盐裂皮肤直接和间接免疫荧光联合应用鉴别诊断表皮下大疱病的研究

本文探讨盐裂皮肤ＤＩＦ和盐裂皮肤ＩＩＦ联合应用鉴别诊断表皮下大疱病的价值。２０例两种盐裂皮肤免疫荧光均阳性的病例比较表明，盐裂皮肤ＩＩＦ示抗基底膜带抗体结合表皮侧或真皮侧与盐裂皮肤ＤＩＦ示免疫反应物（ＩｇＧ、ＩｇＡ、Ｃ＿３等）沉积于表皮例或真皮侧的部位基本一致。提示多数情况下盐裂皮肤ＤＩＦ或ＩＩＦ均可单独用于表皮下大疱病诊断，两者对比分析可以提高诊断率。     

Place of human amniotic membrane immunoblotting in the diagnosis of autoimmune bullous dermatoses

Background Fine analysis of antiskin autoantibodies can contribute to the differential diagnosis of autoimmune bullous dermatoses. Objectives To develop a high‐performance immunoblotting method using human amniotic membrane as the antigen source, and to compare it with current laboratory methods. Methods Sera from 113 patients were tested by immunoblotting (IB), rat and monkey oesophagus and salt‐split skin indirect immunofluorescence (IIF), and enzyme‐linked immunosorbent assay (ELISA) quantification of anti‐BP180‐NC16a and anti‐BP230, or antidesmoglein (Dsg) 1 and 3 antibodies. There were 56 cases of bullous pemphigoid (BP), 22 cases of mucous membrane pemphigoid (MMP), eight cases of epidermolysis bullosa acquisita (EBA), two cases of bullous systemic lupus erythematosus (BSLE), 17 cases of pemphigus vulgaris (PV), and four cases each of pemphigus foliaceus (PF) and paraneoplastic pemphigus (PNP). Results In BP, the three methods had similar sensitivity (84–89%) for both anti‐BP180‐NC16a and anti‐BP230 antibody detection. In MMP, autoantibodies (mainly directed against BP180 or laminin 332 subunits) were detected in 77% of patients by IB, compared with only 9% by IIF on rat and monkey oesophagus and 36% on salt‐split skin, and 14% by anti‐BP180‐NC16a and anti‐BP230 ELISA. In patients with pemphigus, ELISA had 92% sensitivity for anti‐Dsg1 and 3, but IB and rat bladder IIF were necessary to confirm PNP by revealing specific and rare patterns (antidesmoplakin I/II, antienvoplakin and antiperiplakin antibodies). IB also revealed anticollagen VII antibodies in 60% of patients with EBA and BSLE, and antibodies to BP180, BP230 and Dsg3 in a few patients who were negative using the other two techniques. Conclusion Amniotic membrane immunoblotting is an interesting diagnostic tool for bullous diseases, as the entire panel of autoantibodies can be detected with a single extract. This method improves the identification of complex and heterogeneous autoimmune processes in conjunction with IIF and ELISA, and is particularly useful for MMP characterization.     

Anatomical distribution and immunological characteristics of epidermolysis bullosa acquisita antigen and bullous pemphigoid antigen

A Japanese patient with epidermolysis bullosa acquisita (EBA) was autopsied, and direct immunofluorescence (DIF) testing was performed. Using this patient's serum (EBA serum) and three bullous pemphigoid (BP) sera, the anatomical distribution and immunological characteristics of EBA antigen and BP antigen were investigated by indirect immunofluorescence (IIF). EBA antigen showed the same anatomical distribution as BP antigen in DIF and IIF studies; both antigens were limited to the skin, tongue, oesophagus, trachea, cornea and bladder. EBA antigen was located on the dermal side of both NaCl and PBS-separated skin, whereas BP antigen was limited to the epidermal side. Ethanol fixation abrogated the antigenic stability of BP antigen, but not that of EBA antigen. No difference was found when acetone or formalin fixation was used. The separation methods and prefixation in ethanol could be useful techniques applicable to the classification of the bullous disorders which manifest circulating anti-BMZ antibodies.     

