an overview of pathophysiologic mechanisms that lead to symptoms or complications of maldigestion (defined as the defective intraluminal hydrolysis of nutrients) or malabsorption (defined as defective mucosal absorption), as well as its clinical consequences, including both gastrointestinal symptoms and extraintestinal manifestations and/or laboratory abnormalities. The normal uptake of nutrients, vitamins, and minerals by the gastrointestinal tract (GI) requires several steps, each of which can be compromised in disease. This article will first describe the mechanisms that lead to poor assimilation of nutrients, and secondly discuss the symptoms and nutritional consequences of each specific disorder. The clinician must be aware that many malabsorptive disorders are manifested by subtle disorders, even without gastrointestinal symptoms (for example, anemia, osteoporosis, or infertility in celiac disease), so the index of suspicion must be high to recognize the underlying diseases in time.

Whipple's disease: a fatal mimic

Whipple’s Disease, a rare diagnosis caused by the slow-growing bacterium Tropheryma whipplei, most often presents with the classically described signs of malabsorption due to gastrointestinal colonization. However, it can also have signs and symptoms that clinically overlap with rheumatic diseases, potentially resulting in misdiagnosis. Furthermore, treatment with modern potent biologic immunosuppressive agents and classic disease modifying anti-rheumatic drugs (DMARDs) can lead to serious exacerbation of undiagnosed infections. We present the case of a middle-aged woman with long term complaints of arthalgias, who was diagnosed with seronegative rheumatoid arthritis and subsequently treated for almost 7 years with such immunosuppressive therapies. The patient’s disease course included chronic diarrhea that abruptly intensified and culminated in fatal hypovolemic shock/sepsis. A diagnosis of WD was made by autopsy examination, wherein several organ systems were found to be heavily involved by Tropheryma whipplei organisms, and their identification was confirmed with histochemical and molecular evaluation. Notably, most bacterial organisms were located deeply in the submucosa/muscularis of affected organs, a practical reminder to practicing pathologists that challenges the classic histopathologic description of Whipple disease as an infiltration of predominantly lamina propria, and the potential for sampling bias in typically superficial endoscopic biopsies during routine procedures.

Whipple's disease orbitopathy: case report and review of literature

A 59-year-old female patient was diagnosed with Whipple's disease (WD) after several months of constitutional complaints and adenopathies that were initially misinterpreted as sarcoidosis. Initial treatment included doxycycline, hydroxychloroquine and prednisolone, which was suspended due to long-term clinical stability. Four months after prednisolone suspension, the patient presented with right periorbital oedema and erythema. Ophthalmological examination revealed restricted eye movements. A computed tomography (CT) scan demonstrated signs of myositis. The patient was treated with anti-inflammatory and antibiotic drugs, that induced remission of the orbitopathy. During the following two years, she presented three relapses, affecting both the right or the left eyes. The last episode was also associated with systemic corticosteroid tapering. Orbitopathy is a rare form of WD presentation and the diagnosis of this condition may be challenging. As the clinical spectrum may range from an incidentaloma to a severe compressive neuropathy, proper recognition and management of WD orbitopathy is essential.

Whipple's endocarditis: a case report of a blood culture-negative endocarditis

Background

Whipple's disease is caused by Tropheryma whipplei and causes a self-limiting gastrointestinal infection. The majority of the population is an asymptomatic carrier, however, in some patients, it causes an invasive infection with for example arthritis, endocarditis, or involvement of the eyes.

Case summary

This case describes a man with long-lasting complaints of progressive dyspnoea caused by heart failure due to total destruction of the aortic and mitral valve as a result of T. whipplei endocarditis, diagnosed with serum polymerase chain reaction. The patient was treated with ceftriaxone and prolonged co-trimoxazole therapy and surgical replacement of the aortic and mitral valve. He was discharged to a rehabilitation centre.

