Monitoring disease activity in pemphigus with enzyme-linked immunosorbent assay using recombinant desmogleins 1 and 3

BACKGROUND: Pemphigus is an antidesmoglein (Dsg) autoimmune disease that is divided into two major subtypes: pemphigus foliaceus (PF) and pemphigus vulgaris (PV). We previously developed enzyme-linked immunosorbent assays (ELISAs) using recombinant Dsg1 and Dsg3 to detect IgG autoantibodies in patients with pemphigus. The protocol for the ELISAs was optimized for serological diagnosis, but under the conditions used, these assays were not particularly useful for monitoring disease activity in certain patients. That is, the sera from some patients with high-titre antibodies continued to show high index values in the ELISA after clinical improvement. OBJECTIVES: In the study reported here, we modified the ELISA protocol to obtain 'true' index values that exhibit a better correlation with disease activity. METHODS: We tested two cases of pemphigus foliaceus (PF) and four cases of pemphigus vulgaris (PV), each with ELISA index values greater than 150 for Dsg1 or Dsg3. We ran an ELISA with sera from these patients serially diluted from 1 : 100 to 1 : 12,800. We then performed ELISA with a series of PV No. 1 sera diluted to 1 : 800 and PV No. 2-4 and PF No. 1-2 sera diluted to 1 : 1600, after which we plotted the ELISA index values against the time course of disease activity. RESULTS: In each of these cases, there was no apparent decline, over the course of the disease activity, in the ELISA index values at a serum dilution of 1 : 100, probably because the antigen-antibody reaction was saturated at that dilution. After running an ELISA with sera serially diluted from 1 : 100 to 1 : 12,800 we found that a linear dose-dependency between the dilution value and the index value was only observed when sera were diluted to 1 : 800 or more in one case (PV No.1) and to 1 : 1600 or more in the other five cases (PV No. 2-4, PF No. 1-2). After performing ELISA with these series as outlined above we plotted the ELISA index values against the time course of disease activity and found that the index values obtained from these appropriately diluted sera fluctuated in parallel with disease activity, and declined with clinical improvement. CONCLUSIONS: These findings indicate that when appropriate dilutions are used in Dsg1 and Dsg3 ELISA, these assays can provide useful serological information for assessing disease activity in PF and PV.     

Evaluating efficacy of plasmapheresis for patients with pemphigus using desmoglein enzyme-linked immunosorbent assay

BACKGROUND: Pemphigus is an autoimmune bullous disease caused by circulating IgG autoantibodies against cell-cell adhesion molecules between keratinocytes: desmoglein (Dsg) 3 and Dsg1. Plasmapheresis is often used to treat severe cases of pemphigus. Enzyme-linked immunosorbent assays (ELISAs) against recombinant Dsg3 and Dsg1 have recently become available, allowing us to quantify IgG autoantibodies against Dsg3 and Dsg1. OBJECTIVES: Using ELISA against recombinant Dsg3 and Dsg1, to evaluate the efficacy of plasmapheresis in pemphigus. METHODS: Sera obtained from 10 patients with pemphigus vulgaris and one with pemphigus foliaceus following a total of 16 cycles of centrifugal plasmapheresis and 12 effluents from the plasmapheresis were subjected to ELISA against Dsgs. The percentage of IgG autoantibodies removed was calculated using two different formulae: one used serum titres before and immediately after plasmapheresis and the other used the absolute amounts of IgG autoantibodies in the effluents. The percentage fall of anti-Dsg antibody level was also calculated using the serum titres 1 day after plasmapheresis. RESULTS: Using serum titres immediately after plasmapheresis, there was a mean fall per treatment in anti-Dsg 3 antibody level of 43.0% (n = 12) and in anti-Dsg1 antibody level of 48.4% (n = 7). By contrast, calculated from the effluents, on average one treatment removed only 14.6% of anti-Dsg3 antibodies (n = 12) and 16.4% of anti-Dsg1 antibodies (n = 7). This should reflect the correct percentage as it is based on the absolute amounts of IgG autoantibodies removed. Using serum titres 1 day after plasmapheresis, there was a mean fall per treatment in anti-Dsg 3 antibody level of 12.9% (n = 2) and in anti-Dsg1 antibody level of 8.4% (n = 4). The percentage of IgG autoantibodies removed 1 day after plasmapheresis was lower than that found to be removed immediately after plasmapheresis (n = 6). CONCLUSIONS: One centrifugal plasmapheresis procedure eliminates about 15% of the IgG autoantibodies from the whole body. The percentage fall of anti-Dsg IgG antibody level differed depending on when the serum samples were obtained after plasmapheresis. The change in the percentage fall of anti-Dsg antibody level within 1 day after plasmapheresis is thought to be attributable to the passive diffusion of the IgG autoantibodies from the extravascular space to the intravascular space. Therefore, removal of IgG autoantibodies calculated using serum titres only should be evaluated carefully considering the equilibration of the IgG autoantibodies between the different body spaces.     

