Yuji Ishikawa

Indomethacin blocks the anorexic action of interleukin-1

It has been reported recently that the central nervous system actions of interleukin-1 are mediated by the prostaglandin system in the brain. The present study was therefore performed in order to examine the hypothesis that indomethacin, an inhibitor of prostaglandin biosynthesis, might alleviate the interleukin-1-induced suppression of food intake in rats. The i.p. injection of interleukin-1 (2 micrograms/rat) resulted in a significant decrease in food intake. The pre-injection of indomethacin (0.5 mg/rat), however, completely blocked the anorexic action of the monokine, while indomethacin on its own did not affect food intake. These results suggested that indomethacin might be clinically useful for improvement of the anorexic state of patients with acute infectious diseases.

Development of Em18-immunoblot and Em18-ELISA for specific diagnosis of alveolar echinococcosis

Extensive experience has documented that Em2(plus)-ELISA, Em10-ELISA and Em18-immunoblot and Em18-ELISA are reliable serologic methods for detection of alveolar echinococcosis (AE) caused by the metacestodes of Echinococcus multilocularis. Among these, tests based on detection of antibodies to the specific Em18 antigen, either immunoblot or ELISA, appears to be the most specific for AE. Between 90 and 97% of AE cases with characteristic hepatic lesions detectable by image analysis have been positive in Em18-serology. In contrast Antigen B (8 kDa)-immunoblot is the most sensitive for all forms of echinococcosis, although it can not differentiate AE from cystic echinococcosis (CE). Primary serologic screening for echinococcosis, especially for CE using hydatid cyst fluid of Echinococcus granulosus appears to be highly sensitive in endemic areas. Glycoproteins (GPs) purified from cyst fluid of Taenia solium are highly specific for diagnosis of T. solium neuorcysticercosis (NCC). Using currently available antigens it is not difficult to differentiate these three larval cestodiases serologically. We recommend that (1) primary screening of CE in endemic areas should be carried out using hydatid cyst fluid of E. granulosus prepared from cysts in either sheep, human or mouse for immunoblot and from sheep or mouse for ELISA, (2) both primary screening and confirmation of AE in endemic areas should be carried out using Em18-ELISA, Em18-immunoblot or Em2(plus)-ELISA. Serodiagnosis in areas where both AE and CE are endemic, such as in China, should be carried out as a combination of (1) and (2), and (3) serology of NCC should be carried out using GP-ELISA or GP-immunoblot. All samples showing antibody to Em18 are exclusively from echinococcosis cases. There have been no false positive test reactions with sera from other diseases. Strongest Em18 responders are all from patients with AE but some weaker responses may be found in sera of persons with advanced complex lesions of CE. These highly reliable serodiagnostic methods using native, recombinant and synthetic antigens are briefly summarized and experiences with these methods in Japan is reviewed. We believe that use of these specific antigens in screening and confirmation programs for AE in Japan will improve specificity and reduce the confusion, anxiety and expense in persons whose sera give false positive reactions with crude echinococcal antigens.

Evaluation of an Enzyme-Linked Immunosorbent Assay (ELISA) with Affinity-Purified Em18 and an ELISA with Recombinant Em18 for Differential Diagnosis of Alveolar Echinococcosis: Results of a Blind Test

ABSTRACT Alveolar echinococcosis (AE) is the most potentially lethal parasitic zoonosis of the nontropical areas in the northern hemisphere, where cystic echinococcosis (CE) is also endemic. Both AE and CE are highly endemic in China, and both serologic detection of echinococcosis, either AE or CE, and differentiation of AE from CE are crucial problems. Evaluation of Western blot analysis (WB) and enzyme-linked immunosorbent assay (ELISA) for the Em18 antigen, using affinity-purified and recombinant Em18, was carried out “blindly” using 60 human sera from patients diagnosed in France. The results were compared with those obtained using a commercially available Echinococcus WB immunoglobulin G (IgG) kit developed in France. The Em18 WB and Echinococcus WB IgG showed very similar results for detection of AE. Both affinity-purified Em18 or a recombinant Em18 WB and Echinococcus WB IgG seem useful for identification of AE, and the latter seems appropriate for both AE and CE, whereas affinity-purified Em18 ELISA and the newly developed recombinant Em18 ELISA appear to be suitable for detection of AE, especially for epidemiological surveys.

