Genetic control of antinuclear antibodies in mice inoculated with the moloney leukaemia virus.

The production of antinuclear antibodies (ANA) was studied after inoculation with Moloney leukaemia virus (M-MuLV) in different H-2 congenic strains of mice. Using a new sensitive method for ANA detection, it was demonstrated that M-MuLV-induced ANA were genetically controlled by several different factors. A high viral production was first required for ANA triggering. Among viremic animals both high and low ANA producers were observed. H-2 and non H-2-linked genes were involved in the control of M-MuLV-induced ANA; these genes were different from those involved in the control of viremia. The H2b haplotype was associated with an increased ANA response, the transmission of the responder phenotype being intermediate. Non-H-2-linked genes must also control M-MuLV-induced ANA, as demonstrated in mice having the same H-2 haplotypes, since with equivalent viremias they produced different amounts of ANA. No linkage with X chromosome was found.

Isoprinosine delays the early appearance of autoimmunity in NZB/NZW F1 mice treated with interferon.

NZB/NZW F1 hybrid mice treated for long periods with type beta interferon developed early symptoms of autoimmune disease. In these animals the level of anti-dsDNA antibody begins to increase at 4-6 months while untreated NZB/NZW mice do not display similar levels until 12 months. The concomitant administration of isoprinosine and interferon delays the early appearance of autoimmune disorders. In interferon-treated NZB/NZW mice the cytotoxic activity of natural killer lymphocytes is maintained at high levels until the age of 5 months. Nevertheless, the natural killer activity is even stronger and detected until at least 7 months in NZB/NZW mice receiving a single dose of interferon 16 hr prior to the test. Lymphoblastoid ascitic tumours appeared early (2-3 months) during interferon treatment in all groups of NZB/NZW mice. However, in the presence of isoprinosine only a few animals developed tumours. Thus, isoprinosine seems to protect NZB/NZW mice both from early autoimmune disorders due to interferon and from early tumour development.

Hidden anti-nuclear antibodies in rheumatic diseases.

Hidden anti-nuclear antibodies are demonstrated by immunofluorescence using smears of rat nuclei as substrate and rat liver section technique when sera are incubated with penicillamine. The non-detection of hidden anti-nuclear antibodies by tissue sections in the absence of a splitting agent may be due to the formation of high molecular weight complexes between rheumatoid factors and anti-nuclear antibodies. These high molecular weight complexes containing anti-nuclear antibodies do not have access to tissue nuclear antigens, but can react directly with free nuclei. It is postulated that anti-nuclear antibodies may represent the early pathway of both rheumatoid arthritis and connective tissue diseases. The demonstration of hidden anti-nuclear antibodies in seropositive sera indicates that rheumatoid factors may have a protective effect. It may explain dissimilarities observed in the clinico-immunological profile of rheumatoid arthritis and systemic lupus erythematosus. The splitting effect of penicillamine observed in vitro may be similar in vivo. It can explain clinical improvement and immunological side effects observed in rheumatoid arthritis patients treated with this drug.

[Interactions between rheumatoid factors and antinuclear autoantibodies: their occurrence in a concealed state in rheumatoid disease (arthritis); effect of D-penicillamine]. / Interactions entre des facteurs rhumatoïdes et des autó-anticorps antinucléaires: fréquence de ceux-ci à l'état masqué au cours de la maladie (arthrite) rhumatoïde; action de la D-Pénicillamine.

In this paper it is demonstrated that IgM rheumatoid factor (RF) can inhibit the detection of antinuclear antibodies (ANA) by the classical rat liver cryostat section method. This "inhibition" of IgG-ANA by IgM-RF may be due to the formation of high molecular weight complexes. It would be the same in vivo. This masking effect can explain interesting similarities and dissimilarities observed in the clinico-immunological profiles of rheumatoid arthritis and systemic lupus erythematosus. D-Penicillamine can restore ANA activity by dissociating ANA-RF complexes. A new technique is described for the detection of these masked ANA.

Interactions between IgM antiglobulins and IgG antinuclear antibodies. Some aspects of D-penicillamine activities.