The clinical transition between pemphigus foliaceus and pemphigus vulgaris correlates well with the changes in autoantibody profile assessed by an enzyme-linked immunosorbent assay

BACKGROUND: There are a number of reports of pemphigus with clinical shifting between pemphigus foliaceus (PF) and pemphigus vulgaris (PV). On the other hand, a novel enzyme-linked immunosorbent assay (ELISA) against recombinant baculoproteins of desmoglein 1 (Dsg1) (PF antigen) and Dsg3 (PV antigen) has been established and found to be extremely sensitive and specific. OBJECTIVES: To characterize the change in the antibody profiles in a series of pemphigus cases with mixed features of PF and PV by various methods, including the novel ELISA. Patients/methods Sera were obtained from eight cases undergoing a shift between PF and PV and three cases of coexistent PF and PV. The autoantigens were analysed by ELISA, as well as by immunofluorescence using normal human skin sections and immunoblotting using normal human epidermal extracts. RESULTS: The results of the ELISA, immunofluorescence and immunoblotting studies showed that the transition between PF and PV correlates well with the changes of autoantibodies against either Dsg1 or Dsg3. CONCLUSIONS: The clinical phenotype at each stage is defined by the anti-Dsg antibody profile in the serum of these pemphigus patients showing mixed features of PF and PV. In addition, ELISA using recombinant baculoproteins was particularly useful in distinguishing PF and PV.     

IgG/IgA pemphigus with IgG and IgA antidesmoglein 1 antibodies detected by enzyme-linked immunosorbent assay

Pemphigus is an autoimmune mucocutaneous bullous disease characterized by autoantibodies against the cell surfaces of epidermal keratinocytes. Six cases with deposition of both IgG and IgA on keratinocyte cell surfaces have been reported in the recent literature. We provisionally termed these cases IgG/IgA pemphigus. We describe a 42-year-old Japanese woman with clinical and histopathological features resembling herpetiform pemphigus who demonstrated in vivo bound and circulating anticell surface autoantibodies of both IgG and IgA classes on immunofluorescence examination. Enzyme-linked immunosorbent assay using baculovirus-expressed recombinant desmoglein (Dsg) 1 and Dsg 3 showed that both IgG and IgA antibodies reacted with Dsg1. The reactivity was completely adsorbed with preincubation of serum with Dsg1 baculoprotein, further confirming the exclusive reactivity of both IgG and IgA antibodies with Dsg1. This is the second case of IgG/IgA pemphigus in which the human target antigens for both IgG and IgA antibodies have been unequivocally identified. This study provides further evidence that IgG/IgA pemphigus is a distinct disease entity.     

