IgE, IgG1, and IgG4 Reactivity to Dermatophagoides pteronyssinus Glycosylated Extract in Allergic Patients.

BACKGROUND: House dust mites are important allergen sources and some of these allergenic proteins may contain carbohydrate moieties, which are able to be isolated using lectins, as Concanavalin A (ConA). This study aimed to investigate allergenicity (IgE) and antigenicity (IgG1 and IgG4) of ConA-unbound and ConA-bound Dermatophagoides pteronyssinus (Dpt) crude extracts using sera of mite-allergic patients as well as inhibition capacity of antibody binding. MATERIAL AND METHODS: We obtained mannose-enriched and mannose-depleted fractions from Dpt by ConA affinity chromatography. Both ConA-bound and ConA-unbound fractions were evaluated by ELISA and Western Blotting for specific IgE, IgG1, and IgG4 reactivity with sera obtained from 95 mite-allergic patients (DP+) and 92 nonallergic (NA) subjects. Inhibition ELISA was used to assess cross-reactivity between Dpt extract and its fractions. RESULTS: Among the DP+ patients, no difference was found between ConA-unbound and ConA-bound fractions regarding the levels of specific IgE, IgG1, and IgG4. Nonallergic subjects had the same levels of specific IgG1 to both ConA-unbound and ConA-bound fractions, although for specific IgG4, values were higher for ConA-bound. A positive correlation was found among specific IgE, IgG1, and IgG4 levels when Dpt was compared to ConA-unbound and ConA-bound fractions. Recognition of crude Dpt by IgE, IgG1, and IgG4 was highly inhibited by ConA-unbound and ConA-bound fractions. Western Blotting revealed a broad spectrum of bands ranging from 14 to 116 kDa recognized by specific IgE and IgG4. However, IgG1 reached higher frequency values on high molecular weight polypeptides. CONCLUSION: ConA-unbound and ConA-bound fractions derived from D. pteronyssinus crude extract revealed important components involved in the IgE recognition in allergic patients as well as IgG1 and/or IgG4 in allergic and healthy subjects.

Diversity of allergen exposure: implications for the efficacy of environmental control.

UNLABELLED: The prevalence of allergic diseases such as asthma, rhinitis, allergic conjunctivitis and atopic dermatitis has increased in the last decades. The relationship between allergen exposure, atopic sensitization and development of allergic diseases is widely described in the literature. AIM: To evaluate measures for reducing allergen exposure as part of the treatment of allergic diseases. METHODS: An analysis was made of previous studies on allergen exposure done with a similar methodology in the central region of Brazil; the study included homes, hotels, cinemas, cars, taxis, buses and scholar transportation. RESULTS: High levels of Der p 1 and Der f 1 mite allergens were found in a large proportion of the sample in most of the environments included in those studies; there were higher levels of pet allergens in cars and school transportation vehicles. CONCLUSION: The diversity of allergen exposure demonstrates the need for education about allergic diseases for patients and their families, as well as measures of reducing allergens in homes. This should be part of a global strategy of the management of allergic diseases, given that individuals live in society, not only in their houses.

Diversidade da exposição alergênica: implicações na obtenção da eficácia do controle ambiental: [revisão] / Diversity of allergen exposure: implications for the efficacy of environmental control: [review]

