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2.
Clin Exp Immunol ; 167(1): 129-36, 2012 Jan.
Article in English | MEDLINE | ID: mdl-22132892

ABSTRACT

The disturbed cytokine-chemokine network could play an important role in the onset of diseases with inflammatory processes such as chronic idiopathic urticaria (CIU). Our main objectives were to evaluate the relation between proinflammatory chemokine serum levels from CIU patients and their response to autologous skin test (ASST) and basophil histamine release (BHR). We also aimed to assess the chemokine secretion by peripheral blood mononuclear cells (PBMC) upon polyclonal stimulus and to evaluate chemokine C-C ligand 2/C-X-C chemokine 8 (CCL2/CXCL8) and Toll-like receptor-4 (TLR-4) expression in monocytes. We observed significantly higher serum levels of the CXCL8, CXCL9, CXCL10 and CCL2 in CIU patients compared to the healthy group, regardless of the BHR or ASST response. The basal secretion of CCL2 by PBMC or induced by Staphylococcus aureus enterotoxin A (SEA) was higher in CIU patients than in the control group, as well as for CXCL8 and CCL5 secretions upon phytohaemagglutinin stimulation. Also, up-regulation of CCL2 and CXCL8 mRNA expression was found in monocytes of patients upon SEA stimulation. The findings showed a high responsiveness of monocytes through CCL2/CXCL8 expression, contributing to the creation of a proinflammatory environment in CIU.


Subject(s)
Chemokine CCL2/biosynthesis , Interleukin-8/biosynthesis , Leukocytes, Mononuclear/metabolism , Monocytes/metabolism , Urticaria/genetics , Adult , Aged , Aged, 80 and over , Basophil Degranulation Test , Chemokine CCL2/genetics , Chemokine CCL2/physiology , Chemokines/blood , Chronic Disease , Enterotoxins/pharmacology , Female , Gene Expression Regulation/drug effects , Humans , Inflammation , Interleukin-8/genetics , Interleukin-8/physiology , Leukocytes, Mononuclear/drug effects , Lymphocyte Activation/drug effects , Male , Middle Aged , Monocytes/drug effects , Phytohemagglutinins/pharmacology , Real-Time Polymerase Chain Reaction , Skin Tests , Toll-Like Receptor 4/biosynthesis , Toll-Like Receptor 4/genetics , Up-Regulation/drug effects , Urticaria/blood , Urticaria/immunology , Young Adult
3.
Clin Exp Immunol ; 166(2): 291-8, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21985375

ABSTRACT

Immunological dysfunction has been described to occur in chronic idiopathic urticaria (CIU), most notably in association with an inflammatory process. Some pharmacological agents as statins--drugs used in hypercholesterolaemia--display a broad effect on the immune response and thus should be tested in vitro in CIU. Our main objectives were to evaluate the effects of statins on the innate and adaptive immune response in CIU. Simvastatin or lovastatin have markedly inhibited the peripheral blood mononuclear cells (PBMC) proliferative response induced by T and B cell mitogens, superantigen or recall antigen. Simvastatin arrested phytohaemaglutinin (PHA)-induced T cells at the G0/G1 phase, inhibiting T helper type 1 (Th1), Th2, interleukin (IL)-10 and IL-17A cytokine secretion in both patients and healthy control groups. Up-regulation of suppressor of cytokine signalling 3 (SOCS3) mRNA expression in PHA-stimulated PBMCs from CIU patients was not modified by simvastatin, in contrast to the enhancing effect in the control group. Statin exhibited a less efficient inhibition effect on cytokine production [IL-6 and macrophage inflammatory protein (MIP)-1α] induced by Toll-like receptor (TLR)-4, to which a statin preincubation step was required. Furthermore, statin did not affect the tumour necrosis factor (TNF)-α secretion by lipopolysaccharide (LPS)-stimulated PBMC or CD14+ cells in CIU patients. In addition, LPS-activated PBMC from CIU patients showed impaired indoleamine 2,3-dioxygenase (IDO) mRNA expression compared to healthy control, which remained at decreased levels with statin treatment. Statins exhibited a marked down-regulatory effect in T cell functions, but were not able to control TLR-4 activation in CIU patients. The unbalanced regulatory SOCS3 and IDO expressions in CIU may contribute to the pathogenesis of the disease.


