Complexed autoantibodies in patients with juvenile connective tissue diseases, isolated by rate-zonal ultracentrifugation.

Selected sera from one patient with systemic lupus erythematosus, two with mixed connective tissue disease, one with dermatomyositis, one with progressive systemic sclerosis and one with juvenile rheumatoid arthritis were investigated for autoantibodies after fractionation by computerized rate-zonal ultracentrifugation. Anti-Smith antibodies sedimented in an area from 6-11 S and anti-ribonucleoprotein from 6-13 S. IgG anti-IgG and IgG antinuclear antibodies (ANA) were present in free or complexed form in the 6-13 S area. IgM ANA occurred as 7 S IgM in patients with systemic lupus erythematosus and mixed connective tissue disease, whereas IgM ANA sedimented in the 19 S area in patients with dermatomyositis and progressive systemic sclerosis. Complexes containing IgG anti-IgG and ANA, positioned in the 6-13 S area are likely to play a significant role in the pathogenesis of systemic lupus erythematosus and mixed connective tissue disease.

Immunoglobulins, anti-IgG antibodies and antinuclear antibodies in paired serum and synovial fluid samples. A comparison between juvenile and adult rheumatoid arthritis.

Paired samples of serum and synovial fluid (SF) from 13 patients with juvenile rheumatoid arthritis (JRA) and 10 patients with adult rheumatoid arthritis (RA) were examined regarding the level of immunoglobulins and the occurrence and titres of anti-IgG antibodies and antinuclear antibodies (ANA). The levels of immunoglobulins were lower in SF than in serum. In JRA the SF/serum ratio of IgG was equal to that of albumin, pointing to a local production of IgG. The SF/serum ratio of IgM was equal to that of alpha 2-macroglobulin. In JRA the SF/serum ratios of immunoglobulins tended to be lower than in RA, the difference being significant for IgM. IgD autoantibodies and IgA anti-IgG were not found in JRA. IgE autoantibodies occurred in some cases, but in RA in more than 60%. In JRA the SF titres of anti-IgG and ANA were most often lower than the serum titres. In RA the SF titres were often higher than the serum titres. In 9 of 10 paired SF samples from patients with RA the SF/serum ratios were mutually different with regard to one or several immunoglobulins. Evidence of synovial production of anti-IgG antibodies of classes other than IgG distinguished RA from JRA. Otherwise the differences were quantitative.

IgE anti-IgG antibodies in patients with juvenile and adult rheumatoid arthritis including Felty's syndrome.

Anti-IgG antibodies (anti-IgG) of the IgE class were studied in sera from patients with juvenile rheumatoid arthritis (JRA), rheumatoid arthritis (RA) and patients with Felty's syndrome (FS) by use of an indirect immunofluorescence technique. Forty-two per cent of 26 patients with JRA had IgE anti-IgG in serum all in low titers. Positive reactions prevailed in patients with multiple joint involvement. Sixty-three per cent of 30 patients with RA and 80% of 20 patients with FS had IgE anti-IgG, the titers found in FS patients being significantly higher. In JRA and FS patients the IgE anti-IgG titers were correlated to the titers of anti-IgG of the IgG class, and for FS patients also with the IgM and IgA classes of anti-IgG. In six of 10 patients with RA the synovial fluid samples from both knees contained IgE anti-IgG. In four of these patients the titers of IgE anti-IgG were higher than in the corresponding serum sample, pointing to a local production. After G-200 Sephadex chromatography IgE anti-IgG were demonstrated in the void volume indicating the presence of these autoantibodies in immune complexes. IgE anti-IgG may be involved in the pathogenesis of JRA and RA by eliciting Type I and III reactions.

The significance of antinuclear antibodies in juvenile rheumatoid arthritis associated with chronic bilateral iridocyclitis.

