The 13carbon urea breath test for the diagnosis of Helicobacter pylori infection in subjects with atrophic gastritis: evaluation in a primary care setting.

BACKGROUND: (13)Carbon urea breath testing is reliable to detect current infection with Helicobacter pylori but has been reported to be of limited value in selected patients with atrophic body gastritis or acid-lowering medication. AIM: To evaluate the accuracy of (13)carbon urea breath testing for H. pylori detection in 20 asymptomatic patients with histologically confirmed atrophic body gastritis in a primary care setting. METHODS: (13)Carbon urea breath testing and serology were compared with H. pylori culture of a corpus biopsy as reference test. RESULTS: All tests were in agreement in 12 patients, being all positive in six and all negative in six. One patient was positive for serology and culture but negative for (13)carbon urea breath testing, five patients had only positive serology and two patients had only positive (13)carbon urea breath testing. (13)Carbon urea breath testing showed an accuracy with culture of 85% and anti-H. pylori serology with culture of 75%. (13)Carbon urea breath testing carried out in patients with positive serology showed an accuracy of 92%. Receiver operating characteristic curve analysis of (13)carbon urea breath testing shows optimal discrimination at the prescribed cut-off value. CONCLUSIONS: (13)Carbon urea breath testing can be used as diagnostic H. pylori test in asymptomatic patients with atrophic body gastritis, preferably in addition to serology, to select subjects for anti-H. pylori therapy.

Pitfalls and fallacies of cat scratch disease serology: evaluation of Bartonella henselae-based indirect fluorescence assay and enzyme-linked immunoassay.

The diagnostic value of the detection of immunoglobulin G (IgG) and IgM by Bartonella henselae-based indirect fluorescence assay (IFA) and enzyme-linked immunoassay (EIA) for the diagnosis of cat scratch disease (CSD) was evaluated. The IFA was performed either with B. henselae that was cocultivated for a few hours with Vero cells or with noncocultivated B. henselae as the antigen. Additionally, the performance of a Bartonella PCR hybridization assay based on the 16S rRNA gene was determined and compared with those of the serologic assays. The study group consisted of 45 patients suspected of suffering from CSD by fulfilling one or more of the classical criteria. The specificities of the immunoassays were set at > or = 95% by analysis of sera from 60 healthy blood donors. It is shown that the sensitivities of the IgG assays are very low (40.9% for the IFA with noncocultivated B. henselae as antigen) and that those of the IgM assays are higher (71.4% for the EIA) for patients who fulfilled two or more criteria for CSD. The IgM EIA showed the highest sensitivity: 71.4% in patients with two or more criteria for CSD and 80.6% for patients with a positive Bartonella PCR result. The results indicate that the specificities of both IFA and EIA IgG serologies and the sensitivity of the IFA IgM serology need to be improved. The PCR hybridization assay showed a sensitivity of 86.4% for patients who fulfilled two or more criteria for CSD and 100% for seven patients who fulfilled three or more criteria. The kinetics of IgG and IgM antibody production were studied in 18 patients with CSD on the basis of a positive B. henselae IFA IgM serology. The results indicate that there is no standard course of anti-B. henselae IgG and IgM production in patients with CSD, because some patients produced high levels of both IgG and IgM, others produced only high levels of IgM, and a few patients produced only low levels of antibodies.

[Intravenously-administered immunoglobulins as first-choice agent in juvenile dermatomyositis]. / Intraveneus toegediend immunoglobuline als middel van eerste keuze bij juveniele dermatomyositis.

Dermatomyositis is an acquired disease characterised by symmetric predominantly proximal muscle weakness of the arms and legs, and misery. It may be associated with myalgia and there is often a characteristic rash. The mainstay of therapy is corticosteroids. Recently efficacy of intravenous immunoglobulin (IVIg) in chronic refractory dermatomyositis was reported. Because corticosteroids can cause serious side effects, we treated a seven-year-old girl suffering from dermatomyositis with IVIg as initial therapy. After two courses of IVIg infusions at a dose of 0.4 g/kg/day for five consecutive days, the patient made a rapid and complete recovery. This case shows that IVIg may be effective as initial therapy in patients with dermatomyositis. Whether IVIg is really a better treatment than corticosteroids should be investigated in a randomised study.

