Diagnostic accuracy of a rapid E1-antigen test for chikungunya virus infection in a reference setting.

OBJECTIVES: Rapid diagnostic tests targeting virus-specific antigen could significantly enhance the diagnostic capacity for chikungunya virus infections. We evaluated the accuracy of an immunochromatographic antigen test for diagnosis of chikungunya in a reference laboratory for arboviruses. METHODS: An immunochromatographic rapid test that uses mouse monoclonal antibodies as a tracer against the E1-envelope protein of chikungunya (ARKRAY, Inc. Kyoto, Japan) was evaluated. Sensitivity was tested in sera from travellers with RT-PCR confirmed chikungunya virus infection (Eastern/Central/Southern African (ECSA) genotype) (n=9) and from patients diagnosed during the 2014-2015 chikungunya outbreak on Aruba (Asian genotype, n=30). Samples from patients with other febrile and non-febrile illnesses (n=26), sera spiked with Flavivirus and Alphavirus reference strains (n=13, including non-spiked serum), and samples containing other selected pathogens (n=20) were used to test specificity of the E1-antigen test. RESULTS: Sensitivity of the E1-antigen test was 8/9 (88.9%, 95% CI 56.5-98.0) for the ECSA genotype, but only 10/30 (33.3%, 95% CI 19.2-51.2) for the Asian genotype. Overall diagnostic specificity was 49/59 (83.1%, 95% CI 71.5-90.5). CONCLUSIONS: The E1-antigen test we evaluated had fair diagnostic sensitivity for ECSA genotype chikungunya, but low sensitivity for Asian genotype, and poor overall specificity. Antibodies that react across genotypes will be required for further development of a rapid test for chikungunya. Performance of new tests should be evaluated against different chikungunya genotypes.

Remission of splenic marginal zone lymphoma in a patient treated for hepatitis B: a case of HBV-associated lymphoma.

Splenomegaly is a common finding in chronic hepatitis B infection. We present the case of a man with an acute flare of chronic hepatitis B infection, where splenomegaly in absence of portal hypertension led to the diagnosis of splenic marginal zone lymphoma (SMZL) with bone marrow involvement. Adequate suppression of the hepatitis B virus (HBV) viral load with tenofovir resulted in complete remission of the lymphoma.

Column chromatographic characterization of complex formation of pro-IGF-II isoforms with acid labile subunit and IGF-binding proteins associated with non-islet cell tumour induced hypoglycaemia.

OBJECTIVE AND DESIGN: Non-islet cell tumour induced hypoglycaemia (NICTH) is a paraneoplastic phenomenon that is associated with the formation of several isoforms of pro-insulin like growth factor 2 (pro-IGF-II), or so called "big" IGF-II. Disturbance of ternary complex formation by big IGF-II is assumed to be a crucial early event in the pathogenic cascade of hypoglycaemia. By size-exclusion chromatography, we investigated complex formation by adding different naturally occurring isoforms of pro-IGF-II to pooled normal adult serum. Results were compared with the analysis of the serum from a patient with NICTH. RESULTS: Gel filtration experiments with the serum of a patient with NICTH demonstrated that ternary complex formation was severely compromised. The various forms of pro-IGF-II did not induce a shift of IGF-binding protein 3 (IGFBP-3) from 150kD towards smaller binary complexes in the normal adult serum, suggesting that they did not interfere with the interaction between the acid labile subunit and IGFBP-3. Instead, unglycosylated recombinant pro-IGF-II[1-104] was capable of forming a 150kD complex. In contrast, predominantly glycosylated and unglycosylated pro-IGF-II[1-87] eluted in the free unbound form. We showed that mature IGF-II and isoforms of pro-IGF-II were able to phosphorylate the IGF-I receptors of MC7 cells, albeit to a markedly lesser extent than IGF-I. When the patient's serum was tested in this system, the IGF-I receptor phosphorylation activity was considerably less than that in sera from age matched healthy individuals. CONCLUSION: We postulate that, alongside the presence of big IGF-II in the circulation, additional steps are required to stimulate the release of IGF-II and pro-IGF-II isoforms from IGFBPs in vivo. These factors may be proteases, that are present in the local environment of the tumour and in insulin-sensitive tissues.

[Diagnostic image (360). A woman with lowered consciousness]. / Diagnose in beeld (360). Een vrouw met gedaald bewustzijn.

A 42-year-old woman presented with lowered consciousness, ataxia and ophthalmoplegia; MRI of the brain revealed abnormalities compatible with Wernicke encephalopathy (thiamine deficiency).

Prevotella bivia necrobacillosis following infectious mononucleosis.

A case of Lemierre's syndrome is reported. Although Fusobacterium species are commonly associated with this presentation, Prevotella bivia was the causative micro-organism identified in this case. The finding that disseminated anaerobic sepsis followed primary EBV infection led to the construction of a hypothetical model of infection.

[Clinical reasoning and decision-making in practice. A man with jaundice, renal function disorder, thrombocytopenia, muscular pain and confusion]. / Klinisch denken en beslissen in de praktijk. Een man met icterus, nierfunctiestoornissen, trombocytopenie, spierpijn en verwardheid.

A 51-year-old man became jaundiced, after experiencing flu-like symptoms for a week. On admission anaemia, thrombocytopenia, and hepatic and renal function disorders were present. One month previously he had had sinusitis. Thrombotic thrombocytopenic purpura (TTP)/haemolitic-uraemic syndrome (HUS) was suspected, but the thrombocyte count rose spontaneously. The leukocytosis indicated an infectious cause of the symptoms and the jaundice appeared to originate from intrahepatic cholestasis. All symptoms could be traced to leptospirosis icterohaemorrhagica (known as 'Weil's disease'). The source was possibly the patient's fishpond. He recovered spontaneously and was also treated with antibiotics. Leptospirosis, a multi-organ disease is seen ever more infrequently as an occupational disease in stock farmers and increasingly frequently in people whose hobbies involved animals.