Autoimmune diseases can be either organ-specific, such as diabetes, or non-organ specific, such as systemic lupus erythematosus (SLE). Because of the chronic nature of these diseases, their treatment results in a tremendous cost burden to the health care system, and a significant reduction in quality of life in affected individuals. We have an excellent model to study how immune system imbalances
produce autoimmunity in an endemic area polluted with xenobiotics. EPF has been described in foci in countries in South and Central America and in Tunisia, Africa. EPF is an orphan disease. We discovered a new variant of EPF in El Bagre, Colombia, South America (El Bagre-EPF). El Bagre EPF resembles a mixture of SLE and pemphigus. El Bagre-EPF is characterized by the presence of autoantibodies and complement at the basement membrane zone (BMZ) of the skin, as well as simultaneous deposition of them in an intercellular manner between epidermal keratinocytes (ICS). Familial cases of EPF and an increase in autoantibody titers to EPF antigens are common features seen in relatives of the patients, and, to a lesser extent, in unrelated people living in the same geographic area; these findings indicate that something in the environment may trigger the autoimmunity. Nonendemic, sporadic pemphigus exists in the USA. In Brazil, EPF is known as fogo selvagem (FS), affecting both s*xes equally, and demonstrating its highest incidence of onset at 10-30 years of age. In contrast, El Bagre-EPF occurs in a gold mining region, spares the first and second age decades and predominantly affects males 40 to 60 years old and a few post-menopausal females. El Bagre-EPF patients are significantly exposed to mercuric selenides and other xenobiotics due to regional gold mining, resulting in environmental pollution. El Bagre-EPF patients are also exposed to several tropical diseases, including endemic dengue fever, malaria and leishmaniasis. Notably, it also has been shown that FS patients display higher tissue concentrations of copper, relative to controls from the endemic areas in Brazil . Some publications:
A unique form of endemic pemphigus in northern Colombia.Abrèu-Velez AM, Hashimoto T, Bollag WB, Tobón Arroyave S, Abrèu-Velez CE, Londoño ML, Montoya F, Beutner EH.J Am Acad Dermatol. 2003 Oct;49(4):599-608. PMID:14512903. Abstract BACKGROUND: Endemic forms of pemphigus are a unique group of autoimmune diseases that represent opportunities to study interactions of the environment and genetics with the immune system. The restriction to relatively well-defined regions of South and Central America and perhaps Africa characterizes these diseases. OBJECTIVES: The aims of this study were to confirm the endemic nature of a new type of autoimmune disease occurring in a mining town in northeastern Colombia in the El Bagre area, to characterize it, and to compare it with other forms of endemic pemphigus. METHODS: A 10-year prospective, controlled epidemiologic, humanitarian, and immunologic fieldwork case-control survey was performed in El Bagre, Colombia. RESULTS: Our work revealed that this disease is endemic in rural areas surrounding El Bagre. The disease appeared in 4.7% of middle-aged and older men and postmenopausal women from these rural areas. This disease differs from previously described forms of endemic pemphigus. It shares some heterogeneous immunoreactivity with paraneoplastic pemphigus but is not associated with malignant tumors. The disease resembles Senear-Usher syndrome (pemphigus and lupus) but occurs endemically either with a localized stable clinical course or in a systemic form. This systemic form may affect organs other than skin and is characterized by episodic relapses and poor prognosis in comparison with the localized form. CONCLUSION: We have confirmed endemic pemphigus foliaceus in El Bagre as an autoimmune disease that shares features with Senear-Usher syndrome but occurs in an endemic fashion. Heterogeneous antigenic reactivity is observed as in paraneoplastic pemphigus but with no evidence of association with neoplasia. In addition, constant exogenous antigenic stimulation and a genetic predisposition may be required in the pathogenesis of this disease.