As doenças alérgicas, como a asma, rinite, conjuntivite alérgica e a dermatite atópica têm apresentado um aumento na sua prevalência nas últimas décadas. A relação entre exposição alergênica, sensibilização atópica e desenvolvimento de doenças alérgicas são amplamente descrita na literatura. OBJETIVO: Discutir a dificuldade no controle ambiental da exposição alergênica como parte do tratamento das doenças alérgicas. MÉTODOS: Analisar trabalhos de exposição alergênica realizados com metodologia similar na região central do Brasil, incluindo casas, hotéis, cinemas, carros, táxis, ônibus e transporte escolar. RESULTADOS: Níveis elevados dos alérgenos do grupo 1 de Dermatophagoides pteronyssinus (Der p 1) e de D. farinae (Der f 1), capazes de causar sensibilização e exacerbação de sintomas foram encontrados na maioria dos ambientes estudados em uma larga proporção das amostras, enquanto os alérgenos de animais domésticos atingiram maiores níveis em carros e veículos de transporte escolar. CONCLUSÃO: A diversidade da exposição alergênica mostra a necessidade de uma compreensão da doença alérgica pelos pacientes e familiares, e que as medidas de controle do ambiente doméstico fazem parte de uma estratégia global do tratamento das doenças alérgicas, uma vez que os indivíduos vivem em uma sociedade e não isoladas no interior de seus domicílios.

The prevalence of allergic diseases such as asthma, rhinitis, allergic conjunctivitis and atopic dermatitis has increased in the last decades. The relationship between allergen exposure, atopic sensitization and development of allergic diseases is widely described in the literature. AIM: To evaluate measures for reducing allergen exposure as part of the treatment of allergic diseases. METHODS: An analysis was made of previous studies on allergen exposure done with a similar methodology in the central region of Brazil; the study included homes, hotels, cinemas, cars, taxis, buses and scholar transportation. RESULTS: High levels of Der p 1 and Der f 1 mite allergens were found in a large proportion of the sample in most of the environments included in those studies; there were higher levels of pet allergens in cars and school transportation vehicles. CONCLUSION: The diversity of allergen exposure demonstrates the need for education about allergic diseases for patients and their families, as well as measures of reducing allergens in homes. This should be part of a global strategy of the management of allergic diseases, given that individuals live in society, not only in their houses.

[Indoor allergen sensitization profile in allergic patients of the allergy clinic in the University Hospital in Uberlândia, Brazil]. / Perfil de sensibilização a alérgenos domiciliares em pacientes ambulatoriais.

OBJECTIVE: To evaluate allergens among patients with allergic respiratory disease attended at the Allergy Clinic of the University Hospital-Federal University of Uberlândia. METHODS: A retrospective study was performed using medical records. Patients were included if their ISAAC questionnaires were correctly filled out and their skin prick tests were positive to at least one of the allergens from Dermatophagoides pteronyssinus (Der p), Dermatophagoides farinae (Der f), Blomia tropicalis (Blo t), Canis familiaris (Can f), Felis domesticus (Fel d), Blattella germanica (Bla g) and Alternaria alternata. RESULTS: Two-hundred and twelve medical records fulfilled the inclusion criteria. Allergic rhinitis was the main clinical diagnosis (32%), followed by concomitant manifestation of asthma and rhinitis (29.7%), and asthma, rhinitis and atopic dermatitis (9.4%). Asthma alone was found only in 1.9% of patients. The total sensitization observed was 73.5%, of which 61.7%, 59.9%, 54.7%, 45.7%, 38.2%, 33.3%, 9.9% were sensitized to Der p, Der f, Blo t, Bla g, Can f, Fel d and Alternaria, respectively. No significant difference was found between allergic disease types and source of allergen sensitization. CONCLUSION: The highest sensitization in allergic patients under study was to dust mites, especially Der p and Der f. It is noteworthy that the number of patients sensitized to cockroach extract was uncommonly high when compared to previous studies.

Perfil de sensibilização a alérgenos domiciliares em pacientes ambulatoriais / Indoor allergen sensitization profile in allergic patients of the allergy clinic in the University Hospital in Uberlândia, Brazil

