Bullous pemphigoid: a correlative study of autoantibodies, circulating immune complexes and dermo-epidermal deposits

Twenty bullous pemphigoid (BP) patients were studied to establish any correlation between free anti-basement membrane zone (BMZ) antibodies, circulating immune complexes (CIC) and dermo-epidermal junction deposits. CIC levels were evaluated by 2% polyethylene glycol (PEG) precipitation. The twenty patients were found to have IgG and/or C3 deposited in the BMZ. Eight of the twelve patients who had no free anti-BMZ antibodies displayed a positive in vivo C4 and/or C_Iq staining and high levels of CIC. Moreover, CIC were detected in only one patient with positive circulating free anti-BMZ antibodies. The presence of free anti-BMZ antibodies was generally found to correlate with the absence of cutaneous deposits of C1q and/or C4 and with negative CIC; on the other hand, the absence of free anti-BMZ antibodies was generally found to correlate with high levels of CIC and with deposits of C3 and C_Iq and/or C4. The absence of circulating free anti-BMZ antibodies in BP patients, could be explained by the formation of CIC. It is possible that BMZ antigens released from damaged tissue could combine with free antibodies and form complexes in the blood. The release could involve locally formed immune complexes. Elevated CIC levels were generally found to correlate with the presence of active disease.     

Anti-basement membrane antibodies in sera from patients without bullous pemphigoid.

Sera from 208 individuals were examined for antibasement membrane (anti-BM) antibodies by means of an indirect immunofluorescence technique. In sera from patients with bullous pemphigoid 19 of 25 had anti-BM antibodies in titres varying from 80 to 32 000. In 2 of 42 sera from patients with psoriasis, anti-BM antibodies were demonstrated (titres 40-640). Of 58 sera from patients with leg ulcers, antibodies were found in 4 (titres 40-320). Antibodies were found in 2 of 43 patients with cardio-vascular disease (titre 80) and in 1 of 40 control persons (titre 40). Serum from one of the patients with leg ulcers caused a punctate staining pattern unlike the tubular pattern seen in all other positive sera.     

Prevalence and antigen specificity of anti-histone antibodies in patients with polymyositis/dermatomyositis

Anti-histone antibodies have been detected in the sera of patients with various autoimmune diseases. The existence of anti-histone antibodies in patients with polymyositis/dermatomyositis, however, has not been reported. We found anti-histone antibodies in eight (17%) of 46 sera from patients with polymyositis/dermatomyositis by an enzyme-linked immunosorbent assay. One serum was positive for both IgG anti-histone antibodies and IgM anti-histone antibodies. Six sera were positive only for IgG anti-histone antibodies. One serum was positive only for IgM anti-histone antibodies. An indirect immunofluorescence analysis using HEp-2 cells as the substrate showed that all sera positive for anti-histone antibodies produced homogeneous nuclear fluorescence. This immunofluorescence pattern disappeared after absorption of anti-histone activity with total histones. An immunoblotting analysis demonstrated that the anti-histone antibodies were predominantly directed against histone H1 in all seven sera with IgG anti-histone antibodies. Weak reactivity with H2B and H4 were also found in three sera from the patients with polymyositis/dermatomyositis. Sera from two patients with polymyositis/dermatomyositis displayed anti-H2A and H3 activity. One of the two sera showed IgM anti-histone antibodies in the enzyme-linked immunosorbent assay reacted with H1, H2A, H2B, H3, and H4, whereas the other serum reacted with no fractions of total histones. The activity of anti-histone antibodies disappeared in immunoblotting after absorption with total histones. All of the patients with anti-histone antibodies were free from lung fibrosis or internal malignancies. Thus, our data indicate that the presence of anti-histone antibodies is classified as one of the serologic abnormalities observed in polymyositis/dermatomyositis.     