In this report we describe an in vitro masking action of IgM rheumatoid factor (IgM-RF) towards IgG antinuclear antibodies (IgG-ANA) which can be recovered by using D-penicillamine (DP) as an unmasking agent. The mechanism of this masking effect was elucidated by using smears of rat free nucleus as substrate, instead of the classical rat liver cryostat sections technique. It was postulated that the 'inhibition' of IgG-ANA by IgM-RF may be due to the formation of high molecular weight complexes (HMWC); this would be the same in vivo. Allowing the formation of HMWC which can be removed from the circulation, IgM-RF may have a protective effect by preventing or minimizing systemic lesions. Therefore, IgM-RF may be considered as a defence response against potentially noxious ANA or antigen-antibody complexes. Induced nephropathy and the high frequency of detection of ANA observed in rheumatoid arthritis (RA) patients treated by DP may be the result of the dissociating effect of this drug on HMWC, in which the activity of pre-existing ANA is hidden when rat liver sections are used for its detection.

[Lymphocyte subpopulations in adjuvant arthritis of rats. Effects of corticoids and gamma irradiation]. / Etude des sous-populations de lymphocytes dans la polyarthrite à adjuvant de rat. Effet des corticoïdes et del l'irradiation gamma.

Experimental model of human chronic inflammatory arthritis, adjuvant arthritis may be induced only in several strains of inbred Rats: it is well developed in LEW and practically absent in WAG. After adjuvant injection, the PHA-stimulable lymphocytes subpopulation quite disappears from the blood, if polyarthritis is well developed. These cells are probably capted in the tissues implicated in immunological conflict. On the contrary, the ConA-stimulable subpopulation is enhanced in both strains after adjuvant injection, earlier and more intense in WAG than in LEW and that phenomenon is probably linked to a stimulation of suppressor T lymphocytes. Treatment with prednisone or gamma rays inhibits partially and delays the appearance of arthritis in LEW, acting essentially on ConA-stimulable subpopulation.

Swan mice: autoimmune mice without xenotropic type C virus production.

Swan mice are characterized by various autoimmune disorders and the Swan disease resembles that of (NZB X NZW)F1 hybrids. A virological study of these animals shows that: (a) they do not produce xenotropic type C viruses at a detectable level; (b) old Swan mice can produce ecotropic type C virus but at a low level; and (c) this virus production and the appearance of antinuclear antibodies are dissociated in some mice. These results do not support the role of xenotropic type C viruses in murine autoimmune pathology. A possible role of ecotropic type C viruses cannot be definitely excluded, but appears unlikely.

A new experimental model of systemic connective tissue disease in immunized rabbit.

In rabbit, the immumizations with whole Mycobacterium Tuberculosis injected intradermally and its crude cytoplasmic W.S.E. injected intraarticulary induce not only a self-perpetuating synovitis in the stimulated knee but also chronic systemic lesions of connective tissue (non-stimulated knee, both shoulders, aortic artery adventitial valvular endocardium, liver, kidneys and lungs). W.S.E. stimulates precipitating antibody synthesis, skin reaction and lymphoblastic transformation of lymphocytes in vitro. Furthermore, rabbits develop tuberculin skin test and lymphocytic response to P.P.D. The intensity of inflammation in stimulated knee is in direct ratio to intensities of humoral and cellular immunological responses. On the contrary, the incidence of systemic lesions is in inverse ratio to immune responses and intensity of inflammation in stimulated knee.

The failure of long term effect of cyclophosphamide on systemic immunologic connective tissue disease in rabbit.

Cyclophosphamide is given intravenously in the high dose of 12 mg/kg/day during 2 months from the beginning of immunological systemic connective tissue disease in rabbits, according to the modified Glynn's model. The effects of this alkylating drug are studied after the termination of treatment. At short term (15 days), cyclophosphamide depresses the inflammation of synovia in stimulated and non-stimulated joints, the humoral and cellular immunities, but the drug does not modify the other systemic lesions. At long term (between 1 and 6 months), these effects of cyclophosphamide disappear completely.

Immunofluorescence of synovial membrane multifactorial analysis of the results.

Synovial membrane taken by needle biopsy from the knee joint of 61 patients with various rheumatic diseases were studied using immunofluorescence methods. Staining techniques and their controls were detailed. Classical statistical tests and principal components multifactorial analysis of the data emphasized some differences between the pathological groups. Connective tissue diseases seemed to be characterized by plasma cells fluorescence and mixed immunoglobulins and complement deposits. These were mostly localized to extracellular spaces in sero-positive rheumatoid arthritis and to blood vessels in sero-negative rheumatoid arthritis and systemic lupus erythematosus. On the contrary, isolated immunoglobulins without complement were mostly found in the other inflammatory arthritis, while negative results were obtained in non inflammatory arthropathy. Immunoglobulin classes did not seem to have any diagnostic value. On the contrary, rheumatoid factor was specific for rheumatoid arthritis, whatever the serological pattern was, and it was particularly frequent in patients suffering from rheumatoid arthritis associated with a Sj5AOGREN SYNDROME. A strict relationship between classical histological findings and immunofluorescence results was not always found; so, immunological methods can be aquivocal.