Subject(s)
Adaptive Immunity/drug effects , Immunity, Innate/drug effects , Lovastatin/pharmacology , Simvastatin/pharmacology , Urticaria/immunology , Adult , Aged , Cell Cycle/drug effects , Cell Proliferation/drug effects , Chemokine CCL3/biosynthesis , Chronic Disease , Female , Humans , Indoleamine-Pyrrole 2,3,-Dioxygenase/biosynthesis , Indoleamine-Pyrrole 2,3,-Dioxygenase/genetics , Interleukin-10/biosynthesis , Interleukin-10/metabolism , Interleukin-17/biosynthesis , Interleukin-17/metabolism , Interleukin-6/biosynthesis , Leukocytes, Mononuclear/drug effects , Male , Middle Aged , Phytohemagglutinins/pharmacology , RNA, Messenger/biosynthesis , Suppressor of Cytokine Signaling 3 Protein , Suppressor of Cytokine Signaling Proteins/biosynthesis , Suppressor of Cytokine Signaling Proteins/genetics , T-Lymphocytes/drug effects , Th1 Cells/drug effects , Th2 Cells/drug effects , Toll-Like Receptor 4/metabolism , Tumor Necrosis Factor-alpha/biosynthesis , Tumor Necrosis Factor-alpha/metabolism , Urticaria/drug therapy , Young Adult
4.
Br J Dermatol ; 164(6): 1271-9, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21198536

ABSTRACT

BACKGROUND: Understanding the early events of the immune response, through the activation of plasmacytoid dendritic cells (pDC) by Toll-like receptor (TLR)9-sensing, could contribute to the evaluation of immune dysregulation in chronic idiopathic urticaria (CIU). OBJECTIVES: We decided to investigate innate immunity in CIU and the mechanisms implicated in the modulation of interferon (IFN)-α production by pDC upon TLR9 activation. METHODS: Patients with CIU (n = 31) and healthy control subjects (HC, n = 36) were enrolled in the study. Leucocytes cultured with the TLR9 ligand, CpG type A, or with inhibitory-oligodeoxynucleotide (ODN) were used to determine IFN-α secretion by enzyme-linked immunosorbent assay. Enumeration of pDC, intracellular IFN-α and signal transducers and activators of transcription protein (STAT) (1 and 4) phosphorylation were assessed by flow cytometry. TLR9 and regulatory factor-7 mRNA transcripts were evaluated by real-time polymerase chain reaction. Evidence of pDC in the skin lesions of patients was analysed with immunohistochemistry staining. RESULTS: The findings show a decreased IFN-α secretion induced by CpG A by leucocytes, due to the diminished IFN-α expression on pDC in CIU. It was mediated by TLR9-activation since inhibitory-ODN further suppressed TLR9-induced IFN-α secretion. A normal pDC percentage and degree of activation by the expression of costimulatory molecules was observed in CIU, with the rare presence of pDC in the skin lesion. In addition, an increased constitutive STAT1 phosphorylation on nonstimulated lymphocytes and a downregulation of TLR9 mRNA transcripts after CpG A activation were verified in patients with CIU. CONCLUSIONS: The findings showed an innate immune response in CIU disturbed by impairment of the pDC response to TLR9 activation.


Subject(s)
Dendritic Cells/metabolism , Immunity, Innate/immunology , Interferon-alpha/metabolism , Toll-Like Receptor 9/physiology , Urticaria/immunology , Adult , Aged , Chronic Disease , Down-Regulation , Female , Flow Cytometry , Humans , Immunohistochemistry , Leukocytes, Mononuclear/immunology , Male , Middle Aged , Oligodeoxyribonucleotides/pharmacology , Phosphorylation , STAT1 Transcription Factor/metabolism , STAT4 Transcription Factor/metabolism , Toll-Like Receptor 9/antagonists & inhibitors , Young Adult
6.
Mycopathologia ; 165(4-5): 303-12, 2008.
Article in English | MEDLINE | ID: mdl-18780466