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Analyses of autoantigens in a new form of endemic pemphigus foliaceus in Colombia. Abrèu-Velez AM, Beutner EH, Montoya F, Bollag WB, Hashimoto T. J Am Acad Dermatol. 2003 Oct;49(4):609-14. PMID:14512904
BACKGROUND: We previously described a new focus of endemic pemphigus foliaceus in rural areas of El Bagre, Colombia, with clinical and direct immunofluorescence characteristics of pemphigus erythematosus. OBJECTIVE: The aim of this study was to characterize autoantigen profiles for 34 serum samples obtained from patients with this condition. METHODS: Immunofluorescence, various immunoblot analyses with different antigen sources and detection methods, and immunoprecipitation were performed. RESULTS: Immunofluorescence with the use of human skin sections showed IgG autoantibodies against keratinocyte cell surfaces in all 34 serum samples. Some samples also showed weak reactivity with the basement membrane zone. The results of immunoblot and immunoprecipitation analysis indicated that all sera had antibodies reactive with desmoglein 1, the pemphigus foliaceus antigen. In addition, in various immunoblot assays, many sera reacted with several other proteins with molecular weights of 250 kd, 210 kd, and 190 kd, which appear to correspond to desmoplakin I, envoplakin, and periplakin, respectively. CONCLUSION: This endemic pemphigus disease in El Bagre showed immunologic features similar to pemphigus foliaceus or erythematosus. In addition, paraneoplastic pemphigus-like reactivity with various epidermal antigens was detected.
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Comparative study of autoantigen profile between Colombian and Brazilian types of endemic pemphigus foliaceus by various biochemical and molecular biological techniques. Hisamatsu Y, Abreu Velez AM, Amagai M, Ogawa MM, Kanzaki T, Hashimoto T. J Dermatol Sci. 2003 Jun;32(1):33-41. PMID:12788527
BACKGROUND: Besides Brazilian endemic pemphigus foliaceus (EPF), we have described another focus of EPF in Colombia. Our previous study suggested that Colombian EPF seemed to react various plakin family proteins, such as envoplakin, periplakin and BP230. OBJECTIVE: To further characterize the Colombian EPF and study the difference from Brazilian EPF, we examined the antigen profile of the two types of EPF. METHODS AND RESULTS: Immunoblotting using normal human epidermal extracts revealed that 38% Colombian EPF sera and 25% Brazilian EPF sera showed IgG antibodies reactive with desmoglein (Dsg) 1, pemphigus foliaceus antigen. The sera of both types of EPF showed protein bands co-migrating with plakin family proteins, particularly periplakin. Immunoblotting analyses using recombinant proteins of various domains of envoplakin, periplakin and BP230 revealed that a considerable number of Colombian EPF sera reacted with recombinant proteins of periplakin, while only few Brazilian sera reacted with some of the recombinant proteins of any plakins. Enzyme-linked immunosorbent assay (ELISA) for Dsg1 and Dsg3 showed that Dsg1 was reacted by almost all sera of both types of EPF. However, unexpectedly, while none of Colombian EPF sera reacted with Dsg3, about half of Brazilian EPF sera reacted with Dsg3. CONCLUSION: These results suggested that the Colombian EPF is basically similar to Brazilian EPF in terms that major antigen is Dsg1, but there were some different antigen profiles between the two types of EPF
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Detection of mercury and other undetermined materials in skin biopsies of endemic pemphigus foliaceus. Abréu Vélez AM, Warfvinge G, Herrera WL, Abréu Vélez CE, Montoya M F, Hardy DM, Bollag WB, Hashimoto K. Am J Dermatopathol. 2003 Oct;25(5):384-91. PMID:14501287
A novel variant of endemic pemphigus foliaceus (EPF) was described among individuals in an area surrounding El Bagre, Colombia, South America. The population in this rural mining community is exposed to high environmental levels of mercury, used for gold extraction, as well as other minerals, metalloids, and trace elements (e.g., quartz, rutile, granite, magnetite, and almenite) and ultraviolet radiation. Fifty control subjects and fifty EPF patients in the endemic area were examined for the presence of mercury in skin biopsies and hair, using autometallographic and mass spectroscopic analyses, respectively. Simultaneously, serum levels of IgE were measured, and cutaneous tests for hypersensitivity reactions were performed. Using autometallography, mercuric sulfides/selenides were detected in 14 of 51 skin biopsies distributed similarly in the control and patient groups. However, significantly higher serum IgE levels and mercury concentrations in hair, urine, and nails were found in patients compared with controls. Microscopic analysis revealed mercuric sulfides/selenides concentrated within and around the sweat gland epithelium, as well as in dendritic cells. Five skin biopsies from EPF patients and five from controls that tested positive for the presence of mercuric sulfides/selenides by autometallography were randomly selected for electron microscopic analysis. This analysis revealed a mixed electron-dense and electron-light material closely associated with desmosomes in patients. However, there were intracellular vesicles containing an amalgam of electron-dense and electron-light materials only in the EPF patients. Thus, EPF-affected individuals are exposed to high levels of environmental mercuric sulfides/selenides and other elements. This is the first study reporting mercuric sulfides/selenides in skin biopsies from people living in a focus of EPF, and these compounds may play a role in the pathogenesis of autoimmunity.