Two groups of bullous pemphigoid antigens are identified by affinity-purified antibodies

The bullous pemphigoid antigen was originally described as a 240-kD protein extracted from human epidermis, but a subsequent report has described patients' sera which react with epidermal proteins of molecular masses 240, 200, 180, 97, and 77 kD. We have evaluated the heterogeneity of the pemphigoid antigens identified by the sera of 10 patients with clinically typical bullous pemphigoid. We used indirect immunofluorescence and Western immunoblots of epidermal extracts prepared from epidermis separated by either 1 M salt or 20 mM EDTA to characterize the reactivity of both crude sera and affinity-purified antibodies. Affinity purification of antibodies was performed with either normal human epidermis or protein bands blotted onto nitrocellulose as immunoabsorbents. The anti-basement membrane antibody titers determined by indirect immunofluorescence on the saline- and EDTA-separated epidermis were identical. Despite this, Western blots of extracts prepared from EDTA-separated epidermis demonstrated greater amounts of the 240-kD antigen than saline split skin. Multiple antigens were recognized in epidermal extracts on Western blots by most crude BP sera, including bands at 240, 200, 160, and 100 kD. Different sera reacted with these antigens with a markedly different intensity, falling into two major groups, those bearing antibodies to the 240-200-kD antigens and those with antibodies to the 160-100-kD components. When epidermis was used as a substrate for affinity purification of bullous pemphigoid antibodies, the eluted antibodies reacted with multiple bands on Western blots, demonstrating the reactivity of anti-basement membrane zone antibodies with multiple proteins. Antibodies eluted from several individual bands of immunoblots were found to react with the basement membrane on indirect immunofluorescence. When these nitrocellulose-purified antibodies were reapplied to Western blots, they cross-reacted within two groups, the 240-200 kD antigens and the 160-100 kD antigens. We conclude that pemphigoid antigens are best demonstrated when EDTA-split skin is used for extraction and that different pemphigoid sera may contain antibodies to two separate groups of basement membrane zone antigens.     

Immune complexes in the sera of patients with anti-RNP antibodies

Circulating immune complexes were detected by the polyethylene glycol precipitation method in the sera of patients with antibodies to ribonucleoprotein (RNP). Levels of immune complexes were significantly higher than in normal control sera and correlated well with disease activity as defined by clinical manifestations, decreased levels of complement and increased fluorescent anti-nuclear antibody titers. Analysis of IgG-aggregates in the sera of patients revealed the following characteristics: molecular weight of about 900,000 daltons, sensitivity to RNase, resistance to DNase, no Clq-binding activity and no RF activity.     

Anti-hapten antibodies and autoantibodies in Japanese patients with lepromatous leprosy

Summary In the sera of patients with lepromatous leprosy anti-DNP antibodies were detected in order to determine the mode of ployclonal B-cell activation. Anti-DNP antibodies were found in 30% of the patients with active lepromatous leprosy and in 8% of those with inactive lepromatous leprosy. The level of anti-DNP antibodies in active patients was significantly higher than the level in inactive patients and control. However, the presence of anti-DNP antibodies was unrelated to the production of circulating immune complexes and antinuclear antibodies. These results suggest that polyclonal B-cell activation might occur but that the B-cell clones stimulated by M. leprae are different from patient to patient.     

白癜风患者血清抗人黑素浓集素受体-1自身抗体的检测及分析

目的检测白癜风患者血清中抗黑素浓集素受体-1(MCHR1)的自身抗体,探讨其在白癜风发病中的意义。方法构建真核表达载体pcDNA3.1/MCHR1,经限制性内切酶双酶切及DNA测序鉴定后,用阳离子脂质体介导转染CHO细胞,经G418筛选,利用ELISA,RTPCR及蛋白印迹法鉴定表达MCHR1蛋白的阳性克隆。采用活细胞ELISA法检测白癜风患者血清抗MCHR1及抗黑素细胞(MC)膜表面抗原的自身抗体。结果白癜风患者血清中抗MCHR1自身抗体阳性率为17.1%,抗MC膜表面抗原的自身抗体阳性率为41.4%,所有抗MCHR1自身抗体阳性的血清抗MC膜表面抗原自身抗体均为阳性,正常人血清中抗MC膜表面抗原及抗MCHR1抗体均为阴性。结论白癜风患者血清中存在抗MCHR1的自身抗体,MCHR1是MC膜表面的白癜风相关抗原。     

The inaccessibility of the outer membrane of adherent Treponema pallidum (Nichols strain) to anti-treponemal antibodies, a possible role of serum proteins.

