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E A Rivitti

Publications and source records attributed to E A Rivitti.

At least 19 recordsLinked to original sources
PubMed2006

Clinical and serological follow-up studies of endemic pemphigus foliaceus (fogo selvagem) in Western Parana, Brazil (2001-2002).

BACKGROUND: Fogo selvagem (FS) has been described in several regions of Brazil, including the Western regions of the state of Parana. In 1990, Empinotti et al. reported case studies of 213 patients with FS that were collected from 1976 to 1988. The same author (J.C.E.) has observed that the frequency of cases in these regions of Parana has decreased. OBJECTIVES: The purpose of this study was to clinically and serologically evaluate a small group of the patients originally reported in 1990 and compare data with a group of control individuals. These patients were treated at the onset of the disease with systemic steroids. PATIENTS AND METHODS: Patients with FS, their unaffected relatives (n = 80) and genetically unrelated controls (n = 15) were identified during a field study from 1 May 2001 to 30 June 2002. Sera from nine patients with FS and six normal controls that were collected in the 1976-1988 evaluation were available for this study. The sera were tested by indirect immunofluorescence, enzyme-linked immunosorbent assay (ELISA) and immunoprecipitation using recombinant human desmoglein 1 (Dsg1). RESULTS: Only 16 of the originally identified 213 patients with FS were found during the field studies. Thirteen of the 16 patients were in clinical and serological remission; 20% of normal controls (19 of 95) were positive in the Dsg1 ELISA. The majority of these subjects (17 of 19) were genetically related to FS patients. Six normal controls that were positive in the Dsg1 ELISA in the original survey were found to be negative or weakly positive in this evaluation. CONCLUSION: The reduced frequency of positive serological markers of disease in patients and normal controls from Western Parana, as well as the absence of recurrent disease in previously identified patients, suggest that environmental antigenic stimulation of the population at risk may have decreased in recent years.

Autoantibodies↗
PubMed2005

'Decubital candidosis': a study of 26 cases.

BACKGROUND: Candidoses are infections caused by yeasts of the genus Candida. 'Decubital candidosis' is a particular form of cutaneous candidosis that occurs on the dorsal skin of chronically bedridden patients; there are very few studies about this presentation in the medical literature. OBJECTIVE: To study the clinical, mycological and histopathological features of 26 cases of 'decubital candidosis' along with factors that may predispose to it. METHODS: Twenty-six patients were included and their general characteristics and clinical lesions were carefully studied. The presence of candidosis in other organs and the occurrence of predisposing factors were searched by reviewing the medical records. Mycological studies were performed and cutaneous biopsies were taken. RESULTS: Median age of patients was 46 years, 11 were male and 15 were female, 25 were caucasian, one was Asian and no one was Afro-Carribean. This finding suggests a greater resistance of Afro-Carribean skin to this form of candidosis. The median time of hospitalization until rash occurrence was 24.8 days. Clinical lesions consisted of erythema, erosions, pustules, papules and desquamation. The most significant predisposing factors for this eruption were prolonged bedrest and broad-spectrum antibiotics. Candidosis on other body sites was diagnosed in 10 cases and additional specific predisposing factors were observed in all 10. Potassium hydroxide examination was a reliable test for diagnosing this disease. Candida albicans was the agent in all 26 cases. Spongiform pustules were the most significant histopathological findings and yeasts were restricted to the horny layer in all biopsied cases. CONCLUSION: 'Decubital candidosis' is probably induced by prolonged bedrest and facilitated by long-term use of antibiotics. This cutaneous infection does not seem to predispose to systemic candidosis.

Adolescent↗
PubMed2003

The role of subclass switching in the pathogenesis of endemic pemphigus foliaceus.

Endemic pemphigus foliaceus, like the sporadic form seen in the developed world, is mediated by IgG antibodies to desmoglein-1. We studied an endemic focus in Limao Verde, Brazil, where disease prevalence is 3.4%. We previously detected IgG antibodies to desmoglein-1 in 97% of patients, but also in 55% of normal subjects in the endemic focus, with progressively lower levels in normal subjects in surrounding areas. An environmental trigger is hypothesized to explain these and other findings. In this study we sought to determine if patients and enzyme-linked-immunosorbent-assay-positive normal subjects in Limao Verde differ in IgG subclass response to desmoglein-1. We developed a sensitive and specific subclass enzyme-linked immunosorbent assay using recombinant desmoglein-1 and standardized the assay to enable comparability between the four subclasses. We found that normal subjects have an IgG1 and IgG4 response, whereas patients have similar levels of IgG1 but a mean 19.3-fold higher IgG4 response. Patients in remission have a weak IgG4 response, and a 74.3-fold higher IgG4 response is associated with active disease. Finally, in five patients in whom we had blood samples from both before and after the onset of clinical disease, a mean 103.08-fold rise in IgG4 was associated with onset of clinical disease, but only a mean 3.45-fold rise in IgG1. These results suggest that the early antibody response in normal subjects living in the endemic area and in patients before the onset of clinical disease is mainly IgG1. Acquisition of an IgG4 response is a key step in the development of clinical disease.