The detection of IgG and IgA autoantibodies to desmocollins 1-3 by enzyme-linked immunosorbent assays using baculovirus-expressed proteins, in atypical pemphigus but not in typical pemphigus

BACKGROUND: We have shown previously that human desmocollin (Dsc) 1 is recognized by IgA autoantibodies of subcorneal pustular dermatosis (SPD) type IgA pemphigus. However, the presence of IgG anti-Dsc autoantibodies is still controversial, and antibodies to Dsc2 and Dsc3 have not been clearly identified. OBJECTIVES: To investigate this by producing recombinant proteins consisting of the entire extracellular domains of human Dsc1, 2 and 3 in baculovirus, and to use them to establish an enzyme-linked immunosorbent assay (ELISA). METHODS: By this ELISA, we examined in total 165 cases of various types of autoimmune bullous diseases, as well as 23 normal controls. RESULTS: None of 45 sera of classical pemphigus showed either IgG or IgA antibodies to any Dsc. In contrast, one atypical pemphigus serum showed both IgG and IgA antibodies to Dsc1, which were adsorbed by incubation with Dsc1 baculoprotein. Furthermore, this ELISA detected both IgA and IgG anti-Dsc3 antibodies in one atypical case, and IgA antibodies to both Dsc2 and Dsc3 in another. This reactivity was confirmed by positive IgA immunofluorescence with Dsc2 and Dsc3 expressed on COS-7 cells. These results show that both IgG and IgA autoantibodies against all of Dsc1-3 are present in the sera of particular cases of nonclassical pemphigus, except for IgG antibodies to Dsc2, but that they are not detected in classical pemphigus. Unexpectedly, although IgA antibodies of all of eight SPD type IgA pemphigus sera reacted with Dsc1 expressed on COS-7 cells, only one serum was positive in Dsc1 ELISA for IgA. CONCLUSIONS: This result indicates either that Dscs expressed by baculovirus may not adopt the correct conformation or that Dscs may need association with other molecules to express all the epitopes for autoantibodies.     

Neonatal pemphigus vulgaris with extensive mucocutaneous lesions from a mother with oral pemphigus vulgaris

The clinical phenotype of pemphigus is well explained by the combination of desmoglein (Dsg) 1 and Dsg3 distribution pattern and antiDsg autoantibody profile (Dsg compensation theory). It has been reported that neonatal skin has a similar Dsg distribution pattern to adult mucosal epithelia. We describe a newborn girl with mucocutaneous pemphigus vulgaris (PV) from a mother with mucosal dominant PV. The mother had had painful oral erosions for at least 7 months. Histopathological examination and direct and indirect immunofluorescence studies confirmed the diagnosis of PV and neonatal PV in the mother and daughter, respectively. The mother had a high titre of anti-Dsg3 IgG and a low titre of antiDsg1 IgG, while the neonate had only a high titre of anti-Dsg3 IgG, but no detectable antiDsg1 IgG. AntiDsg3 IgG, which caused the oral dominant phenotype in the mother, induced extensive oral as well as cutaneous lesions in the neonate. Our case provides clinical evidence for the Dsg compensation theory in neonatal PV.     

A study of desmoglein 1 autoantibodies in pemphigus vulgaris: racial differences in frequency and the association with a more severe phenotype

BACKGROUND: Pemphigus vulgaris (PV) is characterized by pathogenic autoantibodies to desmoglein (Dsg) 3, but additional antibodies to Dsg1, the pemphigus foliaceus antigen, are detectable in some cases. OBJECTIVES: To investigate the clinical significance of the presence of both Dsg 1 and 3 antibodies. METHODS: In 79 subjects with PV, enzyme-linked immunosorbent assays were used to detect IgG autoantibodies reactive with the ectodomain of Dsg1 and Dsg3. RESULTS: There was a clear association between the clinical phenotype and the Dsg antibody profile. All subjects had Dsg3 autoantibodies and 61% had coexisting Dsg1 antibodies (Dsg3+/Dsg1+). PV limited entirely to the mucosal surfaces was seen only in Dsg3+/Dsg1- patients, while additional Dsg1 antibodies (Dsg3+/Dsg1+) predicted cutaneous in addition to mucosal involvement. Although minor cutaneous involvement was observed in most Dsg3+/Dsg1- patients, severe cutaneous involvement was seen only in Dsg3+/Dsg1+ patients. Dsg1 antibodies were detectable early in the course of disease and their appearance did not relate to the use of systemic therapy. The proportion of Dsg1+ patients was higher in those of Indian origin compared with white northern Europeans (P < 0.05). CONCLUSIONS: These data suggest that the presence of Dsg1 antibodies is predictive of a potentially more severe disease and that genetic factors may determine the Dsg antibody profile.     