OBJETIVO: Conhecer o perfil de sensibilização dos pacientes com diagnóstico de doenças alérgicas atendidos no Ambulatório de Alergia do Hospital de Clínicas da Universidade Federal de Uberlândia. MÉTODOS: Foi realizado um estudo retrospectivo por meio da análise de prontuários de pacientes atendidos no serviço, que foram submetidos ao teste cutâneo de puntura (TCP) para os alérgenos de Dermatophagoides pteronyssinus (Der p), Dermatophagoides farinae (Der f), Blomia tropicalis (Blo t), Canis familiaris (Can f), Felis domesticus (Fel d), Blattella germanica (Bla g) e Alternaria alternata, e respondido corretamente ao questionário ISAAC. RESULTADOS: Foram analisados 212 prontuários de pacientes que preenchiam os critérios de inclusão. A rinite alérgica isoladamente foi a maior causa de atendimento (32 por cento), seguida das associações asma e rinite (29,7 por cento) e asma, rinite e eczema (9,4 por cento). Pacientes com asma isoladamente perfizeram apenas 1,9 por cento dos atendimentos. A sensibilização dos pacientes observada foi de 73,5 por cento, sendo de 61,7 por cento para Der p, 59,9 por cento para Der f, 54,7 por cento para Blo t, 45,7 por cento para Bla g, 38,2 por cento para Can f, 33,3 por cento para Fel d e 9,9 por cento para Alternaria. Não houve diferenças significantes entre as patologias encontradas e os perfis de sensibilização. CONCLUSÃO: Os principais alérgenos sensibilizantes determinados pelo TCP foram os ácaros, com predomínio de Der p e Der f, chamando a atenção a elevada prevalência de sensibilização ao último. Ainda foi observada elevada sensibilização aos alérgenos de B. germanica, superior aos estudos anteriores realizados no País.

OBJECTIVE: To evaluate allergens among patients with allergic respiratory disease attended at the Allergy Clinic of the University Hospital - Federal University of Uberlândia. METHODS: A retrospective study was performed using medical records. Patients were included if their ISAAC questionnaires were correctly filled out and their skin prick tests were positive to at least one of the allergens from Dermatophagoides pteronyssinus (Der p), Dermatophagoides farinae (Der f), Blomia tropicalis (Blo t), Canis familiaris (Can f), Felis domesticus (Fel d), Blattella germanica (Bla g) and Alternaria alternata. RESULTS: Two-hundred and twelve medical records fulfilled the inclusion criteria. Allergic rhinitis was the main clinical diagnosis (32 percent), followed by concomitant manifestation of asthma and rhinitis (29.7 percent), and asthma, rhinitis and atopic dermatitis (9.4 percent). Asthma alone was found only in 1.9 percent of patients. The total sensitization observed was 73.5 percent, of which 61.7 percent, 59.9 percent, 54.7 percent, 45.7 percent, 38.2 percent, 33.3 percent, 9.9 percent were sensitized to Der p, Der f, Blo t, Bla g, Can f, Fel d and Alternaria, respectively. No significant difference was found between allergic disease types and source of allergen sensitization. CONCLUSION: The highest sensitization in allergic patients under study was to dust mites, especially Der p and Der f. It is noteworthy that the number of patients sensitized to cockroach extract was uncommonly high when compared to previous studies.

Pollen allergic disease: pollens and its major allergens.

Patients with grass pollen allergy, commonly called pollinosis, often present reactivity to pollen allergens from a number of grass species due to cross-reactivity of IgE antibodies to pollen proteins present in pollen grasses. In this context, Italian rye grass (Lolium multiflorum) pollen of the Poaceae family cultivated in Southern Brazil has been considered a major sensitizing agent in patients with pollinosis. In this region, Italian rye grass is capable of producing a great amount of pollen. In addition to L. multiflorum, other Poaceae grasses are naturally grown as weed in Southern Brazil, but with no clinical relevance. Pollen extracts derived from homologous or heterologous grasses are often used for both diagnosis and treatment of seasonal allergy. However, no standardized L. multiflorum pollen extract is commercially available in Brazil and mixed grass extracts are commonly used for diagnosis and immunotherapy of grass pollen allergy. Further studies are required to better characterize the cross-reactivity between L. multiflorum and other grass pollen allergens for improving the diagnosis and immunotherapy to L. multiflorum pollen allergy.