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The tryptic cleavage product of the mature form of the bovine desmoglein 1 ectodomain is one of the antigen moieties immunoprecipitated by all sera from symptomatic patients affected by a new variant of endemic pemphigus. Abréu-Vélez AM, Javier Patiño P, Montoya F, Bollag WB. Eur J Dermatol. 2003 Jul-Aug;13(4):359-66. PMID:12948916
Multiple antigens are recognized by sera from patients with pemphigus foliaceus (PF). Several have been identified including keratin 59, desmocollins, envoplakin, periplakin, and desmogleins 1 and 3 (Dsg1 and Dsg3). In addition, an 80 kDa antigen was identified as the N-terminal fragment of Dsg1 using as antigen source an insoluble epidermal cell envelope preparation. However, still unsolved was the identity of the most important antigenic moiety, a 45 kDa tryptic fragment which is recognized by all sera from patients with fogo selvagem, pemphigus foliaceus, by half of pemphigus vulgaris sera and by a new variant of endemic pemphigus in E1 Bagre, Colombia that resembles Senear-Usher syndrome. Here, we report the identification of the 45 kDa conformational epitope of a soluble tryptic cleavage product from viable bovine epidermis. To elucidate the nature of this peptide, viable bovine epidermis was trypsin-digested, and glycosylated peptides were partially purified on a concanavalin A (Con-A) affinity column. This column fraction was then used as an antigen source for further immunoaffinity purification. A PF patient's serum covalently coupled to a Staphylococcus aureus protein A column was incubated with the Con-A eluted products and the immuno-isolated antigen was separated by SDS-PAGE, transferred to a membrane, and visualized with Coomassie blue, silver and amido black stains. The 45 kD band was subjected to amino acid sequence analysis revealing the sequence, EXIKFAAAXREGED, which matched the mature form of the extracellular domain of bovine Dsg1. This study confirms the biological importance of the ectodomain of Dsg1 as well as the relevance of conformational epitopes in various types of pemphigus.
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A sensitive and restricted enzyme-linked immunosorbent assay for detecting a heterogeneous antibody population in serum from people suffering from a new variant of endemic pemphigus. Abréu-Vélez AM, Yepes MM, Patiño PJ, Bollag WB, Montoya F Sr. Arch Dermatol Res. 2004 Mar;295(10):434-41. Epub 2004 Jan 17. PMID:14730452
We recently described a new variant of endemic pemphigus foliaceus (EPF) in El Bagre, Colombia, that resembles Senear-Usher syndrome and identified autoantibodies to desmoglein 1 (Dsg1), as well as to multiple known and unknown antigens including plectins, in the serum of these patients. Here, we developed a cost-effective ELISA assay capable of detecting the heterogeneous antibody population observed in these EPF patients, and useful for serum epidemiological studies. A protein extract obtained from trypsin-digested fresh bovine skin and further purified on a concanavalin A matrix was used as antigen. This extract contains an important conformational epitope (a 45 kDa tryptic fragment of the Dsg1 ectodomain), which is recognized by antibodies in serum from patients with all varieties of pemphigus foliaceus (PF), and from half of those with pemphigus vulgaris with active clinical disease. The cut-off and threshold values were normalized using human serum obtained from both endemic and non-endemic areas for PF. The efficiency of this ELISA was tested using 600 serum samples from controls and patients diagnosed with EPF, non-endemic PF and other bullous diseases. The overall sensitivity and specificity of the assay were determined to be 95% and 72%, respectively, with reproducibilities of 98% (intraassay) and 95% (interassay). Comparing the ELISA with other tests to detect EPF autoantibodies, this ELISA was the most sensitive, followed by direct immunofluorescence (DIF), indirect immunofluorescence using anti-IgG4 monoclonal antibodies and immunoprecipitation (IP), respectively. The most specific assay was IP, followed by DIF. Immunoblotting to Dsg1 exhibited both poor sensitivity and poor specificity, although plectins were well visualized. We conclude that this ELISA is an excellent tool for field serological studies, allowing testing of multiple serum samples simultaneously and for detecting, with appropriate restriction and sensitivity, the heterogeneous antibody population seen in patients with this variant of EPF. Finally, autoantibody serum levels obtained with this ELISA correlated well with the clinical activity and extent of disease in patients with El Bagre EPF.
