The Usefulness of Indirect Immunofluorescence in Pemphigus and the Natural History of Patients With Initial False-Positive Results: A Retrospective Cohort Study.

The specificity and the predictive values of indirect immunofluorescence (IIF) in real-life settings is yet to be firmly established. The natural history of patients with false-positive results has not been sufficiently elucidated. The primary aim of the current study is to evaluate the diagnostic value of IIF analysis on monkey esophagus in pemphigus, utilizing a large cohort arising from the real-life experience of a tertiary referral center. The secondary endpoint was to determine the clinical outcomes of patients with false-positive results. This was a retrospective cohort study including all patients who were tested for the presence of intercellular autoantibodies by IIF on monkey esophagus between 2000 and 2017. Overall, 770 sera from different individuals were tested by IIF microscopy. Of those, 176 patients had been diagnosed with pemphigus vulgaris (PV) and 29 patients with pemphigus foliaceus (PF). The sensitivity of this immunoassay was significantly higher for the diagnosis of PV (87.4%; 95% CI, 81.5-91.9%) as compared to PF (69.0%; 95% CI, 49.2-84.7%; P = 0.018). The specificity for the diagnosis of pemphigus was 93.5% (95% CI, 91.1-95.4%). Patients with false-positive results (n = 37) were followed for a median duration of 5.3 years contributing 280.8 person-years. Thirty patients (81.1%) were eventually diagnosed clinically and immunopathologically with subepidermal autoimmune bullous diseases, whereas the remaining patients (18.9%) were diagnosed clinically and histologically with other inflammatory dermatoses, but none of them developed pemphigus during the follow-up duration. Of note, 7.0% (n = 23) of all patients diagnosed with bullous pemphigoid (BP) in the same period (n = 328) were tested positive for IgG intercellular antibodies. Histopathological review of the biopsy specimens of these patients did not reveal acantholysis. In conclusion, the predictive value of negative test in IIF on monkey esophagus is particularly reliable to exclude a diagnosis of pemphigus. Individuals tested positive for intercellular antibodies without an initial overt pemphigus did not show an increased risk for developing pemphigus subsequently. A sizable fraction of patients with BP showed circulating intercellular autoantibodies by IIF, without a histopathological evidence for acantholysis.

Human cervix: an alternative substrate for detecting circulating pemphigus antibodies.

Monkey esophagus (ME) is a well-accepted substrate for diagnosing pemphigus vulgaris (PV) by indirect immunofluorescence (IIF). However, its availability is sometimes limited due to ethical concerns. This study aimed to investigate the usefulness of human cervix (HC) as a substrate in the diagnosis of PV by IIF. Initially, serum from 1 PV patient was incubated with tissues from 48 HCs. Median IIF titers on HCs that had different demographic and clinical characteristics were compared. Sera from 5 PV patients were then incubated with ME and 21 HCs. For each serum, the titer of IIF on HC that was not different from ME by more than two-fold dilutions was acceptable. Last, sera from 42 PV, 14 pemphigus foliaceous, and 62 non-pemphigus patients were used to evaluate sensitivity and specificity. The results demonstrate that differences in demographic data among HCs did not affect IIF titers. Titers obtained from ME and HC were comparable (81-100 % acceptable values). Sensitivity of HC for diagnosis of PV was better than for diagnosis of pemphigus foliaceus (90.5 and 71.4 %, respectively). Specificity for PV and PF was 96.2 %. We proposed that HC substrate can be used as an alternative substrate for diagnosis of PV by IIF.

Atopic dermatitis with possible polysensitization and monkey esophagus reactivity.