Fresh and aged adherent T pallidum were used to study the accessibility of their outer membrane to antibodies by means of an indirect immunofluorescent technique. The integrity of the outer membrane was demonstrated by the non-reactivity with a monoclonal antibody directed against the axial filaments. Using the sera from patients with sero-positive primary and secondary syphilis no binding of IgG and IgM antibodies was observed. However, IgG and IgM antibody fractions isolated from the sera of patients with secondary syphilis, gave with the fresh fibroblast-adhering treponemes a mean of 14.5% IgG- and of 43.2% IgM positive treponemes. These means were 32.1% and 87.3% respectively for aged treponemes. Lower percentages were observed when fibronectin adhering treponemes were used. This demonstrates the inability of the outer membrane to bind antibodies in a majority of the fresh treponemes. This is partly lost on in vitro aging. Absence of IgG- and IgM fluorescence was also observed when sequential incubations with the antibody fractions and control sera were used. This was accompanied by the deposition of the third complement factor (C3) around the treponemes. Incubations of IgG- or IgM pre-coated adherent treponemes with heat-inactivated control sera or a C3 deficient serum did not result in the deposition of C3, and partially restored the detection of human antibodies. The most likely explanation for the absence of fluorescence is that antibodies become buried in an extra-cellular layer of serum proteins. The deposition of C3 from control sera alone most probably points to the classical pathway of complement activation and suggests that antibodies of rabbit origin constitute a part of the extracellular layer of treponemes.     

Basement membrane antibodies in sera of haematopoietic cell recipients are associated with graft‐versus‐host disease

Background Graft‐versus‐host disease (GvHD) occurs frequently after haematopoietic cell transplantation (HCT). Mucocutaneous lesions of GvHD may mimic bullous autoimmune dermatoses, and 10 cases of concurrent GvHD and a bullous autoimmune disease have been reported in the literature. Objective To determine the frequency of circulating antibodies to the cutaneous basement membrane zone (BMZ) in HCT patients with GvHD in comparison with HCT patients without GvHD, psoriasis patients and healthy controls. Subjects and methods We examined 42 patients with chronic GvHD, 18 HCT patients without GvHD, 11 psoriasis patients and 40 healthy controls, prospectively. Sera were tested by indirect immunofluorescence (IIF) on salt‐split skin, NC16a‐ELISA and immunoblot using keratinocyte extracts. Univariate statistical analyses and logistic regression were performed to assess possible correlations of graft and patient characteristics with the presence of BMZ antibodies. Results Circulating basement membrane zone (BMZ) antibodies were detected in 10/42 (24%) GvHD sera by immunoblot, but not in any of the HCT sera from patients without GvHD (0/18; 0%). The antibodies targeted collagen VII, BP230, collagen XVII/BP180 or p200/laminin γ1. Clinically manifest bullous autoimmune dermatoses (bullous pemphigoid or epidermolysis bullosa acquisita) were found in two GvHD patients. 1/11 (9%) psoriasis sera and 1/40 (2.4%) healthy control sera reacted with collagen XVII or BP230, respectively. Conclusions Circulating BMZ antibodies are significantly associated with chronic GvHD in contrast to uncomplicated HCT. Recurrent mucocutaneous lesions in chronic inflammatory skin disorders may liberate antigens, which may lead to production of BMZ antibodies, particularly in the context of GvHD‐mediated reduced self‐tolerance.     

Autoantibody formation against a 190-kDa antigen of the desmosomal plaque in pemphigus foliaceus

Summary We report changes in the antigen recognition pattern of sera from two pemphigus foliaceus patients with a long-term follow-up. The patients' sera were analysed by immunoblotting using different antigenic sources: cultured human keratinocytes, bovine tongue epithelium and a recombinant protein corresponding to the C-terminal end of the 230-kDa bullous pemphigoid antigen. While initial serum samples reacted exclusively with the 160-kDa desmoglein 1, the later sera reacted both with desmoglein 1 and a 190-kDa antigen immunolocalized to the desmosomal plaque, previously demonstrated to be recognized by sera of some patients with paraneoplastic pemphigus. lgG subclass analysis further showed that antidesmoglein 1 antibodies were of lgGl and/or IgG4 subclasses, while anti-190-kDa antibodies were lgG3. The patients were free of malignancy.     