Serum samples from 8 children with juvenile rheumatoid arthritis (JRA) and chronic bilateral iridocyclitis were significantly distinguished from 5 children with JRA and no eye symptoms by the presence of large immune complexes (IC) greater than 22S, IgM antinuclear antibodies (ANA), IgG granulocyte-specific (GS-) ANA, C3 fixing ANA, and IgM anti-IgG. One serum with and two sera without IC greater than 22S, all from patients with iridocyclitis, were fractionated by rate zonal ultracentrifugation. Each fraction relevant for the study was separately concentrated and reexamined. In one of the sera without IC greater than 22S this technique exposed the presence of IgA GS-ANA not detectable in the corresponding whole serum. IgG ANA were precipitated in an area with higher molecular weight than the one for IgG indicating the presence of aggregated IgG ANA. Fractionation of the serum with IC greater than 22S demonstrated IgM GS-ANA not present in whole serum. The results support previous suggestions that ANA may be involved in the pathogenesis of chronic iridocyclitis and may explain why ANA (in particular C3 fixing ANA) negative patients with JRA rarely develop chronic iridocyclitis.

Anti-IgG antibodies during immunotherapy with purified grass pollen extracts.

In a double blind study 40 patients were allocated specific immunotherapy (hyposensitization) with partially purified timothy extract or two timothy major allergens 19, 25. All patients had typical grass pollen hay fever, in 27% associated with grass pollen asthma and in 13% with birch pollen allergy. Serum IgG anti-IgG antibodies were determined after dithiothreitol treatment. Before hyposensitization, IgG anti-IgG titres greater than or equal to 9 were demonstrated in 45% of the patients. During hyposensitization IgG anti-IgG titres showed a slight initial increase followed by a decrease below pretreatment level. Neither increase nor decrease was statistically significant. Reactions to rabbit IgG F(ab')2 fractions were only obtained during hyposensitization. The occurrence of anti-IgG antibodies did no correlate with symptoms, side effects, or the level of allergen-specific IgG. In a previous study it was demonstrated that patients with multiallergy hyposensitized with combined allergen extracts showed a statistically significant increase in IgG anti-IgG titres during treatment. The increase failed to appear in the present patients allergic only to pollen and treated with purified allergen extracts. It is therefore suggested that a multiallergic condition and the combination and/or purification of allergen extracts administered during hyposensitization may influence the production of IgG anti- IgG antibodies.

Anti-IgG antibodies and antinuclear antibodies in allergic patients.

With an indirect immunofluorescence technique 77% of 96 patients with type I allergy and 40% of 20 patients with intrinsic bronchial asthma showed positive reactions for IgG anti-IgG antibodies in serum. They were present partly in an aggregated state not directly detectable before treatment with dithiothreitol. The aggregates could be removed by precipitation with polyethylene glycol. The IgG anti-IgG in hyposensitized patients were directed against both F(ab')2 and Fc fragments of rabbit IgG. Thirty of the type I allergic patients were examined once during hyposensitization as well. Before treatment 87% had IgG anti-IgG (titres 9-72). After greater than or equal to 13 months of treatment 100% were positive (titres 36-288). Eight patients were also examined after hyposensitization had been discontinued for at least 12 months. The titres of IgG anti-IgG had then reverted to the levels obtained before hyposensitization. Of 116 controls matched for sex and age, 7% had IgG anti-IgG antibodies. It is suggested that the production of IgG anti-IgG may be stimulated by the presence of immune complexes and that purity, amount and/or combination of allergens administered during hyposensitization may influence the production of anti-IgG antibodies. Neither IgE anti-IgG nor antinuclear antibodies seem to be of particular significance in allergic patients.

Anti-IgG antibodies in juvenile rheumatoid arthritis.

