Whipple's disease: new aspects of pathogenesis and treatment

Efficacy of ceftriaxone or meropenem as initial therapies in Whipple's disease

BACKGROUND & AIMS

Whipple's disease is a chronic infection caused by the actinomycete Tropheryma whipplei. We conducted a randomized controlled trial of the efficacy of antimicrobials that are able to cross the blood-brain barrier and to which T whipplei is susceptible.

METHODS

Patients from central Europe with previously untreated Whipple's disease (n = 40) were assigned randomly to groups given daily infusions of either ceftriaxone (1 x 2 g, 20 patients) or meropenem (3 x 1 g, 20 patients) for 14 days, followed by oral trimethoprim-sulfamethoxazole for 12 months. The primary outcome measured was maintenance of remission for 3 years, determined by a composite index of clinical and laboratory data as well as histology.

RESULTS

All patients were observed for the entire follow-up period (median, 89 mo; range, 71-128 mo); all achieved clinical and laboratory remission. Remission was maintained in all patients during the time of observation, except for 2 who died from unrelated causes. A single patient with asymptomatic cerebrospinal infection who was resistant to both treatments responded to chloroquine and minocycline. The odds ratio for the end point (remission for at least 3 years) was 0.95 (95% confidence interval, 0.05-16.29; P = 1.0).

CONCLUSIONS

This was a randomized controlled trial to show that treatment with ceftriaxone or meropenem, followed by trimethoprim-sulfamethoxazole, cures patients with Whipple's disease. One asymptomatic individual with infection of the cerebrospinal fluid required additional therapy.

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

BACKGROUND & AIMS

Whipple's disease is a chronic multisystemic infection caused by Tropheryma whipplei. Host factors likely predispose for the establishment of an infection, and macrophages seem to be involved in the pathogenesis of Whipple's disease. However, macrophage activation in Whipple's disease has not been studied systematically so far.

METHODS

Samples from 145 Whipple's disease patients and 166 control subjects were investigated. We characterized duodenal macrophages and lymphocytes immunohistochemically and peripheral monocytes by flow cytometry and quantified mucosal and systemic cytokines and chemokines indicative for macrophage activation. In addition, we determined duodenal nitrite production and oxidative burst induced by T whipplei and by other bacteria.

RESULTS

Reduced numbers of duodenal lymphocytes, increased numbers of CD163(+) and stabilin-1(+), reduced numbers of inducible nitric synthase+ duodenal macrophages, and increased percentages of CD163(+) peripheral monocytes indicated a lack of inflammation and a M2/alternatively activated macrophage phenotype in Whipple's disease. Incubation with T whipplei in vitro enhanced the expression of CD163 on monocytes from Whipple's disease patients but not from control subjects. Chemokines and cytokines associated with M2/alternative macrophage activation were elevated in the duodenum and the peripheral blood from Whipple's disease patients. Functionally, Whipple's disease patients showed a reduced duodenal nitrite production and reduced oxidative burst upon incubation with T whipplei compared with healthy subjects.

CONCLUSIONS

The lack of excessive local inflammation and alternative activation of macrophages, triggered in part by the agent T whipplei itself, may explain the hallmark of Whipple's disease: invasion of the intestinal mucosa with macrophages incompetent to degrade T whipplei.

False-positive PCR detection of Tropheryma whipplei in cerebrospinal fluid and biopsy samples from a child with chronic lymphocytic meningitis

We report the case of a teenager with chronic lymphocytic meningitis for whom Tropheryma whipplei 16S rRNA PCR results were positive in two cerebrospinal fluid samples and one duodenal biopsy specimen. PCR targeting another specific sequence of Tropheryma whipplei and sequencing of the initially amplified 16S rRNA fragment did not confirm the results.

Endocarditis due to Tropheryma whipplei: rapid detection, limited genetic diversity, and long-term clinical outcome in a local experience

The characteristic features of Whipple's disease include abdominal pain, diarrhoea, wasting, and arthralgias, with the causative agent, Tropheryma whipplei, being detected mainly in intestinal biopsies. PCR technology has led to the identification of T. whipplei in specimens from various other locations, including the central nervous system and the heart. T. whipplei is now recognized as one of the causes of culture-negative endocarditis, and endocarditis can be the only manifestation of the infection with T. whipplei. Although it is considered a rare disease, the true incidence of endocarditis due to T. whipplei is not clearly established. With the increasing use of molecular methods, it is likely that T. whipplei will be more frequently identified. Questions also remain about the genetic variability of T. whipplei strains, optimal diagnostic procedures and therapeutic options. In the present study, we provide clinical data on four new patients with documented endocarditis due to T. whipplei in the context of the available published literature. There was no clinical involvement of the gastrointestinal tract. Genetic analysis of the T. whipplei strains with DNA isolated from the excised heart valves revealed little to no genetic variability. In a selected case, we describe acridine orange staining for early detection of the disease, prompting early adaptation of the antibiotic therapy. We provide long-term follow-up data on the patients. In our hands, an initial 2-week course of intravenous antibiotics followed by cotrimoxazole for at least 1 year was a suitable treatment option for T. whipplei endocarditis.