Doença alérgica polínica: polens alergógenos e seus principais alérgenos / Pollen allergic disease: pollens and its major allergens

Pacientes com alergia a pólen de gramíneas, comumente denominada polinose, freqüentemente apresentam reatividade a alérgenos de pólen de inúmeras gramíneas devido às reatividades cruzadas entre anticorpos IgE dirigidos contra proteínas presentes nos polens de gramíneas. Nesse contexto, pólen de Italian ryegrass (Lolium multiflorum), ou azevém anual, gramínea da família Poaceae cultivada no Sul do Brasil, é considerado o principal agente sensibilizante em pacientes com polinose. Nessa região, o azevém é capaz de produzir grande quantidade de pólen. Adicionalmente, outras gramíneas da família Poaceae crescem naturalmente no Sul, entretanto, sem relevância clínica. Extratos de pólen derivados de gramíneas homólogas ou heterólogas são freqüentemente empregados no diagnóstico e tratamento da alergia sazonal a pólen, sendo que para esses fins não se encontra comercialmente disponível no Brasil extrato padronizado de pólen de L. multiflorum. Futuros estudos serão importantes para melhor caracterizar a reatividade cruzada entre alérgenos de pólen de L. multiflorum e alérgenos de outras gramíneas com o objetivo de aprimorar o diagnóstico e imunoterapia de pacientes com alergia a pólen causada por L. multiflorum.

Patients with grass pollen allergy, commonly called pollinosis, often present reactivity to pollen allergens from a number of grass species due to cross-reactivity of IgE antibodies to pollen proteins present in pollen grasses. In this context, Italian rye grass (Lolium multiflorum) pollen of the Poaceae family cultivated in Southern Brazil has been considered a major sensitizing agent in patients with pollinosis. In this region, Italian rye grass is capable of producing a great amount of pollen. In addition to L. multiflorum, other Poaceae grasses are naturally grown as weed in Southern Brazil, but with no clinical relevance. Pollen extracts derived from homologous or heterologous grasses are often used for both diagnosis and treatment of seasonal allergy. However, no standardized L. multiflorum pollen extract is commercially available in Brazil and mixed grass extracts are commonly used for diagnosis and immunotherapy of grass pollen allergy. Further studies are required to better characterize the cross-reactivity between L. multiflorum and other grass pollen allergens for improving the diagnosis and immunotherapy to L. multiflorum pollen allergy.

Strongyloides ratti antigenic components recognized by IgE antibodies in immunoblotting as an additional tool for improving the immunodiagnosis in human strongyloidiasis.

IgE antibody response in human strongyloidiasis was evaluated by enzyme-linked immunosorbent assay (ELISA) and immunoblotting (IB) using Strongyloides ratti saline extract as heterologous antigen. A total of 50 serum samples of patients who were shedding S. stercoralis larvae in feces (group I, copropositive), 38 of patients with other intestinal parasites (group II), and 38 of subjects with negative results in three parasitologic assays (group III, copronegative) were analyzed. Levels of IgE anti-Strongyloides expressed in ELISA Index (EI) were significantly higher in patients of group I (1.32) than in group II (0.51) and group III (0.81), with positivity rates of 54%, 0%, and 10.5%, respectively. Fifteen S. ratti antigenic components were recognized in IB-IgE by sera of group I, with frequency ranging from 8% to 46%. In group II, only two antigenic bands (101, 81 kDa) were detected in a frequency of 10% and no reactivity was found in group III. Sera with EI values > 1.5 recognized five from 13 specific antigenic bands (70, 63, 61, 44, 7 kDa). It can be concluded that these five antigenic components recognized by IB-IgE using S. ratti antigen might be employed as an additional tool for improving the immunodiagnosis in human strongyloidiasis.

