Identification of the major allergen of Macrobrachium rosenbergii (giant freshwater prawn)

Objective: To characterize the major allergens of Macrobrachium rosenbergii (giant freshwater prawn). Methods: Raw and cooked extracts of the giant freshwater prawn were prepared. The IgE reactivity pattern was identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting technique with the sera of 20 skin prick test (SPT) positive patients. The major allergen identified was then characterized using the proteomics approach involving a combination of two-dimensional (2-DE) electrophoresis, mass spectrometry and bioinformatics tools. Results: SDS-PAGE of the raw extract showed 23 protein bands (15-250 kDa) but those ranging from 40 to 100 kDa were not found in the cooked extract. From immunoblotting experiments, raw and cooked extracts demonstrated 11 and 5 IgE-binding proteins, respectively, with a molecular mass ranging from 15 to 155 kDa. A heat-resistant 36 kDa protein was identified as the major allergen of both extracts. In addition, a 42 kDa heat-sensitive protein was shown to be a major allergen of the raw extract. The 2-DE gel fractionated the prawn proteins to more than 50 different protein spots. Of these, 10 spots showed specific IgE reactivity with patients’ sera. Matrix assisted laser desorption/ionization-time of flight (MALDI-TOF) analysis led to identification of 2 important allergens, tropomyosin and arginine kinase. Conclusions: It can be concluded that the availability of such allergens would help in component-based diagnosis and therapy of prawn allergies.

Identification of the major allergen of Macrobrachium rosenbergii (giant freshwater prawn)

<p><b>OBJECTIVE</b>To characterize the major allergens of Macrobrachium rosenbergii (giant freshwater prawn).</p><p><b>METHODS</b>Raw and cooked extracts of the giant freshwater prawn were prepared. The IgE reactivity pattern was identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting technique with the sera of 20 skin prick test (SPT) positive patients. The major allergen identified was then characterized using the proteomics approach involving a combination of two-dimensional (2-DE) electrophoresis, mass spectrometry and bioinformatics tools.</p><p><b>RESULTS</b>SDS-PAGE of the raw extract showed 23 protein bands (15-250 kDa) but those ranging from 40 to 100 kDa were not found in the cooked extract. From immunoblotting experiments, raw and cooked extracts demonstrated 11 and 5 IgE-binding proteins, respectively, with a molecular mass ranging from 15 to 155 kDa. A heat-resistant 36 kDa protein was identified as the major allergen of both extracts. In addition, a 42 kDa heat-sensitive protein was shown to be a major allergen of the raw extract. The 2-DE gel fractionated the prawn proteins to more than 50 different protein spots. Of these, 10 spots showed specific IgE reactivity with patients' sera. Matrix assisted laser desorption/ionization-time of flight (MALDI-TOF) analysis led to identification of 2 important allergens, tropomyosin and arginine kinase.</p><p><b>CONCLUSIONS</b>It can be concluded that the availability of such allergens would help in component-based diagnosis and therapy of prawn allergies.</p>

Identification of the major allergen of Macrobrachium rosenbergii (giant freshwater prawn)

Objective To characterize the major allergens of Macrobrachium rosenbergii (giant freshwater prawn). Methods Raw and cooked extracts of the giant freshwater prawn were prepared. The IgE reactivity pattern was identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting technique with the sera of 20 skin prick test (SPT) positive patients. The major allergen identified was then characterized using the proteomics approach involving a combination of two-dimensional (2-DE) electrophoresis, mass spectrometry and bioinformatics tools. Results SDS-PAGE of the raw extract showed 23 protein bands (15-250 kDa) but those ranging from 40 to 100 kDa were not found in the cooked extract. From immunoblotting experiments, raw and cooked extracts demonstrated 11 and 5 IgE-binding proteins, respectively, with a molecular mass ranging from 15 to 155 kDa. A heat-resistant 36 kDa protein was identified as the major allergen of both extracts. In addition, a 42 kDa heat-sensitive protein was shown to be a major allergen of the raw extract. The 2-DE gel fractionated the prawn proteins to more than 50 different protein spots. Of these, 10 spots showed specific IgE reactivity with patients' sera. Matrix assisted laser desorption/ionization-time of flight (MALDI-TOF) analysis led to identification of 2 important allergens, tropomyosin and arginine kinase. Conclusions It can be concluded that the availability of such allergens would help in component-based diagnosis and therapy of prawn allergies.

