Autoantibodies to nucleolar antigens in systemic scleroderma: clinical correlations

Indirect immunofluorescence(IIF) and double immunodiffusion (DID) were performed on the sera of 64 patients who had a nucleolar immunofluorescence pattern on HEp-2 cells. Forty-nine of the sera were from 296 patients with systemic scleroderma (SSc) and 15 sera were from 214 patients with systemic lupus erythematosus (SLE). A homogeneous nucleolar staining pattern was found in 45 of the 64 sera (70.3%), a clumpy fluorescence associated with fibrillarin antibody in 14 (21.8%) and a speckled pattern was found in five of the sera (7.8%). There was a clear correlation between the sera which showed a homogeneous nucleolar staining pattern with symptoms of the polymyositis/scleroderma overlap syndrome that differed from SSc with concomitant myositis. The clumpy pattern was mainly associated with diffuse scleroderma and the speckled pattern with limited scleroderma (previously called acrosclerosis).     

The PM-Scl (polymyositis-scleroderma) autoantibody and its nucleolar fluorescence pattern

By indirect immunofluorescence studies of antinuclear antibodies on hamster liver imprints as a substrate performed to determine the nuclear staining pattern of sera from patients with connective tissue diseases 10 sera showed a distinct homogeneous nucleolar staining pattern associated with weaker speckled or homogeneous nucleoplasmic fluorescence. In all 10 cases the antibodies revealed the PM-Scl specificity in immunodiffusion. Clinically 9 patients had an acrosclerosis, in 56% overlapped with symptoms of polymyositis. Only one patient had a diffuse scleroderma. The homogeneous nucleolar immunofluorescence pattern of PM-Scl should be distinguished from mixed nucleolar and diffuse reticular nucleoplasmic pattern of Scl-70.     

Nucleolar, homogeneous and peripheral fluorescence of epidermal nuclei in direct immunofluorescence: 4 cases (author's transl)]

Epidermal nucleolar IgG deposition on direct immunofluorescence of covered normal skin was found in two patients with scleroderma and high serum concentrations of antibody to nucleolar antigen. Epidermal homogeneous and peripheral IgG deposition was also observed in two patients with systemic lupus erythematosus, antinuclear antibody of homogeneous staining pattern, but without antibody to extractable nuclear antigen. Epidermal nuclear IgG deposition in a speckled, nucleolar, homogeneous or peripheral pattern appears to correlate with high titer serum antinuclear antibody giving on immunofluorescence the same staining pattern. These immunopathologic findings cannot be considered as being specific of a subset of connective tissue disease.     

The speckled epidermal nuclear immunofluorescence of mixed connective tissue disease seems to develop as an in vitro phenomenon

The pathogenesis of speckled epidermal nuclear immunofluorescence in patients with mixed connective tissue disease (MCTD) was studied by reproducing this reaction in guinea-pigs, using serum samples containing high litre antibody to ribonucleoprotein (RNP). Immunofluorescence studies on specimens obtained from guinea-pig skin into which scrum samples containing high titre RNP antibody had been injected intradermally, revealed positive epidermal nuclear staining for IgG. This speckled immunofluorescence was demonstrable immediately after injection and remained so for 24 or 48 h. The pattern of fluorescence was similar in all cases, and there was no penetration of RNP antibody through the cell membrane. The epidermal nudear fluorescence was not detected with sera at a dilution of 1:100 or more. These results provide strong evidence that the epidermal nuclear immunofluorescence observed in patients with high titre antibody to RNP develops as an in vitro phenomenon.     

Elevated serum BAFF levels in patients with localized scleroderma in contrast to other organ-specific autoimmune diseases

Serum levels of B-cell activating factor belonging to the tumor necrosis factor family (BAFF), a potent B-cell survival factor, are elevated in patients with systemic autoimmune diseases, such as systemic lupus erythematosus (SLE), rheumatoid arthritis and systemic sclerosis (SSc). The objective of this study was to determine serum BAFF levels and relate the results to the clinical features in patients with organ-specific autoimmune diseases of the skin, such as localized scleroderma and autoimmune bullous diseases. Serum BAFF levels were examined by enzyme-linked immunosorbent assay in 44 patients with localized scleroderma, 20 with pemphigus vulgaris/pemphigus foliaceus, 20 with bullous pemphigoid and 30 healthy controls. Twenty patients with SSc and 20 with SLE were also examined as disease controls. Serum BAFF levels were elevated in localized scleroderma patients compared with healthy controls. Concerning localized scleroderma subgroups, patients with generalized morphea, the severest form of localized scleroderma, had higher serum BAFF levels than linear scleroderma or morphea patients. The BAFF levels of generalized morphea were comparable with those of SSc or SLE. Furthermore, serum BAFF levels correlated positively with antihistone antibody levels and the severity of skin lesion as well as the number of skin lesions. By contrast, serum BAFF levels were not significantly elevated in patients with pemphigus or pemphigoid. These results suggest that BAFF may be contributing to autoimmunity and disease development in localized scleroderma.     

