Autoantibodies against neutrophils and monocytes: tool for diagnosis and marker of disease activity in wegener's granulomatosis

Although the rate of acute severe adverse cutaneous reactions to medications is low, these reactions can affect anyone who takes medications and can result in death or disability1. Even a small number of cases associated with a particular drug may alter the recommendations for its use2–4. Prompt differentiation of severe adverse cutaneous reactions from less serious skin disorders may be difficult. Rapid recognition of severe reactions is essential. Prompt withdrawal of the offending drug is often the most important action to minimize morbidity. Adverse cutaneous reactions to drugs are frequent, affecting 2 to 3 percent of hospitalized . . .

Severe Adverse Cutaneous Reactions to Drugs

Anti-neutrophil cytoplasmic autoantibodies have been found in patients with systemic arteritis and glomerulonephritis We studied the disease distribution and antigen specificity of these autoantibodies Anti-neutrophil cytoplasmic autoantibodies were identified by indirect immunofluorescence microscopy in 27 of 35 patients with idiopathic necrotizing and crescentic glomerulonephritis, in whom the manifestations of disease ranged from injury limited to the kidney to systemic arteritis The incidence and titers of the autoantibodies did not differ between patients with disease limited to the kidney and those with systemic disease Anti-neutrophil immunostaining was detected in 5 of 11 patients with lupus nephritis, 4 of 71 patients with other renal diseases, and none of 50 normal controls This distribution of autoantibodies was confirmed by an enzyme-linked immunosorbent assay (ELISA) using neutrophil lysate as antigen According to ELISA, anti-neutrophil cytoplasmic autoantibodies were found to be specific for constituents of primary granules Two types of autoantibodies were identified; one with reactivity with myeloperoxidase on ELISA produced an artifactual perinuclear immunostaining of alcohol-fixed neutrophils, and another with no reactivity with myeloperoxidase on ELISA produced diffuse cytoplasmic immunostaining The presence of the same serologic marker in patients with kidney-limited and arteritis-associated necrotizing and crescentic glomerulonephritis, including Wegener's granulomatosis and polyarteritis nodosa, suggests that these clinically diverse diseases may have a similar pathogenesis, initiated by autoantibody-mediated activation of neutrophils

Anti-neutrophil cytoplasmic autoantibodies with specificity for myeloperoxidase in patients with systemic vasculitis and idiopathic necrotizing and crescentic glomerulonephritis

Immune thrombocytopenic purpura, which may lead to bleeding, is typically caused by antibodies directed against the platelet glycoprotein IIb/IIIa complex. Since the management of the disorder is different for children and adults, the authors of this up-to-date review provide separate sections on the two age groups. Along with advances in management, they also discuss the current understanding of pathophysiology and, in particular, the way in which autoantibodies against platelets are generated.

Immune thrombocytopenic purpura.

Oxidatively modified lipoproteins have been implicated in atherogenesis, but the mechanisms that promote oxidation in vivo have not been identified. Myeloperoxidase, a heme protein secreted by activated macrophages, generates reactive intermediates that oxidize lipoproteins in vitro. To explore the potential role of myeloperoxidase in the development of atherosclerosis, we determined whether the enzyme was present in surgically excised human vascular tissue. In detergent extracts of atherosclerotic arteries subjected to Western blotting, a rabbit polyclonal antibody monospecific for myeloperoxidase detected a 56-kD protein, the predicted molecular mass of the heavy subunit. Both the immunoreactive protein and authentic myeloperoxidase bound to a lectin-affinity column; after elution with methyl mannoside their apparent molecular masses were indistinguishable by nondenaturing size-exclusion chromatography. Peroxidase activity in detergent extracts of atherosclerotic lesions likewise bound to a lectin column and eluted with methyl mannoside. Moreover, eluted peroxidase generated the cytotoxic oxidant hypochlorous acid (HOCl), indicating that enzymatically active myeloperoxidase was present in lesions. Patterns of immunostaining of arterial tissue with antihuman myeloperoxidase antibodies were similar to those produced by an antimacrophage antibody, and were especially prominent in the shoulder region of transitional lesions. Intense foci of myeloperoxidase immunostaining also appeared adjacent to cholesterol clefts in lipid-rich regions of advanced atherosclerotic lesions. These findings identify myeloperoxidase as a component of human vascular lesions. Because this heme protein can generate reactive species that damage lipids and proteins, myeloperoxidase may contribute to atherogenesis by catalyzing oxidative reactions in the vascular wall.

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Myeloperoxidase, a catalyst for lipoprotein oxidation, is expressed in human atherosclerotic lesions.