Comparative sensitivity of indirect immunofluorescence to immunoblot assay for the detection of circulating antibodies to bullous pemphigoid antigens 1 and 2

Summary The sera of 263 patients with bullous pemphigoid (BP) were tested by indirect immunofluorescence (IIF) on salt-split skin (SSS) and immunoblot (IB) assay, in order to assess the diagnostic sensitivity of these techniques. Among the 263 sera tested. 198 sera (75%) contained antibasement membrane zone antibodies demonstrable by IIF reacting to the epidermal (98%) or both the dermal and epidermal sides (2%) of SSS. One hundred and eighty-two of the 263 sera (69%) reacted by IB with BP antigens (Ag), most commonly the BPAgl (93 cases, 51%), and a complex of BPAgl and the 180kDa minor BP antigen (BPAg2) (47 cases, 26%). BPAg2 alone was found in 42 cases (23%). A good correlation was found between the detection of autoantibodies by IIF and labelling of BPAg1 and/or BPAg2 by IB assay, in which 152 of 198 sera with an epidermal pattern in IIF identified a BP antigen. IB analysis of the 65 sera negative by IIF yielded positive results in 30 cases (46%). Thirty-one per cent (13 of 42) of sera recognizing by IB BPAg2, were negative by IIF, as compared with 12% (11 of 93) of those recognizing BPAg1 (P < 0.01). Comparing the sensitivity of the two tests, IIF (75%) was found to be more sensitive than IB (69%). Thirty-five of the 263 sera (13%) remained negative by both techniques. It can be concluded from this study that IIF on SSS appears to be a sensitive and reliable assay for screening BP;IB should be performed for the sera that are negative by IIF as it may reveal circulating antibodies, particularly to BPAg2.     

Comparison of an indirect immunofluorescence assay and a modified sensitive immunoblot assay for the study of the autoantibody in pemphigus vulgaris

Some patients with pemphigus vulgaris (PV) have positive direct immunofluorescence (DIF) but are negative by indirect immunofluorescence (IIF). The purpose of this study was (1) to compare the sensitivity of an IIF assay with an immunoblot (IB) assay, (2) to compare the IIF and the IB assay in PV patients in whom the clinical picture and DIF were consistent, but the IIF was negative and (3) to compare the IIF and the IB assay in patients in clinical remission for 3 years or more. A comparison was made of the titers of PV autoantibody in the IIF assay using monkey esophagus as substrate and the modified sensitive IB assay using preabsorbed normal human skin lysate and COLO-16 lysate as a substrate in the three groups of patients. The sensitivity of the Western blot was enhanced by modifications in the extraction procedure of the lysate, by absorption of lysate with normal human serum and by the use of an enzygraphic web. In group 1, comprising 23 PV patients with active generalized disease, the titers of the autoantibody in the IB assay were 2–4-fold higher than in the IIF assay. This difference was highly significant (P=0.0001). In group 2, comprising 10 patients with limited or minimal PV who were positive on DIF and negative on IIF, all the patients were positive in the IB assay. In group 3, comprising 9 patients clinically free of disease and off all therapy for at least 3 years and negative in IIF assay, all the patients were positive in the IB assay. An additional two such patients who had low titers in the IIF assay had significantly higher titers in the IB assay. In the IB assay normal human skin and COLO-16 cell lines produced similar results even though PV sera bound to a 130 kDa protein on normal human skin lysate and a 105 kDa protein on COLO-16 lysate. The availability of this modified sensitive IB assay will have significant clinical benefit in the diagnosis of PV patients when IIF is negative, and in the study of autoantibody production.     

A comparative study of antibody titers of blister fluid and serum in patients with subepidermal immunobullous diseases

