Randomized Controlled Trial of Oropharyngeal Colostrum Administration in Very-low-birth-weight Preterm Infants.

OBJECTIVE: The purpose of this study was to evaluate the effects of oropharyngeal colostrum administration in the incidence of late-onset clinical and proven sepsis and in concentrations of immunoglobulin A (IgA) in very-low-birth-weight (VLBW) infants. METHODS: We conducted a double-blinded, randomized, placebo-controlled trial and assigned 113 VLBW infants to receive 0.2 mL of maternal colostrum or sterile water (placebo) via oropharyngeal route every 2 hours for 48 hours, beginning in the first 48 to 72 hours of life. Neonates of both groups were fed breast milk from the first 3 days of life until a volume of at least 100 mL ·â€Škg ·â€Šday. IgA was measured in serum and urine before and after treatment. Clinical data during hospitalization were collected. RESULTS: We found no statistically significant differences between colostrum and placebo groups in the incidence of late-onset clinical sepsis (odds ratio 0.7602; CI 95% 0.3-1.6) and proven sepsis (odds ratio 0.7028; CI 95% 0.3-1.6). The measurement of IgA was similar in serum before (P value 0.87) and after treatment (P value 0.26 day 4 and 0.77 day 18). No differences were also observed in IgA in urine before (P value 0.8) and after treatment (P value 0.73 day 4 and 0.52). CONCLUSIONS: This study could not confirm the hypothesis that oropharyngeal administration of maternal colostrum to VLBW could reduce the incidence of late-onset sepsis and increase the levels of IgA. We believe that this finding can be justified by the practice of feeding VLBW infants exclusively with breast milk in the first days of life and reinforces the prior knowledge of the importance of early nutrition, especially, with human milk. It also suggests that oropharyngeal administration of colostrum should be reserved for neonates who cannot be fed in first few days of life.

Specific IgA and IgG antibodies in paired serum and breast milk samples in human strongyloidiasis.

Strongyloidiasis, caused by the nematode Strongyloides stercoralis, is one of the major worldwide parasitic infections in humans. Breastfeeding may offer a potential protection against this infection. Feces, serum and milk samples were obtained from 90 lactating women from Clinical Hospital of Universidade Federal de Uberlândia, Brazil. The fecal samples were collected for parasitological diagnosis and the serum and milk samples were examined for specific S. stercoralis IgA and IgG antibodies using the indirect fluorescent antibody test (IFAT) and enzyme-linked immunosorbent assay (ELISA). Fecal examination showed that the rate of prevalence of S. stercoralis infection in the lactating women was 4.4%. IFAT manifested a 16.7% positivity rate for specific IgA antibody in serum and a 28.9% rate in milk samples; specific IgG was 41.1% in serum and 25.5% in milk samples. According to ELISA the positivity rate for specific IgA antibody was 21.1% in serum and 42.2% in milk samples; specific IgG was 40% in serum and 18.9% in milk samples. In serum samples, these immunological tests showed a concurrence of 91.1% and 94.4%, respectively, in detecting specific IgA and IgG antibodies. In milk samples, they showed a concurrence of 70% and 78.9%, respectively, in detecting specific IgA and IgG antibodies. There was a statistically significant difference between concordant and discordant results of immunological tests (P<0.0001). IFAT and ELISA highly concurred in their detection of specific S. stercoralis IgA and IgG antibodies in serum and in milk samples reconfirming prior studies that the serological method is a complement to the direct diagnosis of the parasite, and suggesting that immunological methods using milk samples can also be helpful. Furthermore, in endemic areas, infants may acquire antibodies to S. stercoralis from breast milk, possibly, contributing to the enhancement of specific mucosal immunity against this parasite.

IgG1, IgG4, and IgE antibody responses in human strongyloidiasis by ELISA using Strongyloides ratti saline extract as heterologous antigen.

The aim of this study was to evaluate total IgG, IgG1, IgG4, and IgE antibody responses in human strongyloidiasis by enzyme-linked immunosorbent assay (ELISA) using Strongyloides ratti saline extract as heterologous antigen for a possible clinical utility of the assay. A total of 40 serum samples of patients who were shedding Strongyloides stercoralis larvae in feces (group I), 30 sera from patients with other intestinal parasites (group II), and 30 sera from subjects with negative results in three parasitological assays (group III) were analyzed to detect total IgG, IgG1, IgG4, and IgE to Strongyloides spp. by ELISA and expressed in ELISA index. Levels of total IgG anti-Strongyloides spp. were significantly higher in patients of group I than in groups II (p=0.0005) and III (p<0.0001). Levels of specific IgG1, IgG4, and IgE of group I were also significantly higher than in groups II and III, respectively. There was a significant positive correlation between specific IgE and IgG4 (r=0.6524; p=0.0084) and IgG1 and IgG4 (r=0.5398; p=0.0171). It can be concluded that the detection of specific IgE, IgG1, and IgG4 subclasses rather than total IgG antibodies to Strongyloides spp. using the S. ratti antigen showed to be an additional tool for improving the serodiagnosis of human strongyloidiasis.