ABSTRACT

Published studies on the association between cancer and paracoccidioidomycosis consist either isolated cases or clinical data based on hospital cohorts of paracoccidioidomycosis. The frequency of neoplasia in series of > or = 80 patients with paracoccidioidomycosis ranges from 0.16 to 14.1%, mean of 3.96%. There are only two retrospective controlled studies, one of them showing greater incidence of carcinoma in biopsy and necropsy samples of paracoccidioidomycosis (12 cases in 147 patients with the mycosis: 8.2%) than in the necropsies of the control group (320 cases in 7,302 necropsies: 4.9%). In the other, 22,409 autopsies were reviewed and 4,372 cases of cancer were found; of the 85 patients with paracoccidioidomycosis, 12 were diagnosed with cancer. No differences were observed in the frequency of malignancies between the group of patients with paracoccidioidomycosis (14.1%) and the control group (19.5%). Considering all the reported cases, carcinoma was more frequent than hematological malignancies, and was more often found at the same site or in a neighboring site affected by the mycosis, usually occurring after the diagnosis of the mycosis. Commonly, the basic cause of death was related to secondary infections or neoplasia. Lymphoma was associated with poorly organized rich in fungi granuloma. The clinical course and mortality were related to the cancer evolution or secondary infections and was worse in lymphoid series, metastatic carcinoma or in patients under cytotoxic chemotherapy. Additionally, as in several cases the clinical and histopathological data may mimick neoplasia, the correct diagnosis of both diseases is essential to guarantee an early and safe intervention.


Subject(s)
Neoplasms , Paracoccidioidomycosis , Adult , Aged , Carcinoma/complications , Carcinoma/epidemiology , Female , Humans , Leukemia/complications , Leukemia/epidemiology , Lymphoma/complications , Lymphoma/epidemiology , Male , Middle Aged , Neoplasms/complications , Neoplasms/epidemiology , Paracoccidioidomycosis/complications , Paracoccidioidomycosis/epidemiology
7.
Br J Dermatol ; 158(5): 979-86, 2008 May.
Article in English | MEDLINE | ID: mdl-18341658

ABSTRACT

BACKGROUND: Basophils and mast cells are the main target cells in chronic idiopathic urticaria (CIU). Besides the basopenia, intrinsic defects of the anti-IgE cross-linking signalling pathway of basophils have been described in CIU. OBJECTIVES: We sought to investigate the profile of expression of activation markers on basophils of patients with CIU and to explore the effect of interleukin (IL)-3 priming upon anti-IgE cross-linking stimuli through expression of activation markers and basophil histamine releasability. METHODS: Evaluation of the surface expression of FcepsilonRIalpha, CD63, CD203c and CD123 on whole blood basophils of patients with CIU undergoing autologous serum skin test (ASST) was performed by flow cytometry. The effect of pretreatment with IL-3 in the anti-IgE response was analysed by the expression of basophil activation markers and histamine release using enzyme-linked immunosorbent assay. RESULTS: Blood basophils of patients with CIU were reduced in number and displayed increased surface expression of FcepsilonRIalpha, which was positively correlated with the IgE serum levels. Upregulation of expression of both surface markers CD203c and CD63 was verified on basophils of patients with CIU, regardless of ASST response. High expression of IL-3 receptor on basophils was detected only in ASST+ patients with CIU. Pretreatment with IL-3 upregulated CD203c expression concomitantly with the excreting function of blood basophils and induced a quick hyper-responsiveness to anti-IgE cross-linking on basophils of patients with CIU compared with healthy controls. CONCLUSIONS: Basophils of patients with CIU showed an activated profile, possibly due to an in vivo priming. Functionally, basophils have high responsiveness to IL-3 stimulation, thereby suggesting that defects in the signal transduction pathway after IgE cross-linking stimuli are recoverable in subjects with chronic urticaria.


Subject(s)
Antigens, CD/metabolism , Basophils/drug effects , Histamine Release/drug effects , Immunoglobulin E/immunology , Interleukin-3/pharmacology , Urticaria/immunology , Adult , Aged , Basophils/immunology , Biomarkers/analysis , Chronic Disease , Enzyme-Linked Immunosorbent Assay , Female , Flow Cytometry , Humans , Immunoglobulin E/blood , Male , Middle Aged , Receptors, IgE/metabolism
11.
Br J Dermatol ; 155(2): 446-50, 2006 Aug.
Article in English | MEDLINE | ID: mdl-16882187

ABSTRACT

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.


Subject(s)
Autoantibodies/blood , Desmoglein 1/immunology , Pemphigus/immunology , Enzyme-Linked Immunosorbent Assay/methods , Female , Fluorescent Antibody Technique, Indirect , Follow-Up Studies , Humans , Male , Pedigree , Pemphigus/genetics , Pemphigus/pathology , Prognosis
12.
J Eur Acad Dermatol Venereol ; 19(3): 296-300, 2005 May.
Article in English | MEDLINE | ID: mdl-15857454

ABSTRACT

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.


