Ronald I. Carr

DNA:Anti-DNA Complexes: Their Detection in Systemic Lupus Erythematosus Sera

Antibody to DNA was measured before and after treatment of systemic lupus erythematosus (SLE) sera with bovine pancreatic deoxyribonuclease (DNase I). In 11 of 15 cases of SLE with active renal disease there was a significant increase in DNA-binding after DNase digestion, while no such increase was noted in inactive SLE, normal controls or in patients with nonlupus renal disease. The significant rise in DNA-binding after digestion indicated that DNA had bound in vivo to the anti-DNA in these sera. A striking correlation between the occurrence of these complexes and disease activity was shown. In eight cases of SLE nephritis where serial blood samples were obtained, the greatest increase in DNA-binding after DNase digestion occurred at the time of the severest renal disease. In addition, serum from a case of SLE with acute cerebritis but without evidence of renal disease also had a significant rise in binding during the acute phase. This assay provides proof of the existence of circulating DNA:anti-DNA complexes in some cases of SLE and can also be used to measure an apparently critical parameter of disease activity.

Chronic Membranous Glomerulonephritis Caused by Hepatitis B Antigen-Antibody Immune Complexes

Abstract The immunopathogenesis of chronic membranous glomerulonephritis was investigated in a 42-year-old man with chronic active hepatitis, type B. In two renal biopsies, 14 months apart, immunof...

Oral Exposure to Alloantigen Generates Intragraft CD8+ Regulatory Cells

We have previously reported that oral administration of allogeneic rat spleen cells before kidney allotransplantation significantly prolongs graft survival. This prolongation was alloantigen specific and was associated with a decrease in graft-infiltrating cells (GIC) and an increase in transcription of IL-4 mRNA in the GIC. In this study increased splenic mixed lymphocyte responses from animals orally exposed to alloantigen before kidney transplantation suggested that the kidney allograft prolongation was not due to a masking of allorecognition, but to an immunomodulation of the immune response. We have assessed GIC T cell subsets on day 5 post-transplant and found decreased numbers of CD4+ T cells in fed animals compared with controls, but there was no change in CD8+ T cell numbers. The CD8+ GIC from fed animals transcribed substantial levels of perforin, granzyme, and Fas ligand mRNA, indicating the presence of active CTL. Direct CTL assays showed that the GIC from fed recipients exhibited higher allo-CTL activity than GIC from control unfed recipients. In addition, the CD8+ GIC exhibited high levels of IL-4 mRNA, suggesting Tc2-type regulatory cells. Prolonged graft survival in the face of active CTL and Tc2 cells suggests the presence of a CD8+ regulatory cell population in the allograft. To confirm this, cell transfer experiments were performed. Prolongation of graft survival was transferred from rats orally exposed to alloantigen to naive animals by transfer of CD8+ GIC. This is the first report that oral exposure to alloantigen prolongs kidney allograft survival by the generation of intragraft CD8+ regulatory cells.

Vasculitis in chronic urticaria

Abstract We have explored the problem of the histologic basis of chronic urticaria and its relation to vasculitis and immune complex disease. In a prospective study, 42 consecutive patients with chronic urticaria (from twice weekly to daily episodes lasting more than 6 wk) had skin biopsies and were studied for immunologic variables. Twenty-two patients (52%) had vasculitis on biopsy as defined by the presence of cellular infiltrates within the vessel wall. The other 20 patients (48%) had either edema only or perivascular infiltrates with mononuclear cells (perivasculitis). The group with vasculitis could be subdivided into seven patients with neutrophilic venulitis including three with fibrinoid change, seven with mixed-cellular vasculitis, four with lymphol monocytic vasculitis, and four with eosinophilic vasculitis. Vascular deposits of immunoreactants were found in only four (18%) of the vasculitis patients, compared with 65% of concurrently studied patients who had cutaneous venulitis manifested as palpable purpura, i.e., Henoch-Schonlein syndrome. Urticarial patients with vasculitis were more often male and had a longer mean duration of hives compared with the nonvasculitis group. We saw no differences between the vasculitis and nonvasculitis cases of urticaria with regard to the incidence of arthralgia, elevated erythrocyte sedimentation rate (ESR), or hypocomplementemia. The group with vasculitis did not have more generalized disease nor were the hives more resistant to therapy. We have discussed the definition and histologic criteria for the diagnosis of vasculitis when it occurs in very small blood vessels.