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Rare clinical form in two patients affected by a new variant of endemic pemphigus in northern Colombia. Abrèu Velez AM, Avila IC, Segovia J, Yepes MM, Bollag WB. Skinmed. 2004 Nov-Dec;3(6):317-21. ABSTRACT: Recently, the authors described a new variant of endemic pemphigus foliaceus in rural areas surrounding El Bagre, Colombia, but without association with malignant tumors. METHODS: The authors' 10-year fieldwork provided the opportunity to observe various manifestations of El Bagre endemic pemphigus foliaceus, including the presence of bilateral plaques in pretibial areas. RESULTS: Based on personal experience and literature reviews, the authors have correlated the auto-antibody profile with the appearance of pretibial plaques. CONCLUSION: Since pretibial plaques occur in patients with both fogo selvagem and El Bagre variants of endemic pemphigus foliaceus, as well as in other forms of pemphigoid, these diseases must be considered in the differential diagnosis of patients with clinical, immunologic, and/or epidemiologic risk factors.
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Autoantibodies to sweat glands detected by different methods in serum and in tissue from patients affected by a new variant of endemic pemphigus foliaceus. Abreu-Velez AM, Howard MS, Hashimoto K, Hashimoto T. Arch Dermatol Res. 2009 Oct;301(10):711-8. Epub 2009 Jun 23. PMID:19547994
Examining the patients with a new variant of endemic pemphigus foliaceus (EPF) in El Bagre, Colombia, (El Bagre-EPF), we noted several polymorphic clinical lesions around their axillary areas. Based on our clinical findings and on previous histopathological studies on the skin of these patients that showed abnormalities in their sweat glands, and the presence of mercuric selenides and iodines by autometallography assay, we decided to investigate immunoreactivity to the sweat glands in these patients. We tested for autoreactivity utilizing direct and indirect immunofluorescence (DIF, IIF). To be able to distinguish between non-specific immune deposits and real autoimmune response, and knowing that sweat glands have some intrinsic autofluorescence for the presence of lipofuscin granules (that naturally fluoresce under the UV light microscope), as well as by the presence of secretory IgA, we used simultaneously immunohistochemistry (IHC). We tested ten El Bagre-EPF patients, ten healthy controls from the endemic area and ten healthy controls from the United States. We were able to visualize a specific autoreactivity to sweat glands in 8/10 cases of El Bagre-EPF by DIF, IIF and by IHC. In addition when using anti-human monoclonal antibodies to CD3, CD68, and CD20, we confirmed the presence of several specific immune responses in situ, an around the sweat glands. No healthy control cases yielded positive findings. In some chronic cases, decrease and sometimes a complete absence of sweat glands and other skin appendices was found. In addition to this, sclerodermoid changes or early sclerodermatous changes sometimes extending into the adipose tissue as a membranous lipodystrophy were observed. Autoreactivity to the neurovascular components around the sweat glands were also observed. Our data demonstrate for the first time that there is immunoreactivity toward sweat glands in El Bagre-EPF patients that seems to destroy some of these structures.
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Broad histopathologic patterns of non-glabrous skin and glabrous skin from patients with a new variant of endemic pemphigus foliaceus-part 1.Howard MS, Yepes MM, Maldonado-Estrada JG, Villa-Robles E, Jaramillo A, Botero JH, Patiño PJ, Hashimoto T, Abreu-Velez AM. J Cutan Pathol. 2010 Feb;37(2):222-30. Epub 2009 Jul 13. PMID:19615020
Abstract
A prospective, controlled epidemiologic survey performed in El Bagre, Colombia revealed a new variant of endemic pemphigus disease, occurring in a gold mining region. The disease resembled Senear-Usher syndrome, and occurred in an endemic fashion. The aim of this study is to describe the most frequent histopathologic patterns in non-glabrous skin and in glabrous skin observed in these patients, and their clinical correlation. The study was performed on non-glabrous skin biopsies of 30 patients from the dominantly clinical affected areas (either on the chest, arms or face). Simultaneously, biopsies from the palms were obtained in 10 randomly chosen patients of the 30 total patients. The specimens were examined following hematoxylin and eosin (H&E) staining. The most common blisters observed were subcorneal, although in some cases intraspinous and subepidermal blisters were visualized. Our results showed a very heterogeneous pattern of histopathologic patterns in non-glabrous skin, which seemed to correlate with the clinical features. The most common pattern was typical pemphigus foliaceus-like, with some lupus erythematosus-like features. A non-specific, chronic dermatitis pattern prevailed in the clinically controlled patients taking daily corticosteroids. In the patients who have had the most severe and relapsing pemphigus, early sclerodermatous changes and scleredermoid alterations prevailed in their reticular dermis. In addition to the scleredermoid alterations, the reticular dermis showed a paucity of appendageal structures. On the contrary, in the palms, a similar pattern was seen in all cases, including thickening of the stratum corneum, hypergranulosis, edema in the papillary and reticular dermis and a dermal perivascular lymphocytic infiltrate. The direct immunofluorescence of the glabrous vs. the non-glabrous skin also showed some differences. We conclude that the histopathologic features of this new variant of endemic pemphigus are complex, therefore, classical histopathologic features previously described for superficial, endemic pemphigus cannot be used alone to diagnose this disease.