Usefulness of recombinant Em18-ELISA to evaluate efficacy of treatment in patients with alveolar echinococcosis.

Alveolar echinococcosis (AE) is a rare parasitic disease caused by Echinococcus multicularis and most commonly involves the liver. Early diagnosis is essential to improve the prognosis of patients with AE of the liver. Em18, an 18-kD diagnostic antigen from Echinococcus multilocularis, is highly specific and sensitive to detect AE. We previously reported that an enzyme-linked immunosorbent assay (ELISA) system using a recombinant Em18 antigen (RecEm18) was highly useful in the differential serodiagnosis of AE. In this report, we present seven AE patients who showed dynamic changes in RecEm18-ELISA values in the course of long-term follow up of albendazole (ABZ) chemotherapy, and/or resections of the liver or bone metastasis. All seven AE patients revealed positive values, over the cutoff level, of the RecEm18-ELISA before the treatments. The values in six patients fell below the cutoff level after the treatments, but the value in a patient with recurrence never fell below the cutoff level, and increased again. From these results, it seems that the RecEm18-ELISA is useful to evaluate the efficacy of treatment and predict recurrence in patients with AE. RecEm18-ELISA may be an important examination for: (a) the mass screening of AE in Japan, (b) the confirmative diagnosis of AE prior to surgical and/or chemotherapeutic treatments,

Serological Monitoring of Progression of Alveolar Echinococcosis with Multiorgan Involvement by Use of Recombinant Em18

ABSTRACT Two cases of alveolar echinococcosis (AE) with multiple-organ involvement (the liver, lungs, and bone) were monitored by imaging and serology for 20 years. Resection of the bone lesion was complete in one case but incomplete in the other case. Albendazole treatment was markedly to moderately effective against hepatic and pulmonary AE lesions in both cases, whereas it had almost no effect against the bone lesion in one case. The results of the serological tests with recombinant Em18 antigen coincided with the clinical findings in each case. An enzyme-linked immunosorbent assay for the detection of immunoglobulin G (IgG) responses, especially IgG4 responses, is expected to be a real-time indicator of the dynamics of active AE.

Comparison of the antigenicity of protoscoleces and microvesicles of Echinococcus multilocularis prepared from rats

Rats are known to be relatively resistant to infection with Echinococcus multilocularis. However, when rats are inoculated with the parasite tissues, E. multilocularis proliferates slowly at first but after 6 months the cysts increase in size considerably and contain large numbers of protoscoleces. As rats survive for 18 months or longer, approximately 100 ml of packed protoscoleces can be produced from each rat. A comparison of the antigenicity of the protoscoleces and microvesicles by immunoblot methods showed that both Em18 and Em16 are shared components between both protoscoleces and microvesicles, although the latter have some additional antigenic components. In antigens prepared from protoscoleces, the banding patterns around Em18 were much simpler than those from microvesicles. Therefore, for serodiagnosis of E. multilocularis, antigens should be carefully prepared from protoscoleces rather than microvesicles from the rat.

Immunodiagnosis of alveolar echinococcosis using urine samples

Alveolar echinococcosis (AE) is one of the most lethal zoonotic parasitic infections. The diagnosis is based on the combination of the abdominal imaging including CT, MRI and PET, and serology. To develop a new diagnostic tool for AE with urine as samples, mouse-Echinococcus multilocularis (Em) model and then human cases were studied. The antibody levels of urine and serum samples from the infected mice and AE cases were well correlated with each other. The sensitivity and specificity of the method with urine were 91% and 98%, respectively, when IgG4 to crude Em was examined. Comparing with serum samples, the collection of urine is easier and safer and the urine diagnostic tool makes surveys of this silent disease easier.