Sixty-two patients, 48 children and 14 adults, with juvenile rheumatoid arthritis (JRA) and 62 age and sex matched controls were studied for anti-IgG antibodies of the classes IgG, IgM and IgA by an indirect immunofluorescence method. IgG anti-IgG occurred in 88% of 48 children less than or equal to 16 years and in 64% of 14 patients greater than 16 years with JRA against 2% of the controls. IgM anti-IgG occurred in 4% of the children, in 24% of the adults and in 2% of the controls. IgA anti-IgG occurred in 2% of the patients and in none of the controls. The prevalence of IgG anti-IgG was the same in pauciarticular, polyarticular and systemic cases, whereas the titres were higher in polyarticular than in pauciarticular cases, and higher in children with a disease duration of more than 5 years. Higher titres were related to higher ESR and lower hemoglobin values. The relationship of higher titres to clinically active disease was not statistically significant. No relationship was found to age, sex, age at onset, or to the duration of disease. The titres were not related to the concentrations of serum IgG or to the titres of antinuclear antibodies. IgG anti-IgG are common to all the clinical types of JRA, whereas antinuclear antibodies separate the systemic type from pauci- and polyarthritis. Their possible pathogenic significance must therefore be different.

Autoantibodies in serum and sputum from patients with cystic fibrosis.

Sera from 89 patients with cystic fibrosis (CF) and 88 control persons were examined for the occurrence of rheumatoid factors (RF) of the IgG, IgA and IgM classes by an indirect immunofluorescence method and by the latex fixation slide test. The prevalence of RF-IgG was significantly higher (88%) (p less than 0.0005) among the CF patients than among the control persons (7%), while no difference was found between the two groups with regard to RF of the IgA or IgM classes. Fifty-five of the CF patients had chronic Pseudomonas aeruginosa infection in their lungs and two or more precipitins against these bacteria in their sera determined by crossed immunoelectrophoresis. These CF patients did not differ from the 34 CF patients without chronic P. aeruginosa infection, neither with regard to prevalence nor titer of RFs, but there was a positive correlation between the number of P. aeruginosa precipitins in the 55 chronically infected CF patients and their titers of IgG-RF. Nineteen CF patients were examined also for RFs, antinuclear antibodies (ANA) and anti-DNA antibodies in their sputum sol phase and corresponding sera. RFs were demonstrated in the sputum sol phase from 6 of the patients by the latex fixation test, whereas their sera were negative in this test, possibly indicating a local production of RF. Positive reactions for ANA and anti-DNA antibodies were found in 7 and 10 of the sputa respectively, and in higher titers than in the corresponding sera, also suggesting a local production. Titers of autoantibodies in sputum were low and no difference was found between patients with chronic P. aeruginosa infection and patients without P. aeruginosa infection. The possible role of autoantibodies in the patogenesis of pulmonary tissue damage in CF patients is discussed.

IgG-, IgM- and IgA-rheumatoid factors in healthy adults and rheumatoid patients determined by an indirect immunofluorescence method.

Sera from 173 healthy adults and 55 rheumatoid patients were studied for IgG-, IgM- and IgA-rheumatoid factors (RFs) by a modification of Este's indirect immunofluorescence method. Rabbit IgG bound to smeared sheep red cells was used as antigen. With each serum tested a smear on non-sensitized cells was used as control antigen. Anti-IgG of the sera studied, binding to the antigen, was demonstrated by fluorescein-conjugated antisera, monospecific for gamma, mu and alpha chains, and not containing antibodies to sheep erythrocytes or rabbit IgG. Positive reactions were obtained with IgG as antigen, but not with the F(ab')2 fragment. The sera tested were treated with dithiothreitol before they were assayed for IgG-RF, in order to abolish false-positive reactions due to IgM-RF activity. The detection limit for IgM-RF was 1 IU per ml. IgM-RF titres of 9 occurred in 7% of healthy adults and 73% of rheumatoid patients, titres greater than or equal to 18 in 3.5% and 67% respectively. IgG-RF titres of 9 occurred in 9% of healthy adults, 21% of seronegative and 24% of seropositive rheumatoid patients. Titres of 18 occurred in 3% of healthy adults and in 14% of seronegative rheumatoid patients. Titres of greater than or equal to 18 occurred in 22% of seropositive rheumatoid patients. IgG-RF was correlated with an involvement of more than 20 joints. IgA-RF was found in 83% of seropositive, 11% of seronegative rheumatoid patients and in none of the healthy adults (serum dilution 1:9).