Discussion

Tropheryma whipplei is one of the possible microorganisms classified as causing blood culture-negative endocarditis, with predominantly afebrile patients that do not fulfil the Dukes criteria, which makes it difficult to diagnose. Polymerase chain reaction is the cornerstone of the diagnosis. It requires long-term antibiotic treatment up to 12 months. It is recommended by the European Society of Cardiology to discuss treatment in an Endocarditis Team because Whipple's endocarditis has only rarely been described in the literature previously. Whipple's endocarditis has high mortality and relapse rates.

Whipple's Disease: A Case Report

OBJECTIVE

Whipple's disease is a very rare systemic infectious disease with an annual incidence of 3 in one million, which may be fatal if not diagnosed and treated appropriately.

CLINICAL PRESENTATION AND INTERVENTION

Herein we describe a 49-year-old patient admitted to the hospital with symptoms of severe malabsorption and diagnosed with Whipple's disease. The diagnosis was based on the histopathological findings of small intestine biopsies and PCR analysis.

CONCLUSION

Whipple's disease should be kept in mind while dealing with patients with severe malabsorption, even in the absence of accompanying features of the 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's disease and Tropheryma whipplei infections: when to suspect them and how to diagnose and treat them

PURPOSE OF REVIEW

The delay between first clinical signs and diagnosis of Whipple's disease and Tropheryma whipplei infections is more than 6 years, and relapses are frequently observed, resulting in a need for clinicians to be aware of this infection.

RECENT FINDINGS

18 FDG-PET is useful in the diagnosis and the follow-up of patients (particularly in case of neurological involvement). Histological involvement remains the goldstandard for classic Whipple's disease diagnosis. PCR performed on biopsies of fluid is the main tool for the diagnosis of localized chronic infections. PCR performed on urine samples should become an important role of noninvasive diagnostic strategies, while T. whipplei PCR performed on saliva and stool lack specificity. Because of lifetime susceptibility to T. whipplei and in-vitro susceptibility data, a 1-year course of doxycycline and hydroxychloroquine followed by a lifelong treatment by doxycycline is recommended for Whipple's disease, localized endocarditis and encephalitis.

SUMMARY

Clinical involvement of the different T. whipplei infections is well described, as well as the treatment of Whipple's disease, endocarditis and encephalitis. The place of PCR performed on urine remains to be clarified for diagnosis of localized T. whipplei infections and acute infections as well as the optimal treatment for arthritis and acute infections.

Epidemiology of Whipple's Disease in the USA Between 2012 and 2017: A Population-Based National Study

OBJECTIVE

Prior studies on the epidemiology of Whipple's disease are limited by small sample size and case series design. We sought to characterize the epidemiology of Whipple's disease in the USA utilizing a large population-based database.

METHODS

We queried a commercial database (Explorys Inc, Cleveland, OH), an aggregate of electronic health record data from 26 major integrated healthcare systems in the USA. We identified a cohort of patients with a diagnosis of Whipple's disease based on systemized nomenclature of medical terminology (SNOMED CT) codes. We calculated the overall and age-, race-, ethnicity, and gender-based prevalence of Whipple's disease and prevalence of associated diagnoses using univariate analysis.

RESULTS

A total of 35,838,070 individuals were active in the database between November 2012 and November 2017. Of these, 350 individuals had a SNOMED CT diagnosis of Whipple's disease, with an overall prevalence of 9.8 cases per 1 million. There was no difference in prevalence based on sex. However, prevalence of Whipple's disease was higher in Caucasians, non-Hispanics, and individuals > 65 years old. Individuals with a diagnosis of Whipple's disease were more likely to have associated diagnoses/findings of arthritis, CNS disease, endocarditis, diabetes, malignancy, dementia, vitamin D deficiency, iron deficiency, chemotherapy, weight loss, abdominal pain, and lymphadenopathy.

CONCLUSIONS

To our knowledge, this is the largest study to date examining the epidemiology of Whipple's disease. In this large population-based study, the overall prevalence of Whipple's disease in the USA is 9.8 cases per 1 million people. It affects men and women at similar rates and is more common in Caucasians, non-Hispanics, and people > 65 years old.