Identification of Major and Minor Allergens of Black Tiger Prawn (Penaeus monodon) and King Prawn (Penaeus latisulcatus)

Background: Prawns and shrimp are a frequent cause of seafood allergy mediated by IgE antibodies. Penaeus monodon and Penaeus latisulcatus, commonly known as black tiger prawn and king prawn, respectively, are among the most frequently consumed prawns in Malaysia. The aim of thi s study was to identify the IgE-binding proteins of these 2 prawn species. Methods: Raw and boiled prawn extracts were prepared and then resolved by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). IgE-immunoblotting was then performed using sera from patients with positive skin prick tests to the raw prawn extracts. Results: SDS-PAGE analysis of the raw extracts of both prawn species revealed 23 protein bands; the boiled extracts yielded fewer protein bands. The bands in the range of 40 to 100 kDa were sensitive to heat and therefore were not found in the boiled extracts. Immunoblot of raw extracts of black tiger prawns and king prawns yielded 14 and 11 IgE-binding proteins, respectively, with molecular weights of between 15 and 200 kDa. Proteins at 36, 42, and 49 kDa were detected as the major allergens in both species of prawns. A protein of 75 kDa was also identified as a major allergen in black tiger prawns. Other potential allergens were also observed at various molecular masses. Conclusion: Proteins of 36, 42, and 49 kDa were identified as the major allergens of both species of prawns. The 36 and 42 kDa proteins are hypothesised to be tropomyosin and arginine kinase, respectively. A high molecular weight protein of 75 kDa was found to be an additional major allergen in black tiger prawns.

Immunofluorescence (IF) Pattern, Autoantigens of Anti-neutrophil Cytoplasmic Antibodies (ANCA) and Their Clinical Associations / Jurnal Sains Kesihatan Malaysia

Antineutrophil cytoplasmic antibodies (ANCA) are autoantibodies directed against primary granules of neutrophils and monocytes’ lysosomes. In general, c-ANCA is strongly associated with vasculitic disorders mainly in ANCA-associated systemic vasculitis (AASV). p-ANCA have been identified in several diseases such as primary (AASV) and secondary vasculitis such as collagen vascular diseases, rheumatoid arthritis and inflammatory bowel diseases given the term ‘ANCA-associated disease.’ The objective of this study was to determine the rate of ANCA positivity by indirect immunofluorescent (IF) and enzyme linked immunosorbent assay (ELISA) and its association with AASV and ANCA associated diseases. Serum from patients with history suspicion of systemic vasculitis were tested for ANCA by IF. Those samples positive for ANCA by IF were further tested for antibodies against myeloperoxidase (MPO) and proteinase 3 (PR3) using the ELISA. Clinical data from medical records were obtained and analyzed. Of 468 samples, a total of 110 were positive for ANCA by IF. IF results showed a p-ANCA pattern in 96 patients and c-ANCA in 14. Of 110 IF positive ANCA, 45 patients were positive by ELISA. Seventeen were positive for MPO-ANCA, 9 were PR3-ANCA positive and 19 were both MPO and PR3 positive. Only 2 patients were classified AASV ie Wegener granulomatosis and the other with microscopic polyangiitis. The remaining patients (n = 108) may be classified as ANCA associated diseases. Our study showed that p-ANCA (87.3%) was the more common ANCA pattern and 40.9% of IF positive samples were positive for PR3- and MPOANCA.

Heterogeneous t(4;11) fusion transcripts in two infants with acute lymphoblastic leukemia

An RT-PCR assay detected the t(4;11) translocation in two infants with acute lymphoblastic leukemia (ALL). Case P76 was a 10-month-old, female infant, who presented with a WBC of 137.4 x 10(9)/l and a pre-pre-B ALL immunophenotype. Case P120 was a 6-month-old female infant, with a WBC > 615 x 10(9)/l and a pre-pre-B ALL immunophenotype. RT-PCR of cDNA from both these cases generated a 656 bp and a 542 bp respectively, which sequencing confirmed as t(4;11) fusion transcripts. The primers and conditions selected for this assay are compatible with a one-step multiplex PCR for the main translocations in childhood ALL.