Treatment of refractory Whipple disease with interferon-gamma

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review of the literature on WD unusually presenting with exclusively neurological symptoms, including two previously unpublished cases.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.

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.

Treatment of disseminated nocardiosis: a host-pathogen approach with adjuvant interferon gamma

Disseminated nocardiosis is a rare, life-threatening disease. Particularly at risk are immunocompromised patients, highlighting the crucial role of host factors. Conventional intensive antibiotic treatment has improved survival rates, but the overall prognosis of patients with disseminated nocardiosis remains unsatisfactory. In this Grand Round, we present a case of severe nocardiosis that did not respond to standard therapy. The patient's condition deteriorated when antibiotic therapy was given alone and improved substantially only after coadministration of interferon gamma. We review the literature relevant to adjuvant interferon gamma therapy of nocardiosis and discuss its potential harms and benefits. Overall, we consider such treatment as beneficial and low risk if the patient is followed-up closely. We conclude that clinicians should consider this regimen in refractory cases of severe Nocardia infection.

Long-term morbidity and mortality in Whipple's disease: a single-center experience over 20 years

Background: Little is known about long-term morbidity and mortality in Whipple's disease (WD). Aim: To describe morbidity and mortality in patients with WD on a long-term follow-up. Materials & methods: Comorbidities, mortality and causes of death were retrospectively registered. Results: A total of 35 patients with WD (9F, 54 ± 11 years) were followed-up for a median of 104 months. Nine patients developed ten complications; three patients died. A total of 31 severe comorbidities apparently unrelated to WD were found in 20 patients: preneoplastic/neoplastic disorders in seven, thromboembolic and cardiovascular events in seven, pneumonia in four, candidiasis in ten patients. Conclusion: WD is frequently complicated by potentially life-threatening infectious, neoplastic and thromboembolic disorders, thus highlighting the need for a life-long multidisciplinary follow-up.

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.

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.

Tropheryma whipplei infection and Whipple's disease

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

Systematic review: Whipple's disease (Tropheryma whipplei infection) and its unmasking by tumour necrosis factor inhibitors

BACKGROUND

The classical form of Whipple's disease (WD), clinically characterised by arthropathy, diarrhoea and weight loss, is rare. Recently, other more frequent forms of Tropheryma whipplei infection have been recognised. The clinical spectrum includes an acute, self-limiting disease in children, localised forms affecting cardiac valves or the central nervous system without intestinal symptoms, and asymptomatic carriage of T. whipplei which is found in around 4% of Europeans. Genomic analysis has shown that T. whipplei represents a host-dependent or opportunistic bacterium. It has been reported that the clinical course of T. whipplei infection may be influenced by medical immunosuppression.

AIM

To identify associations between immunomodulatory treatment and the clinical course of T. whipplei infection.

METHODS

A PubMed literature search was performed and 19 studies reporting on immunosuppression, particularly therapy with tumour necrosis factor inhibitors (TNFI) prior to the diagnosis in 41 patients with Whipple?s disease, were evaluated.

RESULTS

As arthritis may precede the diagnosis of WD by many years, a relevant percentage (up to 50% in some reports) of patients are treated with immunomodulatory drugs or with TNFI. Many publications report on a complicated Whipple?s disease course or T. whipplei endocarditis following medical immunosuppression, particularly after TNFI. Standard diagnostic tests such as periodic acid-Schiff stain used to diagnose Whipple?s disease often fail in patients who are pre-treated by TNFI.

CONCLUSIONS

In cases of doubt, Whipple?s disease should be excluded before therapy with TNFI. The fact that immunosuppressive therapy contributes to the progression of T. whipplei infection expands our pathogenetic view of this clinical entity.