BACKGROUND: Subepidermal autoimmune bullous diseases (SABD) comprise several disorders, such as bullous pemphigoid (BP), cicatricial pemphigoid (CP), epidermolysis bullosa acquisita (EBA), herpes gestationis (HG), and linear immunoglobulin A (IgA) dermatosis (LAD), and are characterized by antibody production against the basement membrane structures of the skin and mucosa. Although indirect immunofluorescence (IIF) on serum is a routine test for the detection of basement membrane zone antibodies, there have only been a few studies related to IIF on blister fluid. Aim To perform IIF on blister fluid and to compare the results with those of serum. METHODS: IIF on salt-split skin was performed on the serum and blister fluid of 35 patients with SABD (25 bp, three EBA, three HG, three LAD, and one bullous systemic lupus erythematosus) with conjugated IgG, IgA, and C3. RESULTS: Twenty-eight of the 35 patients showed IIF-positive blister fluid with a titer similar or less than that of serum. In 25 patients with BP, the most common disease in this study, 23 cases (92%) had positive IIF on serum, 23 cases (92%) on blister fluid, and 24 cases (96%) on either serum or blister fluid. Immunoreactant titers in BP blister fluid and serum did not show significant differences (P > 0.05). Epidermal binding of immunoreactants was the most prevalent staining pattern of IIF on salt-split skin (92%) in BP. CONCLUSIONS: From the findings of this study, the blister fluid of patients with SABD can be used for IIF. Although IIF sensitivity on blister fluid is no more than that on serum, the performance of this test on blister fluid in addition to serum may reduce the number of false negative results of IIF found using either of these two substrates alone.     

The study of the participation of basement membrane zone antibodies in the formation of the lupus band in systemic lupus erythematosus

BACKGROUND: The lupus band test (LBT) is an important auxiliary method in the diagnosis of systemic lupus erythematosus (SLE), but the mechanism of its formation is still unknown. There are many kinds of autoantibodies, such as basement membrane zone autoantibodies (BMZ-Abs), in patients with SLE. AIM: To detect whether skin BMZ-Abs participated in the formation of the lupus band in SLE. Methods Immunoglobulin G (IgG)-type BMZ-Abs in 15 SLE patients were detected by means of immunofluorescence (IF), immunoblotting (IB), and immunoelectron microscopy (IEM). RESULTS: Direct immunofluorescence (DIF) on salt-split skin showed epidermal fluorescence in 12 of the 15 SLE patients. Two of the 12 patients also showed dermal fluorescence. Indirect immunofluorescence (IIF) on salt-split skin revealed that, in 12 of the 15 (80%) sera, antibodies were bound to the epidermal roof of the salt-split skin. IB showed that, in 14 SLE sera, autoantibodies reacted to 230, 200, 180, 130, and 97 kDa epidermal extracts and 75 kDa dermal extracts. Direct (DIEM) and indirect (IIEM) immunoelectron microscopy showed that gold particles were directed to every region of the BMZ, including hemidesmosomes, lamina lucida, lamina densa, and sublamina densa. CONCLUSIONS: BMZ-Abs in SLE sera may participate in the formation of the lupus band.     

1mol／L NaCl分离表皮DIF染色法的临床实用价值

对１９例大疱性类天疱疮（ＢＰ）和５例获得性大疱性表皮松解症（ＥＢＡ）病人进行了常规ＤＩＦ、１ｍｏｌ／Ｌ ＮａＣｌ分离表皮ＤＩＦ和１ｍｏｌ／Ｌ ＮａＣｌ分离正常人皮肤ⅡＦ的对比研究。结果显示１ｍｏｌ／Ｌ ＮａＣｌ分离皮肤ＤＩＦ染色法是诊断和鉴别诊断ＢＰ和ＥＢＡ的一种简单、可靠、敏感的方法。     

Use of recombinant pemphigus vulgaris antigen in development of ELISA and IB assays to detect pemphigus vulgaris autoantibodies