Anti-U1RNP antibodies in patients with localized scleroderma

Abstract Antibodies to U1 ribonucleoproteins (RNP) have been detected in serum from patients with various autoimmune diseases. However, the presence of anti-U1RNP antibodies in patients with localized scleroderma has not been reported. In this study, we examined the frequency of anti-U1RNP antibodies using immunoprecipitation of U small nuclear RNAs and determined the antigen specificity by immunoblotting. Of 70 serum samples from patients with localized scleroderma, 2 (3%) immunoprecipitated U1 small nuclear RNA. Indirect immunofluorescence using HEp-2 cells as substrate showed coarse speckled nuclear fluorescence without nucleolar staining in both of the samples positive for anti-U1RNP antibodies. In addition, the presence of anti-U1RNP antibodies in each serum sample was confirmed by immunodiffusion against HeLa cell extracts. Immunoblotting analysis showed anti-70 kDa antibodies in each serum sample. This reaction against 70 kDa protein in the patients with localized scleroderma was analogous to that in patients with systemic sclerosis or mixed connective tissue disease. Both patients with positive serum were diagnosed as having linear scleroderma, but neither had evidence of Raynaud’s phenomenon or sclerodactyly. These results indicate that the presence of anti-U1RNP antibodies is one of the serological abnormalities in localized scleroderma, and that the mechanism of induction of anti-U1RNP antibodies in patients with localized scleroderma might be similar to that in patients with systemic sclerosis and mixed connective tissue disease. Received: 12 February 2001 / Revised: 27 April 2001 / Accepted: 11 July 2001     

EPIDERMAL NUCLEAR IMMUNOFLUORESCENCE

In sixteen patients, the relationship of epidermal nuclear immunofluorescence to the spectrum of connective tissue diseases and to serum antibodies was investigated. The clinical diagnoses were mixed connective tissue disease (7 patients), systemic lupus erythematosus (5 patients), scleroderma (3 patients) and rheumatoid arthritis (1 patient). Detailed serologic evaluation in 13 of the 16 patients revealed positive rheumatoid factor (7 patients), antinuclear antibody (13 patients), anti-DNA (2 patients), anti-n-RNP (11 patients), anti-Sm (2 patients), anti-SS-A (3 patients) and anti-RANA (5 patients). Anti-SS-B and anti-Scl-70 were absent in all. Epidermal nuclear immunofluorescence on skin biopsy correlated with serum anti-n-RNP and is a useful marker for mixed connective tissue disease. However, it did not appear to serve as a specific marker for any one connective tissue disease. We discuss the mechanism(s) for this immunofluorescent pattern and believe it is an in vivo phenomenon.     

Antibodies to the Borrelia burgdorferi flagellum in patients with scleroderma, granuloma annulare and porphyria cutanea tarda

It is generally accepted that cutaneous Lyme borreliosis comprises erythema chronicum migrans, lymphadenosis benigna cutis, and acrodermatitis chronica atrophicans. In recent years the tick-borne spirochete Borrelia burgdorferi has been associated with a number of other cutaneous disorders. We therefore investigated sera from 175 patients with localized scleroderma (morphea) (n = 64), systemic sclerosis (n = 74), granuloma annulare (n = 16) and porphyria cutanea tarda (n = 21) with the new, highly sensitive and specific Borrelia burgdorferi flagellum ELISA assay. As controls (n = 297) served normal healthy volunteers and patients with other skin diseases. It was found that the distribution of individual antibody values and the median antibody levels were identical in controls and in patients with scleroderma, granuloma annulare and porphyria cutanea tarda. These data do not support the hypothesis of an etiological association between Borrelia burgdorferi infection and scleroderma, granuloma annulare or porphyria cutanea tarda.     