CONTEXT: Atopic dermatitis is a chronic inflammatory skin disease resulting from interactions between environmental and genetic factors. Recent studies link atopic dermatitis with asthma and with eosinophilic esophagitis. CASE REPORT: Based on this association, we investigated by indirect immunofluorescence the immunoreactivity patterns on monkey esophagus substrate utilizing the serum of a patient with severe atopic dermatitis. We also examined the patient's skin biopsy by H&E histology and immunohistochemistry. We detected strong deposits of albumin, IgE, IgG, IgD, IgA, Complement/C1q and mast cell tryptase in multiples structures of the skin, as well as a broad pattern of intraepithelial staining on monkey esophagus. Strong staining positivity was also detected within the inflammatory infiltrate around the upper dermal vessels, as well as additional positive staining for the human leukocyte antigen system antigens DR DP and DQ. CONCLUSION: Our findings demonstrate that there could be an indication for testing patients with severe atopic dermatitis for autoreactivity to filaggrin (anti-keratin antibodies) utilizing monkey esophagus. Larger studies are needed to clarify any immunologic interaction between the reactivity to albumin and food allergens that may sensitize patients via the esophageal mucosa.

Eficacia del cordón umbilical humano como sustrato para detección de anticuerpos anti endomisio / Efficiency of human umbilical cord as substrate or detection of antiemdomysium antibodies / Aeficácia do cordÒo umbilical humano como substrato para a detenþÒo de anticorpos anti-endomísio

Los anticuerpos anti endomisio IgA (EMA) están dirigidos hacia antígenos del tejido conectivo que rodea a las fibras del músculo liso. El objetivo de este trabajo fue evaluar la eficacia del cordón umbilical humano (CUH) como sustrato para detectar EMA mediante inmunofluorescencia indirecta y compararlo con una de las metodologías disponibles comercialmente, la cual utiliza como sustrato esófago de mono. Se obtuvieron 100 sueros de pacientes con diagnóstico de enfermedad celíaca y 50 sueros de pacientes clínicamente sanos con biopsia de mucosa intestinal normal, los cuales realizaron su consulta y atención en el Hospital Privado Centro Médico de Córdoba, en un periodo de tiempo comprendido entre los años 2006 y 2009. Los resultados obtenidos mostraron una "muy buena" concordancia entre ambos métodos. Se estimó para el método que utiliza CUH una sensibilidad y especificidad de 98% (93-99%) y 100% (93-100%) respectivamente con una eficacia del 99%. De acuerdo con lo anterior se concluye que utilizar CUH como sustrato para evaluar la presencia de EMA es confiable y efectivo para detectar pacientes con enfermedad celíaca no tratada.(AU)

The antiendomysium antibodies (EMA) are directed toward antigens of connective tissue that surrounds the smooth muscle fibers. The aim of this study was to evaluate the efficiency of human umbilical cord (HUC) as substrate to detect EMA by indirect immunofluorescence and to compare it with one of the commercially available methodologies which use monkey esophagus as substrate. Serum samples obtained from 100 patients with celiac disease diagnosis and 50 healthy controls with normal intestinal mucosa were evaluated. Patients were treated at the Hospital Privado Centro Médico de Córdoba over a period of time between 2006 and 2009. The results showed an "almost perfect" concordance between both methods. The calculated sensitivity and specificity for HUC was 98% (93-99%) and 100% (93-100%) respectively, with an efficiency of 99%. This results indicate that the use of HUC as substrate to evaluate the presence of EMA is reliable and effective for the detection of patients with untreated celiac disease.(AU)

Os anticorpos anti-endomísio IgA (EMA) sÒo direcionados contra os antígenos do tecido conectivo que cercam as fibras do músculo liso. O objetivo deste trabalho foi avaliar a eficácia do cordÒo umbilical humano (CUH) como substrato para detectar EMA através da imunofluorescÛncia indireta e compará-lo com uma das metodologias disponíveis comercialmente, a qual utiliza como substrato es¶fago de macaco. Foram obtidos 100 soros de pacientes com diagnóstico de doenþa celíaca e 50 soros de pacientes clinicamente saudáveis com biópsia de mucosa intestinal normal, os quais realizaram sua consulta e atendimento no Hospital Privado Centro Médico de Córdoba, em um período de tempo compreendido entre os anos 2006 e 2009. Os resultados obtidos mostraram uma "ótima" concordÔncia entre ambos os métodos. Foi calculada para o método que utiliza CUH uma sensibilidade e especificidade de 98% (93-99%) e 100% (93-100%) respectivamente com uma eficácia de 99%. De acordo com o acima exposto, se conclui que utilizar CUH como substrato para avaliar a presenþa de EMA é confiável e eficaz para detectar pacientes com doenþas celíacas nÒo tratadas.(AU)