Serum and salivary desmoglein 1 and 3 enzyme‐linked immunosorbent assay in pemphigus vulgaris: correlation with phenotype and severity

Background To the best of our knowledge there is only one report about salivary desmoglein (Dsg) 1 and 3 enzyme‐linked immunosorbent assay (ELISA) in pemphigus vulgaris (PV), whereas several studies have been performed on serum. Aims To find the sensitivity of serum and salivary anti‐Dsg1 and 3 antibodies in the diagnosis of PV, and to determine the relationship between disease severity and phenotype with antibody levels. Methods Fifty new patients with PV were included in this study. The diagnosis of PV was confirmed by histopathology and direct immunofluorescence. Demographical data, disease severity and phenotypes were recorded on questionnaire sheets. Dsg1 and Dsg3 ELISA were performed on serum and salivary samples of patients and controls. Results Thirty‐seven patients had mucocutaneous phenotype; whereas mucosal dominant and cutaneous dominant phenotypes were seen in 11 and 2 patients respectively. The sensitivities of serum anti‐Dsg3 and anti‐Dsg1 were 94% and 72% respectively. The sensitivities of salivary anti‐Dsg3 and anti‐Dsg1 antibodies were accordingly 94% and 70%. Compared with mucosal phenotype, serum and salivary anti‐Dsg1 antibodies were significantly higher in the patients with mucocutaneous phenotype. Serum Dsg1 antibodies were related with cutaneous and serum Dsg3 antibodies with mucosal severity scores. Salivary Dsg1 antibodies were significantly correlated with mucosal severity (P = 0.00); however there was no correlation between this antibody and cutaneous severity (P = 0.07). Salivary Dsg3 antibodies were not correlated with mucosal severity (P = 0.16). Conclusion Saliva Dsg ELISA could be used for diagnosis of PV. Salivary Dsg1 antibodies had a significant correlation with mucosal severity.     

The transition of pemphigus vulgaris into pemphigus foliaceus: a reflection of changing desmoglein 1 and 3 autoantibody levels in pemphigus vulgaris

The transition of pemphigus vulgaris (PV) into pemphigus foliaceus (PF) is rare and the immunological changes underlying this event are not well understood. We report a 44-year-old woman who presented with oral and cutaneous erosions typical of PV. Over a 9-year period, the clinical features evolved into those of PF. To examine whether quantitative changes in desmoglein (Dsg) antibodies were associated with this transition, Dsg1 and Dsg3 antibody levels were measured by enzyme-linked immunosorbent assay in 82 sequential serum samples collected over this period. At presentation, when the phenotype was PV with oral and cutaneous erosions, antibodies to both Dsg1 and Dsg3 were detected. The disappearance of oral involvement was associated with a decline in Dsg3 antibodies, which are now undetectable, while the development of more severe skin involvement was associated with rising Dsg1 antibody levels. These data strongly suggest that the change in clinical features is a reflection of qualitative and quantitative changes in antibody profile. It is not known whether the transition to PF is permanent or whether disease relapses in the future may be associated with the re-emergence of Dsg3 antibodies, oral ulceration and a PV phenotype.     

Coexistence of IgA antibodies to desmogleins 1 and 3 in pemphigus vulgaris, pemphigus foliaceus and paraneoplastic pemphigus