Subject(s)
Candidiasis, Cutaneous/etiology , Pressure Ulcer/etiology , Adolescent , Adult , Aged , Candidiasis, Cutaneous/pathology , Female , Humans , Infant , Male , Middle Aged , Pressure Ulcer/pathology
13.
J Invest Dermatol ; 120(1): 104-8, 2003 Jan.
Article in English | MEDLINE | ID: mdl-12535205

ABSTRACT

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.


Subject(s)
Cadherins/immunology , Immunoglobulin Class Switching , Immunoglobulin G/classification , Pemphigus/etiology , Adolescent , Adult , Aged , Child , Desmoglein 1 , Endemic Diseases , Enzyme-Linked Immunosorbent Assay , Female , Humans , Immunoglobulin G/blood , Male , Middle Aged , Pemphigus/epidemiology , Pemphigus/immunology
14.
N Engl J Med ; 343(1): 23-30, 2000 Jul 06.
Article in English | MEDLINE | ID: mdl-10882765

ABSTRACT

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.


Subject(s)
Autoantibodies/blood , Cadherins/immunology , Endemic Diseases , Pemphigus/immunology , Autoantigens/immunology , Brazil/epidemiology , Desmoglein 1 , Enzyme-Linked Immunosorbent Assay , Female , Humans , Indians, South American , Male , Pemphigus/blood , Pemphigus/epidemiology , Prevalence , Reference Values
15.
J Clin Invest ; 105(2): 207-13, 2000 Jan.
Article in English | MEDLINE | ID: mdl-10642599

ABSTRACT

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.


Subject(s)
Autoantigens/immunology , Cadherins/immunology , Pemphigus/immunology , T-Lymphocytes/immunology , Adolescent , Adult , Aged , Antigens, CD/biosynthesis , Autoantigens/genetics , Cadherins/genetics , Clone Cells/cytology , Clone Cells/immunology , Cytokines/biosynthesis , Desmoglein 1 , Epitopes/genetics , Epitopes/immunology , Female , Flow Cytometry , Genes, MHC Class II/genetics , Histocompatibility Testing , Humans , Immunophenotyping , Lymphocyte Activation , Male , Middle Aged , Receptors, Antigen, T-Cell, alpha-beta/biosynthesis , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/immunology , T-Lymphocytes/cytology
16.
Hautarzt ; 51(12): 945-9, 2000 Dec.
Article in German | MEDLINE | ID: mdl-11189845

ABSTRACT

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.


Subject(s)
Leprosy, Lepromatous/diagnosis , Polyarteritis Nodosa/diagnosis , Aged , Diagnosis, Differential , Erysipelas/diagnosis , Erysipelas/pathology , Female , Humans , Leprosy, Lepromatous/pathology , Microcirculation/pathology , Middle Aged , Polyarteritis Nodosa/pathology , Skin/blood supply
17.
Pediatr Dermatol ; 16(3): 228-31, 1999.
Article in English | MEDLINE | ID: mdl-10383783

ABSTRACT

Potassium hydroxide (KOH) is a strong alkali that has long been known to digest proteins, lipids, and most other epithelial debris of skin scrapings to identify fungal infections. To our knowledge, KOH has never been used for the treatment of molluscum contagiosum (MC). We evaluated 35 children with MC for the clinical effectiveness of treatment with topical 10% KOH aqueous solution. The solution was applied by the parents of affected children, twice daily, on each MC lesion. The therapy was continued until all lesions underwent inflammation and superficial ulceration. Thirty-two of 35 patients achieved complete clinical cure after a mean treatment period of 30 days. Three children discontinued treatment: two reported severe stinging of the lesions and refused further applications; the other, with giant MC lesions, developed a secondary infection with prolonged treatment. Therapy with KOH was found to be effective and safe in the treatment of MC in children.


Subject(s)
Hydroxides/therapeutic use , Molluscum Contagiosum/drug therapy , Potassium Compounds/therapeutic use , Adolescent , Child , Child, Preschool , Female , Humans , Hydroxides/adverse effects , Hyperpigmentation/chemically induced , Hypertrophy/chemically induced , Hypopigmentation/chemically induced , Infant , Male , Potassium Compounds/adverse effects , Skin/drug effects , Skin/pathology , Treatment Outcome
20.
J Med Entomol ; 35(2): 120-31, 1998 Mar.
Article in English | MEDLINE | ID: mdl-9538571

ABSTRACT

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.


Subject(s)
Diptera , Indians, South American , Insect Bites and Stings , Pemphigus/epidemiology , Animals , Brazil/epidemiology , Cattle , Dogs , Equidae , Female , Geography , Horses , Humans , Prevalence
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