Alexandre M. Périgo

Prevalence of antinuclear autoantibodies in the serum of normal blood dornors

OBJECTIVE To examine the presence of serum antinuclear autoantibodies in a healthy population. METHODS Serum of 500 normal blood donors between 18 and 60 years of age were tested for the presence of autoantibodies. Antinuclear antibodies were detected by indirect immunofluorescence technique using HEp-2 epithelial cells as the substrate. The presence of dnaN was detected by indirect immunofluorescence technique using Critidia lucillae as the substrate. Anti-SSA (RO), anti-SSB (LA), anti-Sm, and anti-RNP were determined by double radial immunodiffusion. RESULTS In the evaluation of the presence of serum antibodies, antinuclear antibodies were detected in 22.6% of the sera. The presence of other antibodies was not significant. The majority of the titers were 1:40. CONCLUSION The presence of autoantibodies is not necessarily pathologic and has to be related to the age group, gender, and clinical condition of the patient.

Imunofluorescência direta e indireta

Immunofluorescence is a valuable auxiliary diagnostic tool for autoimmune bullous diseases and inflammatory disorders, since their clinical and histopathologic findings may be inconclusive. It is a feasible laboratory method that requires experienced technicians and detects in situ and circulating immune deposits that may be involved in the pathogenesis of such skin diseases.

Endemic pemphigus foliaceus (fogo selvagem) and pemphigus vulgaris: immunoglobulin G heterogeneity detected by indirect immunofluorescence

UNLABELLED Pemphigus are autoimmune intraepidermal blistering diseases in which immunoglobulin G (IgG) autoantibodies are directed against desmosomal glycoproteins. The aim of this study was to determine the IgG subclass profile of endemic pemphigus foliaceus (fogo selvagem) and pemphigus vulgaris utilizing indirect immunofluorescence. PATIENTS AND METHODS Twenty-five patients with pemphigus vulgaris, 25 with endemic pemphigus foliaceus (fogo selvagem), and 25 healthy controls were analyzed by indirect immunofluorescence for circulating autoantibodies (total IgG and its subclasses). RESULTS Our data revealed a significant correlation (P <.05) of disease activity and autoantibody levels in both forms of pemphigus, i.e., negative titers related to clinical remission, whereas positive results related to active disease. Immunoglobulin G subclass analysis in fogo selvagem demonstrated that in patients in remission, 56% showed positive immunoglobulin G4; in active disease, immunoglobulin G4 was the predominant subclass (100% positive in all cases). The IgG subclass profile in pemphigus vulgaris showed that in patients in remission, only 10% were positive for immunoglobulin G4; in active disease, positivity for immunoglobulin G4 was present in 78% to 88% of the cases. CONCLUSION Subclass characterization of immunoglobulin G autoantibodies is a useful tool for pemphigus follow-up, since immunoglobulin G4 (IgG4) is the subclass that is closely related to recognition of pathogenic epitopes, and consequently with disease activity. Careful monitoring should be performed for fogo selvagem in clinical remission with a homogeneous IgG4 response, since this may indicate more frequent relapses.

Imunomapeamento nas epidermólises bolhosas hereditárias

Immunological mapping, an immunofluorescence technique, is currently the method most used to diagnose and differentiate the principal types of hereditary epidermolysis bullosa, since this technique is capable of determining the level of cleavage of this mechanobullous disease.

Vulvo-cervico-vaginal manifestations and evaluation of Papanicolaou smears in pemphigus vulgaris and pemphigus foliaceus