[Drug therapy of infectious diarrhea. Part 2: Chronic diarrhea]

Diarrheal diseases are among the most common diseases worldwide. In this review the current treatment recommendations for acute (Part 1) and chronic (Part 2) infectious diarrhea are summarized and typical enteropathogens are discussed. The second part of the article describes chronic diarrhea, its related pathogens and treatment. In contrast to acute diarrhea which is mainly caused by viral and typical bacterial pathogens, chronic diarrhea has mainly non-infectious origins. Protozoal pathogens, such as Giardia lamblia and Entamoeba histolytica in particular are found and more rarely bacterial pathogens, such as Tropheryma whipplei. Opportunistic pathogens cause diarrhea in immunocompromised patients, such as in HIV patients. In these patients cytomegalovirus (CMV) colitis or infections with Cryptosporidium spp., Cyclospora cayetanensis, Isospora belli or microsporidia have to be considered. Besides targeted specific antimicrobial therapy, anti-retroviral drugs improving the underlying immunosuppression and thus the reconstitution of the adaptive immune response remain a cornerstone of the treatment in HIV-positive patients.

Whipple's Disease: Our Own Experience and Review of the Literature

Whipple's disease is a chronic infectious systemic disease caused by the bacterium Tropheryma whipplei. Nondeforming arthritis is frequently an initial complaint. Gastrointestinal and general symptoms include marked diarrhoea (with serious malabsorption), abdominal pain, prominent weight loss, and low-grade fever. Possible neurologic symptoms (up to 20%) might be associated with worse prognosis. Diagnosis is based on the clinical picture and small intestinal histology revealing foamy macrophages containing periodic-acid-Schiff- (PAS-) positive material. Long-term (up to one year) antibiotic therapy provides a favourable outcome in the vast majority of cases. This paper provides review of the literature and an analysis of our 5 patients recorded within a 20-year period at a tertiary gastroenterology centre. Patients were treated using i.v. penicillin G or amoxicillin-clavulanic acid + i.v. gentamicin for two weeks, followed by p.o. doxycycline (100 mg per day) plus p.o. salazopyrine (3 g per day) for 1 year. Full remission was achieved in all our patients.

Whipple disease

Whipple disease (WD) is a rare disease caused by Tropheryma whipplei. The classic profile of the patient is that of a middle-aged man presenting with fever, chronic diarrhea, and arthralgias. Extragastrointestinal manifestations are not rare. A high degree of clinical suspicion for the disease is needed in atypical cases. Trimethoprim-sulfamethoxazole is the treatment of choice. We present two patients with WD. The first presented with melena and generalized hyperpigmentation. The second had depression for two years before the typical symptoms. Both hyperpigmentation and long-lasting depression without the typical manifestations of the disease are rare. Histologic examination of tissue biopsies was diagnostic for WD. Both patients were treated successfully with trimethoprim-sulfamethoxazole.

Tropheryma whipplei Infection

Whipple’s disease was initially described in 1907. Over the next century, the clinical and pathological features of this disorder have been better appreciated. Most often, weight loss, diarrhea, abdominal and joint pain occur. Occasionally, other sites of involvement have been documented, including isolated neurological disease, changes in the eyes and culture-negative endocarditis. In the past decade, the responsible organism Tropheryma whipplei has been cultivated, its genome sequenced and its antibiotic susceptibility defined. Although rare, it is a systemic infection that may mimic a wide spectrum of clinical disorders and may have a fatal outcome. If recognized, prolonged antibiotic therapy may be a very successful form of treatment.

