Arthralgia as an early extraintestinal symptom of Whipple's disease. Report of five cases

Whipple's in the valleys: a case of Whipple's with thrombocytopenia and endocarditis

INTRODUCTION

This case report details the second described case of Whipple's disease-related thrombocytopenia in the medical literature. Whipple's disease is a rare multisystem infection caused by the actinomycete Tropheryma whipplei, first described by George Whipple in 1907. The key clinical manifestations are weight loss, diarrhoea and malabsorption, but arthralgia and endocarditis are also well described.

CASE PRESENTATION

A 62-year-old Caucasian female presented with weight loss, anaemia and behavioural changes but denied any abdominal symptoms. Thrombocytopenia subsequently developed rapidly. Bone marrow examination showed abundant megakaryocytes in keeping with peripheral platelet sequestration. In addition, there was significant polyclonal plasmacytosis. She was also found to have a 1.6 cm tricuspid vegetation. The diagnosis was confirmed by presence of foamy macrophages on duodenal biopsy, positive periodic acid-Schiff staining and visualisation of T whipplei actinomycetes on electron microscopy. Tissue PCR performed mid-treatment showed traces of T whipplei DNA. The infection was treated with a 2-week intravenous course of ceftriaxone followed by 12 months of oral co-trimoxazole. The thrombocytopenia and anaemia resolved rapidly with antibiotic therapy, her behaviour returned to normal and she remains clinically well.

CONCLUSIONS

This report confirms the association of thrombocytopenia with Whipple's disease, likely due to peripheral platelet sequestration, which resolves rapidly with treatment. In patients with a long history of unintended weight loss, Whipple's disease is a rare but important differential diagnosis as it is ultimately fatal if left untreated.

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.

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.

Hypertrophic osteoarthropathy can indicate recurrence of Whipple's disease

We report the case of a patient with Whipple's disease (WD) who developed hypertrophic osteoarthropathy (HOA) characterized by digital clubbing, periostosis of the tubular bones, and polysynovitis. The HOA disclosed the recurrence of the patient's WD, since polymerase chain reaction (PCR) analysis clearly demonstrated the presence of Tropheryma whippelii in the synovial fluid from the patient's left knee. Initiation of appropriate antibiotic therapy resulted in complete healing of all clinical rheumatologic manifestations within 2 months and in disappearance of radiographic bone changes at 7-month followup. We suggest that HOA be included within the spectrum of rheumatologic manifestations of WD, and that an evaluation for WD should be considered in patients, especially middle-aged men, presenting with HOA even without gastrointestinal symptoms. PCR analysis may be useful in accurate diagnosis and management of early WD with unusual clinical manifestations, and may contribute to decreased morbidity and mortality.

Whipple's arthritis: direct detection of Tropheryma whippelii in synovial fluid and tissue

We describe 2 patients presenting with polyarthritis in whom the synovial fluid (1 patient) or synovial tissue (1 patient) was positive for Tropheryma whippelii, the Whipple's disease-associated bacillus, when examined by polymerase chain reaction (PCR) and DNA sequencing. Histopathologic findings were consistent with articular Whipple's disease in the synovial fluid of 1 patient and the synovial tissue of the other. In both patients, bowel mucosal specimens were negative for Whipple's disease features by histologic and PCR methods. One patient was positive for T whippelii in the peripheral blood. Control synovial fluid specimens from 40 patients with other arthritides, including Lyme arthritis, were negative. Sequencing of a 284-basepair region of the 16S ribosomal RNA gene confirmed that the sequence is closely related to the known T whippelii sequence. Both patients responded to treatment with antibiotics.