Is measurement of IgM and IgA rheumatoid factors (RF) in juvenile rheumatoid arthritis clinically useful?

The prevalence and clinical relevance of IgM and IgA RF detected by ELISA were studied in 91 patients with juvenile rheumatoid arthritis (JRA) and 45 healthy children. IgM and IgA RF were detected, respectively, in 33 and 44% of the patients, compared to 6.7 and 15.6% of the healthy children (p = 0.001 and 0.0006, respectively). The frequency of IgM RF was significantly higher in patients with polyarticular (52%) as compared to systemic onset JRA (21%; p = 0.04). Five out of ninety-one patients and none of the control group were IgM RF positive by the latex test. High levels of IgM RF were detected more frequently in patients with active disease (p = 0.01) and positive latex agglutination test (p < 0.001) and had a marginally significant association with severe radiological deformities (p = 0.05). The presence of IgA RF was associated with active disease in polyarticular onset JRA children (p = 0.04). In conclusion, high levels of IgM RF and the detection of IgA RF can be useful in assessing clinical activity in a subset of patients with JRA.

Sensitization to Lolium multiflorum grass pollen in pollinosis patients: evaluation of allergenic fractions recognized by specific IgE antibodies.

BACKGROUND: Lolium multiflorum (Lm) pollen allergens are the major causative agents for rhinoconjunctivitis in Southern Brazil. There have been no studies about the sensitization and allergenic cross-reactivity between Lm and other grass pollens. We evaluated the sensitization of Brazilian pollinosis patients to Lm pollen allergens through skin prick test (SPT) and immunoassays (ELISA and immunoblot). METHODS: Serum samples from 60 patients with pollinosis and positive SPT to grass pollen extracts (Lm+ group), 30 patients with negative SPT to grass pollen, but positive SPT to mite extracts (Lm- group), and 30 nonatopic subjects (NA group) were tested by SPT, ELISA, and immunoblot using Lm extract. Inhibition immunoassays with Lolium perenne (Lp), mixed grass (Gmix) and Lm extracts were also performed. RESULTS: A high concordance was found between the Gmix and Lm extracts in SPT. Positivity rates in SPT were also highly concordant with IgE-ELISA results. The assay was able to detect Lm-specific IgE in >95% of Lm+ patients. A significant self- and cross-inhibition was observed in IgE-ELISA, reflecting a high cross-reactivity between the grass pollen allergens. Immunoblot revealed 13 IgE-binding Lm fractions, from which the bands 28-30 kDa and 31-34 kDa were recognized by >90% of Lm+ patients. CONCLUSION: Lm-specific IgE antibodies are highly cross-reactive with pollen proteins from other grass species. The results indicate that Lm extracts could be used in both SPT and ELISA for a more specific evaluation of IgE responses to Lm grass pollen in Brazilian pollinosis patients.

Heterogeneidade da resposta de anticorpos IgE aos alérgenos principais de Dermatophagoides pteronyssinus entre pacientes com alergia respiratória: Implicações para a imunoterapia específica com alérgenos / Heterogeneity of the IgE antibody response to major allergens from Dermatophagoides pteronyssinus among patients with respiratory allergy: Implications for allergen-specific immunotherapy