Strongyloides ratti antigenic components recognized by IgE antibodies in immunoblotting as an additional tool for improving the immunodiagnosis in human strongyloidiasis

IgE antibody response in human strongyloidiasis was evaluated by enzyme-linked immunosorbent assay (ELISA) and immunoblotting (IB) using Strongyloides ratti saline extract as heterologous antigen. A total of 50 serum samples of patients who were shedding S. stercoralis larvae in feces (group I, copropositive), 38 of patients with other intestinal parasites (group II), and 38 of subjects with negative results in three parasitologic assays (group III, copronegative) were analyzed. Levels of IgE anti-Strongyloides expressed in ELISA Index (EI) were significantly higher in patients of group I (1.32) than in group II (0.51) and group III (0.81), with positivity rates of 54 percent, 0 percent, and 10.5 percent, respectively. Fifteen S. ratti antigenic components were recognized in IB-IgE by sera of group I, with frequency ranging from 8 percent to 46 percent. In group II, only two antigenic bands (101, 81 kDa) were detected in a frequency of 10 percent and no reactivity was found in group III. Sera with EI values > 1.5 recognized five from 13 specific antigenic bands (70, 63, 61, 44, 7 kDa). It can be concluded that these five antigenic components recognized by IB-IgE using S. ratti antigen might be employed as an additional tool for improving the immunodiagnosis in human strongyloidiasis.

Heterologous antigen extract in ELISA for the detection of human IgE anti-Strongyloides stercoralis

Extrato contendo larvas de Strongyloides ratti foi usado na padronização de um ELISA para detecção de IgE gênero-específica na estrongiloidíase humana. Foram analisadas 40 amostras de soro de pacientes monoinfectados que estavam eliminando larvas de S. stercoralis nas fezes (Grupo I), 40 de pacientes com outros parasitos intestinais (Grupo II), e 40 indivíduos copronegativos (Grupo III). Níveis de IgE gênero-específica (índice ELISA: EI) foram significativamente maiores no Grupo I (EI = 1,43) do que no II (EI = 0,70) e III (EI = 0,71), mostrando positividade de 55 por cento, 2,5 por cento e 0 por cento, respectivamente. Similarmente, soros dos pacientes copropositivos (Grupo I) apresentaram níveis significativamente maiores de IgE total (866 IU/mL) quando comparados com os soros dos Grupo II (302 IU/mL) e III (143 IU/mL). Uma significativa correlação positiva foi encontrada entre os níveis de IgE específica a Strongyloides sp. e IgE total nos soros de pacientes com estrongiloidíase. Em conclusão, extrato heterólogo de S. ratti mostrou ser uma ferramenta útil para detecção de IgE gênero-específica por ELISA, desta forma contribuindo para melhor caracterização do perfil da resposta imune na estrongiloidíase humana.

Heterologous antigen extract in ELISA for the detection of human IgE anti-Strongyloides stercoralis.

Strongyloides ratti larval extract was used for the standardization of ELISA to detect genus-specific IgE in human strongyloidiasis. Forty serum samples from monoinfected patients shedding S. stercoralis larvae (Group I), 40 from patients with other intestinal parasites (Group II), and 40 from copronegative healthy subjects (Group III) were analyzed. Genus-specific IgE levels (ELISA Index: EI) were significantly higher in the group I (EI = 1.43) than groups II (EI = 0.70) and III (EI = 0.71), showing positivity rates of 55%, 2.5% and 0%, respectively. Similarly, sera from copropositive patients had significantly higher levels of total IgE (866 IU/mL) as compared to those from group II (302 IU/mL) and III (143 IU/mL). A significant positive correlation was found between levels of Strongyloides specific-IgE and total IgE in sera from patients with strongyloidiasis. In conclusion, S. ratti heterologous extract showed to be a useful tool for detecting genus-specific IgE by ELISA, contributing for a better characterization of the immune response profile in human strongyloidiasis.

[IgA, IgE and IgG subclasses to Candida albicans in serum and vaginal fluid from patients with vulvovaginal candidiasis]. / IgA, IgE e subclasses de IgG anti-Candida albicans no soro e lavado vaginal de pacientes com candidíase vulvovaginal.