Aim/Objective The objectives of this study are: (1) to measure the titers of pemphigus vulgaris (PV) autoantibody in the sera of patients with active disease, using three different assays: (a) Indirect immunofluorescence (IIF) using monkey esophagus as a substrate, (b) immunoblot (IB) and, (c) enzyme-linked immunosorbent assay (ELISA) using recombinant PV antigen (rPVA). (2) To compare the sensitivity of these three assays. Background The titer of PV autoantibodies and disease severity and extent do not always correlate. This could be due to the lack of consistency and specificity of the substrate. Different results are obtained using different substrates. A standard substrate with uniformly controlled source of antigen would be more useful and clinically beneficial. Methods In this study we studied 25 PV patients, six each with bullous pemphigoid (BP), ocular cicatricial pemphigoid (OCP), mucous membrane pemphigoid (MMP), and herpes gestationis (HG), and sera from 16 normal subjects. IIF was used to determine the PV autoantibody using monkey esophagus. IB assay was used according to standard protocol using normal human epidermis and rPVA as substrates. ELISA was performed using rPVA as antigens expressed in E. coli. Results Sera of all 25 PV patients showed binding to the rPVA, normal human sera and the sera from the six BP, six OCP, six MMP, and six HG patients did not show any binding. In addition, we used antisera from rabbits immunized with PVA peptides (Bos-1, Bos-6) which also showed binding to rPVA, whereas normal rabbit sera did not show any reactivity. ELISA and IB titers in all the patients were 2.5 to 160 times higher than with the conventionally used IIF assay. The titers of the PV specific autoantibody measured using the rPVA did not show statistically significant differences between the ELISA and IB assays. Conclusions IB and ELISA are superior to IIF in evaluating the antibody levels in PV patients. ELISA is more practical and is preferable to IB and is recommended for clinical use.     

Rat bladder epithelium: a sensitive substrate for indirect immunofluorescence of bullous pemphigoid

Serological diagnosis of bullous pemphigoid is based on immunoblotting or indirect immunofluorescence on normal human salt-split skin. These methods are expensive or time-consuming and not available as a routine test in all laboratories. We used rat bladder epithelium as substrate for indirect immunofluorescence and compared it with other substrates and with immunoblotting. Twenty-nine bullous pemphigoid sera were studied on rat bladder epithelium, monkey oesophagus, salt-split skin and with immunoblotting on human keratinocyte cultures. Indirect immunofluorescence on rat bladder epithelium proved to be more sensitive (72%) than on monkey oesophagus alone (45%) and less sensitive than on salt-split skin (97%). Rat bladder epithelium, when tested on 41 sera of a control group, showed a very high specificity: 2/41 (95%). In combination with immunoblotting on keratinocyte extracts, indirect immunofluorescence on rat bladder epithelium allowed 93% of sera to be recognized, a value close to the salt-split skin alone. Rat bladder epithelium appears to be a more sensitive substrate than monkey oesophagus for the diagnosis of bullous pemphigoid and, although less specific, it is easier and faster than using salt-split skin, which remains indispensable to distinguish bullous pemphigoid from epidermolysis bullosa acquisita.     

盐裂皮肤-间接免疫荧光方法优化及在大疱性类天疱疮抗体检测中的应用

目的:优化盐裂皮肤-间接免疫荧光方法（IIF-SSS）,评价其在大疱性类天疱疮（BP）抗体检测中的应用。方法:通过调整试验条件,利用正常人包皮或非包皮皮肤制备盐裂底物,分为3组：传统组在4 ℃旋转皮肤48~72 h;低温浸泡组在4 ℃浸泡皮肤48~72 h;室温浸泡组在室温25 ℃（23 ℃~27 ℃）浸泡皮肤24 h...     

Value of routine diagnostic criteria of bullous pemphigoid

Background and design The clinical, histologic, and direct (DIF) and indirect (IIF) immunofluorescence findings are used in a critical, although arbitrary, manner in the routine diagnostic process of bullous pemphigoid (BP). Our purpose was to estimate their relative value. In the present retrospective study, a follow-up of at least 18 months was used as a prerequisite for the final diagnosis of BP (63 patients) and controls ( n = 159).
Results The clinical, histologic, DIF, and IIF diagnostic criteria of BP were found to vary independently of each other. Positive DIF was the most sensitive (90.5%) typical for BP histology and positive IIF were the most specific (99%). Immunopathologic tests were the most valuable, especially in the atypical varieties of BP. Nearly 25% of patients in this group would have been misdiagnosed if IF tests had not been performed. Atypical cases (40%) seemed to represent a clinical continuum over the whole spectrum of the disease. Patients with exclusively immunoglobulin G (IgG) and C3 basal membrane zone (BMZ) deposits were significantly more often seropositive than the rest of the DIF-positive cases; however, the class of BMZ immunoreactants varied according to the site of biopsy. C3 was almost invariably deposited at the BMZ of DIF-positive patients. When Igs were also present, they were only exceptionally (5% of cases) of greater fluorescence intensity than C3.
Conclusions The combination of clinical data plus one positive immunopathologic test provide the best combination of sensitivity and specificity (98%), and seem to be most appropriate in defining patient populations for study purposes. The relationship between the classes of immunoreactants should be better evaluated with reference to the site of skin biopsy. It may be suggested, however, that the likelihood of BP existence is very low when in vivo C3 is absent or of lower intensity of fluorescence than the concomitant Ig(s).     

