Non-pathogenic anti-desmoglein 3 IgG autoantibodies in Fogo Selvagem

The endemic form of pemphigus foliaceus, fogo selvagem, is caused by IgG autoantibodies directed against desmoglein 1 (Dsg1). Hilario-Vargas and his colleagues describe a high prevalence of IgG autoantibodies against Dsg3, the target antigen of pemphigus vulgaris, in a Brazilian population where fogo selvagem is endemic, although those patients do not develop any apparent clinical phenotype of pemphigus vulgaris.

Pemphigus in the Mediterranean region of Turkey: A study of 148 cases

BACKGROUND

The purpose of this study was to describe the epidemiological and clinical features, course, response to treatment, and prognosis of pemphigus in the Mediterranean region of Turkey.

METHODS

All patients with confirmed pemphigus were prospectively enrolled in two major dermatology departments in the cities of Adana and Antalya in the Mediterranean region between March 1998 and March 2004. Details including demography, findings of clinical examinations, treatment, course, and prognosis were recorded.

RESULTS

One hundred and forty-eight patients with pemphigus were diagnosed during the 6-year period, with a prevalence of 1.46 and an annual incidence of 0.24 per 100,000 in this region. There was a female predominance with a male to female ratio of 1:1.4. Pemphigus vulgaris (PV) was the most common clinical subtype, identified in 123 patients (83%). The mean age of onset was 43. In 101 (82%) patients with PV, disease began as persistent oral ulcers. The majority of the patients with PV could be managed with middle or high-dose steroids (60-140 mg/day). Complete clinical remission was obtained in 41 (39.4%) patients. The mortality rate was 4.8%.

CONCLUSIONS

A moderately high incidence of pemphigus was found in the Mediterranean region of Turkey as compared with that encountered in other countries. The commonest clinical subtype was PV with a 9.5-fold higher incidence than pemphigus foliaceus. It is more frequent in middle-aged people and has a female predominance. Although a relatively higher dose of steroid was needed to control the PV, the disease completely remitted in a significant proportion of the patients.

Antibodies against desmoglein 1 in healthy subjects in endemic and nonendemic areas of pemphigus foliaceus (fogo selvagem) in Peru

BACKGROUND

Endemic pemphigus foliaceus or fogo selvagem is an autoimmune skin disease characterized by the presence of subcorneal superficial blisters and antibodies of the immunoglobulin G4 (IgG4) class specific for the desmosomal glycoprotein, desmoglein 1. In Peru, no studies have been published on the seroprevalence of antibodies against desmoglein 1 in healthy subjects from endemic foci.

SUBJECTS AND METHODS

This was a cross-sectional study. The sample included 82 healthy subjects, 41 from the Pueblo Libre community, a focus of endemic pemphigus foliaceus, and 41 from a nonendemic urban area in Pucallpa City. Enzyme-linked immunosorbent assay (ELISA) was used to determine the presence of antibodies against desmoglein 1. Samples were processed and tested at the Department of Dermatology and Cutaneous Surgery, School of Medicine, University of Miami, Miami, Florida.

RESULTS

It was found that 31.7% of healthy individuals (13 subjects) from the endemic focus had anti-desmoglein 1 antibodies. A statistically significant association was found between the distance from the endemic focus and the presence of antibodies against desmoglein 1 in subjects living within the endemic focus [Mantel-Haenszel odds ratio (OR), 3.34; P = 0.03; 95% confidence interval (CI), 1.06-10.48]. Agriculture as an occupation showed a statistically significant association with the presence of antibodies against desmoglein 1 (Mantel-Haenszel OR, 7.84; P < 0.001; 95% CI, 2.47-24.87).

CONCLUSIONS

Antibodies against desmoglein 1 are present in healthy subjects exposed to an endemic focus of pemphigus foliaceus (fogo selvagem). Agriculture is associated with a high risk of development of antibodies against desmoglein 1 in the endemic focus of the Pueblo Libre community.

Pemphigus vulgaris in Iran: epidemiology and clinical profile

BACKGROUND

Although the clinical profile of pemphigus vulgaris is generally well characterized, the epidemiologic differences are important but not widely evaluated. This study was conducted to evaluate the incidence and clinical profile of pemphigus patients in a large central province of Iran.

METHODS

Demographic variables, clinical manifestations, and side effects of treatment in 188 patients in a 10-year period were studied.

RESULTS

The annual incidence rate of pemphigus vulgaris was 5/100,000, with a 1.6:1 ratio of incidence in women compared with men. The mean age of onset was 41.1+/-13.7 years. In 74% of patients, the initial presentation of the disease was mucosal involvement, and in the remaining 26% the disease initially presented on the skin.