Remission of histiocytic ulcerative colitis in Boxer dogs correlates with eradication of invasive intramucosal Escherichia coli

BACKGROUND

Historically, histiocytic ulcerative (HUC) (or granulomatous) colitis of Boxer dogs was considered an idiopathic immune-mediated disease with a poor prognosis. Recent reports of dramatic responses to enrofloxacin and the discovery of invasive Escherichia coli within the colonic mucosa of affected Boxer dogs support an infectious etiology.

HYPOTHESIS

Invasive E. coli is associated with colonic inflammation in Boxer dogs with HUC, and eradication of intramucosal E. coli correlates with clinical and histologic remission.

ANIMALS

Seven Boxer dogs with HUC.

METHODS

Prospective case series. Colonic biopsies were obtained at initial evaluation in 7 dogs, and in 5 dogs after treatment with enrofloxacin. Biopsies were evaluated by standardized histopathology, and fluorescence in situ hybridization (FISH) with probes to eubacteria and E. coli.

RESULTS

Intramucosal E. coli was present in colonic biopsies of 7/7 Boxers with HUC. Clinical response was noted in all dogs within 2 weeks of enrofloxacin (7 + or - 3.06 mg/kg q24 h, for 9.5 + or - 3.98 weeks) and was sustained in 6 dogs (median disease-free interval to date of 47 months, range 17-62). FISH was negative for E. coli in 4/5 dogs after enrofloxacin. E. coli resistant to enrofloxacin were present in the FISH-positive dog that relapsed.

CONCLUSIONS AND CLINICAL RELEVANCE

The correlation between clinical remission and the eradication of mucosally invasive E. coli during treatment with enrofloxacin supports the causal involvement of E. coli in the development of HUC in susceptible Boxer dogs. A poor response to enrofloxacin treatment might be due to colonization with enrofloxacin-resistant E. coli.

Community analysis of chronic wound bacteria using 16S rRNA gene-based pyrosequencing: impact of diabetes and antibiotics on chronic wound microbiota

Background

Bacterial colonization is hypothesized to play a pathogenic role in the non-healing state of chronic wounds. We characterized wound bacteria from a cohort of chronic wound patients using a 16S rRNA gene-based pyrosequencing approach and assessed the impact of diabetes and antibiotics on chronic wound microbiota.

Methodology/Principal Findings

We prospectively enrolled 24 patients at a referral wound center in Baltimore, MD; sampled patients' wounds by curette; cultured samples under aerobic and anaerobic conditions; and pyrosequenced the 16S rRNA V3 hypervariable region. The 16S rRNA gene-based analyses revealed an average of 10 different bacterial families in wounds—approximately 4 times more than estimated by culture-based analyses. Fastidious anaerobic bacteria belonging to the Clostridiales family XI were among the most prevalent bacteria identified exclusively by 16S rRNA gene-based analyses. Community-scale analyses showed that wound microbiota from antibiotic treated patients were significantly different from untreated patients (p = 0.007) and were characterized by increased Pseudomonadaceae abundance. These analyses also revealed that antibiotic use was associated with decreased Streptococcaceae among diabetics and that Streptococcaceae was more abundant among diabetics as compared to non-diabetics.

Conclusions/Significance

The 16S rRNA gene-based analyses revealed complex bacterial communities including anaerobic bacteria that may play causative roles in the non-healing state of some chronic wounds. Our data suggest that antimicrobial therapy alters community structure—reducing some bacteria while selecting for others.

Multisegmental spondylitis due to Tropheryma whipplei: case report

We report a patient who presented with inflammatory back pain due to multisegmental spondylitis. Following a vertebral biopsy which failed to detect an infectious organism, the patient was treated with etanercept, a tumor necrosis factor (TNF)-α inhibitor, for suspected undifferentiated spondyloarthritis. The back pain worsened and the spondylitic lesions increased. Only in a vertebral rebiopsy with polymerase chain reaction (PCR) amplification of Tropheryma whipplei, the causative agent of Whipple's disease was identified. Tropheryma whipplei should be considered as a cause of spondylitis even with multisegmental involvement and in the absence of gastrointestinal symptoms. In this clinical setting, routine PCR for Tropheryma whipplei from vertebral biopsies is recommended.

Disorders of intestinal secretion and absorption

The gastrointestinal tract possesses a huge epithelial surface area and performs many different tasks. Amongst them are the digestive and absorptive functions. Disorders of intestinal absorption and secretion comprise a variety of different diseases, e.g. coeliac disease, lactase deficiency or Whipple's disease. In principle, impaired small intestinal function can occur with or without morphological alterations of the intestinal mucosa. Therefore, in the work up of a malabsorptive syndrome an early small intestinal biopsy is encouraged in conjunction with breath tests and stool analysis to guide further management. In addition, there is an array of functional tests, the clinical availability of which becomes more and more limited. In any case, early diagnosis of the underlying pathophysiology is most important, in order to initiate proper therapy. In this chapter, diagnostic procedure of malabsorption is discussed with special attention to specific disease like coeliac disease, Whipple's disease, giardiasis and short bowel syndrome. Furthermore, bacterial overgrowth, carbohydrate malabsorption and specific nutrient malabsorption (e.g. for iron or vitamins) and protein-losing enteropathy are presented with obligatory and optional tests as used in the clinical setting.