In vitro complement activation by antinuclear antibodies in the epidermis from patients with systemic sclerosis

Skin biopsies from twenty-one systemic sclerosis patients with significant serum fluorescent antinuclear antibody (FANA) titres (more than 1:40) were examined by direct immunofluorescence (DIF) and by in vitro immunofluorescent complement (C) activation (C + DIF). Eight patients showed epidermal nuclear ANA deposits by DIF. In vitro complement activation was achieved in epidermal nuclei from all eight patients. In addition, one patient with diffuse scleroderma revealed a dense speckled, and two patients with the CREST syndrome a discrete speckled, epidermal nuclear staining pattern by C + DIF. The latter two patients showed high titres of anticentromere antibody in their sera. We consider that the C + DIF findings of these two patients with the CREST syndrome reflect binding of serum anticentromere antibodies to their antigens in vivo.     

Immunofluorescence studies in progressive systemic sclerosis (scleroderma) and mixed connective tissue disease

Immunofluorescence (IF) investigations of the skin were performed in thirty patients with progressive systemic sclerosis (scleroderma) and eight patients with mixed connective tissue disease (MCTD). The results show that speckled epidermal nuclear immunoglobulin deposition occurs not only in MCTD but also in true scleroderma. Granular IgM deposition at the dermo-epidermal junction of light-exposed skin was detected in both groups of patients, but six of eight MCTD patients also showed a granular IgM band in non-exposed skin. Antinuclear antibodies (ANA) were demonstrated in the sera of 96% and 100% of patients with scleroderma and MCTD respectively. The pattern of nuclear IF staining in scleroderma included dense fine speckles, large coarse speckles, threads, nucleolar and centromere staining. In MCTD, by contrast, the ANA staining pattern consisted of threads. The significance of ANA titres and immunological specificities for the in vivo reaction of serum ANA with epidermal nuclear antigens is discussed.     

Direct immunofluorescent findings in scleroderma syndromes

Cutaneous direct immunofluorescent findings were examined in 78 patients who had either vascular scleroderma (group 1, 52 patients) or scleroderma with features of myositis or lupus erythematosus (group 2, 26 patients). Group 2 had higher antinuclear antibody levels, erythrocyte sedimentation rates, serum IgG concentrations, frequency of positive LE clot test, and rheumatoid factor activity. Ninety-two percent of group 1 (48 patients) had negative direct immunofluorescent findings, whereas 77% of group 2 (20 patients) had positive findings at the basement membrane or in the blood vessels (or both). The 6 patients in group 2 who had negative immunofluorescent findings were all on systemic steroid therapy. Of the 17 patients in group 2 who had tests for antibody to extractable nuclear antigen, only 3 had high-titer antibody to ribonucleoprotein--a pattern characteristic of mixed connective tissue disease. Direct cutaneous immunofluorescence is proposed as a means of identifying those patients with scleroderma who may be steroid-responsive.     

Speckled (particulate) epidermal nuclear IgG deposition in normal skin. Correlation of clinical features and laboratory findings in 46 patients with a subset of connective tissue disease characterized by antibody to extractable nuclear antigen.

Clinical and laboratory findings were correlated from 46 patients with IgG localization in epidermal nuclei in a speckled (particulate) pattern on direct immunofluorescence of normal skin. Cutaneous manifestations included lupus erythematosus (LE), swollen hands or sclerodactyly, alopecia, vasculitis, and dyspigmentation. Systemic manifestations included arthritis or arthralgia, Raynaud's phenomenon, serositis, vascular headaches, mild renal disease, myositis, and sicca syndrome. High titer (mean = 1:142, 800) serum antibody to extractable nuclear antigen (ENA) was found in 81%. Eighty-six percent had antibody to an RNase-sensitive antigenic component of ENA (ribonucleoprotein or RNP); 14% had antibody to an RNase-resistant ENA termed Sm. Deposition of IgG in a speckled pattern in epidermal nuclei is an immunopathologic marker for a subset of connective tissue disease characterized by antibody to ENA. Those with Sm specificity had systemic LE (SLE); Those with RNP specificity had Raynaud's phenomenon usually associated with overlapping features of SLE, scleroderma, and/or dermatomyositis.     

