Lymphocyte abnormalities in ankylosing spondylitis

Ankylosing spondylitis: an autoimmune disease?

Identification of several autoantibodies in serum samples from patients with ankylosing spondylitis or suspected ankylosing spondylitis is reported. Five antibodies associated with ankylosing spondylitis were identified by applying cytoimmunofluorescence and immunoblotting techniques to antigen pools from insect tissue. At least one of these antibodies was found in 82% of serum samples from patients with ankylosing spondylitis. A 36 kD drosophila antigen, which showed the most common and most dominant reaction, was further purified and isolated. Thirty two (34%) of the serum samples from 95 patients with definite ankylosing spondylitis and 12 (28%) of the serum samples from 43 patients with suspected ankylosing spondylitis reacted with this antigen. Antibodies purified from the 36 kD antigen reacted specifically with a 69 kD antigen present in separations of total protein preparations from human lymphocytes and HeLa cells. The 36 kD antibody was not found in 29 patients with rheumatoid arthritis nor in 38 apparently healthy controls. The prevalence of the 36 kD antibody was comparable in HLA-B27 positive and negative patients. In addition, the same immunoreaction was found in patients with so called 'seronegative' spondylarthropathies, particularly of the ankylosing spondylitis-type, suggesting that this antibody is specific for ankylosing spondylitis or other 'seronegative' spondylarthropathies with the typical clinical and radiological changes of ankylosing spondylitis.

Polyclonal B cell activation in ankylosing spondylitis

The peripheral blood lymphocyte response of patients with ankylosing spondylitis (AS) to several polyclonal B cell activators was investigated. No differences were found in the reactivity to pokeweed mitogen and protein A between patients and controls; in contrast, the peripheral blood lymphocyte response to Staphylococcus aureus strain Cowan I (SAC) was significantly higher in patients with AS than in controls. This responsiveness was not influenced either by the presence of the HLA-B27 antigen or by environmental factors or associated diseases, and it was higher in patients with active AS than in those with inactive disease. The percentage of circulating B cells was normal. The responses to T cell mitogens and the percentages of T cell subpopulations were similar in patients and in controls. The peripheral blood lymphocyte hyperactivity of patients with AS to SAC was associated with an increased in vitro production of immunoglobulins.

Progressive ankylosis (ank/ank) in mice: an animal model of spondyloarthropathy. III. Proliferative spleen cell response to T cell mitogens

Murine progressive ankylosis is a spontaneous disorder of mice resulting from a homozygous recessive genetic defect (ank/ank) which produces an inflammatory arthritis of peripheral and axial joints eventually resulting in ankylosis of these joints. This disorder resembles the human spondyloarthropathies clinically, radiographically and histologically. Various studies in humans with spondyloarthropathies have described defects of cellular immunity but these results are conflicting. We measured the spleen cell response to mitogen in ank/ank mice and in normal littermates. The spleen cell response to the T cell mitogens phytohaemagglutinin and concanavalin A was decreased in ank/ank mice compared with their normal littermates. The response to the B cell mitogen lypopolysaccharide was normal in both ank/ank mice and normal littermates. Serum from ank/ank mice did not inhibit spleen cell responses to mitogen. Ank/ank spleen cells were not inhibitory of normal spleen cell responses to mitogens. Addition of irradiated normal spleen cells to ank/ank spleen cells did not restore the mitogen responses to normal. It is possible that the ank/ank gene results in the phenotypic expression of an abnormal or decreased cell product involved in T cell proliferation. Several recently described cytokines could be potential candidates for this product.

T lymphocytes in ankylosing spondylitis and the influence of sulphasalazine treatment

Twenty-nine patients with ankylosing spondylitis (AS) were studied in an attempt to evaluate the role of T lymphocytes in this disease and a possible influence of treatment. The proportions of various T cell subpopulations in blood were assessed with monoclonal antibodies. Before treatment the proportions of Leu-4+ cells and Leu 3a+ cells were decreased while Leu-2a+ lymphocytes appeared in normal proportions. Leu-7+ cells appeared in increased proportions. An increased proportion of Leu-M1 positive cells were identified in the lymphocyte preparation from the patients, possibly reflecting the presence of activated granulocytes. Activation of the different cell types was studied with double staining technique. No activated Leu-3a+ or Leu-2a+ lymphocytes were present in blood when the patients were analyzed as one group, but when divided into subgroups according to inflammatory activity, the highest levels of activated Leu-2a+ lymphocytes were found in the group with active disease. Functional assays measuring DNA synthesis of T and B cells were normal. After three months treatment with sulphasalazine the patients showed clinical and laboratory improvement. The proportion of activated Leu-2a+ cells decreased during treatment, but no other changes occurred in the lymphocyte markers or lymphocyte functional tests. A patient control group showed no clinical improvement nor any changes in T cell markers. Our results support the concept that AS is a disease which affects the lymphocyte system and that the improvement induced by sulphasalazine may involve actions on this system.