Soluble complexes and antiglobulin factors detection by immunofluorescence and immunoadsorption in rheumatoid sera.

In this report is was demonstrated that in rheumatoid factors (RF) positive sera, 19 S IgM rheumatoid factor can form soluble complexes with different proteins (IgG, albumin) of sera. In these complexes the antiglobulin activity of IgM is not inhibited. When immunofluorescence and immunoadsorption procedures are used for the detection of antiglobulin activities of rheumatoid sera, the proteins which are bound to IgM rheumatoid factor, even if they are devoid of any antiglobulin character, may be revealed simultaneously with IgM. Moreover in some cases the detection of IgM may be hindered, while the linked proteins remain detectable. In these conditions, these complexes in RF positive sera may give false negative results for IgM rheumatoid factor, and may give rise to artefactual appearance of IgG and other proteins (albumin antiglobulin-like activities. This paper points out that before investigating IgG and IgA antiglobulin activities, IgM rheumatoid factor should be previously eliminated, for example by immunoadsorption.

Study of the mode of cyclophosphamide action on the rabbit arthritis according to Glynn's model.

A knee joint arthritis is induced in rabbits previously immunized by an intradermal injection of emulsified egg albumin (E.A.) a complete adjuvant, then by an intra-articular injection of E.A. alone. Histologically, the synovium shows at first an Arthus phenomenon and later an immune cellular reaction. Several immunological parameters are studied in these rabbits. Cyclophosphamide (CY), injected intravenously, in a high dose, during a short period from the day of the first immunization, inhibits in the same time the arthritis index, E.A. skin test, humoral and synovial anti-E.A. antibodies and lymphocyte response to P.H.A. Cy, injected I.V., in a low dose, for a long period from the day of the intra-articular immunization, decreases only the arthritis index, but does not modify the various immune reactions to E.A. These results suggest that, according to the timing and the dose, CY inhibits synovial inflammation either by a strict anti-inflammatory action, or by an immunosuppressive effect on the initial phase of the immune reaction inducing subsequently a synovial inflammation.

Physiopathological aspect of Glynn's type of experimental arthritis.

Knee joint arthritis is induced among rabbits previously immunized by intradermal injection with egg albumin (EA) emulsified in adjuvant containing either M. tuberculosis or M. butyricum, then by intra-articular injection with EA. Arthritis evolution involves two phases, an early one during the first 2 months and a late one from 3 months to 1 year. During the early phase, arthritis intensities are similar no matter which Mycobacterium is used. However, during the late phase, only rabbits immunized with M. tuberculosis develop self-perpetuating arthritis. Among more than 50% of arthritic rabbits, immunological lesions of aortic artery and cardiac valvules are found. Among the rabbits immunized with M. tuberculosis, the humoral anti-EA antibody level remains constant during the whole arthritis evolution; but, among the rabbits immunized with M. butyricum, the arthritis intensity decreases from 3 months of evolution. The correlation between arthritis index (AI) and humoral antibody level is only significant among the rabbits with early arthritis. The intradermally immunized rabbits show a positive skin test with EA and tuberculin. The more intense the cutaneous reactions, the greater the chances of developing self-perpetuating arthritis after the EA intra-articular injection. The fluorescent anit-EA antibodies in the synovia and spleen are found only among the early arthritis. After 2 months of evolution, fluorescent antibodies disappear whatever the immunization may be. Among the immunized rabbits, it is probable that antigenic EA does not persist in the synovia. Indeed, the autologous inflamed synovia transplantation, from the donor-challenged knee joint, does not develop an inflammatory reaction in the non-challenged knee joint. The fluorescent immunoglobulins IgG and IgM in the synovium of arthritic rabbits are found with the same percentages as fluorescent anti-EA antibodies. The lymphocyte response to EA, PHA and PWM are positive whatever the immunization and arthritis evolution may be. There is no correlation between AIs and lymphocyte responses to specific and nonspecific mitogens. It is probable that self-perpetuation depends closely on M. tuberculosis whose adjuvant power is much superior than M. butyricum and not on antigenic EA whose essential role would be to trigger the inflammatory process.