PURPOSE: To determine the levels of IgA, IgE, IgG and subclasses (IgG1, IgG4) antibodies specific to C. albicans in serum and vaginal washes from women with or without vulvovaginal candidiasis in order to evaluate the role of these antibodies in the immunopathogenesis of the disease. METHODS: Thirty women with clinical symptoms of vulvovaginal candidiasis (15 positive vaginal culture to C. albicans, 11 negative culture and 4 positive culture to non-C. albicans) and 12 asymptomatic control women were selected. Serum and vaginal wash samples were obtained for the detection of anti-C. albicans antibodies by ELISA. RESULTS: Symptomatic patients with positive culture showed significantly higher levels of specific IgA in vaginal washes and lower in serum than those with negative culture. Specific serum IgE levels were very low compared to vaginal IgE. High levels of total specific IgG were found in serum and vaginal washes in both groups, regardless the fungal presence or absence. Specific IgG1 and IgG4 levels were significantly higher only in vaginal washes from symptomatic patients with positive culture, with a slightly higher IgG1/IgG4 ratio, indicating that the IgG1 antibody response may be predominantly involved in the fungal clearance. CONCLUSION: Our results indicate a pronounced antibody response of IgA, IgG1 and IgG4 to C. albicans in vaginal washes in symptomatic patients with positive culture, suggesting a important role of these antibodies in the local immune response triggered by the presence of the fungus.

IgA, IgE e subclasses de IgG anti-Candida albicans no soro e lavado vaginal de pacientes com candidíase vulvovaginal / IgA, IgE and IgG subclasses to Candida albicans in serum and vaginal fluid from patients with vulvovaginal candidiasis

OBJETIVO: Determinar níveis de anticorpos IgA, IgE, IgG e subclasses (IgG1, IgG4) específicos a C. albicans no soro e lavado vaginal de mulheres com ou sem candidíase vulvovaginal para avaliar o papel destes anticorpos na imunopatogênese desta doença. MÉTODOS: Foram selecionadas 30 mulheres com sintomas clínicos de candidíase vulvovaginal (15 com cultura de secreção vaginal positiva para C. albicans, 11 com cultura negativa e quatro com cultura positiva para Candida não-albicans) e 12 mulheres controles assintomáticas (nove com cultura negativa). Amostras de soro e lavado vaginal foram obtidas para a detecção de anticorpos anti-C. albicans por ELISA. RESULTADOS: Pacientes sintomáticas com cultura positiva apresentaram níveis de IgA específicas significativamente maiores no lavado vaginal e menores no soro do que aquelas com cultura negativa. Níveis séricos de IgE específica foram extremamente baixos em relação ao lavado vaginal. Altos níveis de IgG total específica foram encontrados no soro e lavado vaginal em ambos os grupos, independente da presença do fungo. Níveis de IgG1 e IgG4 específicas foram significativamente maiores somente no lavado vaginal de mulheres sintomáticas e cultura positiva, com relação IgG1/IgG4 ligeiramente maior, indicando que a resposta de anticorpos IgG1 possa estar predominantemente envolvida na resolução da infecção fúngica. CONCLUSÕES: Nossos resultados indicam resposta acentuada de IgA, IgG1 e IgG4 anti-C. albicans no lavado vaginal de mulheres sintomáticas com cultura positiva, sugerindo importante papel destes anticorpos na resposta imune local estimulada pela presença do fungo

Immunoglobulin E-rheumatoid factor in juvenile rheumatoid arthritis.