Whipple's disease-generalized stage

Whipple's disease is a chronic inflammatory systemic disorder in which all organs can be invaded by the rod-shaped bacterium Tropheryma whipplei. It is a rare disease and frequently misdiagnosed, though there is no valid estimate of its actual incidence and prevalence. Only about 1,000-1,500 cases have been reported. The clinical course of untreated Whipple's disease can include three stages: (1) a non-specific prodromal stage which includes migratory polyarthralgias; (2) a classic abdominal manifestation which involves weight loss, weakness, chronic diarrhea, and abdominal pain; and (3) a generalized stage characterized by steatorhea, cachexia, lymphadenopathy, hyper-pigmentation, and cardiovascular, pulmonary, and neurological dysfunction. The authors describe a case of a 39-year-old male patient with about a year's history of generalized adenopathy, inappetence, weight loss, progressive weakness, subfebrilities, and convulsive abdominal pain. Following primary exclusion of a tumor disease, a lymph node biopsy demonstrated a typical picture of a granulomatous inflammation-Whipple's lymphadenitis with partial exemption of the Gram reaction, and stain features corresponding to T. whipplei, which is regarded as the etiological agent causing this disorder. Further tests confirmed the generalized form of the disorder, affecting the lymphatic tissues, gastrointestinal system, respiratory system, and nervous system, with sensory and motor polyneuropathy. HLA-B27 antigen, which is frequent among those with Whipple's disease, was also present. Following treatment for three months with antibiotics a significant reduction of the changes typical of Whipple's disease was found upon follow-up biopsy, hence we assume the applied therapy was successful. In our case study we emphasize the atypical course of the disease with dominant generalized lymphadenopathy and only mild gastrointestinal symptoms.

[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.

Neurological presentation of Whipple's disease after long-term antibiotic treatment: a case report

Introduction

Whipple's disease is a rare systemic infectious disorder caused by Tropheryma whipplei.

Case presentation

We report a 68-year-old male with Whipple's disease of the central nervous system following long-term antibiotic therapy and many years after the initial clinical onset.

Conclusion

The combination of trimethoprim and sulphamethoxazole does not prevent or cure involvement of the central nervous system in all patients with Whipple's disease. If relapse of the central nervous system occurs treatment with meropenem might be a useful alternative.

Whipple's disease: new aspects of pathogenesis and treatment

100 years after its first description by George H Whipple, the diagnosis and treatment of Whipple's disease is still a subject of controversy. Whipple's disease is a chronic multisystemic disease. The infection is very rare, although the causative bacterium, Tropheryma whipplei, is ubiquitously present in the environment. We review the epidemiology of Whipple's disease and the recent progress made in the understanding of its pathogenesis and the biology of its agent. The clinical features of Whipple's disease are non-specific and sensitive diagnostic methods such as PCR with sequencing of the amplification products and immunohistochemistry to detect T whipplei are still not widely distributed. The best course of treatment is not completely defined, especially in relapsing disease, neurological manifestations, and in cases of immunoreconstitution after initiation of antibiotic treatment. Patients without the classic symptoms of gastrointestinal disease might be misdiagnosed or insufficiently treated, resulting in a potentially fatal outcome or irreversible neurological damage. Thus, we suggest procedures for the improvement of diagnosis and an optimum therapeutic strategy.

Possible case of CNS Whipple's disease in an adolescent with AIDS

An adolescent with HIV/AIDS presented subacutely with progressive encephalopathy, spastic quadraplegia, and diarrhea. His brain biopsy was suggestive of central nervous system Whipple's disease, a disease rarely described in HIV patients. Due to overlapping, nonspecific symptoms associated with several opportunistic infections and to the difficulty in culturing the causative organism Tropheryma whipplei, Whipple's disease may be more common than previously suspected, and it is an important consideration in patients with AIDS.

Whipple disease

PURPOSE OF REVIEW

The availability of and advantages in molecular technology and immunology have led to an improved understanding of the etiology and pathogenesis of Whipple disease. As this rare infection represents a model disease reflecting the input of novel findings into clinical medicine and therapy, this review intends to highlight newer findings and put them in context.

RECENT FINDINGS

Sequencing of 16S rRNA allowed the phylogeny of the bacterium to be determined. The culture and subsequent genome analysis have led to improved diagnosis and monitoring of the disease, for example by PCR or immunohistochemistry. New experimental approaches hint of defects in T-cell and macrophage immunity in patients. Antibiotic therapy will soon be based on data from the first prospective therapy study.