Tropheryma whipplei Endocarditis: Case Presentation and Review of the Literature

Whipple’s disease is a rare infective condition, classically presenting with gastrointestinal manifestations. It is increasingly recognized as an important cause of culture-negative endocarditis. We present a case of Whipple’s endocarditis presenting with heart failure. A literature review identified 44 publications documenting 169 patients with Whipple’s endocarditis. The average age was 57.1 years. There is a clear sex predominance, with 85% of cases being male. Presenting symptoms were primarily articular involvement (52%) and heart failure (41%). In the majority of cases, the diagnosis was made on examination of valvular tissue. Preexisting valvular abnormalities were reported in 21%. The aortic valve was most commonly involved, and multiple valves were involved in 64% and 23% of cases, respectively. Antibiotic therapy was widely varied and included a ceftriaxone, trimethoprim, and sulfamethoxazole combination. The average follow-up was 20 months, and mortality was approximately 24%. Physician awareness is paramount in the diagnosis and management of this rare condition.

[The rich diversity of Whipple's disease]

Whipple's disease (WD) is a rare, chronic multiorgan disease which can caused by Tropheryma whipplei, a ubiquitous gram positive bacterium. Detection of T. whipplei is mostly performed histologically using periodic acid-Schiff (PAS) staining in affected tissues to visualize characteristic PAS-positive macrophages and by the polymerase chain reaction (PCR). Clinically, WD is often characterized by gastrointestinal symptoms (diarrhea, colic-like abdominal pain and weight loss). Arthritis is a common presentation of WS, often leading to a misdiagnosis of seronegative rheumatoid arthritis and as a consequence to immunosuppressive therapy. The clinical presentation of WD is highly polymorphic affecting different organ systems (e. g. cardiac or neurological manifestation) and making an appropriate clinical diagnosis and even the diagnostic process itself difficult. This article reports on three cases presenting with completely different leading symptoms (initially misdiagnosed as seronegative rheumatoid arthritis, spondyloarthritis and adult onset of Still's disease, respectively) that illustrate the rich diversity of WD. The cases were chosen to draw attention to the fact that although WD is mainly associated with the field of gastroenterology and gastrointestinal (GI) involvement is common, it may appear without GI symptoms. In cases of a clinical suspicion of WD, diagnostic efforts should be made to detect the bacterium in the affected organ. The German S2k guidelines on GI infections and WD published in January 2015 summarized the current state of the art for WD. The currently recommended primary treatment is antibiotics that can infiltrate the cerebrospinal fluid, e. g. ceftriaxone, followed by cotrimoxazole, which should be maintained over several months.

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 (C_t ) 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 C_t 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.

Tropheryma whipplei colonization in HIV-infected individuals is not associated with lung function or inflammation

Studies demonstrate that Tropheryma whipplei (T. whipplei) is present in the lungs of healthy individuals without acute respiratory symptoms or acute respiratory infection and is more common in the lungs of HIV-infected individuals and in smokers. The impact of T. whipplei colonization in the lung on local inflammation and pulmonary dysfunction in HIV-infected individuals is currently unknown. In this study, we performed specific polymerase chain reaction (PCR) and sequencing for T. whipplei in bronchoalveolar lavage (BAL) and induced sputum (IS) samples in 76 HIV-infected participants from three clinical sites. Pulmonary function and proinflammatory cytokine and chemokine levels in BAL were measured. Frequency of T. whipplei in either BAL or IS was 43.4%. The sensitivity and specificity of IS compared to BAL for detection of T. whipplei was 92.3% and 84.2%, respectively, and isolates of T. whipplei in the BAL and IS in the same subject shared genetic identity. Pulmonary function measures were not associated with T. whipplei colonization, and proinflammatory cytokine and chemokine levels in BAL and plasma as well as percentages of inflammatory cells in BAL and IS were not higher in colonized individuals. Overall, these results indicate that T. whipplei colonization in the lung is common, but may not be associated with decreased pulmonary function or inflammation in HIV-infected individuals.