Adolescent↗
PubMed2000

The prevalence of antibodies against desmoglein 1 in endemic pemphigus foliaceus in Brazil. Cooperative Group on Fogo Selvagem Research.

BACKGROUND: Pemphigus foliaceus is an autoimmune skin disease mediated by autoantibodies against desmoglein 1. The endemic form is thought to have an environmental cause. The Terena reservation of Limão Verde in Mato Grosso do Sul, Brazil, is a recently identified focus of the disease, with a prevalence of 3.4 percent in the population. We tested the hypothesis that normal subjects living in an endemic area have antibodies against desmoglein 1. METHODS: We used an enzyme-linked immunosorbent assay to detect antibodies against desmoglein 1 in serum samples from 60 patients with endemic pemphigus foliaceus (fogo selvagem) who lived in Limão Verde or elsewhere in Brazil, 372 normal subjects (without pemphigus foliaceus) from Limão Verde and surrounding locations, and 126 normal subjects from the United States and Japan. RESULTS: Antibodies against desmoglein 1 were detected in 59 of the 60 patients with fogo selvagem (98 percent) but in only 3 of the 126 normal subjects from the United States and Japan (2 percent). Antibodies were also detected in 51 of the 93 normal subjects from Limão Verde (55 percent) and in 54 of the 279 normal subjects from surrounding areas (19 percent). Serum samples obtained one to four years before the onset of disease were available for five patients; all five had antibodies in the initial serum samples, and the onset of disease was associated with a marked increase in antibody values. CONCLUSIONS: The prevalence of antibodies against desmoglein 1 is high among normal subjects living in an area among where fogo selvagem is endemic, and the onset of the disease is preceded by a sustained antibody response. These findings support the concept that the production of antibodies against desmoglein 1 is initiated by exposure to an unknown environmental agent.

Autoantibodies↗
PubMed2000

[Postinfectious Lucio phenomenon in diffuse leprosy. Report of 2 cases].

In the clinical classification of leprosy the diffuse nonnodular form belongs to the lepromatous subtype. In these patients only a diffuse cutaneous infiltration without nodules or plaques is seen. Although the cutaneous features can be difficult to identify, the reactional state in these cases may lead to a serious necrotizing vasculitis, known as Lucio's phenomenon. We describe two cases of Lucio's phenomenon triggered by erysipelas. The diagnosis of leprosy was established only after the immunologic reaction had occurred. Both patients were treated with steroids and thalidomide. In the second case, the bacterial infection led to sepsis and death. In at-risk patients with a necrotizing vasculitis, leprosy should be considered in the differential diagnosis.

Aged↗
PubMed2000

Desmoglein-1-specific T lymphocytes from patients with endemic pemphigus foliaceus (fogo selvagem).

Fogo selvagem (FS), the endemic form of pemphigus foliaceus, is a cutaneous autoimmune disease characterized by subcorneal blistering of the epidermis and the production of autoantibodies against the desmosomal antigen desmoglein-1 (Dsg1). Previously, we showed that mice injected with autoantibodies from FS patients develop a skin disease that reproduces the clinical, histological, and immunological features of FS, indicating that autoantibodies play an essential role in the development of this disease. The purpose of this study was to characterize the autoimmune T-cell response associated with FS. We provide here the first evidence, to our knowledge, that the great majority of FS patients have circulating T lymphocytes that specifically proliferate in response to the extracellular domain of Dsg1. Long-term T cells developed from these patients also responded to Dsg1, and this antigen-specific response was shown to be restricted to HLA-DR molecules. These Dsg1-reactive FS T cells exhibited a CD4-positive memory T-cell phenotype and produced a T helper 2-like cytokine profile. These findings represent the initial steps in defining the role of T cells in FS autoimmunity.

Adolescent↗
PubMed1998

Lymphocyte subsets and Langerhans cells in sun-protected and sun-exposed skin of immunosuppressed renal allograft recipients.