Wheat protein antibodies in dermatitis herpetiformis

An enzyme-linked immunosorbent assay was used to detect class-specific antibodies to wheat protein antigens. Antibodies which we detected by this technique reacted indistinguishably with antigens prepared from crude gluten, crude gliadin, alpha-gliadin, Frazer fraction III, and subfraction B and B3 of Frazer fraction III. No sera reacted with a human serum albumin control antigen. The prevalence of IgG antibodies to wheat protein antigens was significantly greater in patients with gluten sensitive enteropathy, 12 of 17, (p = .00011) and in patients with dermatitis herpetiformis, 5 of 14, (p = .046) than in normal control subjects. Strongly positive reactions for IgG antibodies were present only in patients with gluten sensitive enteropathy or dermatitis herpetiformis. IgA antibodies to wheat protein antigens were found only in gluten-sensitive enteropathy patients. We have found this to be a sensitive, precise technique for measurement of antibodies to wheat protein antigens and feel that it will prove useful in evaluation of the role of immune complexes involving wheat protein antigens and their antibodies in the pathogenesis of dermatitis herpetiformis.     

Psoriasis vulgaris: immunologlobulin binding to human epidermis after limited proteolysis]

Immune complexes isolated from sera of psoriatic patients and healthy controls show an identical pattern in sodiumdodecylsulfate polyacrylamide gel electrophoresis. And so it seems to be unlikely that the increased provable serum immune complexes by psoriatics contain specific protein antigens.--Following to limited proteolysis of normal human epidermis, antibodies which solely are provable in sera of psoriatic patients could bind to proteolytic altered structures. For achieving a similar process in vivo, the following conditions are to be discussed: (1) an elevated concentration of certain autoantibodies in the sera of psoriatic patients and a temporary increased vessels permeability for antibodies, (2) the availability of structures in the epidermis of psoriatics with increased affintiy to certain antibodies. These structures may be produced by limited proteolysis or as a result of the disturbed differentiation of epidermal cells.     

Immune complexes in pemphigus and bullous pemphigoid

28 serum and 10 blister fluid specimens obtained from 28 pemphigus vulgaris (PV) patients were assayed for immune complexes using the polyethylene glycol (PEG)assay. 11% of sera and 30% of the blister fluids have elevated levels of immune complexes. Anti-intercellular cement substance (ICS) antibody could not be detected in PEG precipitates, but was present in the supernatants from the serum. However, anti-ICS antibody was found in 70 of the precipitated complexes from the blister fluid. 18 serum and 31 blister fluid specimens obtained from 18 bullous pemphigoid (BP) patients were assayed for immune complexes using the PEG assay. 17% of sera and 31% of the blister fluids have elevated levels of immune complexes. Antibasement membrane zone (BMZ) antibody could not be detected in the PEG precipitates, but was present in the supernatants obtained from the sera. Anti-BMZ antibody was found in 57% of the precipitated complexes from the blister fluids. This data further supports the hypothesis that the majority of the complexes in PV and BP are formed in situ.     

大疱性类天疱疮和妊娠疱疹患者血清抗BP180 NC16A抗体的纯化和鉴定

目的 探讨大疱性类天疱疮（BP）和妊娠疱疹（HG）患者血清抗BPl80 NC16A 抗体的纯化和鉴定方法。方法 原核表达系统pGEX-2TBP180NC16A表达GST/NC16A融合蛋白,将融合蛋白与谷胱甘肽琼脂糖凝聚微珠进行共价偶联。微珠亲和层析法纯化BP和HG患者血清中抗BP180 NC16A抗体,并用ELISA、免疫荧光、及Western印迹进行鉴定。结果 原核表达系统pGEX-2TBP180NC16A表达37 000 GST/NC16A融合蛋白,微珠亲和层析法纯化后得单一抗BP180 NC16A抗体。经ELISA方法定量后确定其含量为2.4 mg/ml;该抗体能与人皮肤基底膜带结合,证明抗体活性;免疫印迹可见单一片段,显示抗体纯度。结论 微珠亲和层析法纯化的BP和HG患者血清中抗BP180 NC16A自身抗体活性高、特异性强。     