CONCLUSIONS

Iranian patients have a relatively young age of onset of pemphigus and a higher incidence among women than men, which may reflect geographic, cultural, dietetic, or racial differences in the clinical and biologic behavior of the disease.

Epidemiology of pemphigus in south-western Iran: A 10-year retrospective study (1991-2000)

BACKGROUND

Pemphigus is a disease demonstrating an uneven geographic distribution. This is the first epidemiologic study of pemphigus in Iran.

METHODS

Data were collected from the files of all newly registered patients with pemphigus at the sole dermatologic referral center for south-western Iran located in the city of Shiraz, during the period 1991-2000. The data were analyzed with regard to age, sex, subtypes of pemphigus, clinical presentation, and season of onset.

RESULTS

The results showed that the mean incidence of the disease for the overall population in Shiraz was 0.67/10(5)/year. The male to female ratio was 1 : 1.33. The mean age at onset of the disease was 38 years (range, 12-93 years). The disease was most common in the third to fifth decades (62.1% of the overall patients). Pemphigus vulgaris was the most commonly encountered type, followed by pemphigus foliaceus (87.7% and 9%, respectively). The first manifestations of the illness most often occurred during winter (30.8% of the patients).

CONCLUSIONS

The results reveal a high incidence of pemphigus vulgaris in south-western Iran compared with that encountered in other countries. Our patients also had a relatively young age at onset and a female predominance.

Disease relevant HLA class II alleles isolated by genotypic, haplotypic, and sequence analysis in North American Caucasians with pemphigus vulgaris

Early studies of genetic susceptibility to pemphigus vulgaris (PV) showed associations between human leukocyte antigen (HLA) DR4 and DR6 and disease. The emergence of DNA sequencing techniques has implicated numerous DRB1 and DQB1 loci in various populations, leading to confusion regarding which exact alleles confer susceptibility. The strong linkage disequilibrium among DR and DQ HLA alleles further complicates the investigation of the true susceptibility loci. In this study, we report genotyping data for the largest sampling of North American Caucasian non-Jewish and Ashkenazi Jewish PV patients studied to date and compare our data with other population studies. To pinpoint true susceptibility, alleles among overrepresented sequences, we applied a step-wise reductionist analysis through (1) determination of the degree of linkage disequilibrium (LD) between purportedly associated alleles, (2) haplotype frequencies comparisons, and (3) primary sequence comparisons of disease-associated versus non-disease-associated alleles to identify crucial differences in amino acid residues in putative peptide binding pockets. Collectively, our data provide extended support for the hypothesis that the HLA associations in Caucasian PV patients map to DRB1*0402 and DQB1*0503 alone. Further structure-function studies will be required to define the exact mechanisms of HLA-mediated control of susceptibility and resistance to disease.

Review of 15 cases of pemphigus foliaceus in horses and a survey of the literature

The records of 15 horses with pemphigus foliaceus diagnosed on the basis of their history, clinical signs, histopathology and the exclusion of differential diagnoses were evaluated with respect to the age of onset, the clinical signs and the diagnostic tests used. There was no apparent breed predisposition. The horses' mean age was nine years, with a range from three months to 25.5 years, three were foals up to six months old and eight were nine years old or older. The most frequent lesions were scaling in 11, crusting in 10 and alopecia in 10, and they appeared most commonly on the face, neck and trunk, in 10 horses for each of these sites. The extremities were involved in nine of the horses, pruritus occurred in seven, and four of the horses had pustules. The clinical signs mostly corresponded with those described in previous reports, but signs of pain were not a prominent feature. Acantholytic cells were identified cytologically in four of six of the horses.

Pemphigus

Pemphigus is a rare autoimmune disease that results in blistering of the skin and oral cavity. It is caused by autoantibodies directed against cell-surface antigens on keratinocytes, which when targeted lose their cellular adhesion properties and separate from one another to form blisters within the epidermis. Differences in the particular antigens targeted by the antibodies and in the distribution of these antigens in the different regions of the body and in the separate layers of the epidermis result in different clinical manifestations of the disease. The disease is diagnosed based on its clinical manifestations (flaccid blisters and erosions on skin and oral mucosa), histology (epidermal acantholysis), and immunological abnormalities (circulating and tissue-fixed antibodies against keratinocyte surface antigens). Pemphigus, which if left untreated is almost always fatal, is generally managed with topical, oral, or intralesional corticosteroids. Other options include plasmapheresis and intravenous immunoglobulin (IVIg), coupled with cytotoxic drugs. Immunosupressants, anti-inflammatory drugs, and antibiotics are used as adjuvants, but apart from IVIg, these therapy options are non-specific and more research is needed to develop treatments with improved side-effect profiles.