Eficacia del cordón umbilical humano como sustrato para detección de anticuerpos anti endomisio / Efficiency of human umbilical cord as substrate or detection of antiemdomysium antibodies / Aeficácia do cordão umbilical humano como substrato para a detenção de anticorpos anti-endomísio

Los anticuerpos anti endomisio IgA (EMA) están dirigidos hacia antígenos del tejido conectivo que rodea a las fibras del músculo liso. El objetivo de este trabajo fue evaluar la eficacia del cordón umbilical humano (CUH) como sustrato para detectar EMA mediante inmunofluorescencia indirecta y compararlo con una de las metodologías disponibles comercialmente, la cual utiliza como sustrato esófago de mono. Se obtuvieron 100 sueros de pacientes con diagnóstico de enfermedad celíaca y 50 sueros de pacientes clínicamente sanos con biopsia de mucosa intestinal normal, los cuales realizaron su consulta y atención en el Hospital Privado Centro Médico de Córdoba, en un periodo de tiempo comprendido entre los años 2006 y 2009. Los resultados obtenidos mostraron una "muy buena" concordancia entre ambos métodos. Se estimó para el método que utiliza CUH una sensibilidad y especificidad de 98% (93-99%) y 100% (93-100%) respectivamente con una eficacia del 99%. De acuerdo con lo anterior se concluye que utilizar CUH como sustrato para evaluar la presencia de EMA es confiable y efectivo para detectar pacientes con enfermedad celíaca no tratada.

The antiendomysium antibodies (EMA) are directed toward antigens of connective tissue that surrounds the smooth muscle fibers. The aim of this study was to evaluate the efficiency of human umbilical cord (HUC) as substrate to detect EMA by indirect immunofluorescence and to compare it with one of the commercially available methodologies which use monkey esophagus as substrate. Serum samples obtained from 100 patients with celiac disease diagnosis and 50 healthy controls with normal intestinal mucosa were evaluated. Patients were treated at the Hospital Privado Centro Médico de Córdoba over a period of time between 2006 and 2009. The results showed an "almost perfect" concordance between both methods. The calculated sensitivity and specificity for HUC was 98% (93-99%) and 100% (93-100%) respectively, with an efficiency of 99%. This results indicate that the use of HUC as substrate to evaluate the presence of EMA is reliable and effective for the detection of patients with untreated celiac disease.

Os anticorpos anti-endomísio IgA (EMA) são direcionados contra os antígenos do tecido conectivo que cercam as fibras do músculo liso. O objetivo deste trabalho foi avaliar a eficácia do cordão umbilical humano (CUH) como substrato para detectar EMA através da imunofluorescência indireta e compará-lo com uma das metodologias disponíveis comercialmente, a qual utiliza como substrato esôfago de macaco. Foram obtidos 100 soros de pacientes com diagnóstico de doença celíaca e 50 soros de pacientes clinicamente saudáveis com biópsia de mucosa intestinal normal, os quais realizaram sua consulta e atendimento no Hospital Privado Centro Médico de Córdoba, em um período de tempo compreendido entre os anos 2006 e 2009. Os resultados obtidos mostraram uma "ótima" concordância entre ambos os métodos. Foi calculada para o método que utiliza CUH uma sensibilidade e especificidade de 98% (93-99%) e 100% (93-100%) respectivamente com uma eficácia de 99%. De acordo com o acima exposto, se conclui que utilizar CUH como substrato para avaliar a presença de EMA é confiável e eficaz para detectar pacientes com doenças celíacas não tratadas.