Usefulness of polymerase chain reaction for diagnosing Whipple's disease in rheumatology

Objectives

To determine when Tropheryma whipplei polymerase chain reaction (PCR) is appropriate in patients evaluated for rheumatological symptoms.

Methods

In a retrospective observational study done in rheumatology units of five hospitals, we assessed the clinical and radiological signs that prompted T. whipplei PCR testing between 2010 and 2014, the proportion of patients diagnosed with Whipple’s disease, the number of tests performed and the number of diagnoses according to the number of tests, the patterns of Whipple’s disease, and the treatments used. Diagnostic ascertainment was based on 1- Presence of at least one suggestive clinical finding; 2- at least one positive PCR test, and 3- a response to antibiotic therapy described by the physician as dramatic, including normalization of C Reactive Protein.

Results

At least one PCR test was performed in each of 267 patients. Rheumatic signs were peripheral arthralgia (n = 239, 89%), peripheral arthritis (n = 173, 65%), and inflammatory back pain (n = 85, 32%). Whipple’s disease was diagnosed in 13 patients (4.9%). The more frequently positive tests were saliva and stool. In the centres with no diagnoses of Whipple’s disease, arthritis was less common and constitutional symptoms more common. The group with Whipple’s disease had a higher proportion of males, older age, and greater frequency of arthritis. The annual incidence ranged across centres from 0 to 3.6/100000 inhabitants.

Conclusion

Males aged 40–75 years with unexplained intermittent seronegative peripheral polyarthritis, including those without constitutional symptoms, should have T. whipplei PCR tests on saliva, stool and, if possible, joint fluid.

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.

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.

The role of macrophages in interstitial lung diseases

The finding of collections of macrophages/histiocytes in lung biopsy and bronchoalveolar lavage is relatively common in routine practice. This morphological feature in itself is pathological, but the exact clinical significance and underlying disease should be evaluated together with clinical data, functional respiratory and laboratory tests and imaging studies.

Morphological characteristics of macrophages and their distribution along the different pulmonary structures should be examined carefully by pathologists. Indeed, haemosiderin-laden macrophages are associated with smoking-related diseases when pigment is fine and distribution is bronchiolocentric, while alveolar haemorrhage or pneumoconiosis are the main concerns when pigment is chunky or coarse and the macrophages show an intra-alveolar or perilymphatic location, respectively. In the same way, pulmonary accumulation of macrophages with foamy cytoplasm is generally associated with pathologies leading to broncho-bronchiolar obstruction (e.g.diffuse panbronchiolitis, hypersensitivity pneumonia or cryptogenic organising pneumonia) or alternatively to exogenous lipoid pneumonia, some drug toxicity (e.g.amiodarone exposure or toxicity) and metabolic disorders (e.g.type B Niemann–Pick disease).

This pathology-based perspectives article is aimed at concisely describing the diagnostic possibilities when faced with collection of macrophages in lung biopsy and cytology.

Mesenteric lymphadenitis as a presenting feature of Whipple's disease

Detecting Whipple’s disease, a “great imitator”, requires a high index of suspicion so that antimicrobial treatment can be initiated in a timely manner; a missed diagnosis can be fatal. Although an uncommon cause, Whipple’s disease must be considered in adults with mesenteric lymphadenitis. We report the case of a 39-year-old African American man who presented with chronic joint pain, chronic weight loss, and acute onset epigastric pain. Contrast-enhanced computed tomography of the abdomen and pelvis showed extensive mesenteric lymphadenopathy. A diagnosis of Whipple’s disease was made based upon demonstration of PAS-positive macrophages in the mesenteric lymph node and duodenal biopsies. Antimicrobial therapy resulted in weight gain and resolution of abdominal pain and arthralgia at six months follow-up.

Whipple’s disease can be fatal without antibacterial therapy and it always needs to be considered in individuals presenting with any combination of abdominal pain, weight loss, and diarrhea in the background of nonspecific arthritis or arthralgia. Whipple’s disease must also be considered in adults presenting with mesenteric lymphadenitis. Review of CT scans may be helpful, as Whipple’s disease characteristically causes low attenuation mesenteric lymphadenopathy.