SUMMARY

Within a few years the findings from molecular genetics and immunology as well as concerted research activities from the European Consortium on Whipple Disease which established a data and material bank could be translated into clinical medicine. Thus, for patients with Whipple disease an improved basis for diagnosis and therapy have been achieved.

[Whipple's disease: current problems]

Whipple's disease is a rare multisystemic infectious disease of bacterial origin characterized by variable clinical manifestations, and an insidious and chronic relapsing course. Untreated disease can be even fatal. The presence of the characteristic (though not specific) triad of weight loss, chronic diarrhea and arthralgias may raise its suspicion. When chronic intermittent fever and lymphadenopathy are associated, the suspicion is substantial. Recognition of the causative agent, Tropheryma whippelii with unique characteristics was essential. Despite the presumed ubiquitous presence of the bacteria the disease probably occurs only in cases of immunological host susceptibility. Presence of the bacteria living and multiplying especially in macrophages has suggested alterations of the mononuclear-phagocytic system. (Whipple's disease is commonly mentioned as a macrophage disorder.) Clinical manifestations are quite diverse. While it has traditionally been regarded as a gastrointestinal disease, currently is considered to be a systemic disorder. In cases of suspected infection the approach of first choice is upper gastrointestinal endoscopy. Small, whitish-yellow diffusely distributed plaques alternating with an erythematous, erosive, friable mucosa in the postbulbar region of the duodenum or in the jejunum can appear. Histological samples indicate tissue infiltration of macrophages with intracellular bacterial invasion. The hallmark of Whipple's disease is the presence of PAS positive macrophages in the lamina propria of duodenal biopsy specimens, still the diagnosis needs to be confirmed with the detection of bacteria by PCR. The selection of antibiotics and duration of treatment still remains largely empiric.

Reduced Peripheral and MucosalTropheryma whipplei-Specific Th1 Response in Patients with Whipple’s Disease

Whipple's disease is a rare infectious disorder caused by Tropheryma whipplei. Major symptoms are arthropathy, weight loss, and diarrhea, but the CNS and other organs may be affected, too. The incidence of Whipple's disease is very low despite the ubiquitous presence of T. whipplei in the environment. Therefore, it has been suggested that host factors indicated by immune deficiencies are responsible for the development of Whipple's disease. However, T. whipplei-specific T cell responses could not be studied until now, because cultivation of the bacteria was established only recently. Thus, the availability of T. whipplei Twist-Marseille(T) has enabled the first analysis of T. whipplei-specific reactivity of CD4(+) T cells. A robust T. whipplei-specific CD4(+) Th1 reactivity and activation (expression of CD154) was detected in peripheral and duodenal lymphocytes of all healthy (16 young, 27 age-matched, 11 triathletes) and disease controls (17 patients with tuberculosis) tested. However, 32 Whipple's disease patients showed reduced or absent T. whipplei-specific Th1 responses, whereas their capacity to react to other common Ags like tetanus toxoid, tuberculin, actinomycetes, Giardia lamblia, or CMV was not reduced compared with controls. Hence, we conclude that an insufficient T. whipplei-specific Th1 response may be responsible for an impaired immunological clearance of T. whipplei in Whipple's disease patients and may contribute to the fatal natural course of the disease.

Whipple’s disease

Whipple's disease (WD) is a chronic debilitating disease caused by the bacillus Tropheryma whippleii. WD classically presents with the main clinical symptoms of polyarthralgias, chronic diarrhea, weight loss, and abdominal pain. Given its systemic involvement, it is common for WD to present with a multitude of other clinical scenarios--sometimes with predominant neurologic, cardiac, and dermatologic manifestations. WD can occur at any age, but it generally occurs during the fifth decade and predominantly in men. The diagnosis of WD is established by demonstrating the organism on biopsies from the involved system, by histology, electron microscopy, polymerase chain reaction, and more recently, by culture of bacteria. The histologic features include a coarse granular cytoplasm and foamy macrophages that stain strongly with the period-acid Schiff reagent. Current therapy includes an initial 2-week course of intravenous cephalosporins followed by 1-year oral trimethoprim-sulfamethoxazole.