Antibody producing capacity to the bacteriophage phi X174 in yersinia arthritis

Antibody production in response to the primary immunogen bacteriophage phi X174 was investigated in 14 patients with previous yersinia arthritis (YA) and in 15 controls. HLA-B27 occurred in 10 patients with YA and in three controls. After primary and secondary immunisation the antibody responses were essentially similar both in patients with YA and controls. Consequently our results suggest that antibody response to a foreign antigen does not differ between patients with YA and a normal control population. In addition, there was no difference in peak antibody responses between individuals with HLA-B27 and those without HLA-B27.

Specific cell-mediated responses to bacterial antigens and clinical correlations in reactive arthritis, Reiter's syndrome and ankylosing spondylitis

In 2 cases of ReA seen during the acute phase and shown serologically to be due to Y. enterocolitica 0:3, the LT test showed a marked response using as antigen a freeze dried preparation of the causative organism. The test result correlated with the activity of the disease when repeated during a flare in the 1st case, and during remission in both. Patients with ReA/RS in general showed a significantly higher response to the yersinia and klebsiella antigens tested when compared to AS, suggesting an overall difference in cell-mediated immunity to these enteric bacteria. AS cases reacted significantly less than controls to K. pneumoniae under suboptimal conditions. K. pneumoniae was shown to enhance the LT response to yersinia, possibly through an adjuvant effect. This was found with AS, ReA and in controls, though whether it is of relevance in the etiopathogenesis of AS or ReA/RS remains far from clear. Acute non-traumatic synovitis of the knee, occurring de novo, or in association with psoriasis, inflammatory bowel disease, or as part of RS, may be accompanied by evidence of heightened reactivity to streptococci both by blood and synovial fluid mononuclear cells. In 1 case with serological evidence of streptococcal infection and erythema nodosum, these changes were found to parallel disease activity. ReA can, it appears, follow recent streptococcal infection, and be associated with B27.

Natural killer (NK) cell activity of peripheral blood lymphocytes from patients with Bechterew's syndrome (ankylosing spondylitis)

Sixteen patients with Bechterew's syndrome (ankylosing spondylitis, AS) were investigated. All except one of the patients were HLA B27-positive. Peripheral blood lymphocytes from the patients were examined for spontaneous cytotoxicity against 51Cr-labelled K562 target cells. The cytotoxicity index of the non-T lymphocytes was negatively correlated with the serum CRP concentration (Pearson's r = 0.613, p less than 0.02). This finding seems to be caused by an alteration of the natural killer (NK) cell activity of the non-T lymphocytes during the active phase of the disease and not due to serum factors. The activity of the non-T cell fraction was slightly but not significantly reduced in patients with high disease activity (CRP greater than 0.01 g/l) compared with normal controls, (14.6 +/- 2.8 g/l versus 20.4 +/- 2.4 g/l mean +/- SE; p less than 0.10) Serum IgG and IgA concentrations were increased (p less than 0.001 and p less than 0.05 respectively) Interferon caused normal augmentation in the NK cell activity in AS patients, and no correlation was found between serum gamma interferon titres and the NK cell activity.

Depressed lymphocyte transformation by yersinia and Escherichia coli in yersinia arthritis

Lymphocyte transformation responses were studied in 21 patients with acute yersinia infection followed-up after the acute infection for up to one year. Eight patients had reactive arthritis caused by yersinia. The responses to the causative serotype of yersinia were significantly lower (p less than 0.05) in patients with arthritis than in those without arthritis. Stimulation with Escherichia coli gave lower responses than with yersinia, but with E. coli the difference between arthritic and nonarthritic groups was more significant (p less than 0.02). The responses to yersinia and E. coli were not correlated with the presence of HLA B27. Lymphocyte transformation by purified protein derivative of tuberculin, streptokinase-streptodornase, phytohaemagglutinin, or concanavalin-A revealed no significant differences between the arthritic and nonarthritic groups. The role of the enterobacterial common antigen in the pathogenesis of reactive arthritis and ankylosing spondylitis is discussed.

