[Show abstract][Hide abstract] ABSTRACT: Sera from 20 of 24 patients with pernicious anaemia reacted by immunoblotting with a 65-70 kD protein in canine and rodent gastric mucosal cells enriched for 80-90% parietal cells, and in microsomal preparations derived from these cells. All 20 reactive sera were positive for parietal cell microsomal antibody demonstrated by immunofluorescence. Eighteen parietal cell microsomal antibody-positive sera from patients with unconfirmed pernicious anaemia also reacted with the same 65-70 kD protein. Serum reactivity with the same 65-70 kD protein was not seen with canine and rodent liver cells or with microsomal preparations derived from these cells. Sera from 10 patients with chronic active hepatitis, 10 with scleroderma and 10 with rheumatoid arthritis and 22 healthy persons did not react with the 65-70 kD protein. These results suggest that the 65-70 kD protein is probably the parietal cell microsomal autoantigen. A second antigen of 85-90 kD mol. wt. present only in canine gastric mucosal preparations also correlates with the presence of parietal cell microsomal antibody. However, the contribution of this second antigen to parietal cell microsomal antibody reactivity remains uncertain.
[Show abstract][Hide abstract] ABSTRACT: We examined serum IgG fractions from 20 patients with pernicious anemia and 25 control subjects for their capacity to inhibit binding of [125I]15-leu human gastrin-17 to parietal-cell-enriched gastric mucosal cells. IgG fractions from six patients reduced gastrin binding by 45.6 +/- 12.2 per cent, as compared with a reduction of 1.8 +/- 0.7 per cent by fractions from the 25 controls. The fractions from these six patients also reduced gastrin-stimulated [14C]aminopyrine uptake by gastric cells (an index of gastric acid secretory activity in vitro) by 50.2 +/- 8.4 per cent (mean +/- S.D.), as compared with 9.2 +/- 4.1 per cent for the controls. IgG fractions from six other patients that did not reduce gastrin binding also inhibited gastrin-stimulated [14C]aminopyrine uptake, by 48.1 +/- 9.1 per cent. These reductions in gastrin binding and aminopyrine uptake were abolished by absorption of the IgG fractions with suspensions of viable gastric mucosal cells but not by absorption with liver or kidney cells. The IgG fractions did not inhibit [3H]histamine binding or histamine-stimulated [14C]aminopyrine uptake. These results suggest that serum IgG from some patients with pernicious anemia contains autoantibodies to the gastrin receptor.
No preview · Article · Sep 1985 · New England Journal of Medicine
[Show abstract][Hide abstract] ABSTRACT: We examined 51 sera from patients with pernicious anaemia for their capacity to block maximal gastrin stimulation of acid secretion by isolated rodent gastric parietal cells. 14C-aminopyrine accumulation was used as the index of acid secretion in vitro. Sera from patients with pernicious anaemia gave significantly (P less than 0.005) more block of maximal gastrin stimulation of acid secretion (61.7 +/- 37.8%) than sera from 10 patients with systemic lupus erythematosus (19.6 +/- 17.7%), 10 with scleroderma (34.2 +/- 22.3%), five with rheumatoid arthritis (22.4 +/- 15.6%) or 30 from healthy persons (27.4 +/- 12.8%). Maximal histamine stimulation of acid secretion was not inhibited. The blocking factor was present in serum IgG fractions, and serum and IgG fractions gave parallel dose-response and dilution curves. The serum block was abolished by absorption with gastric mucosal cells and correlated with the presence of parietal cell surface autoantibody. We conclude that serum immunoglobulin in pernicious anaemia can block gastrin stimulation of acid secretion and suggest that this block may be mediated by competition with gastrin for surface receptors on parietal cells.