Objetivo: Analisar os níveis de IgE sérica específica aos alérgenos Der p 1 e Der p 2 de Dermatophagoides pteronyssinus (Dpt) em pacientes com alergia respiratória e comparar com as sensibilizações in vivo (teste cutâneo de puntura - TCP) e in vitro (ELISA- IgE) ao extrato total de Dpt. Métodos: Um total de 73 pacientes atópicos apresentando rinite alérgica com ou sem asma moderada e TCP positivo ao extrato total de Dpt foram estudados. Trinta indivíduos saudáveis com TCP negativo a ácaros da poeira domiciliar foram incluídos como controles. Níveis de IgE total e IgE específica a Dpt, Der p 1 e Der p 2 foram determinados por ELISA em pacientes atópicos (TCP+) e indivíduos controles não atópicos (TCP-). Resultados: Dos 73 pacientes atópicos, 38 (52 por cento) foram IgE duplo positivos aos alérgenos Der p 1 e Der p 2 (Der p 1+/Der p 2+), 11 (15 por cento) foram IgE positivos somente para Der p 1 (Der p 1+/Der p 2–), 7 (10po9r cento) foram IgE positivos somente para Der p 2 (Der p 1–/Der p 2+) e 17 (23 por cento) foram IgE duplo negativos para ambos alérgenos (Der p 1–/Der p 2–). Correlações significativas foram encontradas entre os níveis de IgE anti-Dpt e seus alérgenos (Der p1 ou Der p 2) bem como entre IgE anti-Der p 1 e anti-Der p 2 (P < 0,0001), mas não entre IgE específica a Dpt, Der p 1 ou Der p 2 e resultados do TCP. Pacientes com IgE duplo negativos apresentaram níveis de IgE anti-Dpt (IE = 1,4 ± 0,9) significativamente menores que os outros grupos, embora com altos níveis médios de IgE sérica total e valores de TCP. Conclusões: Os pacientes com alergia respiratória que apresentaram TCP+ ao extrato Dpt mostraram grande heterogeneidade da resposta de anticorpos IgE aos alérgenos principais de D. pteronyssinus, particularmente Der p 1 e Der p 2 e portanto, a determinação desses anticorpos específicos pode ser de grande valia para indicação e/ou seguimento de pacientes sensibilizados a ácaros sob imunoterapia específica com alérgenos.

Mite and pet allergen exposure in Brazilian private cars.

BACKGROUND: The role of mite and pet allergens in the development of allergic diseases has been recognized for many years. OBJECTIVE: To determine mite (Dermatophagoides pteronyssinus [Der p 1] and Dermatophagoidesfarinae [Der f 1]), cat (Felis domesticus [Fel d 1]), and dog (Canis familiaris [Can f 1]) allergen levels in Brazilian private cars. METHODS: Mite, cat, and dog allergens were measured in dust samples collected from 60 upholstered seats of private vehicles using enzyme-linked immunosorbent assays. RESULTS: Mean levels of Der p 1 (0.24 microg/g of dust; range, 0.06-2.05 microg/g of dust) and Der f 1 (0.29 microg/g of dust; range, 0.06-2.07 microg/g of dust) were extremely low in most dust samples analyzed. In contrast, sensitizing mean levels of Can f 1 (1.51 microg/g of dust; range, 0.14-30.96 microg/g of dust) and Fel d 1 (0.43 microg/g of dust; range, 0.02-5.75 microg/g of dust) were observed in 32 (53%) and 12 (20%) samples, respectively. Mean Can f 1 levels were significantly higher in cars whose owners kept dogs at home (3.27 microg/g of dust) than in those without pets (0.57 microg/g of dust; P = .008). There were no significant differences in allergen levels regarding the age of the vehicle or the number of users and whether the owners transport pets inside the vehicles. CONCLUSIONS: Private cars constitute an important pet, but not mite, allergen reservoir for continuous contamination of the indoor environment. Pet allergens may be present even in cars whose owners do not have pets. Effective measures to reduce allergen exposure in cars should be taken routinely, especially for pet-allergic patients.

Mite and cat allergen exposure in Brazilian public transport vehicles.

BACKGROUND: Mites and pets are important sources of indoor allergens. OBJECTIVES: To determine Dermatophagoides pteronyssinus (Der p 1), Dermatophagoides farinae (Der f 1), and Felis domesticus (Fel d 1) allergen levels in buses and taxis and to evaluate the predominant allergen in each vehicle type. METHODS: Mite and cat allergens were measured using enzyme-linked immunosorbent assay in dust samples collected from upholstered seats in 60 natural-ventilation buses (NVBs), 60 artificial-ventilation buses (AVBs), and 60 taxis. Thirty dust samples from AVB air-conditioning filters were also included. RESULTS: Levels of Der p 1 and Der f 1 were significantly higher in AVBs than in NVBs, whereas Fel d 1 levels were not significantly different between bus types. No significant differences were found in mite allergen levels in various sites in both types of buses, whereas Fel d 1 levels were significantly higher in rear and middle seats than in front seats in NVBs. Mite and cat allergen levels in taxis were significantly higher in passenger's rear seats than in driver's seats. A high proportion of dust samples from the vehicles, especially AVBs (82% for Der p 1 and 58% for Der f 1) had sensitizing levels of mite allergens, whereas more than 60% of samples from all vehicles had sensitizing levels of Fel d 1 allergen. In AVBs, samples from seats showed significantly higher levels of mite and cat allergens than those from air-conditioning filters. CONCLUSIONS: Public transport vehicles constitute an important allergen reservoir for continuous contamination of the indoor environment.

