Evaluation of commercial immunodiffusion reagents for detecting serum anti-Paracoccidioides antibodies

ABSTRACT Background: Accurate diagnosis of paracoccidioidomycosis is crucial for improving patient outcomes. Paracoccidioides antibody detection by double immunodiffusion (DID) is a convenient diagnostic tool, but testing performance can vary based on certain factors. Methods: We assessed DID performance using a commercially prepared Paracoccidioides reagents (IMMY, USA), involving 40 serum specimens, including 20 from patients with proven paracoccidioidomycosis and 20 from patients without the disease. The DID test demonstrated a sensitivity of 90% (95% CI=68%-99%) and a specificity of 100% (95% CI=83%-100%). Conclusions: Our findings suggest that DID using commercial reagents may provide a feasible tool with satisfactory testing performance for anti-Paracoccidioides antibody detection.

First record of antibodies to the bluetongue virus in ewe (Ovis aries) in the state of Amazonas, Brazil / Primeiro registro de anticorpos para o vírus da língua azul em ovino (Ovis aries) no estado do Amazonas, Brasil

The objective of this work was to describe the first record of antibodies to the Bluetongue Virus (BTV) in ewe, in the state of Amazonas. The ewe, which was in twin pregnancy, gave birth on May 9, 2015, but a lamb died hours after delivery. Veterinary service was then requested by the owner, where emaciation, loss of wool, pyrexia, apathy, dyspnea, mucoid nasal secretion, facial, lingual and submandibular edema were observed. There was a visit by the Agricultural Defense Agency of the State of Amazonas to the property and blood samples were collected from the animal. The whole blood and serum were sent to the National Agricultural Laboratory, where it was possible to detect the presence of specific antibodies to BTV, through the Agar Gel Double Immunodiffusion. The ewe was submitted to a new blood collection, following the same protocols and the samples were sent to the Biological Institute of São Paulo, confirmed diagnosis. The animal in a serious clinical condition, could not resist and died in July 2015. The occurrence of an allochthonous case, in an area where vector insects occur, can trigger an endemic process in the Amazon region. With this, the epidemiological control of these occurrences is necessary, in order to avoid the spread of the disease in the country.

O objetivo do trabalho foi descrever o primeiro registro de anticorpos para o Vírus da Língua Azul (VLA) em ovino, no estado do Amazonas. A ovelha, que se encontrava em gestação gemelar, pariu no dia 9 de maio de 2015, porém um cordeiro faleceu horas após o parto. Foi então solicitado serviço veterinário por parte do proprietário, onde foi observado emaciação, perda de lã, pirexia, apatia, dispneia, secreção nasal mucoide, edema facial, lingual e submandibular. Houve visita da Agência de Defesa Agropecuária do Estado do Amazonas na propriedade e coletadas amostras de sangue do animal. O sangue total e soro foram enviados ao Laboratório Nacional Agropecuário, no qual foi possível detectar a presença de anticorpos específicos para VLA, através do teste de Imunodifusão Dupla em Gel de Ágar. A ovelha foi submetida a uma nova coleta de sangue, seguindo os mesmos protocolos e as amostras foram enviadas ao Instituto Biológico de São Paulo, confirmando diagnóstico. O animal em estado clínico grave, não resistiu e veio a óbito em julho de 2015. A ocorrência de um caso alóctone, em uma área de ocorrência de insetos vetores, pode desencadear um processo de endemia na região amazônica. Com isso, o controle epidemiológico destas ocorrências, se fazem necessários, afim de se evitar a disseminação da doença no país.

Immunological assays employed for the elucidation of an histoplasmosis outbreak in São Paulo, SP

Several reports showed outbreaks of histoplasmosis acquired while bat-inhabited caves were visited by tourists, miners or researchers. We evaluated the performance of double immunodifusion (DI) and immunoblotting (IB) assays, employed for the histoplasmosis outbreak elucidation occurred in Vale do Paraíba, São Paulo. The existence of epidemiologic link, four patients with clinical signs suggestive of histoplasmosis and mycological confirmation has made that all 35 individuals involved to the cave visit were subjected to serological evaluation. By DI, we observed reactivity against H. capsulatum antigen in a single serum examined nearly 20 days after exposure to fungal propagules. On the other hand, IB showed reactivity against H and M fractions in 50% of samples evaluated. The analysis of the second sample batch, collected two months after the exposure showed that 96.7% were reactive by DI with antibodies titers ranging from 1 to 16 and 100% of reactivity against H and M fractions, by IB, suggesting an acute infection. The analysis of the overall agreement between the methods showed to be reasonable (κ = 0.37). This study confirms the importance and efficacy of more sensitive methodologies, such as IB assay, to early elucidation of disease, especially in cases of patients without mycological information.