[Show abstract][Hide abstract] ABSTRACT: A monoclonal IgMk antibody secreted by a hybrid (MUI-6) of mouse plasmacytoma NS-1 with spleen cells from a mouse immunized with canine parietal cell-enriched gastric mucosal cells was tested for immunofluorescence reactivity with gastric mucosal cells, tissue sections and monolayer cultures of rat fibroblasts. The antibody did not react with the cell membrane of parietal cells but reacted with smooth muscle fibres and skeletal muscle striations. In non-muscle cells, the antibody reacted with parietal cell cytoplasm, liver in a "polygonal" pattern, renal glomeruli, brush borders and peritubular fibrils of renal tubules, thymic medulla, brush borders of small intestinal mucosal cells, and cerebellar astrocytes, synaptic endings and synaptic glomeruli. In fibroblast monolayers, the antibody stained stress fibres in an interrupted pattern and in spreading fibroblasts, the antibody stained the microfibrillar network. Stress fibre staining was disrupted by treatment of cells with cytochalasin B. Immunoblots showed that the antibody reacted with a 200 K protein in 3T3 cells and with a preparation of myosin from rat liver.
No preview · Article · Aug 1985 · Journal of clinical & laboratory immunology
[Show abstract][Hide abstract] ABSTRACT: Freshly isolated canine oligodendrocytes were reacted by indirect membrane immunofluorescence with 44 sera from patients with multiple sclerosis (MS). Using analysis by flow microfluorometry (FMF), we found significant IgM antibody binding to the surfaces of oligodendrocytes in the MS sera. The fluorescence intensity of cell surface reactions for MS sera (F.I. greater than 40 = 37.2 +/- 21.34%) was significantly different (P less than 0.001) to that for 53 sera from normal subjects (10.0 +/- 8.97%), 15 sera from patients with Murray Valley encephalitis (6.18 +/- 5.3%), 22 with brain tumours (6.18 +/- 5.3%), 25 with SLE (13.42 +/- 11.65%), 7 with GBS (9.77 +/- 3.9%) and 7 miscellaneous neurological disorders (6.87 +/- 3.04%). Cell surface binding was restricted to oligodendrocytes and was absorbed out by oligodendrocytes but not by liver cells or kidney cells. Oligodendrocytes were identified by conventional histology, phase-contrast optics, electron microscopy (EM) and by cell surface reactions with anti-galactocerebroside, a specific immunocytological marker for oligodendrocytes. A cell sort of the single 0 degree FMF scatter peak followed by EM examination confirmed that the reactive cells consisted exclusively of oligodendrocytes. Viability of oligodendrocytes before and after the staining reactions, was greater than 80% as assessed by trypan blue and fluorescein diacetate exclusion. The possibility that immune reactions mediated by the surface-reactive antibody with readily accessible cell surface autoantigens in vivo may contribute to the loss of oligodendrocytes and demyelination in MS is raised.
No preview · Article · Jan 1984 · Journal of Neuroimmunology
[Show abstract][Hide abstract] ABSTRACT: Using flow microfluorimetry (FMF), 60 sera from patients with pernicious anaemia (PA) were examined for immunoreactivity with the surface membranes of viable canine parietal cells. FMF analyses showed that the percentage of parietal cells giving a surface staining reaction with a fluorescence intensity greater than 50 arbitrary units was 44.5 +/- 17.5% for sera from 60 patients with PA compared to 13.7 +/- 2.7% for sera from 14 patients with chronic active hepatitis, 10.7 +/- 6.7% for sera from 10 patients with systemic lupus erythematosus and 16.5 +/- 4.4% for sera from 50 healthy persons. Surface staining detected by FMF was restricted to parietal cells and abolished by absorption with parietal cell enriched preparations but not by absorption with dog or rat hepatocytes, dog or rat kidney cells, human fibroblasts, human AB red blood cells or dog gastric microsomes. The intensity of the parietal cell surface staining reactions correlated with the presence of antibody reactions with parietal cell surfaces previously demonstrated by immunofluorescence microscopy but did not correlate with the presence of microsomal or intrinsic factor autoantibodies. The results provide further support for the presence of a parietal cell surface reactive autoantibody distinct from the conventional parietal cell microsomal autoantibody.