Development of an antibody-capture IgM-enzyme-linked immunosorbent assay for diagnosis of acute Epstein-Barr virus infections.

An anti-EBV IgM-ELISA was developed using the antibody-capture principle, to be used for the diagnosis of acute infectious mononucleosis (IM). The test was based on anti-human IgM-coated microtiter plates; nuclei of EBV producer cells were used for antigen; conjugate was prepared by labeling sheep anti-EBV IgG with horseradish peroxidase. The specificity of the anti-EBV IgM-ELISA was studied with a panel of sera from acute infections with hepatitis A virus, rubella virus, Toxoplasma gondii and cytomegalovirus, and sera positive for rheumatoid factors, positive for antinuclear antibodies, as well as with sera from normal blood donors and pregnant women. Specificity in these panels was 98.4%. In a clinical study with 449 sera from patients with IM-like symptoms, 109 of 109 confirmed patients were detected by the anti-EBV IgM-ELISA. Specificity of the anti-EBV IgM-ELISA in this clinical study was 99.7%. The anti-EBV IgM-ELISA detected several acute EBV patients who had negative heterophile antibody titers.

LDH analysis of human thymocytes and thymocyte subsets.

The lactate dehydrogenase (LDH) isoenzyme pattern (expressed as the B:A subunit ratio) and two enzymes of the purine metabolism adenosine deaminase (ADA) and purine nucleoside phosphorylase (PNP) (expressed as the ADA/PNP ratio) were studied in human prenatal thymocytes, in subsets of human infant thymocytes, and in peripheral T lymphocytes. Prothymocytes were enriched by E rosette depletion, cortical thymocytes were enriched with a monoclonal antibody rosette technique using OKT6, and medullary thymocytes were enriched either with a monoclonal antibody rosette technique using OKT3 or with complement-mediated cytolysis using normal fresh rabbit serum. Peripheral T lymphocytes were isolated from normal adult peripheral blood by E rosette sedimentation. Prenatal thymocytes had the lowest B:A ratio. In the infant thymuses, prothymocytes had a lower B:A ratio (0.99 +/- 0.10) than the cortical thymocytes (1.04 +/- 0.08). The medullary thymocytes obtained either by OKT3 selection or normal rabbit serum cytotoxic treatment had higher B:A ratios (1.30 +/- 0.15 and 1.42 +/- 0.17, respectively). The highest B:A ratio is found in peripheral T lymphocytes (2.07 +/- 0.28) together with the lowest ADA/PNP ratio (0.50 +/- 0.07). The B:A ratios are paralleled by a progressive decrease in the ADA/PNP ratio. These findings indicate that during intrathymic T cell development, important changes occur not only in the activities of the enzymes of the purine metabolism but also in the distribution of the LDH isoenzymes.

Anti-thymocyte globulin treatment for aplastic anemia.

20 patients with severe aplastic anemia were treated with anti-thymocyte globulin (ATG), 6 of them in combination with haplo-identical bone marrow. 7 patients (35%) showed a good clinical response within 6 months; they were off transfusions and had greater than or equal to 0.8 x 10(9)/l neutrophils. ATG had the greatest effect on red-cell production and the least on platelet production. The hematological recovery with ATG could not be predicted from the bone-marrow histology, CFU-c growth, or clinical data. However, patients with strong HLA antibodies seemed to respond more often. The actuarial survival was 55% at 5 years. Under intensive supportive care, even 7 out of 12 non-responders were alive after 1 year. ATG appears to be a useful form of therapy for patients with severe aplastic anemia who are not candidates for bone-marrow transplantation.

T lymphocyte function in hairy cell leukaemia.

The high incidence of infections characteristic of impaired cell-mediated immunity in patients with hairy cell leukemia led us to study T lymphocyte function in sixteen patients with the lymphocyte transformation test. All patients showed imparied responses to mitogens, attributable to one or more of the following causes: dilution of responsive T cells by inert hairy cells, shortage of monocytes to give adequate interaction with the T cells and a significant decrease in the number of T cells with Fcmu receptors proportional to the percentage of hairy cells in the peripheral blood. The response to antigens was severely depressed; PPD was one of the few antigens that induced positive reactions in half the cases. We conclude that in patients with hairy cell leukaemia, T lymphocyte function, as tested in a proliferative assay, is severely impaired and that this may contribute to the deficient resistance to infection.