Study on the antigenicity of Streptococcus pneumonia polysaccharide, its derivatives and conjugates by three immunological assays / 中华微生物学和免疫学杂志

Objective To monitor and analyze the antigenicity of Streptococcus pneumonia polysac-charide, its derivatives and conjugates by three immunological assays .Methods Inhibition ELISA and rate nephelometry(RN) were established for this study.Antigenicity of serotype 23F pneumococcal conjugates and their intermediates were analyzed by double immunodiffusion assay , inhibition ELISA and RN .The re-sults derived from three assays were comparatively analyzed to evaluate the changes of antigenicity during the preparing process of serotype 23F conjugate.Results Double immunodiffusion assay, inhibition ELISA and RN were all applicable to antigenicity analysis during the process of conjugate preparation .Inhibition ELISA could quantitatively detect a slight difference of polysaccharide antigenicity during the preparing process . Conclusion The antigenicity of polysaccharide during the preparing process of pneumococcal conjugates could be analytically monitored by using three immunological assays .This study provided evidence for suc-cessfully using immunological assays as the quality control means during the preparing process of pneumococ -cal conjugates .

Serological diagnosis of paracoccidioidomycosis in HIV-coinfected patients

Paracoccidioidomycosis should be differentiated from other opportunistic diseases in human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) patients who live in Latin America. Laboratory investigation can begin with serological tests, which are rapid and efficient. In the present study, double immunodiffusion (DID), counterimmunoelectrophoresis (CIEP) and an enzyme linked immunosorbent assay (ELISA) tests were assessed for the detection of anti-Paracoccidioides brasiliensis antibodies in 40 patients coinfected with HIV. The results were compared to those obtained for 75 non-HIV-infected patients with endemic paracoccidioidomycosis. Anti-P. brasiliensis antibodies were detected in 65 percent (DID), 79 percent (CIEP) and 95 percent (ELISA) of the patients with HIV/AIDS, significantly lower rates than those detected in cases of endemic paracoccidioidomycosis, which were 89 percent, 99 percent and 100 percent, respectively. The reactive sera of HIV-infected patients also showed lower anti-P. brasiliensis antibody titres than those of non-HIV-infected patients. Despite the lower intensity of the specific humoral response, serological tests are useful for the diagnosis of opportunistic paracoccidioidomycosis in the HIV/AIDS population. We suggest optimization of the laboratory diagnosis by combining the ELISA test with CIEP or DID.

Use of serological techniques for determination of Spodoptera frugiperda (J E Smith) predators (Lepidoptera: Noctuidae)

Spodoptera frugiperda (J E Smith) is an important pest of several crops, but especially on maize in Brazil. The implementation of biological control measures hinges on the identification of its predators and other natural enemies. As a means of identifying predators, antibodies against S. frugiperda eggs were generated by inoculating rabbits with macerated S. frugiperda eggs, and the production of antibodies against S. frugiperda egg proteins was verifi ed by double immunodiffusion (DID). These antibodies were then utilized in another serological technique, counterimmunoeletrophoresis (CIE), to identify insects that could have ingested S. frugiperda eggs. Macerates of entire insects collected in maize plantations and of individual parts of their digestive tract, including the crop, were the source of antigens in the CIE, while predators fed S. frugiperda eggs in the laboratory served as the control. Antibodies produced by the inoculated rabbits were effective in detecting S. frugiperda egg proteins, especially if crop macerates were used as antigens. Among the species of insects collected from maize plantations, Lagria villosa Fabricius (Coleoptera: Lagriidae) and a species of Lygaeidae (Hemiptera) were identified as possible S. frugiperda predators.

Detection of Autoantibodies for Extractable Nuclear Antigens by LG Immunoblot Kit / 대한임상병리학회지

BACKGROUND: Identification of antibodies recognizing extractable nuclear antigens (ENAs) is use-ful in the diagnosis and characterization of a variety of connective tissue diseases. Recently, LG ENA Immunoblot (LGCI, Seoul, Korea) was introduced for detecting various autoantibodies to ENAs simultaneously. Performance of this kit was evaluated in this study. METHODS: Sera from 108 SLE patients and 103 RA patients were tested for the presence of spe-cific autoantibodies to ENAs by LG ENA Immunoblot and DID. Concordance rates in each autoan-tibody were obtained. After discordant results were resolved by EIA (ENA ELISA TEST SYSTEM, Zeus Scientific Inc., NJ, USA) and western blot (ANA Western Blot Immunoassay, IMMCO Diag-nostics Inc., NY, USA), sensitivity and specificity of LG ENA Immunoblot were evaluated. Between-day precision was also tested. RESULTS: Concordance rates in each autoantibody in two methods were as follows: anti-RNP (88.0%, 95/108; 100%, 103/103), anti-Sm (87.0%, 94/108; 97.1%, 100/103), anti-SSA (94.4%, 102/108; 99.0%, 102/103), anti-SSB (97.2%, 105/108; 98.1%, 101/103), anti-Scl70 (99.1%, 107/108; 100%, 103/103) in SLE and RA patients, respectively. Sensitivity and specificity of Immunoblot were 92.0% and 99.6% for anti-RNP, 100% and 99.6% for anti-Sm, 100% and 98.6% for anti-SSA, 90.0% and 98.5% for anti-SSB, and 100% and 100% for anti-Scl70, respectively. Between-day precisions were 100% in all anti-ENA antibodies. CONCLUSIONS: LG ENA Immunoblot showed good concordance rates with the conventional DID method and high sensitivity (>90%) and specificity (>98.5%) in detecting all kinds of anti-ENA autoantibodies. LG Immunoblot has another merit in that it can detect several autoantibodies simul-taneously. It is suggested that LG ENA Immunoblot can replace DID for anti-ENA detection without any problem.