Comparative study of indirect immunofluorescence and immunoblotting for the diagnosis of autoimmune pemphigus

The diagnosis of pemphigus relies on immunopathological criteria including the detection of circulating autoantibodies to desmosomal components. In the present work we compared the usefulness of immunoblotting (IB) and indirect immunofluorescence (IIF) in the diagnosis of pemphigus using monkey oesophagus (MO) and rabbit lip (RL) as epithelial substrates. Among 54 sera from patients with well-documented pemphigus (40 pemphigus vulgaris, PV, and 14 pemphigus foliaceus, PF), 46 (85%) proved positive by IFF (46 on MO and 41 on RL) as compared with 44 (81.5%) positive by IB. IIF and IB were equally sensitive (90%) for the diagnosis of PV whereas IIF (on RL) was more sensitive (71%) than IB (57%) for the detection of PF autoantibodies. However, when the two techniques were considered in combination, the sensitivity of the detection of pemphigus autoantibodies rose to 94.5%. An IB study would therefore be warranted in the presence of an (alleged) pemphigus serum that was IIF-negative since approximately 10% of these were found to be positive. Furthermore, the pattern of IB reactivity may assist in classification, since the 130- and the 160-kDa antigens seem specifically correlated with PV and PF, respectively.     

Diagnostic features of pemphigus vulgaris in patients with bullous pemphigoid. Molecular analysis of autoantibody profile

BACKGROUND: The simultaneous presence of features of pemphigus vulgaris (PV) in patients with bullous pemphigoid (BP) has previously been reported in the literature. OBJECTIVE: The purpose of this retrospective study is to present 13 patients with an initial diagnosis of BP, who subsequently demonstrated coexistent serological features of both BP and PV. METHODS: The following information on each patient was documented, at the time of initial diagnosis: clinical profile on presentation, histology, direct immunofluorescence, indirect immunofluorescence (IIF) using monkey esophagus as substrate, salt-split skin (SSS) and an immunoblot assay. Since all 13 patients failed to respond to conventional systemic therapy, intravenous immunoglobulin (IVIg) was used as an alternative treatment modality. Prior to initiating IVIg therapy, in all 13 patients, serological studies were performed. In addition to IIF using monkey esophagus, an immunoblot assay and SSS, an enzyme-linked immunosorbent assay (ELISA) was performed to detect antibodies to desmogleins. These different assays were done to identify pathological autoantibodies typical of BP and PV. A control group of 25 healthy normal individuals, 37 patients with BP, 17 patients with PV and 12 patients with pemphigus foliaceus were used for comparison of serological studies. RESULTS: At the time of initial presentation, histological and immunopathological studies confirmed the diagnosis of BP in all 13 patients. Prior to the initiation of IVIg therapy, results of IIF using monkey esophagus as substrate demonstrated high levels of anti-intercellular cement substance (anti-ICS) or antikeratinocyte cell surface antibody. Sera of all 13 patients on SSS bound to the epidermal side of the split. In an immunoblot, using bovine gingival lysate as substrate, sera of 6 patients bound to both a 230-kD (BP Ag1) and 180-kD protein (BP Ag2), while 7 sera bound to only a 230-kD protein. All 13 patients had high levels of antibodies to desmoglein 3 on ELISA. In a pilot experiment, the anti-ICS antibody in sera from 6 random patients was found to be predominantly of the IgG4 subclass. Use of IVIg resulted in an effective clinical response and the maintenance of a prolonged clinical remission. CONCLUSION: In patients with BP, who are nonresponsive to conventional therapy, the presence of two autoimmune diseases or a dual diagnosis should be considered.     