The HLA alleles DRB1*13 and DQB1*06 are associated to Whipple's disease

BACKGROUND & AIMS

Whipple's disease is a systemic, chronic, relapsing disorder caused by a combination of environmental (Tropheryma whipplei) and unknown host factors. Because it is a rare disease, the association between HLA type and Whipple's disease has been studied in only small numbers of patients; these studies have led to conflicting results. We aimed to investigate whether disease phenotype and outcome are associated with HLA type in 122 patients with Whipple's disease.

METHODS

Genomic DNA was collected from 103 German, 11 Italian, and 8 Austrian patients with Whipple's disease, along with 62 healthy Austrian workers exposed to T whipplei (14 stool samples contained the bacterium). HLA class I and II alleles were identified by polymerase chain reaction analysis. Patient genotypes were compared with those of healthy German and Austrian populations; data for Italian controls were obtained from the Pavia HLA bone marrow donors' bank.

RESULTS

HLA-DRB1*13 and DQB1*06 alleles occurred significantly more frequently in patients with Whipple's disease but not in healthy individuals who had been exposed to T Whipplei. The cumulative odds ratios for disease were 2.23 for the DRB1*13 allele (P < .0001) and 2.25 for the DQB1*06 allele (P < .0001).

CONCLUSIONS

DRB1*13 and DQB1*06 alleles were found to be risk factors in the largest HLA study ever performed in patients with Whipple's disease.

[Fever of unknown origin in gastroenterology]

The gastrointestinal tract may be of major clinical or diagnostic importance in fever of unknown origin. To the classical diseases in this sense belong very different diseases as Whipple's disease, Familiar Mediterranean Fever, isolated mesenterial vasculitis, and manifestations of immune reconstitution inflammatory disease, but also unusual manifestations of otherwise easily recognized diseases like special forms of celiac disease, or inflammatory bowel disease. Endoscopical techniques to obtain biopsies for diagnostic procedures are frequently crucial to solve the diagnostic puzzle. In some cases the bioptic material may not be sufficient to reach a diagnosis and further surgical intervention is necessary (intestinal lymph-nodes or bowel resections) to acquire enough tissue for a definite diagnosis. Nevertheless using these different approaches in most cases of fever of unknown origin the underlying cause can be identified which for many patients means not more or less than significant improvement or even survival.

Complete resolution of primary sclerosing peritonitis ("abdominal cocoon") following long term therapy for Tropheryma whipplei: a case report and review of literature

A 53-year-old man was admitted to our internal medicine unit with intestinal obstruction and signs of systemic inflammatory disease. Clinical history was unremarkable until a few months earlier, when he began suffering from Achilles tendonitis. Diagnostic procedures, including laparotomy, revealed diffuse thickening of the peritoneum resembling sclerosing encapsulating peritonitis. Biopsies showed reactive fibrosis. No known secondary causes were found and surgery was technically not feasible. Clinical conditions worsened daily until, on the basis of the overall spectrum of clinical and radiological findings, Whipple's disease was hypothesised and specific therapy administered, with prompt clinical improvement. Complete disappearance of the cocoon was demonstrated at 1 year clinical/ultrasound/computed tomography follow-up.

Fourteen years of severe arthralgia in a man without gastrointestinal symptoms: atypical Whipple's disease

We report here the case of Whipple's disease in a 60-year-old man with severe arthralgia and systemic disorders but without gastrointestinal manifestations. The patient had different clinical diagnoses over a period of 14 years. We identified Tropheryma whipplei by real-time PCR. Molecular typing was also performed by sequencing the 16S-23S rRNA intergenic spacer region and domain III of the 23S rRNA gene.

[Whipple's disease]

Whipple's disease is a chronic, multisystemic, curable, bacterial infection that usually affects middle-aged men. It has a wide range of clinical manifestations. In the historical presentation, weight loss and diarrhoea are the most common symptoms and are preceded in three-quarters of cases by arthritis for a mean of six years. Long-term, unexplained, seronegative oligoarthritis or polyarthritis of large joints with a palindromic or relapsing course is typical. In most patients, periodic acid-Schiff staining of proximal small bowel biopsy specimens reveals inclusions within the macrophages, corresponding to bacterial structures. However, patients may have no gastrointestinal symptoms, negative jejunum biopsy results and even negative PCR tests. Even in the absence of gastrointestinal symptoms, Whipple's disease should be considered in case of negative blood culture endocarditis, unexplained central neurological manifestations or unexplained arthritis. Identification of the causative bacterium, Tropheryma whipplei, has led to the development of PCR as a diagnostic tool, particularly useful in patients in the early stages of the disease or with atypical disease. The recent cultivation of T. whipplei and the complete sequencing of its genome should improve our understanding and treatment of the disease. The future development of an assay for detection of specific antibodies in the serum and generalization of the immunohistochemical detection of antigenic bacterial structures may allow earlier diagnosis, thereby preventing the development of the severe late systemic and sometimes fatal forms of the disease.