Granulocyte-specific antinuclear factors in serum and synovial fluid in rheumatoid arthritis

Antinuclear antibodies in ankylosing spondylitis, psoriatic arthritis, and psoriasis

Granulocyte-specific antinuclear antibodies (GS-ANA) were detected in the sera of 5 of 88 patients with ankylosing spondylitis (AS) and in 7 of 52 cases of psoriatic arthritis (PsA), but were not found in 91 patients with malignant or non-malignant chest disease nor in 25 cases of psoriasis. Organ non-specific ANA were present in serum from 6 cases of AS and 1 of PsA. None of the sera gave significant levels for soluble immune complexes as detected by a C1q-binding assay. The presence of antinuclear antibodies was not associated with clinical features or drug therapy in either AS or PsA.

Human granulocyte specific nuclear antigen(s). I: Production of antisera and determination of specificity

Non-histone protein-DNA complexes isolated from human lung tissue were used to immunize New Zealand rabbits. Quantitative microcomplement fixation and immunocytochemistry revealed a specific chromatin antigen(s) in the human granulocyte nucleus. The study demonstrates the feasibility of employing antisera against chromosomal non-histone protein-DNA complexes for the immunochemical identification of cell types.

The inflammatory role of immune complexes trapped in joint collagenous tissues

The inflammatory role of immune complexes trapped in joint collagenous tissues has been investigated. Joint collagenous tissues obtained from rabbits with antigen-induced arthritis generated mediators of acute inflammation when incubated with fresh normal rabbit serum as a source of complement. The role of trapped immune complexes in chronic inflammation was also studied by the surgical insertion of menisci, obtained from arthritic and control joints, into the suprapatellar pouches of previously immunized or naive recipient animals. It was shown that when immune complex containing menisci were inserted into immune rabbits, a chronic inflammatory capsule developed around the donor tissue, reminiscent of the inflammatory pannus seen in rheumatoid cartilage. Normal menisci and immune complex containing menisci inserted in naive animals developed capsules rich in fibroplasts and collagen fibres. Since we have previously shown the presence of immune complexes in the great majority of joint collagenous tissues obtained from patients with rheumatoid arthritis, our results suggest that these complexes may play a role in the formation of pannus, which constitutes a major mechanism responsible for cartilage destruction.

Recent progress in the study of autoantibodies to nuclear antigens

Autoantibodies to nuclear antigens can now be classified according to their immunologic specificities. They include antibodies that react with DNA, deoxyribonucleoprotein, nuclear histones, and nuclear acidic protein antigens. It has been established that there are several antinuclear antibodies that react with nuclear acidic proteins, and these include antibodies to Sm antigen, nuclear ribonucleoprotein, and SS-A and SS-B antigens. It has also been established that certain systemic rheumatic diseases, such as systemic lupus erythematosus, Sjögren's syndrome, and scleroderma, are characterized by antibodies of some specificities and not of others. Thus, distinct profiles of antibodies to nuclear antigens may be present, and these may be used as diagnostic aids. Further characterization of these specific nuclear antigen-antibody systems may help in unraveling the etiology and pathogenetic mechanims of these diseases.

Substrate specificity of antinuclear antibodies in scleroderma

Studies of antinuclear antibodies (ANA) were carried out in 39 cases of systemic scleroderma and for comparison in 19 cases of systemic lupus erythematosus (SLE) and 4 of mixed connective tissue disease (MCTD) using indirect immunofluorescence (IF) methods under standard conditions. The results on three different substrates--monkey esophagus, guineapig lip and rat liver--are reported. In 48.7% of scleroderma cases ANA showed a substrate specificity. The highest percentage of positive results in scleroderma was obtained on monkey esophagus (97.4%) and the lowest on rat liver (61.5%). In SLE and MCTD, in contrast, only about 13% of the sera displayed such specificity. If only sera with substrate specificity are considered, the positive results on monkey esophagus and rat liver are 94.7% and 21.1%, respectively. Titers of sera reacting positively on 2 or 3 substrates were mostly in agreement, although some sera both in systemic scleroderma and SLE showed higher titers on monkey esophagus. The IF pattern was usually the same regardless of the substrate, Tests for ANA in scleroderma should be performed on at least 2 substrates simultaneously.

Eosinophil-specific and other granulocyte-specific antinuclear antibodies in juvenile chronic polyarthritis and adult rheumatoid arthritis

Sera from 151 children of whom 112 had juvenile chronic polyarthritis (JCP), and from adults with rheumatoid arthritis (RA), and from healthy pregnant females were tested for the presence of granulocyte-specific antinuclear antibodies (GS-ANA). These were detected in 20% of sera from cases of JCP, in 68% of adult RA, but in none of the controls. Eosinophil-specific ANA were the only ANA present in 18% of positive children and 54% of the positive adults. GS-ANA in children were predominantly IgG and of low titre. Heat-stable GS-ANA were detected in sera from eight children but none bound complement. The presence of GS-ANA was not significantly associated with sex, age of onset, duration of disease, mean active joint count, mean ESR, nor with the presence of fever, rash, splenomegaly, amyloidosis, pericarditis, or rheumatoid factor.

Complement-fixing ability of antinuclear factors. Studies in adult and juvenile rheumatoid arthritis and systemic lupus erythematosus

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Antinuclear factors and chronic articular inflammation

Antinuclear antibodies were looked for in the leucocytes from synovial effusions of subjects with inflammatory arthritis. Antinuclear antibodies were found concentrated in the lysates of synovial fluid leucocytes from five of seven effusions of adults with rheumatoid arthritis, and in low titres from a patient with Reiter's syndrome. In three subjects the antinuclear antibody was detected in cell lysates when it was not demonstrable in the corresponding synovial fluid. These findings are interpreted as evidence that antinuclear antibodies play a role in articular inflammation.