Predominance of IgG1 subclass of anti-Ro/SSA, but not anti-La/SSB antibodies in primary Sjögren's syndrome.

We have developed isotype-specific enzyme-linked immunosorbent assays to assess anti-Ro/SSA and anti-La/SSB IgG subclasses in 31 patients with primary Sjögren's syndrome. The anti-Ro/SSA antibody production was largely but not totally restricted to IgG1, whilst the anti-La/SSB subclass distribution varied from one patient to another. IgG2 and IgG3 anti-La/SSB was more frequent in those patients with extraglandular manifestations. In addition, there were more increases in the IgG2 and IgG4 contribution to anti-La/SSB activity in the 16 DR3-positive patients than in the remaining 10.

Asialylated IgG in the serum and synovial fluid of patients with rheumatoid arthritis.

A novel enzyme linked immunosorbent assay has been developed that detects an asialylation change in the IgG molecules from patients with rheumatoid arthritis (RA) by the binding of biotinylated RCA 1 (ricin) to capture IgG. Elevated levels of asialylated IgG were detected in paired serum and synovial fluids (SF) of patients with RA. When compared with healthy controls, particularly in the SF (p less than 0.05) correlations of the asialylation change were found in paired samples (p less than 0.01) and between asialylated IgG and rheumatoid factors (p less than 0.01), C-reactive protein (p less than 0.02) and the Lee and Ritchie indices p less than 0.02 and 0.05, respectively. We found the proportion of asialylated IgG was higher in DR4 positive patients, indicating a possible association of these individuals to a sialyl transferase abnormality.

Tiopronine-induced reduction of rheumatoid factor functional affinity and asialylated IgG in patients with rheumatoid arthritis.

Serum and synovial fluid (SF) from 16 rheumatoid arthritis patients were evaluated before and after a 2-month treatment with tiopronine (TP). The levels of rheumatoid factor (RF) declined, as did the functional affinity of the remaining RF (p less than 0.01 in serum and p less than 0.05 in SF). Concomitant restoration of the sialylation of IgG was observed (p less than 0.05 in serum and SF). Following an initial increase, a significant reduction was observed in the level of soluble interleukin-2 receptors in serum (p less than 0.05) and SF (p less than 0.05) after treatment with TP.

Galactose terminating oligosaccharides of IgG in patients with primary Sjögren's syndrome.

Using a simple but novel ELISA, we have screened 40 serum samples from patients with primary Sjögren's syndrome and 34 normal controls for IgG glycosylation deficiencies, identified by their specific ricin binding. Elevated levels of asialylated IgG were detected in 24 patients. The extent of asialylation was significantly higher in the patients with extraglandular manifestations than in the others. Interestingly, the correlation of asialylated IgG was apparent only with Raynaud's phenomenon and arthritis, and not other extraglandular manifestations. Strong correlations (P less than 0.01) were noted between asialylated IgG and rheumatoid factor or IgA-containing immune complexes.

Nonorgan-specific autoantibodies in individuals infected with type 1 human immunodeficiency virus.

Fifty-six human immunodeficiency virus-1-positive asymptomatic carriers were tested for the presence of a variety of nonorgan-specific autoantibodies. Antinuclear antibodies were detected in 34 sera, of which 27 were directed to the mitotic spindle apparatus and all were of the IgG isotype. Anti-Golgi complex, anti-centriole, and anti-vimentin antibodies were also present in 20.4, and 4 sera, respectively. Ten patients had less than 500 CD4-carrying T lymphocytes per cubic millimeter. Nine of them had more than one autoantibody. No correlation could be demonstrated between the number of autoantibodies and the level of serum immunoglobulins.

[Decrease of the functional affinity of rheumatoid factors under the effect of tiopronin]. / Réduction de l'affinité fonctionnelle des facteurs rhumatoïdes sous l'effet de la tiopronine.

Sixteen rheumatoid arthritis patients were serologically examined, before and after a 2-month treatment with tiopronine (TP). The titer of agglutinating rheumatoid factor (RF) as well as the level of non-agglutinating RF were significantly reduced in serum and synovial fluid (SF). The functional affinity of the remaining RF was attenuated in serum (p less than 0.01) and SF (p less than 0.05). Conversely, the proportion of asialylated IgG was enhanced in serum (p less than 0.05) and SF (p less than 0.05). These findings would suggest that TP might restore the efficacity of sialyl transferase at the B lymphocyte level.

Lowered Fc IgG receptor-bearing T lymphocytes correlate with non-organ-specific autoantibodies in silicosis.

A survey of silicosis patients and people exposed to silica dust was set up in an effort to look for any relationship between humoral and cell-mediated autoimmune phenomena. It was found that in both sets of subjects, the level of Fc IgG receptor-bearing T lymphocytes was significantly reduced, there was also an inverse correlation between these cell concentrations and IgG- and IgM-circulating immune complex levels. In addition, raised levels of various autoantibodies were found in both groups, however, none of the exposed subjects has developed silicosis to date.

Evidence for relationships between antiperinuclear and IgG rheumatoid factor.

Antiperinuclear factor (APF) and IgG-rheumatoid factor (IgG-RF) has been found in 64% and 48% of cases of rheumatoid arthritis, 36% and 50% of cases of psoriasis and 31% and 45% of cases of primary Sjögren's syndrome. A close relationship between APF and IgG-RF is suggested by statistical and experimental data. Purified IgG-RF has some degree of APF activity.

The use of C3d as a means of monitoring clinical activity in systemic lupus erythematosus and rheumatoid arthritis.

Plasma samples from 44 patients with systemic lupus erythematosus (SLE) and 43 with rheumatoid arthritis (RA) were assayed for C3d, a breakdown product of the third component of complement (C3), which was also measured in parallel. Levels of C3d varied in direct proportion with disease activity in RA, whereas C3 showed little change. Although C3d values also increased with worsening clinical condition in SLE, this trend was not considered to be sufficiently clear to be useful and did not provide any advantage over the routinely performed C3 assay.