Vasculitis and antineutrophil cytoplasmic autoantibodies associated with propylthiouracil therapy

An indirect immunofluorescence technique for the detection of alloantibodies against granulocytes was developed. A major problem was the unspecific fluorescence of granulocytes, due to unspecific adherence of immunoglobulins to the cell membrane. This could be suppressed by the prefixation of the granulocytes with paraformaldehyde. The developed test proved to be specific and sensitive and to have a high reproducibility. Strongly positive reactions were obtained with antisera containing granulocyte-specific agglutinins or granulocyte-cytotoxins, but also with some sera that did not react in either the agglutination or the cytotoxicity test. HLA antisera also gave positive reactions, but strong anti-A, anti-B or anti-D sera did not react. With this technique leucocyte antibodies can be detected in a higher percentage of patients with febrile transfusion reactions.

The detection of granulocyte alloantibodies with an indirect immunofluorescence test.

https://www.kidney-international.org/article/S0085-2538(15)34810-9/pdf

Autoantibodies against myeloid lysosomal-enzymes in crescentic glomerulonephritis

Summary An immunofluorescence test on paraformaldehyde-fixed platelets in suspension was used for the detection of antibodies on platelets and in the sera of patients with idiopathic or secondary thrombocytopenia.



In idiopathic thrombocytopenia, a positive test was found on the patients' platelets in 55 out of 80 cases. The indirect immunofluorescence test with the patient's serum was positive in 28 out of 80 cases. In thrombocytopenia accompanied by other autoimmune diseases, the direct test was positive in 35 out of 39; the indirect test in 13 out of 39 patients. These results are similar to those obtained with other techniques recently described in the literature.



By using FITC-labelled monospecific anti-immunoglobulin reagents, immunochemical characterization of the autoantibodies was possible. Of the 90 patients with a positive direct test, 80 were analysed in this way. Of these, platelet-bound IgG was detected in 76. This was accompanied by IgM in 17 and IgA in three. In four, only IgM was found. The IgG subclasses of platelet-bound IgG were studied in 48 patients. Mainly IgG1 was found (45), often together with IgG3 (22) or IgG4 (14), but rarely with IgG2 (1). Only a few patients had just IgG3 (2) or IgG4 (1) on their platelets.



Platelet-bound autoantibodies could often be eluted (41 out of 86 cases) with ether and were demonstrable in the eluate with the indirect immunofluorescence test. This test was usually positive when the direct test was strongly positive (40 out of 44) and usually negative when it was weakly positive (1 out of 24) or negative (1 out of 18).

Autoimmune thrombocytopenia: detection of platelet autoantibodies with the suspension immunofluorescence test.

Antineutrophil cytoplasmic autoantibodies with specificity for myeloperoxidase (MPO) were found in 53 patient sera that were routinely submitted for antineutrophil cytoplasmic antibody determination. Based on clinical and histologic criteria, 15 of these 53 patients were classified as having systemic necrotizing vasculitis of the polyarteritis group, 11 patients were classified as having Wegener's granulomatosis (WG), and 14 were classified as having idiopathic crescentic glomerulonephritis. The remaining 13 patients did not fulfill the diagnostic criteria for these disorders, although most of these patients had clinical symptoms compatible with these disorders. While all patients with WG had renal involvement, only 4 of the 15 patients with systemic necrotizing vasculitis of the polyarteritis group had glomerulonephritis. The sensitivity of autoantibodies to MPO for either systemic necrotizing vasculitis of the polyarteritis group, WG, or idiopathic crescentic glomerulonephritis was further tested in all our patients with these disorders (n = 104). Twenty-seven of 104 patients had autoantibodies to MPO. Furthermore, 69 of the remaining 77 patients had autoantibodies specific for the 29-kd serine protease, which has been reported to be specifically associated with WG. Sera from 8 patients were negative for either of these antibodies (92% sensitivity of autoantibodies to MPO and/or the 29-kd serine protease). The specificity of autoantibodies to MPO for either systemic necrotizing vasculitis of the polyarteritis group, WG, or idiopathic crescentic glomerulonephritis was also tested in selected groups of patients who had closely related diseases. Two of 144 patients had autoantibodies to MPO (specificity 99%). We conclude that these antibodies are not only associated with idiopathic and vasculitis-associated crescentic glomerulonephritis, but also with classic polyarteritis nodosa, Churg-Strauss syndrome, and the polyangiitis overlap syndrome without renal involvement. The presence of autoantibodies to MPO or the 29-kd serine protease is highly sensitive and specific for systemic necrotizing vasculitis of the polyarteritis group, WG, and idiopathic crescentic glomerulonephritis.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/art.1780330829

A. E. G. Kr. von dem Borne

Papers

Vasculitis and antineutrophil cytoplasmic autoantibodies associated with propylthiouracil therapy

The detection of granulocyte alloantibodies with an indirect immunofluorescence test.

Autoantibodies against myeloid lysosomal-enzymes in crescentic glomerulonephritis

Autoimmune thrombocytopenia: detection of platelet autoantibodies with the suspension immunofluorescence test.

Association of autoantibodies to myeloperoxidase with different forms of vasculitis