Antibodies to and elevations of beta 2 microglobulin in the serum of ankylosing spondylitis patients

Antibodies to beta 2 microglobulin are found in systemic lupus erythematosus patients and are important in the lymphocytotoxic reactions of sera from such patients. In this study, beta 2 microglobulin antibodies were measured with the use of an enzyme-linked immunosorbent assay with purified beta 2 microglobulin antigen and peroxidase-labeled anti-human IgG or IgM. IgG antibodies to beta 2 microglobulin were found in 68% of 22 patients with ankylosing spondylitis. This incidence was higher than the 5% in 80 controls (P less than 0.01) and similar to the 71% incidence found in 35 patients with systemic lupus erythematosus. Eleven (27%) of 41 patients with rheumatoid arthritis had elevated levels of antibodies to beta 2 microglobulin (P less than 0.01). The mean antibody levels expressed in enzyme units were 0.125 for patients with ankylosing spondylitis, 0.157 for those with systemic lupus erythematosus, 0.101 for those with rheumatoid arthritis, and 0.067 for controls. IgM anti-beta 2 microglobulin was not significantly different from controls. A competitive binding assay with enzyme-labeled beta 2 microglobulin was used to determine serum beta 2 microglobulin. These values were also found to be elevated in 48% of patients in all 3 disease categories (P less than 0.01). Beta 2 microglobulin antibodies and serum beta 2 microglobulin did not correlate with each other, renal diseases or antinuclear antibodies in patients with systemic lupus erythematosus, with rheumatoid factor or severity of articular disease in patients with rheumatoid arthritis, or with peripheral arthritis or iritis in those with ankylosing spondylitis. Although antibodies to beta 2 microglobulin might reflect a general disturbance of immune regulation in patients with systemic lupus erythematosus, their presence in those with ankylosing spondylitis, a disease closely associated with a specific HLA allotype and not usually associated with formation of autoantibody, suggests that they might play a role in the pathogenesis of the latter disease.

Immunoregulatory T cells in the peripheral blood of patients with Bechterew's syndrome

Seventeen patients with ankylosing spondylitis (Bechterew's syndrome) were investigated. Only 3 of them had detectable autoantibodies, but the IgA and IgM concentrations in serum were increased (p less than 0.05). The patients had a moderate reduction in con-A-induced suppressor cell activity of peripheral blood lymphocytes as detected in con-A/MLC assay, compared with that of 15 controls (41.0 +/- 8.6% suppression compared with 59.4 +/- 5.2%, mean +/-SEM; 0.05 less than p less than 0.1 one-sided test). No differences were found in the percentages of T gamma cells (suppressor cells) and T mu cells (helper cells) between patients an controls. This is to our knowledge the first report of con-A-induced suppressor cell activity an T lymphocyte subpopulations in the peripheral blood of patients with ankylosing spondylitis.

Subpopulations of T lymphocytes in patients with ankylosing spondylitis

Subpopulations of human blood T lymphocytes were determined in 20 patients with ankylosing spondylitis and in 20 healthy individuals. The proportion of T lymphocytes with receptors for the Fc portion of IgG (TG cells) was increased in 9 patients. The proportion of T lymphocytes bearing receptors for the fc portion of IgM (TM cells) was within the range found in healthy controls in all but 4 patients, who had a decreased level of TM cells.

T and B lymphocytes in patients with acute anterior uveitis and ankylosing spondylitis, and in their household contacts

During episodes of acute anterior uveitis, patients had a T-lymphopenia and a temporary increase in B-lymphocytes. The T-lymphopenia was not present in patients investigated early in their first attacks, and it persisted after the patients recovered clinically. In household contacts of patients with uveitis, there was a temporary T-lymphopenia. A similar degree of T-lymphopenia was present in patients with ankylosing spondylitis who had not had uveitis, but not in their household contacts. In patients with spondylitis, there was no greater reduction of T-cells when they had episodes of uveitis. In all groups of subjects studied, T-lymphopenia could be abolished, in vitro, with thymosin, a bovine thymic-hormone estract. The finding of T-lymphocyte depletion in the contacts of uveitis patients, as well as in the patients themselves, suggests that there may be lateral transmission of an infective agent (or agents) in the households during (or before) attacks of uveitis.

Sequential studies in ankylosing spondylitis. Association of Klebsiella pneumoniae with active disease

A study of 163 patients with ankylosing spondylitis seen on 433 occasions showed that active inflammatory disease was strongly associated with the presence of Klebsiella pneumoniae in the faeces (P less than 0.001). Sequential studies showed that in patients with inactive disease the presence of a positive culture for Klebsiella was associated with the subsequent development of active inflammatory disease (P less than 0.001). These findings support the hypothesis that Kl. pneumoniae may be an initiating agent in ankylosing spondylitis.