The prognostic and therapeutic implications of DNA:Anti-DNA immune complexes in systemic lupus erythematosus (SLE)

Serum samples serially obtained from 50 patients with systemic lupus erythematosus (SLE) were studied for antibody to deoxyribonucleic acid (DNA) and circulating DNA:anti-DNA complexes during the active and inactive phases of their disease. The patients were divided into four categories: Group I: six patients without clinical evidence of central nervous system (CNS) or renal involvement. Group II: three patients with CNS lupus. Group III: nine patients with normal urinalyses and glomerular filtration rates, but morphologic evidence of glomerular disease. Group IV: 32 patients with overt lupus nephritis. Elevated anti-DNA levels were observed in 16 of 18 patients (88 per cent) in groups I, II and III during active disease. This persisted in 14 (77 per cent) during remission. DNA:anti-DNA complexes were demonstrated in four of 18 (22 per cent) during active disease and disappeared in all but one patient with progressive disease. In 30 of the 32 patients (94 per cent) in group IV, DNA binding was increased during active disease; this persisted in 21 (70 per cent) despite remission. Complexes were observed in 25 of the patients in group IV (78 per cent) with active disease. In six of these patients, complexes have persisted; two have died, one has progressed to renal failure and the remaining three patients continue to manifest active disease. This study suggests that measurement of DNA:anti-DNA complexes provides a valuable additional index of disease activity and prognosis in SLE.

Dietary protein antigenemia in humoral immunodeficiency: Correlation with splenomegaly

Enhanced gastrointestinal absorption of dietary substances is an important feature of normal neonatal life that also exists in particular disease states such as selective IgA deficiency and atopic allergy. In these studies, it is shown that patients with hypogammaglobulinemia have increased absorption of dietary bovine antigens and that most patients have large amounts of these proteins present in the serum even after an overnight fast. The amounts of such proteins were found to be correlated with spleen size and/or peripheral lymphoid hypertrophy. Interestingly, three patients with X-linked agammaglobulinemia did not have detectable amounts of these proteins in the serum nor did they have splenomegaly or lymphadenopathy. It is speculated that hypogammaglobulinemic patients have a specific gastrointestinal mucosal lesion that permits the chronic excessive absorption of dietary antigens and may result in lymphoid hypertrophy.

Anti-native DNA antibodies in discoid lupus erythematosus.

Elevated anti-native DNA antibodies were found in certain patients who had discoid lupus erythematosus (DLE). Two of these patients developed systemic lupus erythematosus (SLE). The finding of anti-native DNA antibodies, generally thought to be specific for SLE, is further evidence that DLE might be part of the spectrum of SLE. Patients with DLE whose sera bind more than 15% of iodine 125-labelled native DNA (after correction for normal controls) by the ammonium sulfate precipitation technique, may eventually have systemic manifestations and, therefore, may have a guarded prognosis. In contradistinction to other widely used serologic tests, the presence of elevated anti-native DNA antibodies may be of prognostic value in patients with DLE.

Degradation of circulating DNA by extracorporeal circulation over nuclease immobilized on nylon microcapsules.

Studies were undertaken to determine whether deoxyribonuclease I, (DNase I) once immobilized on activated nylon microspheres, would be capable of degrading circulating DNA in vitro and in vivo in an extracorporeal circulation system in dogs. Nylon microspheres were prepared and after gentle hydrolysis and glutaraldehyde treatment, demonstrated a retention of up to 4.73 mg of Dnase I. In vitro studies showed that DNase I immobilized on microspheres degreded a significant percentage of 125I-native DNA (nDNA) within 15 min. Mongrel dogs were injected with 125I-nDNA and a variation in initial t 1/2 in individual animals was observed. Therefore, for experimental studies, 125I-nDNA was injected and decay was recorded during a control period in which untreated microcapsules were utilized in the extracorporeal system. DNase I microspheres were then introduced into the extracorporeal circuit which resulted in an acceleration of degradation of acid precipitable 125I-nDNA. When 200 mug of unlabeled DNA with 125I-nDNA was injected, a similar augmentation of DNA degradation was noted after extracorporeal circulation over DNase I microcapsules. This effect could not be attributed to release of DNase I from the microspheres since no 131I-DNase was detected in the serum or organs of the dogs at the conclusion of the experiments. 125I-nDNA:anti-DNA complexes were passively injected into dogs and after a similar control period of circulation over untreated microcapsules. DNase I microspheres were introduced. Results showed a rapid acceleration in the degradation rate of 125I-nDNA:anti-DNA complexes precipitable with (NH4)2SO4. Extracorporeal circulation over nylon microspheres resulted in no significant alteration of the hosts hematocrit or platelet count, and little residual cellular debris on the microcapsules. These data suggest that DNAase immobilized on nylon microspheres may have a potential role in the specific therapy of systemic lupus erythematosus, when it is desirable to hydrolyze DNA circulating free or in combination with antibody.

Specific removal of circulating antigen by means of immunoadsorption.

In previous reports the feasibility of specifically removing circulating DNA antibodies in vivo with an immwnoadsorbent was demonstrated [l-3]. The selective removal of antigens and antigen-antibody complexes from the circulation in immune complex disease would be another desirable therapeutic goal. Cuprophan (Enka Glanzstoff, AC, Munich, West Germany), a non-toxic cellulosic membrane commonly employed in hemodialysis, has demonstrated a capacity to non-specifically adsorb proteins [4] and would thus appear to be a potential solid support for antibody adherence. We herein demonstrate that rabbit gamma globulin (RGG) may be conjugated to Cuprophan columns and that these RGG columns are capable of withdrawing specific antigen from plasma circulated through them.