C4d immunohistochemical stain is a sensitive method to confirm immunoreactant deposition in formalin-fixed paraffin-embedded tissue in bullous pemphigoid

Background:  Bullous pemphigoid (BP) is characterized clinically by the onset of pruritic urticarial plaques, vesicles and bullae in a predominantly elderly population. While the diagnosis may be suspected on routine hematoxylin and eosin histology of formalin-fixed paraffin-embedded tissue, fresh-frozen tissue must be used to show the immunologic nature of the bullous process by direct immunofluorescence (DIF). The diagnosis is further confirmed and separated from epidermolysis bullosa acquisita (EBA) by subsequent serologic studies to detect antibodies directed against BP180 and BP230 antigens and characteristic antibody deposition on salt-split skin.
Methods:  Using a polyclonal complement fragment 4d (C4d) antibody, we stained formalin-fixed paraffin-embedded skin biopsy specimens from cases of BP and controls.
Results:  We showed characteristic linear basement membrane deposition of C4d in formalin-fixed paraffin-embedded tissue in seven of nine cases diagnosed as BP vs. EBA by DIF on fresh-frozen tissue. None of the four controls for which we had adequate tissue were positive.
Conclusion:  These results indicate that formalin-fixed paraffin-embedded tissue can be stained for the immunoreactant C4d to show characteristic immunoreactant deposition, potentially obviating the need for repeat biopsy for DIF and allowing clinicians to proceed to serologic confirmation of BP.     

Anti-basement membrane zone antibodies in elderly patients with pruritic disorders and diabetes mellitus

Anti-basement membrane zone (anti-BMZ) antibodies are detectable in a low percentage of elderly subjects without clinical signs of bullous pemphigoid (BP). BP may initially mimic other pruritic dermatoses and may be more common in patients with diabetes mellitus (DM), since DM is frequently associated with pruritic disorders. The aim of the present study was to analyse a possible association of BP and DM and to detect subclinical BP among elderly patients with pruritic dermatoses. Ninety elderly patients (78.6 +/- 4.7 years) treated for dermatologic conditions were divided into four groups: I. DM+/pruritus+, II. DM-/pruritus+, III. DM+/pruritus-, and IV. DM-/pruritus-. Patients' sera were tested by indirect immunofluorescence (IIF) on monkey oesophagus; positive or dubious results were further evaluated by ELISA with human recombinant BP180 and BP230 proteins and purified laminin 5. Positive results were found in 1 of 21 (4.8%) patients in group I, 6/31 (19.3%) patients in group II, 1/18 (5.5%) patients in group III, 3/20 (15%) patients in group IV. In the whole cohort positive anti-BMZ antibodies of linear or basal cell cytoplasmic and membrane pattern were found in 11 cases (12.2%). ELISA was positive in 11/29 (37.9%) tested sera for at least one antigen (BP180, BP230 and laminin 5 ELISA was positive in 7, 5, and 2 sera, respectively). Positive IIF corresponded with positive ELISA in 6/11 (54.5%) cases (ELISA with BP180, BP230, laminin 5 was positive in 5, 3, and 1 serum, respectively). Thus, by IIF, a significant portion of elderly patients had anti-BMZ antibodies and these findings were confirmed by ELISA. There was no statistically significant difference in the presence of anti-BMZ antibodies among the groups I-IV. Thus, the association of anti-BMZ antibodies with age overrules the potential association with DM and/or pruritus.     

Enzyme‐linked immunosorbent assay (ELISA) and indirect immunofluorescence testing in a bullous pemphigoid and pemphigoid gestationis

Enzyme‐linked immunosorbent assay (ELISA) is an excellent tool for detection of circulating antibodies against the NC16A portion of BP180 antigen. We compared the sensitivity and specificity of a commercially available BP180‐NC16a domain ELISA with that of an indirect immunofluorescence (IIF) testing in the evaluation of bullous pemphigoid (BP) and pemphigoid gestationis (PG), and analyzed the relationship between ELISA results and the presence of IgG deposition, in an epidermal or combined pattern, on direct immunofluorescence (DIF) testing of salt‐split skin. ELISA was performed on serum from 28 patients (24 BP, 4 PG) and 50 controls. IIF testing was performed on serum from 27 patients and 98 controls. For the group of 28 patients with BP or PG, ELISA had a sensitivity of 93% and specificity of 96% (P < 0.001), while sensitivity was 74% and specificity 96% (P < 0.001) for IIF testing. In these patients, ELISA has a higher sensitivity than IIF testing, but similar specificity. Evaluation of controls who had IgG deposition on the dermal side of salt‐split skin on DIF testing showed specificity for the ELISA of 100% (all four cases negative) and 80% for IIF testing (one of five positive). Positive ELISA correlated with a diagnosis of BP or PG only in patients who had IgG at the basement membrane zone (BMZ) by DIF testing. Overall, ELISA appears to have greater sensitivity and specificity for BP or PG than does IIF testing.     