BACKGROUND: Pemphigus is a bullous mucocutaneous autoimmune disease characterized by IgG autoantibodies to desmoglein (Dsg) 1 and/or Dsg3. Occasionally direct immunofluorescence of pemphigus skin reveals IgA depositions with an intraepidermal intercellular pattern in addition to the IgG deposition. OBJECTIVES: To investigate if pemphigus patients, in addition to having IgG autoantibodies, also generate IgA antibodies to Dsg1 and/or Dsg3. PATIENTS/METHODS: Sera of 100 pemphigus patients and 36 bullous pemphigoid controls were tested by IgA enzyme-linked immunosorbent assay (ELISA) to the recombinant extracellular domains of Dsg1 and Dsg3. The patients were selected on clinical grounds and positive IgG ELISA index values for Dsg1 and/or Dsg3. They were divided into four groups: patients having IgG to only Dsg1 (n=34), patients having IgG to both Dsg1 and Dsg3 (n=31), patients having IgG to only Dsg3 (n=27) and patients who had paraneoplastic pemphigus (PNP) (n=8). RESULTS: IgA antibodies to Dsg1 were found in 13 (38%) of the patients with IgG to Dsg1, in five (16%) of the patients with IgG to both Dsg1 and Dsg3, in four (15%) of the patients with IgG to Dsg3 and in none of the PNP patients. IgA antibodies to Dsg3 were found in one (3%) of the patients with IgG to Dsg1, in 18 (58%) of the patients with IgG to both Dsg1 and 3, in 18 (67%) of the patients with IgG to Dsg3, and in four (50%) of the PNP patients. Immunofluorescence analysis demonstrated intraepidermal intercellular staining IgA antibodies in serum and intercellular IgA deposits in skin of IgA ELISA-positive patients, although to a lesser extent than by ELISA. CONCLUSIONS: This study shows that in a considerable number of supposedly IgG-mediated pemphigus patients IgA to Dsg1 and Dsg3 is also present. In most cases the antigen specificity of the IgA follows the antigen specificity of the IgG, although in a small number of cases IgA is present against the Dsg not recognized by IgG.     

Paraneoplastic pemphigus without antidesmoglein 3 or antidesmoglein 1 autoantibodies

Paraneoplastic pemphigus (PNP) is an autoimmune mucocutaneous blistering disease characterized by IgG autoantibodies that bind to various epithelia and immunoprecipitate a complex of 250, 230, 210, 190 and 170 kDa proteins. A recent study has suggested that PNP patients have antidesmoglein (Dsg) 3 autoantibody and that the antibody plays a pathogenic role in PNP. We report a 72-year-old woman with PNP associated with thymoma and adenocarcinoma of the lung. Diagnosis of PNP was made by the characteristic clinical, histological and immunopathological findings, as well as immunoprecipitation of characteristic 230, 210 and 190 kDa proteins. Using enzyme-linked immunosorbent assay with baculovirus-expressed recombinant proteins, the patient's serum was negative against both Dsg 3 and Dsg 1. This finding is unusual, and it suggests that the target antigen, which is involved in acantholysis, may be other than Dsg 3 in this case.     

Desmoglein 1 and 3 enzyme-linked immunosorbent assay in Iranian patients with pemphigus vulgaris: correlation with phenotype, severity, and disease activity

BACKGROUND: Pemphigus vulgaris (PV) is a chronic autoimmune blistering disorder of the skin and mucosa characterized by the presence of autoantibodies against desmoglein3 (Dsg3). Some patients also have antibodies against desmoglein1 (Dsg1). The aims of this study were to evaluate the diagnostic value of Dsg enzyme-linked immunosorbent assay (ELISA) in Iranian PV patients, to assess its correlation with the clinical phenotype and severity of disease and to investigate the changes of these antibodies after treatment. METHODS: Seventy-three patients with PV (29 men, 44 women) presenting to the Pemphigus Research Unit at Razi Hospital, Tehran, Iran were enrolled. ELISAs were used to detect IgG autoantibodies reactive with the ectodomains of Dsg1 and Dsg3, and the correlation of antibodies with the clinical phenotype as well as oral and skin disease severity was assessed. In addition, the tests were repeated in 18 patients after treatment and the resulting remission. RESULTS: Anti-Dsg1 and anti-Dsg3 were detected in 56 (76.7%) and 69 (94.5%) patients, respectively. Anti-Dsg1 and anti-Dsg3 antibodies were present in 48 (94.1%) and 50 (98%) patients with mucocutaneous type, in 2 (12.5%) and 15 (93.7%) patients with mucosal type, and in 6 (100%) and 4 (66.7%) patients with cutaneous PV, respectively. The mean anti-Dsg1 index values were significantly higher in cutaneous and mucocutaneous phenotypes than mucosal PV (P < 0.001). The mean anti-Dsg3 index values were significantly lower in cutaneous and mucosal phenotypes than mucocutaneous PV (P < 0.01). The severity of skin lesions (but not oral lesions) was correlated with anti-Dsg1 antibody level (P < 0.001); on the other hand, the severity of oral lesions (P < 0.01) as well as skin lesions (P < 0.001) was significantly correlated with anti-Dsg3 antibody levels. Both anti-Dsg1 and anti-Dsg3 levels were significantly reduced after treatment and clinical remission (P < 0.001). CONCLUSION: Dsg ELISA is not only a sensitive tool for the diagnosis of PV, it can also serve as a predictive means for assessing the severity as well as for monitoring the disease activity. Although, in general, the clinical phenotype is related to the antibody profile, there are occasional cases with discordant phenotype and antibody profile. These discrepancies might be explained by genetic variations or the presence of possible minor antigens involved in the pathogenesis of pemphigus.     

