[Diagnostic issues of Whipple's disease during chronic inflammatory rheumatism: About three cases]

INTRODUCTION

Whipple's disease (WD) can mimic chronic inflammatory rheumatism leading to incorrect prescription of tumor necrosis factor inhibitors (TNFI). Several complicated cases of WD have been reported during TNFI treatment which is strongly suspected to modify the host-pathogen relationship. Tropheryma whipplei asymptomatic carriage is high in the general population, making the diagnosis of WD more difficult face to unexplained arthritis.

OBSERVATIONS

We report three observations that illustrate situations for which the detection of T. whipplei might be valuable to investigate the differential diagnosis of inflammatory rheumatism.

CONCLUSION

The decision to check for T. whipplei infection should rely on individual clinical assessment. It should be considered in the absence of clinical response or in case of worsening of an inflammatory rheumatism under TNFI treatment, especially in front of atypical features. A systematic screening for T. whipplei before anti-TNF treatment seems unjustified since asymptomatic carriers are frequent.

[A systemic disease mimicking a rheumatoid arthritis]

INTRODUCTION

Rare systemic diseases such as amyloidosis can mimic inflammatory rheumatic diseases. Because of their poor prognosis, physicians should rule them out at the onset of inflammatory rheumatism. We report a case of AL amyloidosis misdiagnosed as rheumatoid arthritis.

CASE REPORT

A 71-year-old woman was referred for seronegative rheumatoid arthritis, resistant to three biologic therapies. She had an IgA lambda monoclonal gammopathy of undetermined significance (MGUS). The patient subsequently developed glomerular proteinuria. Abdominal fat and accessory salivary glands biopsies revealed amyloid light-chain (AL) amyloidosis. Treatment with bortezomib-cyclophosphamide-dexamethasone, led to complete hematologic, renal and rheumatologic remission. Ten months after treatment interruption, the patient had an articular and hematologic relapse.

CONCLUSION

Amyloid light-chain amyloidosis arthropathy is probably underdiagnosed. A review of amyloid arthropathy associated with multiple myeloma found that 33% of patients had been misdiagnosed with rheumatoid arthritis.