表皮下大疱病的鉴别诊断和抗原表达区域性差别的研究

通过间接免疫荧光和盐裂皮损周围皮肤直接免疫荧光（简称盐裂ＤＩＦ），分别研究正常人皮肤、类天疱疮（ＢＰ）及获得性大疱性表皮松解症（ＥＢＡ）抗原表达的区域性差别和表皮下大疱病鉴别诊断。 窝、肘窝、上背、下背、股内侧和下腹部皮肤ＢＰ抗原表达率较高；膝、阳窝、足背、肘、肘窝和下腹部皮肤ＥＢＡ抗原表达率较高。皮肤ＤＩＦ显示２５例表皮下大疱病中１６例（６４％）基底膜带有Ｃ３或ＩｇＧ或伴Ｃ３和ＩｇＡ沉积；盐裂ＤＩＦ表明２５例（１００％）均有ＩｇＧ或伴Ｃ３和ＩｇＡ沉积在表皮侧或真皮侧。结果提示，ＢＰ抗原高表达率与皮损好发部位相一致；ＥＢＡ抗原高表达率一部分与皮损好发部位一致。盐裂ＤＩＦ不仅提高ＤＩＦ阳性率，而且根据免疫反应物沉积部位可以鉴别出ＢＰ与ＥＢＡ以及大疱性系统性红斑狼疮。     

Immunofluorescence testing in the diagnosis of autoimmune blistering diseases: overview of 10-year experience

BACKGROUND

Immunofluorescence testing is an important tool for diagnosing blistering diseases.

OBJECTIVE

To characterize the immunofluorescence findings in patients diagnosed with autoimmune blistering skin diseases.

METHODS

We retrospectively analyzed immunofluorescence results encompassing a 10-year period.

RESULTS

421 patients were included and divided into 2 groups: group 1- intraepidermal blistering diseases (n=277) and 2- subepidermal blistering diseases (n=144). For group 1, positive DIF findings demonstrated: predominance of IgG intercellular staining (ICS) and C3 for pemphigus foliaceus-PF (94% and 73% respectively), pemphigus vulgaris-PV (91.5%-79.5%) and paraneoplastic pemphigus-PNP (66%-33%); ICS IgA in 100% of IgA pemphigus cases, and IgG deposits in the basement membrane zone (BMZ) along with ICS in one Hailey-Hailey patient. The IIF findings revealed mean titers of 1:2.560 for PV and 1:1.280 for PF. For paraneoplastic pemphigus, IIF was positive in 2 out of 3 cases with rat bladder substrate. In group 2, positive DIF findings included multiple deposits at basement membrane zone for epidermolysis bullosa acquisita-EBA (C3-89%,IgG-79%,IgA-47%,IgM-21%) mucous membrane pemphigoid-MMP (C3,IgG,IgA,IgM-80%) and bullous pemphigoid-BP (C3-91%,IgG-39%,IgA-11%,IgM-6%), and IgA at basement membrane zone for IgA linear disease (99%) and dermatitis herpetiformis-DH (dermal papillae in 84.6%). For lichen planus pemphigoides, there was C3 (100%) and IgG (50%) deposition at basement membrane zone. indirect immunofluorescence positive findings revealed basement membrane zone IgG deposits in 46% of BP patients, 50% for EBA, 15% for IgA linear dermatosis and 50% for LPP. Indirect immunofluorescence positive results were higher for BP and EBA with Salt-Split skin substrate.

CONCLUSION

Our results confirmed the importance of immunofluorescence assays in diagnosing autoimmune blistering diseases, and higher sensitivity for indirect immunofluorescence when Salt-split skin technique is performed.