IL-16 Is Critical forTropheryma whippleiReplication in Whipple’s Disease

Whipple's disease (WD) is a rare systemic disease caused by Tropheryma whipplei. We showed that T. whipplei was eliminated by human monocytes but replicated in monocyte-derived macrophages (Mphi) by inducing an original activation program. Two different host molecules were found to be key elements for this specific pattern. Thioredoxin, through its overexpression in infected monocytes, was involved in bacterial killing because adding thioredoxin to infected Mphi inhibited bacterial replication. IL-16, which was up-regulated in Mphi, enabled T. whipplei to replicate in monocytes and increased bacterial replication in Mphi. In addition, anti-IL-16 Abs abolished T. whipplei replication in Mphi. IL-16 down-modulated the expression of thioredoxin and up-regulated that of IL-16 and proapoptotic genes. In patients with WD, T. whipplei replication was higher than in healthy subjects and was related to high levels of circulating IL-16. Both events were corrected in patients who successfully responded to antibiotics treatment. This role of IL-16 was not reported previously and gives an insight into the understanding of WD pathophysiology.

Invasion of the central nervous system by intracellular bacteria

Infection of the central nervous system (CNS) is a severe and frequently fatal event during the course of many diseases caused by microbes with predominantly intracellular life cycles. Examples of these include the facultative intracellular bacteria Listeria monocytogenes, Mycobacterium tuberculosis, and Brucella and Salmonella spp. and obligate intracellular microbes of the Rickettsiaceae family and Tropheryma whipplei. Unfortunately, the mechanisms used by intracellular bacterial pathogens to enter the CNS are less well known than those used by bacterial pathogens with an extracellular life cycle. The goal of this review is to elaborate on the means by which intracellular bacterial pathogens establish infection within the CNS. This review encompasses the clinical and pathological findings that pertain to the CNS infection in humans and includes experimental data from animal models that illuminate how these microbes enter the CNS. Recent experimental data showing that L. monocytogenes can invade the CNS by more than one mechanism make it a useful model for discussing the various routes for neuroinvasion used by intracellular bacterial pathogens.

Whipple disease

Whipple disease is a rare disease caused by infection with the bacterium Tropheryma whippelii. Humans are the only known host for the infection. The signs of systemic infection include gastrointestinal problems, weight loss, and arthritis. Signs of central nervous system infection include cognitive changes, supranuclear gaze palsy, altered level of consciousness, and movement disorders. The diagnosis is based on clinical findings as well as microscopic examination of biopsy specimens and, more recently, polymerase chain reaction (PCR) analysis, which has high sensitivity and specificity. Although the organism historically has been difficult to culture, several recent attempts have been successful. Antibiotic treatment is recommended for 1 year while monitoring the clinical signs and cerebrospinal fluid PCR results.

Whipple's disease

Whipple's disease is an infectious disease caused by a gram-positive bacterium, Tropheryma whipplei. The first case was reported in 1907 by GH Whipple. Its classic symptoms are diarrhea and arthralgias, but symptoms can be various. Cardiac or central nervous system involvement, not always associated with digestive symptoms, may also be observed. For a long time, diagnosis has been based on duodenal biopsy, which is positive using periodic acid-Schiff staining. However, for patients without digestive symptoms, results can be negative, leading to a delay in diagnosis. For 10 years, a tool based on polymerase chain reaction targeting the 16S rDNA sequence has been used. In vitro culture of the bacterium, achieved 3 years ago, has allowed new perspectives for diagnosis and treatment. The natural evolution of the disease without treatment is always fatal. Current treatment is based on administration of trimethoprim-sulfamethoxazole for at least 1 year.