[Situation of endemic pemphigus foliaceus in Mato Grosso do Sul, Brazil, 1990-1999]

307 cases were examined to characterize epidemiological aspects of endemic pemphigus foliaceus. The disease was predominantly identified in rural workers between 10 and 42 years old. Incidence was higher in the December, January, February, March and May (average: 30.7 cases/year). Our findings identified a corridor, coinciding with the state watershed.

Pemphigus: Analysis of 1209 cases

BACKGROUND

Pemphigus is a rare and chronic life-threatening disease. The clinical picture varies in reports from different regions of the world.

OBJECTIVE

To define the clinical forms of pemphigus in a large cohort of patients.

METHODS

Prospective analysis of 1209 patients diagnosed and followed at the Pemphigus Research Unit, Tehran University for Medical Sciences, from 1984 to 2003.

RESULTS

The mean age at onset was 42 years with a female to male ratio of 1.5/1. The most frequent form was pemphigus vulgaris. In pemphigus vulgaris, patients' mucous membrane involvement alone was observed in 18%, skin involvement alone in 12%, and both in 70%. Pemphigus foliaceus was observed in 7% of the patients. Most complications were iatrogenic.

CONCLUSION

In Iran, pemphigus vulgaris is the most frequent form of pemphigus. Females are more prone to the disease. The incidence of pemphigus in Tehran is approximately 1.6 per 100,000/year, and in Iran 1.0 per 100,000/year. The age of onset was lower than classically reported. Death occurred in 6.2% of the patients. In pemphigus vulgaris, the mucosal and skin form together had a worse prognosis than the other clinical forms.

Genetic factors in pemphigus

Epidemiological studies performed in different ethnic populations and family studies, notably based on a partial phenotype of the autoimmune process, indicate that genetic factors are involved in the occurrence of pemphigus. However, the precise heritability remains uncertain in the absence of twin concordance rate studies. Among the different strategies available to identify genetic factors participating in autoimmune disease susceptibility, only population studies based on case-control design have been performed in pemphigus. These studies consistently showed that MHC locus, in particular HLA class II alleles, are associated with pemphigus vulgaris and pemphigus foliaceus. Other genes of the MHC locus may also participate in disease susceptibility as shown by studies using microsatellite markers across different regions of the MHC. It is likely that other non-MHC genes are involved in the pathogenesis of pemphigus. In particular, involvement of a polymorphic variant of desmoglein 1 gene was shown to be associated with pemphigus foliaceus and to interact in an epistatic manner with MHC class II genes to contribute to the autoimmune process. Other candidate genes to which a role can be assigned in the disease pathogenesis should be considered to design case-control or family-based association studies. Genome scan studies which require a large number of multiplex families to reach statistical power, should also be considered in the endemic form of pemphigus foliaceus because of the high number of familial cases.

The profile of fogo selvagem (endemic pemphigus foliaceus) at the University Hospital of Brasilia-Brazil. Epidemiological and clinical considerations

BACKGROUND

Endemic pemphigus foliaceus (EPF) or fogo selvagem (FS) is an endemic autoimmune disease, characterized by flaccid bullae induced by IgG(4) subclass antibodies. The authors demonstrate the epidemiological and clinical status of patients who have been followed at the University Hospital of Brasilia (HUB) for more than 15 years.

METHODS

One hundred and ninety-six patients with FS took part in the project. In setting up this study a historical descriptive cohort of patients was put together. In order to collect data, the authors used a questionnaire where the patient indicated the sex, age at the onset, occupation, origin, clinical status, including scalp compromise, evolution, cofactors influencing clinical worsening and the treatment compliance. In order to minimize loss to follow up, the authors used the statistical method of incidence density (patients/years).

RESULTS

The disease occurred in 58.4% of the young patients in the 11-30-year age bracket, and 52% came from urban areas. These patients included students and teachers. Localized disease predominated as compared with the generalized presentation of this condition. Fifty-nine percent of the patients evolved to the recurrent form. Those patients with the evolutional form, in remission for more than 1 year (94%), had been followed for more than 5 years. Even patients with the less active forms of the disease had scalp lesions. Thus scalp lesions are not an indicator of bad prognosis.

CONCLUSIONS

In the present study, the disease affected patients from a higher sociocultural class than previously described. Furthermore, in contrast to other reports, a substantial number of the patients lived in urban areas, although often spending some time in a rural setting for leisure or professional activities. This study suggests that the longer the follow up, the higher the likelihood that the disease would progress to a more controlled clinical presentation. Scalp lesions were not related to adverse prognosis. Sun, heat and infections act as triggering factors for the immunological imbalance, worsening the disease.