BACKGROUND: Patients who have received renal allografts experience early aging of the skin, opportunistic infections, and an increased incidence of skin cancer. OBJECTIVE: We compared the density of lymphocyte subsets and Langerhans cells in normal-appearing skin of renal allograft recipients without skin cancer at 5 to 6 years (group 1) and 14 years after transplant (group 2) with a matched normal control group. METHODS: Biopsy specimens of sun-protected and exposed areas from 18 white, kidney allograft recipients (10 in group 1 and 8 in group 2) with normal renal function and from 10 healthy volunteers were semiquantitatively analyzed for dermal lymphocyte subsets and Langerhans cells. RESULTS: There was a statistically significant decrease in all dermal cell elements in the sun-protected skin of both groups of patients who had received grafts. The sun-exposed skin of group 2 also showed a significant decrease of dermal CD4+ and CD8+ lymphocytes, and group 1 had a significant decrease in dermal CD8+ lymphocytes. The dermal CD1a+ cell population in the sun-exposed skin from both grafted groups did not differ from the control group. CONCLUSION: Kidney transplant recipients showed dermal depletion of cells related to immune surveillance against tumors even before skin cancer occurred, and this depletion seemed to become more marked with the duration of immunosuppression.

Adult↗
PubMed1998

Comparison of black fly species (Diptera: Simuliidae) on an Amerindian reservation with a high prevalence of fogo selvagem to neighboring disease-free sites in the State of Mato Grosso do Sul, Brazil. The Cooperative Group on Fogo Selvagem Research.

Fogo selvagem is an autoimmune blistering skin disease that principally occurs among rural Brazilians living in geographically clumped disease foci. Exposure to hematophagous black flies possibly is related to the cause of the disease. We compared the occurrence, proportions, and richness of simuliid species immatures and the biting activity of adult females within a recently discovered, high prevalence focus of fogo selvagem, the Limão Verde Terena Reservation, to that of neighboring regions with no reported cases of fogo selvagem. Nine black fly species were collected from 12 stream sites during 5 trips to the fogo selvagem focus. The species showed longitudinal (upstream-downstream) trends in occurrence, proportions, and richness, and the abundance of simuliid immatures was greater at downstream sites. The most prevalent species at the focus, Simulium nigrimanum (Macquart), dominated the stream sites with highly abundant simuliid assemblages, and was the most common black fly in human bait collections. This species was absent or in very low numbers in neighboring valleys and villages that did not have cases of fogo selvagem.

Animals↗
PubMed1996

Pemphigus herpetiformis is a rare clinical expression of nonendemic pemphigus foliaceus, fogo selvagem, and pemphigus vulgaris. Cooperative Group on Fogo Selvagem Research.

BACKGROUND: Pemphigus herpetiformis is a rare and atypical variant of pemphigus that resembles dermatitis herpetiformis. Most patients show antiepidermal autoantibodies that stain the epidermal intercellular spaces by immunofluorescence, similar to pemphigus autoantibodies, and lack the immunopathologic features of dermatitis herpetiformis. OBJECTIVE: The study was aimed at characterizing the specificity of the antiepidermal autoantibodies in seven patients with pemphigus herpetiformis. METHODS: The antiepidermal autoantibodies were characterized by immunofluorescence, immunoblotting, and immunoprecipitation studies in seven patients who fulfilled the clinical, histologic, and immunofluorescence diagnostic criteria for pemphigus herpetiformis. RESULTS: Five patients with features of pemphigus herpetiformis either had classic pemphigus foliaceus, or their disease evolved into classic pemphigus foliaceus. One of these patients had fogo selvagem. Two of the seven patients showed features of or had disease that evolved into pemphigus vulgaris. The antiepidermal autoantibodies present in all seven patients recognized desmoglein 1. CONCLUSION: Pemphigus herpetiformis is a rare clinical and histologic expression of nonendemic pemphigus foliaceus, fogo selvagem, and pemphigus vulgaris.

Adult↗
PubMed1996

An active focus of high prevalence of fogo selvagem on an Amerindian reservation in Brazil. Cooperative Group on Fogo Selvagem Research.