[Show abstract][Hide abstract] ABSTRACT: We measured the complement-dependent cytotoxic activity of serum in 60 patients with pernicious anemia. Canine gastric mucosal cells served as the indicator of cytotoxicity, which was expressed as a percentage of the maximal effect produced by a cytolytic agent (Triton X-100). Serum from patients with pernicious anemia showed a higher average activity (11.8 +/- 10.3 per cent, P less than 0.001) than serum from 29 patients with systemic lupus erythematosus (1.0 +/- 1.8 per cent), 10 with scleroderma (0.1 +/- 0.1 per cent), 10 with rheumatoid arthritis (0.6 +/- 0.6 per cent), 22 with multiple sclerosis (0.4 +/- 1.2 per cent), and 23 with chronic persistent hepatitis (0.03 +/- 0.1 per cent), and serum from 64 healthy persons (0.4 +/- 1.0 per cent). Serum from patients with pernicious anemia was not toxic to canine liver or kidney cells. Absorption with gastric mucosal cells and heat inactivation of complement abolished the cytotoxic reaction. The cytotoxic factor resided in the IgG fraction of immunoglobulin, and the amount of cytotoxicity was proportional to the IgG concentration. Cytotoxic activity correlated with the presence of parietal-cell-surface--reactive autoantibody demonstrated by immunofluorescence. We conclude that cytotoxic autoantibodies to parietal cells may contribute to the loss of such cells from the gastric mucosa of patients with pernicious anemia.
No preview · Article · Oct 1983 · New England Journal of Medicine
[Show abstract][Hide abstract] ABSTRACT: We examined, in a 'double blind' study, 60 sera from patients with pernicious anaemia for immunofluorescence reactivity with the surface membranes of viable parietal cells isolated from dog stomachs. Fifty-three sera (88%) gave an IgG autoantibody reaction with the surface membranes of parietal cells. Surface staining was also seen with parietal cells from monkey, pig, rat and mouse. The parietal cell surface reactive autoantibody was not found in any of 14 sera from patients with chronic active hepatitis, 10 from patients with systemic lupus erythematosus and 50 from healthy persons. The surface reactivity autoantibody was present in 13 of 14 sera without parietal cell microsomal antibody, 28 of 31 sera without intrinsic factor antibody and in four of four sera without microsomal and intrinsic factor antibodies. Absorption with parietal cell enriched gastric mucosal cells neutralized the activity of the surface reactive but not the microsomal antibody and cross absorption with gastric microsomes neutralized the activity of the microsomal but not the surface reactive antibody. Surface staining of parietal cells was not abolished by absorption with dog or rat hepatocytes, dog or rat kidney cells, human fibroblasts or human AB red blood cells. The results suggest that the parietal cell surface reactive antibody is probably different from the microsomal antibody. Immune reactions of the cell surface reactive antibody with parietal cell surface antigens may play a role in the pathogenesis of the gastric lesion in pernicious anaemia.
[Show abstract][Hide abstract] ABSTRACT: Sera from 33 patients with scleroderma were examined for immunofluorescent reactivity with viable or acetone-fixed fibroblasts. All 33 sera reacted with the cell surface membranes of viable fibroblasts. 23 of 33 sera (70%) also reacted with nuclei of acetone-fixed fibroblasts. The commonest nuclear staining pattern was homogeneous (46%) followed by nucleolar (36%) and speckled (23%). 70% showed more than 1 staining pattern in the same serum. Antibody titres of homogeneous and nucleolar staining patterns (1:8 to 1:1024) were generally higher than those of the speckled pattern (1:8 to 1:256). No change in pattern or titre was noted in sera from 4 patients over a 10-12 month period. Antibody in sera with homogeneous or nucleolar staining patterns belonged to one or more of the 3 major antibody classes, IgG, IgM or IgA while antibody in sera with a speckled nuclear pattern belonged to the IgM class only. No correlation was found between the pattern of anti-nuclear reactivity and visceral involvement.
No preview · Article · Jun 1982 · Journal of clinical & laboratory immunology