No evidence for increased frequency of autoantibodies during interferon-beta1b treatment of multiple sclerosis.

Interferon-beta1b (IFN-beta1b) is a widespread therapy of multiple sclerosis (MS), reducing the numbers and severity of exacerbations and the total lesion load measured by magnetic resonance imaging of the brain. Since IFN-beta1b has potent immunomodulatory properties, a potential side-effect of IFN-beta1b treatment could be the development of autoimmune responses. The frequencies of antinuclear and smooth muscle antibodies, antibodies against microsomal antigen of thyroid epithelial cells as well as a group of heterophilic antibodies were determined in 26 MS patients treated with IFN-beta1b for 3-20 months. No elevation of antibody titres was found for any of the antibodies studied when compared with paired samples obtained from most of the patients before the initiation of treatment. Although examined on a rather small group of patients, the results show no evidence of increased frequency of autoantibodies during interferon-beta1b treatment of multiple sclerosis.

Development and standardization of solid phase assays for the detection of anti-neutrophil cytoplasmic antibodies (ANCA). A report on the second phase of an international cooperative study on the standardization of ANCA assays.

Anti-neutrophil cytoplasmic antibodies (ANCA) are diagnostic markers for systemic vasculitis. They are classically detected by an indirect immunofluorescence test using normal donor neutrophils as substrate. This assay lacks antigenic specificity and is not quantitative. The 'EC/BCR Project for ANCA Assay Standardization' is an international collaboration study with the aim to develop and standardize solid phase assays for ANCA detection. In this part of the study the isolation and characterization of proteinase-3 and myeloperoxidase, the two main target molecules for ANCA, and the development and standardization of ELISAs with these antigens are described. Six laboratories successfully isolated purified proteinase-3 preparations that could be used. Three of these preparations, together with one myeloperoxidase preparation, were subsequently used for ANCA testing by ELISA. The ELISA technique was standardized in two rounds of testing in the 14 participating laboratories. The coefficient of variation of these new assays decreased from values of approx. 50% in the first round to approx. 20% in the second round. We conclude that purified proteinase-3 and myeloperoxidase can be used in standardized ELISAs for ANCA detection. Whether such procedures offer advantages over the IIF test will be determined in a prospective clinical study.

Incidence and outcome of pauci-immune necrotizing and crescentic glomerulonephritis in adults.

During a seven-year period (1986-1992) 719 adults (age > 16 years) underwent diagnostic renal biopsy in Stockholm (adult population 1.2 million). Seventy-one (10%) new cases of pauci-immune necrotizing and crescentic glomerulonephritis (NCGN) with or without systemic vasculitis were found: 39 females and 32 males (median age 67, range 20-84 years). The mean yearly incidence for the whole period was 0.8/100,000 population. The yearly incidence doubled from 0.6 before to 1.2/100,000 population after 1990. The incidence was highest among those > 65 years of age. Age-corrected incidences for this age group increased from 1.4 before to 3.9/100,000 after 1990. Anti-neutrophil cytoplasmic antibodies (ANCAs) tested in 60, showed antibodies against proteinase 3 (PR3) in 29 patients, against myeloperoxidase (MPO) in 26 and none in five patients. Mortality was highest in the early stages of the disease. From a total of 11 patients, 7 (15%) died within 2.5 months of diagnosis. Forty-six out of all 71 patients with NCGN belonged to the catchment area of our clinic and were studied in more detail. Twenty-six had microscopic polyangiitis (ANCAs were analyzed in 24, of these 16 had anti-MPO, 6 anti-PR3, 2 had none), 13 had Wegener's granulomatosis (ANCAs were analyzed in all, of these 12 had anti-PR3, 1 anti-MPO) and seven had disease limited to the kidneys (ANCAs were analyzed in 6, 5 had anti-MPO, one was negative). At the time of diagnosis, 16 patients had s-creatinine < 300 mumol/l while 14 patients were dialysis-dependent (seven only temporarily). All patients received immunosuppressive therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

The prevalence of antinuclear antibodies in healthy young persons and adults, comparing rat liver tissue sections with HEp-2 cells as antigen substrate.

The prevalence of antinuclear antibodies (ANA) was studied in 290 healthy adults, aged 20-88 years, and in 219 children, aged 1 month to 15 years. Two antigen substrates, rat liver tissue sections and HEp-2 cells, were compared at different serum dilutions. At titre 1/40, the number of positive adult samples was 6.9% with HEp-2 cells and 6.2% with rat liver. Using a lower serum dilution, HEp-2 cells were shown to be significantly more sensitive than rat liver. However, 25% of the positive samples at serum titre > or = 1/40 could only be found on HEp-2 cells, as compared to 17% for rat liver, even after extended investigation. In children, 7.3% of the samples were positive using HEp-2, as compared to 2.3% with rat liver tissue, at titre 1/10. None of the samples were positive for nDNA or other specific antigens as measured by immunodiffusion. One sample had antibodies against core histones and two samples showed antibodies against subcellular antigens by immunoblot. We conclude that the occurrence of ANA in healthy Swedish children and adults is similar to previous studies from other countries. Both rat liver tissue and HEp-2 cells were found to be suitable for screening purposes, if the increased sensitivity of HEp-2 cells is taken into consideration, particularly with regard to children. Furthermore, it may be necessary to use more than one substrate to exclude ANA positivity in clinical practice.