BACKGROUND Vulvo-cervico-vaginal involvement has rarely been reported in pemphigus vulgaris (PV) and has not been reported in pemphigus foliaceus (PF). OBJECTIVES We sought to evaluate genital lesions and Papanicolaou (Pap) smears in female patients with PV and PF. METHODS This prospective study includes all consecutive cases of female patients with PV and PF seen from May 2009 to February 2010. Gynecologic examination was performed and Pap smears were collected for cytologic analysis from each patient. RESULTS A total of 56 patients were given a diagnosis of pemphigus (41 PV and 15 PF). Genital involvement was observed in 9 patients with PV (22%) and the vulva was the most common genital site of involvement. Of these 9 patients, 8 presented with active skin/mucous lesions. Four of 15 patients with PF had genital lesions and vulva was the exclusive site of involvement. Three of 4 patients with PF and genital involvement also showed active cutaneous lesions. Six of 56 patients (5 PV and 1 PF) presented with atypical squamous cells of undetermined significance in Pap smear analysis. Upon further pathologic review, acantholytic cells were seen, confirming the diagnosis of pemphigus. LIMITATIONS A small number of PF cases were studied. CONCLUSIONS Vulvar lesions were the second most frequent site of mucous membrane PV. Herein we report the first case to our knowledge of symptomatic genital lesions in a patient with PF. Moreover, acantholytic cells in Pap smears were found in a patient with PF who was in complete remission off therapy with no clinical genital lesions and no circulating anti-desmoglein-1 and anti-desmoglein-3 autoantibodies. Gynecologic evaluation in patients with pemphigus, including a careful evaluation of Pap smears, should be recommended.

Correlation between Histopathological Findings and Results of Direct Immunofluorescence in the Diagnosis of Canine Localized Cutaneous Chronic Lupus Erythematosus

Background: Localized chronic cutaneous lupus erythematosus (CCLE), also known as discoid lupus erythematosus, is one of the most prevalent canine autoimmune skin diseases. Histopathology is considered the gold standard for the diagnosis of CCLE and the accuracy of which can be increased by use of direct immunofluorescence (DIF). This study aimed to investigate the fluorescence pattern revealed by DIF in cases of canine localized CCLE and to establish and compare its effectiveness with that obtained from histopathology. Materials, Methods & Results: Eleven dogs suspicious to localized CCLE, i.e., those animals that presented mucocutaneous lesions as erythema, leucoderma, erosive-ulcerative lesions, and loss of nasal planum architecture and its transition to the haired skin underwent medical physical and laboratory examinations (blood count, platelet count, determination of alanine transaminase, alkaline phosphatase, total protein, serum albumin, urea, creatinine). Only those animals that proved to be normal across both the physical and laboratorial evaluation were included in Group I. Animals belonging to this group were submitted to general anesthesia to biopsy two samples of lesioned skin from nasal planum to histopathologic examination and DIF test. Five dogs with no skin lesions were included in Group II as negative control to the DIF assay. Two samples of no lesioned skin from nasal planum were biopsied to histopathologic and DIF evaluation. The kappa (k) coefficient was used to determine the degree of agreement and reliability of the results of both tests. A P-value < 5% was considered to be statistically significant. In Group I, all animals were normal across both the physical and laboratorial evaluation. A diagnosis of canine CCLE was established in 81.8% (9/11) of the animals based on histopathology analysis. Two dogs, numbers 10 and 11, respectively, had histopathologic findings suggestive of cutaneous leishmaniasis and compatible with canine demodicosis. The DIF assay confirmed the diagnostic of canine CCLE in 100% (11/11) of the cases, including dogs numbers 10 and 11. Direct immunofluorescence positivity for canine localized CCLE was determined by the presence of homogeneous green fluorescence in the basement membrane zone, with IgM and C3 immunoreagents being found at a significantly higher frequency (P = 0.007) than IgA and IgG (P = 0.017 and P = 0.037, respectively). In Group II, no alterations from histopathologic examination and unspecific fluorescence from DIF reaction were shown in all animals belonging to this group. A substantial and significant degree of agreement or reliability (k = 0.738 and P = 0.002, respectively) was established between the results of both tests. Discussion: In veterinary medicine, there is a lack of studies about DIF around autoimmune dermatoses. This is the first manuscript comparing histopathological and direct immunofluorescence findings in the diagnostic of dogs with localized CCLE. In the present study, the positivity to the DIF assay for canine localized CCLE was established by the presence of green fluorescence of a homogeneous morphologic pattern, especially for IgM and C3, located in the BMZ and cutaneous annexes. Direct immunofluorescence excluded the suspicion of cutaneous leishmaniasis determined by the histopathological findings and confirmed the diagnostic of canine localized CCLE in the dog number 10. Statistically, a substantial degree of agreement and reliability was shown between DIF and histopathology. Therefore, we concluded that the DIF assay is a highly effective and useful complementary examination that improves our ability to diagnose canine CCLE.