Differentiating anti-lamina lucida and anti-sublamina densa anti-BMZ antibodies by indirect immunofluorescence on 1.0 M sodium chloride-separated skin

Sixty-one bullous disease sera containing IgG anti-BMZ antibodies were examined by indirect immunofluorescence on intact skin and skin separated through the lamina lucida by incubation in 1.0 M NaCl. All sera produced an indistinguishable pattern of linear immunofluorescence on intact skin at dilutions of 1:10 or higher. On separated skin, antibodies bound to either the epidermal (epidermal pattern), dermal (dermal pattern), or epidermal and dermal (combined pattern) sides of the separation. The binding patterns were consistent on separated skin from several donors and titers of anti-basement membrane zone antibodies on separated skin were comparable to those on intact skin. Sera from 3 patients with herpes gestationis (HG), 36 patients with bullous pemphigoid (BP), and 1 patient with clinical and histologic features of epidermolysis bullosa acquisita (EBA) showed an epidermal pattern. Sera from 9 patients with BP showed a combined pattern and sera from 6 patients with EBA and 6 patients with clinical and histologic features of BP showed a dermal pattern. Indirect immunoelectron microscopy of selected sera showed antibodies producing the epidermal and combined patterns were anti-lamina lucida antibodies and those producing the dermal pattern were anti-sublamina densa antibodies. These results show indirect immunofluorescence on separated skin is a dependable method for differentiating bullous disease anti-lamina lucida and anti-sublamina densa antibodies and that differentiating between the antibodies is essential for accurate diagnosis in some patients. The results also suggest BP anti-lamina lucida antibodies may have more than one antigenic specificity.     

Circulating basement membrane zone antibodies are found in lichen sclerosus of the vulva

This study was undertaken to investigate the prevalence of basement membrane zone (BMZ) antibodies, their subtypes and clinical correlations in 96 patients attending the Oxford vulval clinic with lichen sclerosus (LS) of the vulva. Indirect immunofluorescence of serum (intact and split skin) to immunoglobulin (Ig)G was performed looking for the presence or absence of staining at the BMZ. Eighteen patients' sera (14 with positive indirect immunofluorescence to IgG) were examined for IgG antibodies of subclasses IgG1, 2 and 3, and 23 sera were examined for IgG4 subclass. Immunoblotting was performed in seven patients, and showed antibodies to BP180 in six patients and BP230 in one. One-third of patients with vulval LS had BMZ antibodies binding to the epidermal side of salt split skin. Immunoblotting showed antibodies to BP180 collagen XVII (six of seven patients) and BP230 in one. The subclasses were chiefly IgG1 and 2, different from those seen in bullous pemphigoid. No clinical correlation was found between the presence of antibodies and the presence of erosions, severity of scarring, age of onset of disease or response to treatment. These antibodies may be a reflection of a tendency to produce autoantibodies or be relevant to pathogenesis.     

Circulating IgA anti-basement membrane zone antibodies in dermatitis herpetiformis.

Criculating anti-basement membrane zone antibodies of the IgA class were detected in the sera of 2 or 6 dermatitis herpetiformis (DH) patients who had linear in-vivo-bound IgA deposits and in 1 of 42 DH patients who had granular vivo-bound IgA deposits. In the former 2 patients the circulating antibodies were localized ultrastructurally to the identical site where the in vivo-bound antibodies were localized and were bound by antigens in either the lamina lucida or the subbasal lamina anchoring fibril area of the basement membrane zone of normal human skin.     