Successful removal of pathogenic autoantibodies in pemphigus by immunoadsorption with a tryptophan-linked polyvinylalcohol adsorber

BACKGROUND: Autoantibodies against the glycoproteins desmogleins 1 and 3 which are components of the desmosomal adhesion complex have been shown to be responsible for the loss of epidermal adhesion characteristic of pemphigus. Elimination of these antibodies should clinically improve the pathology of this group of severe autoimmune blistering skin disorders. OBJECTIVES: To gather information about the efficacy of immunoadsorption in the reduction of pathogenic serum autoantibodies against desmogleins 1 and 3 and to evaluate the clinical benefit of immunoadsorption in the treatment of pemphigus. PATIENTS AND METHODS: Nine patients with pemphigus and detectable circulating desmoglein antibodies were included in this open trial. Two immunoadsorption treatments separated by a 48-h interval were performed per patient. Anti-desmoglein 1 and 3 antibodies in the patients' sera were monitored by enzyme-linked immunosorbent assay and indirect immunofluorescence before and following each immunoadsorption. In addition, the efficacy of the tryptophan-linked polyvinylalcohol adsorber in removing antidesmoglein antibodies was directly evaluated. RESULTS: IgG antibodies against desmogleins 1 and 3 were effectively eliminated from the patients' plasma upon passage through the adsorber and levels of serum autoantibodies were significantly reduced by immunoadsorption. A single immunoadsorption treatment led to a reduction of antidesmoglein autoantibodies of about 30%. Clinically, mucosal and cutaneous lesions improved allowing for a reduction of the systemic immunosuppressive treatment with glucocorticoids. CONCLUSIONS: Immunoadsorption with tryptophan-linked polyvinylalcohol adsorbers holds promise as a highly effective and safe adjuvant therapeutic regimen in pemphigus.     

天疱疮患者病情与抗桥粒芯蛋白抗体水平的相关性研究

目的:研究天疱疮患者血清中抗桥粒芯蛋白(desmoglein,Dsg)1和抗Dsg3抗体水平与其皮肤、口腔黏膜损害严重程度的相关性,同时对间接免疫荧光(IIF)检测的天疱疮抗体滴度与治疗中使用皮质类固醇控制剂量的相关性进行分析。方法:采用酶联免疫吸附试验(ELISA)试剂盒测定55例天疱疮患者血清中抗Dsg1和抗Dsg3抗体水平。结果:抗Dsg1抗体水平与患者皮肤损害严重程度有显著相关性(P<0.01),抗Dsg3抗体水平与口腔黏膜损害严重程度有显著相关性(P<0.01)。天疱疮患者血清IIF滴度与抗Dsg1抗体水平相关(P<0.01),寻常型天疱疮患者IIF滴度与抗Dsg1和抗Dsg3抗体水平均有相关性(P分别<0.01和<0.05)。寻常型天疱疮患者皮质类固醇控制剂量与抗Dsg1抗体水平和IIF滴度显著相关(P<0.05)。结论:ELISA方法检测天疱疮患者抗Dsg1和抗Dsg3抗体对天疱疮的临床诊断、分型、衡量口腔黏膜和皮肤损害严重程度具有一定意义。     

The severity of cutaneous and oral pemphigus is related to desmoglein 1 and 3 antibody levels