Fogo Selvagem (FS) is an autoimmune disease characterized by subcorneal vesicles and antidesmoglein-1 autoantibodies. Previous epidemiologic data have linked the onset of FS to exposure to an environmental antigen(s). This investigation describes a unique human settlement with an extraordinarily high prevalence of FS. This community is made up of Amerindians belonging to the Terena tribe, which has settled on the Limao Verde reservation in the state of Mato Grosso do Sul in Brazil. Twenty-six well-characterized FS cases have been identified within a total population of 998, yielding a prevalence of 2.6%. Seventeen of the patients (65 %) were males, and over 50% were older than 30 y of age. The incidence of the disease shows temporal periodicity, i.e., years with several cases of FS alternating with years with no cases. Over one-half of the cases occurred in genetically related family members. Another Terena reservation, the Ipegue/Taunay, located 90 km west of the Limao Verde reservation, was also evaluated as a control group. This reservation, with a population of 2203, had no recorded cases of FS. Thus, the Limao Verde reservation represents a new focus of FS in which the disease exhibits temporal, geographic, and familial clustering. These results suggest that the environmental antigen or antigens precipitating FS are endemic to the Limao Verde reservation. This reservation appears to be an ideal population for carrying out sero-epidemiologic, genetic, and environmental studies aimed at disclosing the etiology of FS.

Adolescent↗
PubMed1994

Pemphigus foliaceus autoantibodies bind both epidermis and squamous mucosal epithelium, but tissue injury is detected only in the epidermis. The Cooperative Group on Fogo Selvagem Research.

BACKGROUND: Fogo selvagem (FS) is an autoimmune intraepidermal blistering disease mediated by antidesmosomal autoantibodies. Patients with FS do not have mucosal lesions despite extensive skin involvement. OBJECTIVE: Our purpose was to evaluate the epidermis and the oral epithelium of patients with FS as targets of antidesmosomal autoantibodies. METHODS: Fifteen patients were studied clinically, histologically, and immunologically. Biopsy specimens from the skin and the oral mucosa were studied by light microscopy and direct immunofluorescence. The serum of each of these patients was also titrated by indirect immunofluorescence. RESULTS: All patients showed skin lesions and subcorneal acantholyis, but none exhibited oral blisters or erosions. Direct immunofluorescence analysis demonstrated the presence of tissue-bound autoantibodies in both the epidermis and the oral epithelium of all patients with FS. Antiepidermal autoantibodies were also found in the sera of the patients. CONCLUSION: Relevant epitopes on desmoglein 1 molecules of oral epithelium may not be available to react with pathogenic FS autoantibodies.

Adolescent↗
PubMed1994

Brazilian pemphigus foliaceus, endemic pemphigus foliaceus, or fogo selvagem (wild fire).

Brazilian pemphigus foliaceus, also known as fogo selvagem, is the endemic form of pemphigus foliaceus occurring in certain regions of Brazil. Epidemiologic data strongly support the notion that this disease is caused by exposure to an environmental agent or agents. This form of pemphigus foliaceus is a true human autoimmune disease mediated by autoantibodies of the IgG class, IgG4 subclass. These autoantibodies are pathogenic and highly specific for the disease. The environment agent may sensitize the patient to produce autoantibodies. These autoantibodies may cross-react with the epidermis and induce disease in the patient.

Autoantibodies↗
PubMed1992

Environmental risk factors in endemic pemphigus foliaceus (Fogo selvagem). "The Cooperative Group on Fogo Selvagem Research".

Endemic pemphigus foliaceus or Fogo selvagem (FS) is an epidermal organ-specific autoimmune disease mediated by autoantibodies. Individuals at risk are peasants who live and work on farms located in the interior of certain endemic states of Brazil. This case-control study compares a group of 52 FS patients with 52 patients suffering from other dermatoses admitted and followed at the hospital for pemphigus (Hospital do Penfigo) in the city of Goiania, state of Goias. Patients and controls matched 1:1 by age, sex, and occupation were examined by two dermatologists at the time of admission and asked to respond to a prepared questionnaire. This questionnaire concerned current and past (1 and 5 years) exposure to environmental risk factors. The following risk factors were assessed: black fly bites, presence of rodents at home, exposure to cereal dust, exposure to fumes or dust released by tree and shrub removal, and exposure to insecticides. Relative risks were estimated from tabulated data by the odds ratio and tested for significance by the chi-square test. The 95% confidence interval for the odds ratio was also calculated for each of the risk factors. The only risk factor showing an odds ratio significantly different from one was exposure to simuliidae bites (odds ratio 4.7, p less than 0.001). This study reinforces the hypothesis that chronic exposure to black fly antigens may precipitate IgG4 antibody formation in predisposed individuals. These antibodies in turn may cross-react with epidermal antigens and cause acantholysis and the clinical expression of the disease known as FS.

Adolescent↗
PubMed1992

Cutaneous lupus erythematosus: direct immunofluorescence and epidermal basal membrane study.