Mucosal immune response to Tropheryma whipplei

Whipple's disease is a rare infectious disease caused by the ubiquitously occurring Tropheryma whipplei in predisposed persons. Genetic or acquired defects in the mucosal and peripheral immune system become apparent as diminished Th1 immune functions with decreased production of IL-12 and IFN-gamma accompanied by an increased secretion of IL-4. These defects may enable T. whipplei to survive and replicate. The recently established cultivation of the bacterium in HEL cells and the isolation from infected intestinal biopsies enable a multitude of experimental possibilities which may lead to an improved diagnosis as well as understanding of the etiology and pathogenesis of Whipple's disease.

Whipple's disease

Whipple's disease, or intestinal lipodystrophy, is a systemic infectious disorder affecting mostly middle-aged white men. Patients present with weight loss, arthralgia, diarrhoea, and abdominal pain. The disease is commonly diagnosed by small-bowel biopsy; the appearance of the sample is characterised by inclusions in the lamina propria staining with periodic-acid-Schiff, which represent the causative bacteria. Tropheryma whipplei has been classified as an actinomycete and has been propagated in vitro, which allows the possibility of improving diagnostic strategies, for example through antibody-based detection of the bacillus on duodenal tissue or in circulating monocytes. Cell-mediated immunity in active and inactive Whipple's disease has subtle defects that might predispose some individuals to symptomatic infection with this bacillus, which probably occurs ubiquitously. Although most patients respond well to empirical antibiotic treatment, some with relapsing disease have a poor outlook. The recent findings and concerted research might allow development of new strategies for diagnosis, treatment, and monitoring of patients with Whipple's disease.

Dysregulated peripheral and mucosal Th1/Th2 response in Whipple's disease

BACKGROUND & AIMS

An impaired monocyte function and impaired interferon (IFN)-gamma production has been suggested as a possible pathogenetic factor in Whipple's disease (WD) and as a cause for the delayed elimination of Tropheryma whipplei in some patients.

METHODS

We studied, in a series of 20 WD patients with various degrees of disease activity, cellular immune functions.

RESULTS

We found an increased in vitro production of interleukin (IL)-4 by peripheral mononuclear blood cells as determined by enzyme-linked immunosorbent assay, but reduced secretion of IFN-gamma and IL-2 as compared with age- and sex-matched controls. In addition, we observed a significantly reduced monocyte IL-12 production in response to various stimuli in WD patients whereas other cytokines were comparable with controls; these immunologic alterations were not significantly different in patients with various disease activities. At the mucosal level, we found decreased CD4 T-cell percentage and a significantly impaired IFN-gamma secretion.

CONCLUSIONS

Our data define a defective cellular immune response in a large series of WD patients and point to an important pathogenetic role of impaired Th1 responses. The decreased monocyte IL-12 levels may result in reduced peripheral and mucosal IFN-gamma production and lead to an increased susceptibility to T. whipplei infection in certain hosts.

Neurologic presentation of Whipple disease: report of 12 cases and review of the literature

We report 12 cases of Whipple disease in patients with prominent neurologic symptoms, along with 122 cases of Whipple disease with nervous system involvement reported in the literature. We analyzed the clinical signs and results of additional examinations in 2 groups: the first group included patients with predominantly but not exclusively neurologic signs, and the second included patients with clinically isolated neurologic presentation of the disease. Whipple disease is a multisystemic infectious disease due to Tropheryma whippelii that may present with prominent or isolated symptoms of either the central or the peripheral nervous system. Recent reports stress the importance of polymerase chain reaction (PCR) analysis of cerebrospinal fluid, magnetic resonance imaging (MRI) during follow-up, and prolonged antibiotic therapy with drugs able to cross the blood-brain barrier. Cerebrospinal fluid should be analyzed repeatedly during follow-up, and treatment should be discontinued only when the results of PCR assay performed on cerebrospinal fluid are negative. Other examinations to be done include searching for gastrointestinal tract involvement with multiple duodenal biopsies and searching for systemic involvement with lymph node biopsies, which should be analyzed with light microscopy, electron microscopy, and PCR. When all examinations are negative, if Whipple disease is suspected and a lesion is found on brain MRI, a stereotactic cerebral biopsy should be performed. Treating Whipple disease with long-term trimethoprim-sulfamethoxazole is usually effective, but the use of third-generation cephalosporins in case of incomplete response deserves further attention.