BACKGROUND: Pemphigus vulgaris (PV) and foliaceus (PF) are characterized by antibodies to the desmosomal proteins desmoglein 3 (Dsg3) and desmoglein 1 (Dsg1), respectively. Past studies using indirect immunofluorescence (IIF) as a measure of pemphigus antibody levels have failed to demonstrate consistently a relationship between disease severity and IIF titres. However, IIF is not able to measure separately Dsg1 and 3 antibodies, unlike enzyme-linked immunosorbent assays (ELISA), which utilize recombinant proteins. OBJECTIVES: To compare independently Dsg1 and 3 antibody levels with the severity of both cutaneous and oral involvement in PV and PF. Patients and methods Four hundred and twenty-four serum samples were analysed from 80 subjects with PV and 24 with PF. IgG antibodies to Dsg1 and 3 were measured by ELISA. For every sample analysed, the associated severity of skin and oral disease were graded from 0 to 3; quiescent, mild, moderate and severe. RESULTS: A relationship between Dsg1 antibodies and skin severity was demonstrated such that a 10-unit increase in Dsg1 ELISA value was associated with a 34% chance of having a higher severity score [95% confidence interval (CI), 25-45%, P < 0.0005]. This was observed in both PV and PF. Oral severity was associated with Dsg3 antibody levels and a 10-unit increase in the Dsg3 ELISA value was associated with a 25% chance of a higher oral severity score (CI 17-33%, P < 0.0005). We were unable to demonstrate a relationship between Dsg1 antibodies and oral severity, even after adjusting for the effect of Dsg3 antibodies. Similarly, there was no relationship between Dsg3 antibodies and skin severity. CONCLUSIONS: This study suggests that the clinical phenotype of pemphigus, in particular the balance of skin and oral disease, is determined principally by the quantities of Dsg1 and 3 autoantibodies, respectively.     

桥粒芯蛋白1酶联免疫吸附试验检测落叶型天疱疮血清抗体的评价

目的 探讨桥粒芯蛋白1（Dsg1）酶联免疫吸附试验（ELISA）检测落叶型天疱疮（PF）血清学抗体的意义。方法 将80例PF患者和132例对照人群的血清标本进行编盲,用ELISA法检测所有标本中抗Dsg1自身抗体,同时应用间接免疫荧光（IIF）法检测所有标本的抗体滴度,操作过程为随机检测,最后将两方法的结果进行比较。结果 75例PF患者和5例对照人群（包括1例不确定值,大疱性类天疱疮、SLE、皮肌炎、湿疹及健康者各1例）Dsg1 ELISA为阳性,71例PF患者和0例对照人群IIF为阳性。Dsg1 ELISA的敏感性为93.8%（95%可信区间0.85 ~ 0.98）,特异性为96.2%（95%可信区间0.91 ~ 0.99）。IIF的敏感性为88.8%（95%可信区间0.82 ~ 0.96）,特异性为100%（95%可信区间0.96 ~ 1.00）。两者相比,敏感性（P = 0.289）和特异性（P = 1.000）差异均无统计学意义。结论 Dsg1 ELISA是一种简便、敏感、特异的血清学检测方法,可作为诊断PF的一种辅助手段。     

Internalization of constitutive desmogleins with the subsequent induction of desmoglein 2 in pemphigus lesions

Acantholytic blisters in pemphigus vulgaris (PV) and pemphigus foliaceus (PF) are caused by a dissociation of desmosomes mediated by autoantibodies against desmoglein (Dsg) 3 and Dsg 1, respectively. The blistering occurs at the suprabasilar level in PV and at the subcorneal level in PF, which corresponds to the distribution of target antigens in the epidermis: there is a more prominent expression of Dsg 1 in the upper layer, whereas Dsg 3 is more prominent in the lower layer. To elucidate the histogenesis of acantholysis, we studied the alterations of the desmosomal components and the expression pattern of Dsg isoforms in the lesional and perilesional epidermis of pemphigus patients. The results demonstrated an internalization of the desmosomes in the lower epidermis of PV, PF and pemphigus vegetans. A similar phenomenon was induced in monolayers of keratinocytes cultured with PV sera. However, little change was observed in E-cadherin expression until acantholysis became manifest. This internalization occurred prior to overt acantholysis, and was frequently associated with the induction of Dsg 2 expression in the basilar or lower layers of the epidermis. These findings indicate an alteration of Dsg isoform expression in subclinical pemphigus lesions, which might be related to the characteristic acantholytic patterns: the suprabasilar layer in PV and the upper epidermis in PF.     