Spectrum of autoimmune bullous diseases in Kuwait

BACKGROUND

Autoimmune bullous diseases (ABDs) are a rare but significant group of dermatoses that pose great challenges to the treating dermatologist. Most epidemiological studies have focused on a single ABD. Few surveys have been carried out to describe the whole spectrum of ABDs in a region, and no such studies are available from the Arabian Peninsula.

OBJECTIVES

To determine the clinico-epidemiological features of various ABDs in Kuwait, and to compare the results with those reported elsewhere.

METHODS

A total of 128 cases of ABDs were studied over a span of 11.5 years. The diagnosis in all cases was confirmed by histopathology, and direct and indirect immunofluorescence (IMF). The diagnosis of various subepidermal ABDs was further confirmed by indirect IMF on salt-split skin (SSS) and that of pemphigus by desmoglein 1 and 3 enzyme-linked immunosorbent assay (ELISA).

RESULTS

Eighty seven per cent of patients were of Arab ethnicity. Pemphigus was observed to be the commonest ABD (47%), followed by pemphigoid (22%), pemphigoid gestationis (PG) (19%), linear IgA bullous disease (LABD) (7%), lichen planus pemphigoides (LPP) (3%), and epidermolysis bullosa acquisita (EBA) (2.3%). The minimum estimated incidence in the local population was 4.6, 2.14, 1.83, 0.69, 0.30, and 0.23 cases per million per year, respectively. Pemphigus patients were observed to have a younger age of onset (36.50 +/- 11.36 years) than reported elsewhere. BP, although the second commonest ABD, was less prevalent than in Europe and Singapore, and BP patients were observed to have a striking female predominance (85%). The prevalence of PG was much higher than that reported elsewhere. LABD was the fourth commonest ABD, and 89% of patients were children.

CONCLUSIONS

The study suggests that similar surveys from different regions would expand our understanding of ABD.

Higher prevalence of human herpesvirus 8 DNA sequence and specific IgG antibodies in patients with pemphigus in China

BACKGROUND

Environmental factors, including virus infection, may play a role in the onset and/or development of pemphigus. However, it is controversial whether human herpesvirus (HHV)-8 is involved in pathogenesis of pemphigus.

OBJECTIVE

The possible association of pemphigus with HHV-8 was investigated.

METHODS

A total of 36 lesional skin and 13 peripheral blood mononuclear cell specimens from 58 patients with pemphigus, and 18 normal skin and 230 peripheral blood mononuclear cell specimens from healthy individuals, were tested for HHV-8 DNA sequence by a nested polymerase chain reaction assay. In all, 29 sera from the patients and 109 sera from healthy individuals were tested for HHV-8-specific IgG antibodies by enzyme-linked immunosorbent assays using HHV-8-specific oligopeptides as antigens.

RESULTS

Prevalence of both HHV-8 DNA sequence (36.1% and 30.8% in lesional skin and in peripheral blood mononuclear cells, respectively) and HHV-8-specific IgG antibodies (34.5%) for patients with pemphigus was statistically higher than that of control subjects (<8% in both assays). There was no significant difference in HHV-8 prevalence among different types of pemphigus.

CONCLUSION

HHV-8 infection might be a contributing factor in the development of pemphigus.

Prevalence of thyroid autoimmunity in patients with pemphigus vulgaris

Among bullous diseases, pemphigus vulgaris (PV) is a classical variety of this type of skin disorders. To establish the real prevalence of thyroid abnormalities in such a disease, a prospective study was developed. For this reason, thyroid evaluation was performed in 15 consecutive patients who attended the Dermatology Clinic for PV and in a group of 15 healthy volunteers (Control Group) matched by age and gender. Thyroid function was evaluated by measuring T3, T4 and TSH. The presence or absence of goiter was searched by palpation, while thyroid autoimmunity was investigated through the assay of thyroperoxidase antibodies (TPO-Ab). In each group there were 9 women and 6 men, aging 25-65 years (mean = 48.3 y) in the PV Group, and 25-69 years (mean = 45.4 y) in the Control Group. It was found that 7 patients (46.6%) of the PV Group and 1 subject (6.7%) of the Control Group (p < 0.015) disclosed thyroidal alterations. Positive titers of TPO-Ab were observed in 6 patients with PV and in one volunteer. Goiter and subclinical hypothyroidism were found in one PV patient with negative TPO-Ab. Out of the total 7 cases with positive TPO-Ab, only a PV patient had an overt Hashimoto's thyroiditis. All other cases had only the presence of thyroid auto-antibodies without clinical evidences of chronic thyroiditis. It is concluded that PV is highly associated with primary thyroid disorders, mainly with positive titers of TPO-Ab, although most patients do not present overt clinical thyroid disease.