The diagnosis and treatment of Whipple's disease

Whipple's disease is a rare, chronic, and systemic infectious disease caused by the ubiquitously occurring bacterium Tropheryma whippelii. For two reasons, the disease represents a good example for documenting the input of modern molecular-based techniques into pathogenetic, diagnostic, and therapeutic concepts in clinical medicine. First, the unidentified and uncultivable causative organism has been characterized by novel molecular-genetic techniques. Second, in contrast to other chronic inflammatory disorders, clinical manifestations of T. whippelii infection seem to be based on reduced T-cell helper type 1 (TH1) activity. These findings have led to an improved pathophysiologic understanding of the disease and to new aspects in treatment strategies that are discussed in this paper.

Iron loading: a risk factor for Whipple's disease?

Because of impairment of microbial iron acquisition ability, some potential pathogens can cause disease only in iron loaded hosts. Tropheryma whippelii, the etiologic agent of Whipple's disease, is a possible example. Whipple's disease is non-contagious, occurs mainly in middle-aged white males, and displays many, but not all, of the complications of hereditary haemochromatosis. Tropheryma whippelii is a gastrointestinal commensal that causes disease in persons who have a Th1-Th2 imbalance. Host susceptibility may be exacerbated by iron loading. Consideration should be given to have patients evaluated for levels of interferon-gamma and interleukin-4 as well as for serum ferritin and transferrin iron saturation.

Whipple's disease and "Tropheryma whippelii"

Whipple's disease is a rare bacterial infection that may involve any organ system in the body. It occurs primarily in Caucasian males older than 40 years. The gastrointestinal tract is the most frequently involved organ, with manifestations such as abdominal pain, malabsorption syndrome with diarrhea, and weight loss. Other signs include low-grade fever, lymphadenopathy, skin hyperpigmentation, endocarditis, pleuritis, seronegative arthritis, uveitis, spondylodiscitis, and neurological manifestations, and these signs may occur in the absence of gastrointestinal manifestations. Due to the wide variability of manifestations, clinical diagnosis is very difficult and is often made only years or even decades after the initial symptoms have appeared. Trimethoprim-sulfamethoxazole for at least 1 year is usually considered adequate to eradicate the infection. The microbiological diagnosis of this insidious disease is rendered difficult by the virtual lack of culture and serodiagnostic methods. It is usually based on the demonstration of periodic acid-Schiff-positive particles in infected tissues and/or the presence of bacteria with an unusual trilaminar cell wall ultrastructure by electron microscopy. Recently, the Whipple bacteria have been characterized at the molecular level by amplification of their 16S rRNA gene(s). Phylogenetic analysis of these sequences revealed a new bacterial species related to the actinomycete branch which was named "Tropheryma whippelli." Based on its unique 16S ribosomal DNA (rDNA) sequence, species-specific primers were selected for the detection of the organism in clinical specimens by PCR. This technique is currently used as one of the standard methods for establishing the diagnosis of Whipple's disease. Specific and broad-spectrum PCR amplifications mainly but not exclusively from extraintestinal specimens have significantly improved diagnosis, being more sensitive than histopathologic analysis. However, "T. whippelii" DNA has also been found in persons without clinical and histological evidence of Whipple's disease. It is unclear whether these patients are true asymptomatic carriers or whether differences in virulence exist among strains of "T. whippelii" that might account for the variable clinical manifestations. So far, six different "T. whippelii" subtypes have been found by analysis of their 16S-23S rDNA spacer region. Further studies of the pathogen "T. whippelii" as well as the host immune response are needed to fully understand this fascinating disease. The recent cultivation of the organisms is a promising major step in this direction.