Anticytoskeletal antibodies in systemic autoimmune diseases

Aim To investiate the presence of antinuclear and anticytoskeletal autoantibodies in patients with systemic autoimmune and connective tissue diseases. Setting 646 sera of 322 patients with systemic sclerosis, systemic lupus eryhtematosus, mixed connective tissue disease, rheumatoid arthritis with or without secondary Sjögren's syndrome, and localized scleroderma, and 127 healthy controls were tested. Methods ‘Routine’ indirect immunofluorescence technique on HEp-2 cells. Results Antinuclear antibodies were found in 45–91.1% of the sera. Anti-intermediate filament antibodies were detected in 24 patients. Eight of the 24 cases had another (second) organ-specific autoimmune disease, mainly chronic active hepatitis or autoimmune thyroid disease.     

Immunofluorescence studies using skin sections of recessive dystrophic epidermolysis bullosa patients indicated that the antigen of anti-p200 pemphigoid is not a fragment of type VII collagen

BACKGROUND: There are a large number of autoimmune bullous diseases, which have distinct autoantibodies. Several reports on cases with IgG autoantibodies against a novel 200 kDa dermal protein have been published, for which we suggested the term, anti-p200 pemphigoid. However, the nature of this 200 kDa antigen has not been well characterized. OBJECTIVE: In this study, we examined the relationship between the 200 kDa protein and type VII collagen. METHODS: We collected sera from 12 cases of anti-p200 pemphigoid and skin sections from six cases of recessive dystrophic epidermolysis bullosa (RDEB). The reactivity of these sera was examined by indirect immunofluorescence using sections of the disease skin. RESULTS: we have shown that all the 12 anti-p200 pemphigoid sera could react with basement membrane zone of five cases of RDEB, while epidermolysis bullosa acquisita (EBA) sera were negative in these skins. In addition, in a case of RDEB, EBA sera reacted with intracytoplasmic deposition of type VII collagen, while no anti-p200 pemphigoid sera showed this reactivity. CONCLUSION: These results strongly suggested that the 200 kDa antigen is not a fragment of type VII collagen, but a specific autoantigen.     

Elevated levels of antibodies to polyuridylic acid detected and quantitated in systemic scleroderma patients by solid phase radioimmunoassay

A solid support radioimmunoassay has been developed to detect immunoglobulin specific circulating antibodies to polyuridylic acid (Pol U), single-stranded RNA (ss RNA), and single-stranded DNA (ss DNA) in scleroderma and other connective tissue diseases. The assay system uses flex-vinyl microtiter plates on which bovine methyl albumin, the respective polynucleotide, a 1:80 dilution of patient serum, and tritiated high affinity anti-IgG, -IgA, or -IgM are layered. The individual wells containing the sandwich assay are then counted for the presence of labeled immunoglobulins and the results are reported in microgram/ml. Of the 30 scleroderma patients tested, only patients with diffuse systemic scleroderma had antibody levels reactive to Poly U > 4.0 microgram/ml and to ss RNA < 3.0 microgram/ml. Patients with linear scleroderma or morphea had antibody levels to Poly U < 3.0 microgram/ml and very little antibody to ss DNA or ss RNA in their sera. Partial cross reactivity to Poly U was found only in SLE patients with high levels of Ab to ss DNA. Insignificant levels of Poly U antibody were found in patients with other connective tissue diseases and in normal controls. High levels of serum antibody in patients which reacted with Poly U suggest active diffuse systemic scleroderma.     

Epidermal nuclear immunofluorescence: serological correlations supporting an in vivo reaction

Epidermal nuclear deposits of immunoglobulins (Ig) were studied by direct immunofluorescence in three groups of patients: ten scleroderma (SD, systemic sclerosis), seven dermatomyositis (DM) and seven systemic lupus erythematosus (SLE). Each patient had skin biopsies taken from three different sites (nailfold, forearm, buttock) on the same day that a serum sample was also obtained. Epidermal nuclear deposits were observed in nine of twenty-four patients (five SD, two DM, two SLE). A high serum ANA titre correlated significantly with the presence of epidermal nuclear Ig deposits. The nucleolar epidermal nuclear pattern was limited to the SD group, four of ten patients showing this pattern. Two of nine patients with positive results in the nailfold and forearm had negative findings in the buttock, supporting the view that deposition of Ig in the epidermal nuclei occurs in vivo.     

