Background No consensus exists about the combination of clinical, laboratory, and radiological findings that warrant tests for Whipple's disease.
Objectives The primary aim of this multicentre retrospective study was to determine when patients evaluated for rheumatological symptoms should undergo T. whipplei PCR testing. Secondary aims were to describe the clinical patterns and treatments used, to determine the diagnostic yield of PCR testing, and to assess whether centres with higher numbers of tests also had a larger number of Whipple's disease diagnoses.
Methods In a retrospective observational study done in 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.
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%). The main extra-articular signs were constitutional symptoms (n=111, 41.8%), diarrhoea (n=70, 26.5%), fever (n=53, 20%), lymphadenopathy (n=14, 5.3%), and neurological signs (n=11, 4.2%). Whipple's disease was diagnosed in 13 patients (4.9%). The main samples tested and the more frequently positive tests in the centres with diagnoses of Whipple's disease were saliva and stool. In the centres with no diagnoses of Whipple's disease, arthritis was less common, whereas constitutional symptoms, fever, and lymphadenopathy were more common. 11 patients with Whipple's disease had CRP elevation. The annual incidence ranged across centres from 0 to 3.6/100000 inhabitants. The patients group with Whipple's disease had a higher proportion of males, older age, and greater frequency of arthritis.
Conclusions 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.
Disclosure of Interest None declared