Antineutrophil cytoplasmic antibody (cANCA and pANCA) titers in relation to disease activity in patients with necrotizing vasculitis: a longitudinal study.

The significance of the antineutrophil cytoplasmic antibodies, cANCA or pANCA, in relation to disease activity in various types of necrotizing vasculitis was assessed in a longitudinal study. Twenty patients, 14 cANCA positive and 6 pANCA positive were followed for up to seven years. Eleven of the 14 cANCA positive and two out of the 6 pANCA positive patients had Wegener's granulomatosis, two other cANCA patient and one pANCA patient had systemic vasculitis, whereas one cANCA and three pANCA positive patients had disease limited to the kidneys. Disease activity was expressed as a numerical index DAI, based on extent and type of organ involvement (DAI greater than or equal to 5 = active disease). At the time of disease debut the DAI ranged between 11 and 32, cANCA titers between 18 and greater than 1000 U/l, and pANCA titers between 51 and 630 U/l in individual patients. With clinical recovery both c- and pANCA titers declined. Clinical remission (DAI less than 5) occurred within a mean of 2.5 months (range 1 to 4). Almost simultaneously cANCA titers turned negative (less than 10 U/l), although one patient remained positive for seven years. pANCA titers remained positive for long periods of time in 5/6 patients. Five cANCA patients had clinical exacerbations, which in two patients were preceded by seroconversions from - to +, lasting 3 and 12 months before the clinical relapse. One additional cANCA patient had two serological relapses without signs of clinical activity during a 2-year follow-up. In conclusion, we saw a close correlation between DAI and cANCA titers in individual patients: with decreasing clinical activity (DAI), the cANCA titers decrease. Interindividual variation is great; despite a high DAI, the cANCA titers may be relatively low. Serological relapses may indicate forthcoming clinical relapses. Relapses may develop as late as 5-6 years after onset. pANCA titers, on the other hand, tend to remain positive for long periods, despite clinical remission.

The IgG antibody reactivity of sera from patients with active chronic hepatitis to a crude liver antigen and liver specific protein (LSP): analysis by ELISA and immunoblotting.

The antibody reactivity to liver specific protein (LSP) and a crude liver antigen of sera from patients with chronic active hepatitis (CAH) were studied along with other related diseases and healthy individuals. CAH sera containing liver reacting antibodies were selected using an ELISA with a crude liver preparation as antigen and subsequently the specificity was analysed by immunoblotting of SDS-PAGE-separated LSP. The incidence of IgG antibodies to the crude liver antigen and LSP in sera from 15 patients with CAH was 94% and 55% respectively. In the healthy control group (n = 30) the corresponding figures were 3% and 17%. Sera from patients with other autoimmune conditions with considerable reactivity in the crude liver ELISA test were those with antibodies against extractable nuclear antigens (ENA) and thyroid gland antigens, while the anti-nuclear antibody (ANA) group as a whole did not differ from the control group. In immunoblotting of SDS-PAGE-separated crude liver and LSP antigens, the IgG binding pattern of ELISA IgG positive CAH sera and sera from patients with thyroid disease was distinct, with bands corresponding to antigens of molecular weights of 38, 45 and 50 kD which were not observed in ELISA negative CAH sera or in sera from patients with other diseases and among healthy controls.

IgG subclass distribution of autoantibodies against ribonucleoproteins.

The IgG subclass distribution of anti-RNP antibodies was determined in sera from 34 patients. The antibodies were mainly of the complement-fixing IgG1 subclass with minor contributions of IgG3 and IgG4 antibodies. Selected sera contained IgG2 (non-complement fixing) anti-RNP antibodies and may possibly identify a subgroup of patients.

In vitro lymphocyte reactivity to rubella antigen following vaccination.

In vitro lymphocyte stimulation and several serological tests were used to study the development of immunity after subcutaneous immunization with attenuated rubella virus. Maximal lymphocyte reactivity was obtained 3--4 months after vaccination and a decline after 1.5--2.5 years. Lymphocyte reactivity following natural immunity was of a higher magnitude. No correlation between the degree of lymphocyte stimulation and titers of neutralizing, hemagglutination inhibiting and hemolysis-in-gel antibodies was observed. The influence on the results of some methodological factors and different rubella antigens is discussed.