Anti-Desmoglein-1 Antibodies in Onchocerciasis, Leishmaniasis and Chagas Disease Suggest a Possible Etiological Link to Fogo Selvagem

Pemphigus foliaceus (PF) and the endemic form Fogo Selvagem (FS) are mediated by pathogenic antibodies to the EC1-2 domains of desmoglein-1. There is a preclinical phase with antibodies to only EC5. Based on geographic clustering of cases, FS is thought to have an, as yet unidentified, environmental trigger. In this study we have searched for anti-desmoglein-1 antibodies in sera from parasitic (leishmaniasis, Chagas, and onchocerciasis), and infectious diseases (leprosy and South American (SA) blastomycosis), which are prevalent in the same geographic regions of Brazil as FS. A specific and sensitive desmoglein-1 ELISA detected antibodies in 34 of 41 onchocerciasis (83%), 38 of 88 leishmaniasis (43%), 18 of 31 Chagas disease (58%), 7 of 28 SA blastomycosis (25%), and 14 of 83 leprosy sera (17%). These sera recognized epitopes restricted to the EC5 domain. These findings identify several etiological factors for FS. It is hypothesized that a component of insect vector saliva, rather than the parasite itself may trigger an antibody response to EC-5. In persons with the known HLA susceptibility alleles and living in endemic areas, a response to the EC1-2 domains may subsequently develop by epitope spreading with associated clinical signs of FS.

Anti-desmoglein 1 antibodies in Tunisian healthy subjects: arguments for the role of environmental factors in the occurrence of Tunisian pemphigus foliaceus

Pemphigus foliaceus is an autoimmune blistering skin disease mediated by autoantibodies directed against desmoglein 1 and occurs as a sporadic form throughout the world, or as an endemic form called fogo selvagem in Brazil. Healthy subjects living in Brazilian endemic areas produce antidesmoglein 1 antibodies, suggesting the role of environmental factors in the initiation of the autoimmune response. Tunisia was described recently as an endemic area where the disease is characterized by its high rate among young people, especially women. An enzyme-linked immunosorbent assay using recombinant desmoglein 1 as antigen was used to detect antibodies against desmoglein 1 and calibrated with sera from 67 French healthy blood donors, 20 French pemphigus foliaceus patients and patients with other bullous skin diseases. When sera from 179 healthy Tunisian blood donors were tested, 31 (17%) were found positive. The desmoglein 1 binding activity of these 31 sera was confirmed in 10 cases by indirect immunofluorescence analysis and/or immunoblotting using human epidermal extract. Subclass analysis of antidesmoglein 1 antibodies showed that they were almost exclusively of the IgG2 subclass in positive normal sera and of IgG4 subclass in patients with PF. Thus, antibodies against desmoglein 1 are prevalent in normal subjects living in Tunisia which, along with their IgG2 isotype, suggests the role of the environment in the pathogenesis of this endemic type of pemphigus foliaceus and the need for additional factors to switch from a subclinical to a clinical form of the disease.

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

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.

Feline pemphigus foliaceus: a retrospective analysis of 57 cases

Fifty-seven cases of feline pemphigus foliaceus were identified from biopsy specimens submitted to University of Pennsylvania School of Veterinary Medicine's Laboratory of Pathology and Toxicology by veterinary dermatologists from 1991 to 2002. Age at onset ranged from less than 1 year to 17 years; median 5 years. Eighty per cent of cats were reported to have been pruritic. At the time of biopsy, the distribution of lesions varied, but included some combination of face/head, paws, dorsum or ventrum and consisted of crusts, erosions, scale and alopecia. The histological features of 208 biopsy specimens were reviewed and included the following. Acantholytic cells were found in large numbers in both intact and degenerating pustules in most cases. Mast cells were found in the dermal infiltrate more often than reported previously. Seventeen cases were receiving corticosteroids at the time of biopsy; reducing the percentage of diagnostic biopsies per case. Forty-four cases were followed for 1-54 months (median 9 months). Triamcinolone was more successful at inducing remission without significant adverse effects than prednisone or prednisone in combination with chlorambucil. Only 4/44 cats died from their disease or therapy during the study period.

A unique form of endemic pemphigus in northern Colombia

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.

Analyses of autoantigens in a new form of endemic pemphigus foliaceus in Colombia

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.