[Whipple's disease, a non-rheumatoid cause of seronegative arthritis]. / De ziekte van Whipple, een niet-reumatische oorzaak van seronegatieve artritis.

BACKGROUND: In 15-25% of patients with rheumatoid arthritis, the presence of pathognomonic autoantibodies (anti-citrullinated protein (aCCP) or rheumafactor (RF) is lacking. In these cases of seronegative rheumatoid arthritis, diagnosis is based on clinical presentation. However, some of the patients with seronegative rheumatoid arthritis are misdiagnosed. CASE DESCRIPTION: Here we discuss a case of a 64 year old female, with a diagnoses of seronegative rheumatoid arthritis for 18 years. Although extensively treated with immunosuppressive medication, she did not reach remission. After second opinion in our hospital we diagnosed Whipple's disease. CONCLUSION: This case report illustrates the importance of a broad differential diagnosis of seronegative arthritis as well as the importance of re-assessment of patients diagnosed with seronegative rheumatoid arthritis, who do not reach remission upon immunosuppressive treatment.

[Whipple's disease, a non-rheumatoid cause of seronegative arthritis]. / De ziekte van Whipple, een niet-reumatische oorzaak van seronegatieve artritis.

BACKGROUND: In 15-25% of patients with rheumatoid arthritis, the presence of pathognomonic autoantibodies (anti-citrullinated protein (aCCP) or rheumafactor (RF) is lacking. In these cases of seronegative rheumatoid arthritis, diagnosis is based on clinical presentation. However, some of the patients with seronegative rheumatoid arthritis are misdiagnosed. CASE DESCRIPTION: Here we discuss a case of a 64 year old female, with a diagnoses of seronegative rheumatoid arthritis for 18 years. Although extensively treated with immunosuppressive medication, she did not reach remission. After second opinion in our hospital we diagnosed Whipple's disease. CONCLUSION: This case report illustrates the importance of a broad differential diagnosis of seronegative arthritis as well as the importance of re-assessment of patients diagnosed with seronegative rheumatoid arthritis, who do not reach remission upon immunosuppressive treatment.

Fingerstick test quantifying humoral and cellular biomarkers indicative for M. leprae infection.

OBJECTIVES: New user-friendly diagnostic tests for detection of individuals infected by Mycobacterium leprae (M. leprae), the causative pathogen of leprosy, can help guide therapeutic and prophylactic treatment, thus positively contributing to clinical outcome and reduction of transmission. To facilitate point-of-care testing without the presence of phlebotomists, the use of fingerstick blood (FSB) rather than whole blood-derived serum is preferred. This study is a first proof-of-principle validating that previously described rapid serum tests detecting antibodies and cytokines can also be used with FSB. METHODS: Quantitative detection of previously identified biomarkers for leprosy and M. leprae infection, anti-M. leprae PGL-I IgM antibodies (αPGL-I), IP-10 and CRP, was performed with lateral flow (LF) strips utilizing luminescent up-converting reporter particles (UCP) and a portable reader generating unbiased read-outs. Precise amounts of FSB samples were collected using disposable heparinized capillaries. Biomarker levels in paired FSB and serum samples were determined using UCP-LF test strips for leprosy patients and controls in Bangladesh, Brazil, South-Africa and the Netherlands. RESULTS: Correlations between serum and FSB from the same individuals for αPGL-I, CRP and IP-10 were highly significant (p < .0001) even after FSB samples had been frozen. The αPGL-I FSB test was able to correctly identify all multibacillary leprosy patients presenting a good quantitative correlation with the bacterial index. CONCLUSIONS: Reader-assisted, quantitative UCP-LF tests for the detection of humoral and cellular biomarkers for M. leprae infection, are compatible with FSB. This allows near-patient testing for M. leprae infection and immunomonitoring of treatment without highly trained staff. On site availability of test-result concedes immediate initiation of appropriate counselling and treatment. Alternatively, the UCP-LF format allows frozen storage of FSB samples compatible with deferred testing in central laboratories.