Evaluation of clinical and prognostic significance of T cell regulatory subsets in rheumatoid arthritis

Phenotypic analysis of circulating lymphocytes and T cell subsets using monoclonal antibodies was performed on 60 patients with rheumatoid arthritis (RA). A significant lymphopenia was observed in RA patients and correlated with the use of disease suppressant drugs (p less than 0.0001). A significant decrease in the number of suppressor/cytotoxic T cells resulted in an increase in the TH/TS ratio in 40% of RA patients. This elevated ratio did not correlate with disease activity, the presence of extraarticular features, autoantibody production or immune complex formation. We conclude that the evaluation of the TH/TS ratio has no diagnostic or prognostic value.

Determination of circulating immune complexes, C3 and C4 complement components and anti-DNA antibody in different classes of lupus nephritis

Circulating immune complexes (CIC) were measured in 237 sera from children who underwent a renal biopsy during the course of systemic lupus erythematosus. CIC-positive sera contained a lower mean level of C3 but not C4. Anti-DNA antibody was similar in CIC-positive and negative sera. The World Health Organization classification of lupus nephritis was used to categorize the biopsies. CIC, C3, C4 and anti-DNA antibody were determined to assess whether they correlated with the severity of renal lesions. Of 25 sera obtained at renal biopsy from patients with classes 2, 3 and 4, 16 were positive for CIC. C3 was significantly lower in classes 3 and 4 than in class 2. C4 was reduced and anti-DNA antibody was present in classes 2, 3 and 4. Determination of the level of C3 but not C4, CIC or anti-DNA antibody correlates with the severity of lupus nephritis seen on renal biopsies. Nevertheless, performance of a renal biopsy is preferred.

Characteristics of a benign subtype of dense deposit disease: comparison with the progressive form of this disease

Pathologic, clinical and serum complement studies were performed on 18 patients with dense deposit disease (DDD). The patients were divided into 3 groups: group A (10 patients who developed end-stage renal failure within 2.9 +/- 1.0 years of onset) group B (3 patients who developed elevated serum creatinines within 6.8 +/- 4.8 years of onset) and group C (5 patients with no evidence of renal insufficiency after 11.0 +/- 1.4 years of follow-up). Renal biopsies from all patients showed intramembranous, electron-dense deposits in glomerular capillary basement membranes. Most group A and B patients presented with a nephritic and/or nephrotic syndrome and followed an active clinical course. In contrast, group C patients presented with either a nephrotic syndrome or asymptomatic proteinuria +/- hematuria and followed a benign course. Sera from group A and B patients contained reduced concentrations of C3 and factor B and large amounts of C3 nephritic factor (NeF) activity. In contrast, serum of group C patients contained normal amounts of C3 and factor B and low levels of C3 NeF activity. These studies show that some patients with DDD (group C) have a benign illness and that they can be identified by serum levels of C3, factor B and C3 NeF activity.

Circulating immune complexes in patients with progressive systemic sclerosis

Forty-one patients with progressive systemic sclerosis were studied for the presence of immune complexes by the fluid- and solid-phase C1q binding, C1 activation, and the fluid-phase conglutinin assays. Complement activation and autoantibodies were also studied. Immune complexes were detected in only 6 patients (15%); activation of complement was found in 5 others. The clinical and serologic features of patients with complexes were compared with those in whom complexes were not identified. No significant difference was found with respect to serology. Organ involvement was generally more frequent in the group with immune complexes, but the difference was statistically significant only with respect to lung involvement. The present data suggest that, although complement-fixing immune complexes are infrequently detected in progressive systemic sclerosis, they may play a role in the pathogenesis of lung lesions associated with the disease.