Assessment of skin basement membrane zone antibodies in the urine of patients with acquired subepidermal immunobullous diseases

BACKGROUND: In bullous pemphigoid (BP), cicatricial pemphigoid (CP) and linear IgA disease (LAD), autoantibodies to the basement membrane zone (BMZ) are found in skin and mucosa, blood and blister fluid. OBJECTIVES: To assess whether BMZ antibodies might also be detected in urine. METHODS: Urine and serum samples from 62 patients (32 with BP, 17 with CP and 13 with LAD) were analysed for antibody isotypes and subclasses by indirect immunofluorescence, and urine and serum samples from 40 patients (25 with BP, eight with CP and seven with LAD) were screened for target antigens using immunoblotting. RESULTS: Fourteen of 32 patients with BP had detectable levels of IgG BMZ autoantibodies in their urine, and all 32 had positive sera. Of these 14 BP patients, 13 had epidermal-binding serum autoantibodies at a titre > 1 : 160, and one had dermal-binding serum antibodies at a titre of 1 : 40. BMZ autoantibodies were not detected in the urine of the CP or LAD patients, but the corresponding sera were of low titre or negative. IgG subclasses (IgG1-4) were less frequently detected in urine than in serum. IgG4 was the predominant subgroup found (10 urine samples and all 14 sera), followed by IgG1 (two urine samples and 12 sera); IgG2 was detected in a single urine sample and three sera, and IgG3 was not detected. Eight of 25 BP and one of eight CP urine samples were positive on immunoblotting, and bound BP230 and/or BP180 with IgA and/or IgG autoantibodies. IgA autoantibodies were not detected in the urine of the seven LAD patients. The corresponding sera were often more positive, with 21 of 25 BP, five of eight CP and six of seven LAD sera immunoblotting the major BP antigens. CONCLUSIONS: The detection of IgG autoantibodies from urine samples using indirect immunofluorescence correlated with a high titre of IgG autoantibodies in the serum. IgG and IgA autoantibodies in the urine were detected by immunoblotting, although less frequently than in serum. The finding of BMZ antibodies in the urine of many BP patients may have clinical relevance, and may have a restricted application in the diagnosis of immunobullous disease.     

Autoantibodies to Basement Membrane Collagen: Epidermolysis Bullosa Simplex versus Bullous Pemphigoid

As judged by passive hemagglutination and hemagglutination-inhibition assays, sera from six patients in one family with dominant epidermolysis bullosa contain clearly demonstrable titers of antibodies against the collagen C chain which is derived from basement membrane structures. Moreover, the circulating antibodies observed in these patients are apparently specific for the C chain as no titers were observed when using four additional well-characterized collagen chains in the indicated assays. In contrast to the results with sera from epidermolysis bullosa patients, sera from a series of age- and sex-matched healthy controls, as well as from a group of patients with bullous pemphigoid, did not contain antibodies to any of the test antigens. These results thus clearly differentiate the autoimmune response to basement membranes observed in bullous pemphigoid from that observed in epidermolysis bullosa simplex.     

Use of 1M NaCl split skin in the indirect immunofluorescence of the linear IgA bullous dermatoses

We compared 1M NaCl split skin with intact skin as substrates for detection of circulating IgA anti-basement membrane (BMZ) antibodies in linear IgA dermatosis (LAD). The sera of 63 patients with LAD including 27 adults and 36 with chronic bullous dermatosis of childhood (CBDC) were examined. 62% of patients overall had circulating IgA anti-BMZ antibodies detectable on intact skin. 73% of patients had circulating antibodies detectable on lM NaCl split skin as an additional 7 sera were positive. This was a statistically significant increase (p<0.01). The sera were mostly positive at a higher titre on the split skin when compared with intact skin. On routine indirect immunofluorescence (IIF) all positive sera produced linear fluorescence on the epidermal side of the split. Twenty serum samples were incubated with split skin overnight; 4 of these specimens exhibited linear fluorescence on the epidermal and dermal sides of the split after this prolonged incubation. These findings suggest that 1M NaCl split skin is a more sensitive substrate for detection of circulating IgA anti-BMZ antibodies in LAD, that these antibodies are heterogeneous and that the target antigen has an epidermal component.