IgG reactivity against non-conformational NH-terminal epitopes of the desmoglein 3 ectodomain relates to clinical activity and phenotype of pemphigus vulgaris

Pemphigus vulgaris (PV) is an autoimmune disease caused by immunoglobulin G (IgG) autoantibodies against the desmosomal adhesion molecules, desmoglein (Dsg)3 and Dsg1. The aim of the study was to relate IgG reactivity of 123 PV sera and 40 control sera against NH(2)-terminal non-conformational epitopes of Dsg3 and Dsg1 with disease activity and clinical phenotype by enzyme-linked immunosorbent assay. The results show that (i) the overall reactivity and the titres of IgG reactive with the Dsg3 ectodomain, Dsg3(1-566), significantly correlated with the disease activity of the PV patients; (ii) IgG reactivity against the NH(2)-terminus of Dsg3, Dsg3(1-161), was associated with active PV while there was no direct correlation between the IgG titres and the disease activity; (iii) IgG reactivity against the NH(2)-terminus of Dsg3, Dsg3(1-161), was associated with mucosal and mucocutaneous PV; (iv) IgG titres against a small stretch of the NH(2)-terminus of Dsg3, Dsg3(25-88), were associated with active PV; and (v) IgG in the PV sera detected non-conformational epitopes in addition to the previously identified conformation-dependent epitopes of the Dsg3 and Dsg1 ectodomains.     

Detection of autoantibodies against bullous pemphigoid and pemphigus antigens by an enzyme-linked immunosorbent assay using the bacterial recombinant proteins

Abstract To develop a new method to evaluate autoantibodies in various autoimmune bullous skin diseases, we examined reactivity of bullous pemphigoid (BP) and pemphigus vulgaris (PV) patients' sera with partial bacterial fusion proteins of the 230 kD BP antigen (BPAG1) and PV antigen, respectively, by an enzyme-linked immunosorbent assay (ELISA), and compared the results with those of immunoblotting. We used two fusion proteins derived from the mouse BPAG1 and a fusion protein derived from the amino-terminus (EC 1-2) of PV antigen. For both BP and PV sera, the ELISA scores were well correlated with the reactivities on immunoblot assays. The present study indicates that ELISA using recombinant antigen proteins in various autoimmune bullous skin diseases will be a new useful technique to detect the autoantibodies. However, development of recombinant proteins with the entire molecule and correct conformation will be necessary to establish a perfect ELISA system in the future.     

酶联免疫吸附试验和直接免疫荧光检测沙眼衣原体的方法学比较

目的：评价酶联免疫吸附试验（ELISA）和直接免疫荧光（DFA）法检测沙眼衣原体（CT）的灵敏度和特异性。方法：分别采用CT抗原DFA和ELISA法检测泌尿生殖道CT,两法结果不一致时采用荧光定量PCR确证。以DFA和ELISA法均阳性或经PCR确证阳性的结果作为真阳性,分别计算DFA和ELISA法的灵敏度、特异性、阳性预测值和阴性预测值。结果：共检测222份女性宫颈拭子和69份男性尿道拭子,真阳性66例,真阴性225例,其中DFA和ELISA检测结果均阳性63例,另10例两法结果不符的样本经PCR检测阳性3例。ELISA法的灵敏度、特异性、阳性预测值和阴性预测值分别为97．0％、98．7％、95．5％和99．1％,而DFA分别为98．5％,98．2％,94．2％,99．5％。两种方法检测结果符合率为96．6％。结论：ELISA和DFA法检测CT有较高的灵敏度和特异性,均可为临床治疗和性病监测工作提供可靠依据。