Small Intestinal Infections

The differential diagnosis of small intestinal infections is broad, making the identification and management of these disorders challenging. The majority of cases of acute diarrhea are self-limited and do not require diagnostic evaluation or treatment. Most patients do not require specific therapy, and treatment should focus on fluid and electrolyte replacement. In patients with severe, persistent, or chronic diarrhea, a careful medical history and routine stool testing are helpful in determining the cause. Pathogen-specific therapy should be given in patients in whom a pathogen is identified. In those without an identifiable pathogen, antidiarrheal agents are helpful in reducing the number of bowel movements and preventing further dehydration. Endoscopy may be helpful in patients with severe diarrhea and a negative stool evaluation, particularly in HIV-infected patients with chronic diarrhea. Surgery has a limited role in the management of small intestinal infections, but may be lifesaving in patients with intestinal perforation or small bowel obstruction.

Whipple's disease and Tropheryma whippelii: secrets slowly revealed

Whipple's disease was described in 1907 and was designated "intestinal lipodystrophy," despite the detection of bacteria in 1 specimen. This finding was later substantiated by the success of antibiotic therapy, which resulted in dramatic clinical responses, and by use of electron microscopy, which detected monomorphic bacilli in affected tissues. Many attempts at culture failed, and these bacteria were characterized as actinomycetes for the first time by means of broad-range 16S rDNA amplification and molecular phylogenetic methods. The name "Tropheryma whippelii" was proposed for this bacterium. Whipple's disease is a systemic disease that affects many organ systems, producing protean manifestations. This article summarizes recent developments with regard to this topic as well as unanswered questions regarding the pathogenesis and acquisition of infection, the biology and ecology of the organism, the clinical spectrum of disease, diagnosis of the disease, and therapy.

Whipple's disease

Whipple's disease is a systemic bacterial infection and the common though not invariable manifestations are diarrhoea, weight loss, abdominal pain, and arthralgia. Arthritis or arthralgia may be the only presenting symptom, predating other manifestations by years. Virtually all organs in the body may be affected, with protean clinical manifestations. Various immunological abnormalities, some of which may be epiphenomena, are described. The causative organism is Tropheryma whippelii. The disease is uncommon though lethal if not treated. Recent data suggest the disease occurs in an older age group than previously described. The characteristic histopathological features are found most often in the small intestine. These are variable villous atrophy and distension of the normal villous architecture by an infiltrate of foamy macrophages with a coarsely granular cytoplasm, which stain a brilliant magenta colour with PAS. These pathognomonic PAS positive macrophages may also be present in the peripheral and mesenteric lymph nodes and various other organs. The histological differential diagnoses include histoplasmosis and Mycobacterium avium-intercellulare complex. The clinical diagnosis of Whipple's disease may be elusive, especially if gastrointestinal symptoms are not present. A unique sign of CNS involvement, if present, is oculofacial-skeletal myorhythmia or oculomasticatory myorhythmia, both diagnostic of Whipple's disease. A small bowel biopsy is often diagnostic, though in about 30% of patients no abnormality is present. In patients with only CNS involvement, a stereotactic brain biopsy can be done under local anaesthetic. A recent important diagnostic test is polymerase chain reaction of the 16S ribosomal RNA of Tropheryma whippelii. Whipple's disease is potentially fatal but responds dramatically to antibiotic treatment. In this review the current recommended treatments are presented. The response to treatment should be monitored closely, as relapses are common. CNS involvement requires more vigorous treatment because there is a high rate of recurrence after apparently successful treatment.