Humoral immunity and correlation between ELISA, hemagglutination inhibition, and neutralization tests after vaccination against tick-borne encephalitis virus in children.

Vaccination against tick-borne encephalitis (TBE) virus is the measure of choice for disease control in endemic areas, as no treatment is available. In Italy, the province of Belluno is one of the most active TBE virus infection foci. In this study sera were examined from vaccinated children living in areas around Belluno in order to monitor the immune response after anti-TBE vaccination. For the assessment of neutralizing antibodies, a plaque reduction neutralization test (PRNT) was optimized and the correlation between enzyme-linked immunosorbent assay (ELISA), hemaglutination inhibition (HI), and neutralizing antibodies titers was evaluated. All children had high serum levels of TBE IgG in ELISA test after the vaccination, in agreement with previous studies. HI and PRNT titers ranged between very low and high levels. A good correlation between HI and PRNT titers, and with IgG ELISA titers, was observed. PRNT is an useful assay for monitoring protective immunity after the completion of anti-TBE vaccination. This type-specific assay is an important tool for differential diagnosis in cases where the presence of cross-reactive antibodies due to other flavivirus infections or vaccinations cannot be excluded.

Hashimoto's encephalopathy: epidemiologic data and pathogenetic considerations.

BACKGROUND: Hashimoto's encephalopathy (HE) is a condition believed to complicate Hashimoto's thyroiditis (HT). The diagnosis is suspected in the presence of high levels of serum anti-thyroid antibodies. We have recently demonstrated that in patients with HE there is an intrathecal synthesis of anti-thyroid antibodies, and concluded that the diagnosis of HE should be based on this cerebrospinal fluid (CSF) finding. OBJECTIVE: getting an estimate of the prevalence of the disease, verifying the association with HT and investigating the pathogenetic role of anti-thyroid antibodies. METHODS: 34-months prospective study in a hospital setting serving a community of 150,000 people. Patients with unexplained symptoms of acute or subacute encephalopathy or myelopathy or with a history of thyroid disorders were selected for the measurement of anti-thyroid antibodies. In the presence of high serum levels of autoantibodies, the same tests were performed in the CSF. RESULTS: Twelve patients had increased concentrations of serum autoantibodies but HE was diagnosed only in nine patients. The estimated prevalence of HE is 2.1/100,000. Only six HE patients had also HT. Four patients received corticosteroids, five patients were not treated. Five patients improved, four patients spontaneously, one patient after corticosteroids. Repeated CSF examinations showed that the titer of CSF autoantibodies did not correlate with the clinical stage of the disease nor was influenced by corticosteroids. In addition, the course of symptoms was independent of therapy. CONCLUSIONS: The association of encephalopathy and high titers of anti-thyroid antibodies is not sufficient to make a diagnosis of HE. Independent of the clinical status of the thyroid gland, the intrathecal synthesis of autoantibodies is a distinctive marker of this elusive condition.

[p-ANCA and ASCA antibodies in the differential diagnosis between ulcerative rectocolitis and Crohn's disease]. / Gli anticorpi p-ANCA ed ASCA nella diagnosi differenziale fra rettocolite ulcerosa e malattia di Crohn.

UNLABELLED: Anti-Saccaromyces cerevisiae antibodies (ASCA) seem to be associated with Crohn's disease (CD), while anti-neutrophil cytoplasm antibodies (p-ANCA) seem to be a recognised marker for ulcerative colitis (UC). AIM: Of our study was to determine whether the presence of ASCA and p-ANCA antibodies could differentiate CD from UC and IBD from aspecific chronic colitis (ACC). METHODS: Serum samples were obtained from 23 patients with CD and 32 with UC, and from 13 patients with aspecific chronic colitis. Diagnosis was established on clinical findings, endoscopy and histology. Determination of ASCA and p-ANCA antibodies was performed using indirect immunofluorescence technique and ELISA, respectively. RESULTS: 20% CD patients against 50% UC patients expressed p-ANCA (p < 0.05). Vice versa 61% CD patients against 16% UC patients expressed ASCA (p < 0.05). The combination of positive ASCA and negative p-ANCA determined a sensibility, specificity and positive predictive value of 45%, 91% and 75% respectively, for diagnosis of CD. The combination of positive p-ANCA and negative ASCA determined a sensibility, specificity and positive predictive value of 44%, 95% and 94% respectively, for diagnosis of UC. CONCLUSION: Our results indicate that ASCA are principally expressed in patients with CD, by contrast p-ANCA seem to be strongly associated with UC. The combination of these two tests can be useful in evaluating patients with indeterminate colitis, distinguishing UC from CD.