Perfil imunoquímico das vacinas comerciais de D. pteronyssinus para imunoterapia / Immunochemical profile of commercial D. pteronyssinus vaccines for immunotherapy

Objetivo: Analisar diferentes vacinas de alérgenos contendo D. pteronyssinus comercialmente disponíveis com a finalidade de caracterizar o perfil imunoquímico das mesmas e levar ao conhecimento dos médicos especialistas que utilizam estas vacinas como estratégia terapêutica em doenças alérgicas. Métodos: Dosagem de proteína e polissacáride, eletroforese em gel de poliacrilamida (SDSPAGE), quantificação dos alérgenos Der p 1, Der p 2 e Der f 1 por ELISA e imunorreatividade alergênica para detecção de IgE específica por ELISA e Immunoblotting foram realizados. Resultados: Observou-se grande heterogeneidade das vacinas em relação à concentração protéica e perfil eletroforético. As vacinas 2, 3 e 4 apresentaram bandas protéicas em SDSPAGE, em número e intensidade variáveis. Somente na vacina 2 foram detectados valores extremamente altos de Der p 1 (409,9 mg/ml) e Der p 2 (210,7 mg/ml). Imunorreatividade alergênica para IgE foi observada somente em três amostras de vacinas, com níveis de IgE significativos e comparáveis detectados apenas nas vacinas 2 e 3. Por outro lado, immunoblotting IgE demonstrou padrão de reconhecimento antigênico somente com a vacina 2, denotando a presença de quantidades significativas de frações alergênicas na referida vacina, como comprovado pelos resultados obtidos de concentração protéica, perfil eletroforético e dosagem de alérgenos principais (Der p 1 e Der p 2). Conclusões: Os resultados indicam que as vacinas de D. pteronyssinus analisadas apresentam doses dos respectivos alérgenos muito aquém das doses comprovadamente efetivas recomendadas. Assim, as vacinas alergênicas devem ser melhor caracterizadas quanto à potência total e ao teor do alérgeno principal, antes de serem disponibilizadas no mercado.

Sensibilizaçäo a alérgenos inaláveis domiciliares em pacientes asmáticos em Uberlândia, MG / Sensibilization to indoor allergens among asthmatic patients living in Uberlândia, MG

Objetivo: Avaliar a sensibilizaçäo aos alérgenos domiciliares em 89 pacientes asmáticos adultos em Uberlândia/MG, por testes cutâneos (punctura e intradérmico) e ELISA para anticorpos IgE específicos. Métodos: Testes de punctura (P) foram relizados com extratos de D. pteronyssinos (Dp), B. tropicalis (Br), barata, cäo e gato. Testes intradérmicos (ID) foram realizados somente para Dp e Bt. IgE sérica específica aos referidos alérgenos foi determinada por ELISA. Resultados: Foi observada maior sensibilizaçäo aos ácaros Dp (50,6 por cento) e Bt (33,7 por cento) quando comparado à sensibilizaçäo à barata (23,6 por cento), gato (4,5 por cento) e cäo (3,4 por cento) por testes P. Analisando-se o grau de reatividade do teste ID, 78,9 por cento e 61,4 por cento pacientes foram positivos respectivamente a Dp e Bt, com extratos contendo concentraçöes=< 1 Unidades Alergênicas (AU)/ml para Dp e 0,2 µg/ml para Bt. Pelo ELISA, 34,8 por cento pacientes tiveram IgE positiva ao Dp comparados aos 13,5 por cento para B. Menor percentual de IgE específica foi observado para barata (16,8 por cento), cäo (7,9 por cento) e gato (5,6 por cento). A positividade para Dp foi significativamente maior que para Bt para os testes P e ELISA. Observou-se alto índice de concordância (71,9 por cento para Dp e 60,7 para Bt) entre os três testes realizados. Resultados discordantes foram observados principalmente com testes cutâneos positivos (P e/ou ID) e ELISA negativos. Conclusöes: A maior sensibilizaçäo dos pacientes asmáticos adultos em Uberlândia ocorreu com ácaros, especialmente D.pteronyssinus. A sensibilizaçäo pode ser avaliada por testes in vivo e in vitro, levando em consideraçäo os dados clínicos para se obter um diagnóstico etiológico presuntivo e uma conduta apropriada.