OBJECTIVES: To determine the presence of immunoglobulin E-rheumatoid factor in patients with juvenile rheumatoid arthritis and to correlate it with clinical and laboratory parameters. METHODS: A multicenter prospective study was carried out from January 1993 to January 1999 with the enrollment of 3 centers of pediatric rheumatology. Ninety-one children with juvenile rheumatoid arthritis diagnosed according to the American College of Rheumatology criteria were studied: 38 (42%) with systemic, 28 (31%) with pauciarticular, and 25 (27%) with polyarticular onset. Ages ranged from 2.1 years to 22.6 years (mean 10.5 +/- 4.7), with 59 (65%) girls. The control group consisted of 45 healthy children. The detection of immunoglobulin E-rheumatoid factor was carried out utilizing an enzyme-linked immunosorbent assay. Associations of immunoglobulin E-rheumatoid factor with immunoglobulin M-rheumatoid factor (latex agglutination test), total serum immunoglobulin E, erythrocyte sedimentation rate, antinuclear antibody, and functional and radiological classes III or IV were analyzed. RESULTS: Positive immunoglobulin E-rheumatoid factor was found in 15 (16.5%) of the 91 children with juvenile rheumatoid arthritis: 7 (18.5%) with systemic, 5 (18%) with pauciarticular, and 3 (12%) with polyarticular onset. A significant correlation was observed between immunoglobulin E-rheumatoid factor and total serum immunoglobulin E in the juvenile rheumatoid arthritis patients. No correlation was found between immunoglobulin E-rheumatoid factor and positive latex agglutination slide test, erythrocyte sedimentation rate, antinuclear antibody, or the functional and radiological classes III or IV in any disease onset group. In 4 out of 45 control children (8.9%), immunoglobulin E-rheumatoid factor was positive but with no correlation with total serum immunoglobulin E levels. CONCLUSIONS: Immunoglobulin E-rheumatoid factor could be detected in 16.5% of juvenile rheumatoid arthritis patients, particularly in those with high levels of total serum immunoglobulin E, and immunoglobulin E-rheumatoid factor appears not to be associated with disease activity or severity.

Immunoglobulin E-rheumatoid factor in juvenile rheumatoid arthritis

OBJECTIVES: To determine the presence of immunoglobulin E-rheumatoid factor in patients with juvenile rheumatoid arthritis and to correlate it with clinical and laboratory parameters. METHODS: A multicenter prospective study was carried out from January 1993 to January 1999 with the enrollment of 3 centers of pediatric rheumatology. Ninety-one children with juvenile rheumatoid arthritis diagnosed according to the American College of Rheumatology criteria were studied: 38 (42 percent) with systemic, 28 (31 percent) with pauciarticular, and 25 (27 percent) with polyarticular onset. Ages ranged from 2.1 years to 22.6 years (mean 10.5 ± 4.7), with 59 (65 percent) girls. The control group consisted of 45 healthy children. The detection of immunoglobulin E-rheumatoid factor was carried out utilizing an enzyme-linked immunosorbent assay. Associations of immunoglobulin E-rheumatoid factor with immunoglobulin M-rheumatoid factor (latex agglutination test), total serum immunoglobulin E, erythrocyte sedimentation rate, antinuclear antibody, and functional and radiological classes III or IV were analyzed. RESULTS: Positive immunoglobulin E-rheumatoid factor was found in 15 (16.5 percent) of the 91 children with juvenile rheumatoid arthritis: 7 (18.5 percent) with systemic, 5 (18 percent) with pauciarticular, and 3 (12 percent) with polyarticular onset. A significant correlation was observed between immunoglobulin E-rheumatoid factor and total serum immunoglobulin E in the juvenile rheumatoid arthritis patients. No correlation was found between immunoglobulin E-rheumatoid factor and positive latex agglutination slide test, erythrocyte sedimentation rate, antinuclear antibody, or the functional and radiological classes III or IV in any disease onset group. In 4 out of 45 control children (8.9 percent), immunoglobulin E-rheumatoid factor was positive but with no correlation with total serum immunoglobulin E levels. CONCLUSIONS: Immunoglobulin E-rheumatoid factor could be detected in 16.5 percent of juvenile rheumatoid arthritis patients, particularly in those with high levels of total serum immunoglobulin E, and immunoglobulin E-rheumatoid factor appears not to be associated with disease activity or severity