Biopsy specimens of cutaneous discoid lesions of 71 patients with cutaneous lupus erythematosus (CLE) were studied. The material was examined by direct immunofluorescence (DIF) to establish positivity and morphologic patterns of immunoglobulins and complement deposits in the basement membrane zone (BMZ). A correlation between DIF results and thickening of the epidermis basement membrane (BM) stained by periodic acid-Schiff (PAS), obtained from 31 matched biopsy specimens, also is presented. Direct immunofluorescence had positive results in 66.20% of the 71 examinations and 70.97% of the matched examinations, whereas PAS showed BM thickening in 100% of the specimens. This observation stresses the importance of such histopathologic findings in the diagnosis of discoid lesions in CLE. There was no correlation between DIF patterns and PAS-stained BMZ thickening. These findings merit additional study. In conclusion, an accordance between PAS-stained BM thickening and immunoglobulin deposits has occurred in 70.97% of cases. This phenomenon does not depend on the presence of immunocomplexes, for it occurs even in cases in which immunocomplex deposits were not detected.

Adolescent↗
PubMed1991

HLA antigens and risk for development of pemphigus foliaceus (fogo selvagem) in endemic areas of Brazil.

Endemic pemphigus foliaceus (EPF), is an autoimmune disease associated with production of IgG antibodies against epidermal antigens. We have tested 38 patients and 50 control subjects living in endemic areas to investigate whether HLA genes are associated with host factors that determine whether or not exposed individuals will develop this disease. A variant of HLA-DR1, an antigen common in Blacks (DRB1*0102), was found to be the main susceptibility factor (relative risk = 7.3, P less than 0.0002). Two amino acids, in positions 85 and 86 of DRB1, distinguish DRB1*0102 from DRB1*0101. These residues appear to be involved in the formation of a functional epitope that causes T cell recognition and determines disease susceptibility. Moreover, subjects having DQw2 did not develop the disease, while the frequency of DQw2 in controls was 22% (RR = 0.04, P less than 0.006). Thus HLA genes appear to play a crucial role in the response to an environmental factor which in this setting frequently leads to the development of autoimmune disease. An HLA-DQ allele, DQw2, appears to be associated with factors that prevent the development of the disease in exposed individuals.

Autoimmune Diseases↗
PubMed1990

A soluble and immunoreactive fragment of pemphigus foliaceus antigen released by trypsinization of viable human epidermis.

Pemphigus foliaceus (PF) antigen is a transmembrane desmosomal glycoprotein (desmoglein I), part of which is located on the keratinocyte surface. Previous studies have shown that after trypsinization of viable human epidermis, this antigen is no longer detected on the surface of detached keratinocytes. It was not known, however, if this loss of antigenic activity was due to destruction, internalization, or cleavage of the antigen itself. In the present study we investigated the fate of the PF antigen after trypsinization of viable human skin. By using Concanavalin-A agarose affinity chromatography, we could partially purify an antigenic glycoprotein fraction that was released by trypsinization into the medium. This antigenic fraction was radiolabeled and tested by immunoprecipitation using sera from endemic pemphigus foliaceus or fogo selvagem (FS), non-endemic pemphigus foliaceus (NEPF), pemphigus vulgaris (PV), and bullous pemphigoid (BP) patients, and sera from normal subjects as controls. Immunoprecipitated labeled proteins were analyzed by SDS-PAGE and autoradiography. All FS sera (20 of 20 FS and five of five NEPF) and 46% of the PV sera (six of 13) immunoprecipitated a band of 45-kD molecular weight. Sera from FS patients in prolonged clinical and serological remission (seven of 10), sera from BP patients (five of five), and sera from normal donors (nine of nine) did not precipitate this 45-kD band. This study showed that a fragment of the PF antigen is released by trypsinization of human skin as a soluble immunoreactive glycopeptide of 45-kD molecular weight. Additionally, this procedure has generated sufficient quantities of the PF antigen for further biochemical characterization.

Antigens, Surface↗
PubMed1990

Endemic pemphigus foliaceus in western Parana, Brazil (1976-1988). Cooperative Group for Fogo Selvagem Research.

Endemic pemphigus foliaceus or fogo selvagem (FS) is a blistering autoimmune disease indigenous to certain states of Brazil. In the state of Parana the disease has been reported in the north-central regions where a total of 632 cases were documented in the period of 1940-80. The present study describes a new focus of FS in the western region of the state of Parana. This focus includes a total of 213 new cases of FS and only 11 cases of pemphigus vulgaris seen in this region from February 1976 to July 1988. Over 90% of these patients were peasants working in agriculture or involved in other outdoor activities.

Adolescent↗