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Palm tissue displaying a polyclonal autoimmune response in patients affected by a new variant of endemic pemphigus foliaceus in Colombia, South America. Abreu Velez AM, Howard MS, Hashimoto T. Eur J Dermatol. 2010 Jan-Feb;20(1):74-81. Epub 2009 Nov 4. PMID:19889592
Abstract
We previously described a new variant of endemic pemphigus foliaceus in El Bagre, Colombia, South America (El Bagre-EPF). On physical examination, the palms and soles of El Bagre-EPF patients reveal an edematous texture and mild hyperkeratosis, in comparison with the non-glabrous skin of the patients where blisters, pustules or other lesions are commonly found. Based on the preceding observation, we tested the palms of 20 El Bagre-EPF cases and 20 controls from the endemic area for any pathological alterations in the samples by direct immunofluorescence (DIF). Our DIF demonstrated pathological deposits of fibrinogen and albumin, as well as IgG, IgA, IgM, IgD and C3c, at 1) the epidermal basement membrane zone; 2) around isolated areas in the epidermis, 3) within the dermal vessels and nerves, and 4) in areas surrounding dermal neurovascular structures and sweat glands. Specific markers for blood vessels, including 1) anti-intercellular adhesion molecule 1 (ICAM-1)/CD54, and 2) anti-junctional adhesion molecule (JAM-A); as well as specific markers for nerves, including 1) anti-glial fibrillary acidic protein (GFAP), and 2) anti-human neuron specific enolase (NSE) co-localized with the patients' autoantibodies. Although no blisters, ulcerations, pustules or erosions are clinically observed on the palms of El Bagre-EPF patients, our DIF detected distinct immunoreactivity in palm tissue. These alterations may contribute to the clinically edematous texture of the palms and the mild clinical hyperkeratosis found in most of these patients. We propose that normal glabrous skin and non-glabrous skin may be different with regard to the expression of selected molecules, which may vary in number, size or structural organization depending on their anatomical site. Our findings may also partially explain the hyperkeratotic palms that have been clinically well documented in the chronic phase of fogo selvagem i.e., endemic pemphigus foliaceus, in Brazil.
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Formalin deposition as artifact in biopsies from patients affected by a new variant of endemic pemphigus foliaceus in El Bagre, Colombia, South America. Abreu Velez AM, Howard MS, Restrepo-Isaza M, Smoller B. J Cutan Pathol. 2010 Aug;37(8):835-42. Epub 2009 Dec 9. PMID:20015189
BACKGROUND: Most autoimmune diseases occur sporadically; however, endemic pemphigus foliaceus (EPF) is present in specific locales restricted to some geographic rural regions mostly in South America, Central America and in Tunisia (Africa). Its geographic restriction makes it an invaluable natural model for studying how the environment, genetic background and host response contribute to the development of autoimmunity. We described a new variant of EPF in El Bagre, Colombia, (El Bagre-EPF). When we examined the skin biopsies from 10 patients and controls from the endemic area, we detected in a systematic manner several types of pigmentation, sometimes intracellular, and sometimes in the extracellular matrix in most biopsies. Aim: We aim to determine the nature of this pigment in these skin biopsies. METHODS: We studied 10 patients and 10 controls matched by s*x, age and work activity living in the endemic area by routine hematoxylin and eosin (H&E). RESULTS: We were unable to find any bacteriological or parasitic organism. Specifically, we searched for several tropical disease agents as possible causative agents of this pigment. Iron stains and melanin pigment bleaching techniques failed to determine the etiology of this pigment. We then tried the removal of formalin pigment using picric acid. The pigment was removed after very strong treatment with different acids including picric acid. CONCLUSIONS: Formalin pigment shares many properties with hemozoin. In this case, the authors recommend the use of neutral buffered formalin to prevent the formation of formalin pigment especially after long periods of fixation when taking biopsies under extreme temperature and environmental humidity.