The fibrillarin (Scl-34) autoantibody in systemic scleroderma

Reexamination of ANA positive sera with nucleolare fluorescence staining on HEp-2 cells and hamster liver imprints revealed 3 sera with an uniform characteristic pattern. It is characterized by: 1. Strong clumpy fluorescence of nucleoli in the interphase. 2. Missing nucleoplasma staining (pure nucleolar). 3. Characteristic granular staining of the cytoplasma from the condensed chromosoma in mitosis. 4. Additive fluorescence of a nucleolus-like body. 5. Extremely high antibody titers. 6. Negative immunodiffusion. This nucleolar staining pattern was described by Bernstein et al. as a clumpy nucleolar pattern. It is produced through an antibody to the dense fibrillar component of the nucleolus (fibrillarin). This antigen is a protein of the U3 RNP with a molecular weight 34 kDa. Clinically is the fibrillarin antibody highly specific for systemic scleroderma especially with diffuse skin involvement. We found it in 1% of scleroderma patients. Its pathogenetic importance is not known.     

Anti-keratin filament autoantibodies

IgG anti-keratin-filament autoantibodies occur in all human sera and reach high titres in the sera of patients with various cutaneous and non-cutaneous diseases. At indirect immunofluorescence, these autoantibodies may, depending on their titre, appear as 'upper-cytoplasmic' antibodies or 'stratum-corneum' antibodies. In vitro, IgG anti-keratin-filament autoantibodies significantly enhance (as opsonins) the phagocytosis of keratin-filament aggregates by human monocytes and polymorphonuclear leucocytes. They may therefore, also in vivo, play a role in the removal of insoluble extracellular keratin-filament aggregates generated by necrotic or apoptotic cell death. Keratin (Civatte) bodies and deposits of localized cutaneous amyloid are examples of such keratin-filament aggregates that are found in various skin diseases but are also regularly present in large amounts in normal human skin. IgM anti-keratin-filament autoantibodies, which may, at indirect immunofluorescence, appear as 'general cytoplasmic' antibodies, also occur in all human sera and reach high titres in the sera of patients with various diseases. The regular presence of IgM in keratin bodies or deposits of localized cutaneous amyloid therefore probably represents the binding of IgM anti-keratin-filament autoantibodies to their respective antigens. To what extent these in vivo-bound autoantibodies prevent any further damaging reaction by the immune system in response to the liberation of keratin-filament autoantigen is as yet unclear.     

Some further features for differential diagnosis between squamous cell carcinomas and basal cell epitheliomas

Two further methods for the characterization of epidermal skin tumors are described: the antinuclear antibody (ANA) immunofluorescent test, which consists of indirect immunofluorescence with known high titer sera containing homogenous ANAs on epidermal skin tumors, and the ammoniacal-silver cytochemical method, which specifically stains nuclear histones. Squamous cell carcinomas (SCCs), basal cell epitheliomas (BCEs) as well as control specimens from normal skin and benign epidermal hyperplasias were studied. The ANA immunofluorescent test was positive for most SCCs, mixed SCC and basal cell carcinomas and metatypical BCEs. The ammoniacal-silver method gave a characteristic staining pattern shared among SCCs, mixed carcinomas and metatypical BCEs. BCEs, besides metatypical ones, were always negative by the ANA immunofluorescent test and the same applied for the control specimens. The ammoniacal-silver method gave a characteristic staining pattern for BCEs and control sections quite different from the staining pattern of the more aggressive forms of epidermal tumors. The two methods usually yielded parallel results.     

Histologic Observations of Pleomorphic, Variably Acid-fast Bacteria in Scleroderma, Morphea, and Lichen Sclerosus et Atrophicus

ABSTRACT: Variably acid-fast cocoid forms, suggestive of cell wall deficient forms of mycobacteria, were observed in the dermis in microscopic sections of skin from six patients with generalized scleroderma, 10 patients with localized scleroderma (morphea), and four patients with lichen sclerosus et atrophicus(LSA). These cocoid forms werde found within the collagen bundles, around the adnexae (Hair shafts, pilosebaceous units, eccrine glands), and less commonly around the blood vessels and nerves. These cocoid forms may be related to cocci and also to granular cocoid elements of corynebacteria-like coccobacilli, which, on occasion, can be cultured from the skin of these three diseases. The findings in this study support the three-decade old hypothesis concerning the constant association of pleomorphic acid-fast bacteria with scleroderma. The study also suggests that closely related diseases, such as morphea and LSA, are also associated with the presence of similar appearing microbes.