Tumor-associated proteins in rat submandibular gland induced by DMBA and irradiation / 대한구강악안면방사선학회지

This study was performed in order to identify changes of the plasma membrane proteins in rat submandibular gland tumors induced by 7,12-dimethylbenz[a]anthracene [DMBA] and X-irradiation. Two kinds of tumor associated membrane proteins (protein A and B) were isolated with 3 M KCl extraction from rat submandibular gland tumors induced by DMBA and X-irradiation. To identify their antigenicities, immunoelectrophoresis and double immunodiffusion was carried out with various proteins extracted from liver, heart, skin and pancreas of adult rats and from embryonic liver, heart and skin. The rabbit antisera against the protein A did not cross-react with any of the proteins extracted from the above mentioned tissues, suggesting that protein A might be tumor specific antigen. However, the rabbit antisera against protein B was precipitated with proteins extracted from the liver of adult and embryonic rats. Polyacrylamide gel electrophoresis of these two proteins (A and B) showed that protein A was a dimer with molecular weights of 69,000 and 35,000 dalton, whereas protein B was a monomer with molecular weight of 50,000 dalton.

Autoantibody Profile using Double Immunodiffusion, Elisa, Western Blot and Its Clinical Association in Patients with Ssystemi Lupus Erythematosus / 대한류마티스학회지

OBJECTIVE: To investigate the autoantibody profile and its clinical association in patients with systemic lupus erythematosus. METHODS: The frequency and clinical correlation of autoantibodies were studied in 73 patients with systemic lupus erythematosus who have been followed in Seoul National University Hospital. Double immunodiffusion, ELISA and immunoblot were used for the detection of autoantibodies. RESULTS: The frequency of each autoantibody measured by double immunodif fusion was as follows; anti-Ro 53.4%, anti-La 11.0%, anti-Sm 20.5%, anti-U1 RNP 20.5%. The frequency of each autoantibody by ELISA was as follows; anti-Ro 69.9%, anti-La 27.4%, anti-Sm 54.8%, anti-Ul RNP 68.5%, anti-dsDNA 72.6%, anti-cardiolipin 47.2% (IgG 43.1?0, igM 15. 3%). The frequency of each autoantibody by immunoblot was as follows; anti-Ro 15.1?0, anti-La 42. 5%, anti-Sm 46. 6%, anti-U1 RNP 42. 5%. anti-ribosomal P(P0) 27.4%. Anti-Ro was associated with decreased frequency of nephrotic syndrome. Anti-U1 RNP was associated with increased frequency of malar rash, Raynaud phenomenon and decreased frequency of nephritis. Patients with both anti-Ro and anti La had more frequent serositis than those with anti-l~o only. Patients with both anti-Sm and anti-U1 RNP had less frequent thrombocytopenia than those with anti-U1 RNP only. And patients with anti-Sm and anti-dsDNA had more frequent arthritis than those with only one of both antibodies. There was a positive correlation of autoantibody titers between anti-Ro and anti-La, anti-Sm and anti-U1 RNP, anti-dsDNA and anti-cardiolipin(IgG). Taking the result of immunoblot as a standard, both of double immunodiffusion and ELISA showed low sensitivity but high specficity for anti La. As for anti-Sm and anti-U1 RNP, double immunodiffusion showed low sensitivity but high specificity, whereas ELISA showed high sensitivity but low specificity. CONCLUSIONS: In our study, some autoantibodies (anti-Ro, anti-U1 RNP) were associated with certain clinical manifestations while others not. Immunoblot being used as a standard method, ELISA showed higher sensitivity but lower specificity for anti-La, anti-Sm and anti-U1 RNP compared with immunodiffusion. It is recommended that in interpretating the laboratory findings of these autoantibodies these parameters of each method should be considered.