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Human eyelid meibomian glands and tarsal muscle are recognized by autoantibodies from patients affected by a new variant of endemic pemphigus foliaceus in El-Bagre, Colombia, South America. Abreu-Velez AM, Howard MS, Hashimoto T, Grossniklaus HE. J Am Acad Dermatol. 2010 Mar;62(3):437-47. Epub 2010 Jan 12. PMID:20061054
Abstract
BACKGROUND: Previously, we described a new variant of endemic pemphigus foliaceus (EPF) in Colombia, South America (El Bagre-EPF). OBJECTIVE: Continuing our characterization of this variant of EPF, we now focus on one of our previously reported clinical findings: the presence of ocular lesions. These ocular lesions are seen in patients having extensive skin involvement, as measured by the Lund and Browder scale, which is generally used for patients with skin burns. METHODS: We specifically searched for evidence of autoreactivity to various eyelid structures in these patients and correlated our immunologic data with the clinical findings. We performed indirect immunofluorescence studies using normal-appearing human eyelid skin from routine blepharoplasties as substrate tissue. We tested sera from 12 patients with El Bagre-EPF and ocular lesions, 5 patients with sporadic (nonendemic) pemphigus foliaceus, and 20 healthy control subjects (10 from the El Bagre-EPF endemic area and 10 from nonendemic areas). We used fluorescein isothiocyanate conjugated goat antiserum to human total IgG/IgA/IgM as a secondary antibody. In addition, we used fluorescein isothiocyanate conjugated antibodies to human fibrinogen, albumin, IgG, IgE, C1q, and C3, Texas Red (Rockland Immunochemicals, Inc, Gilbertsville, PA), Alexa Fluor 555, or Alexa Fluor 594 (Invitrogen, Carlsbad, CA). Ki-67 (a cell proliferation marker) was used to determine the cell proliferation rate, and nuclear counterstaining was performed with either 4', 6-diamidino-2-phenylindole or Topro III (Invitrogen, Carlsbad, CA). RESULTS: We observed autoreactivity to multiple eyelid structures, including meibomian glands and tarsal muscle bundles at different levels, and some areas of the epidermis and the dermis close to the isthmus of the eyelids. Tarsal plate autoreactivity was seen in 10 of 12 of the El Bagre-EPF sera and in one control with pemphigus erythematosus. Furthermore, immunoprecipitation using an eyelid sample as a substrate with 1 mmol/L of sodium orthovanodate showed autoreactivity to several antigens, including some of possible lipid origin. LIMITATIONS: The main limitation of this study is the fact that the antigen or antigens remain unknown. CONCLUSION: We identified for the first time to our knowledge autoantibodies to meibomian glands and tarsal muscle in El Bagre-EPF. Our findings suggest that the autoantibodies to the ocular structures cause the clinical and histopathological findings in the ocular lesions in El Bagre-EPF.
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Neural system antigens are recognized by autoantibodies from patients affected by a new variant of endemic pemphigus foliaceus in Colombia. Abreu-Velez AM, Howard MS, Yi H, Gao W, Hashimoto T, Grossniklaus HE. J Clin Immunol. 2011 Jun;31(3):356-68. Epub 2011 Jan 6. PMID:21210298
BACKGROUND: Endemic pemphigus foliaceus (EPF), is also known as "fogo selvagem" or "wild fire," reflecting the intense burning sensation of the skin reported by patients with this disease. Based on this finding, we tested for neural autoreactivity in patients affected by a new variant of EPF (El Bagre-EPF). METHODS: We tested 20 El Bagre-EPF patients, 20 normal controls from the endemic area, and 20 age- and s*x-matched normal controls from outside the endemic area. We tested for autoreactivity to several immunoglobulins and complement. Both human skin and bovine tail were used as antigens. RESULTS: We detected autoreactivity to neural structures, mechanoreceptors, nerves, perineural cell layers of the arachnoid envelope around the optic nerve, brain structures, and to neuromuscular spindles; these structures colocalized with several neural markers. The patient antibodies also colocalized with desmoplakins 1 and 2, with the armadillo repeat protein deleted in velo-cardio-facial syndrome and with p0071 antibodies. Autoreactivity was also found associated with neurovascular bundles innervating the skin, and immunoelectron microscopy using protein A gold against patient antibodies was positive against the nerve axons. Paucicellularity of the intraepidermal nerve endings and defragmentation of the neural plexus were seen in 70% of the cases and not in the controls from the endemic area (p
