The objective of this study was to determine the Immunoglobulin E-binding proteins (IgE) and major allergens of Scomberomorus commerson Lacepede (Narrow-barred Spanish mackerel). Allergen extracts were obtained from uncooked and cooked fish by homogenization in phosphate-buffered saline followed by continuous extraction at 4oC or on ice. Protein profiles and IgEbinding patterns were then detected by means of sodium dodecyl polyacrylamide gel electrophoresis (SDS PAGE) and immunoblotting using sera from patients sensitized to the fish. SDS-PAGE of the uncooked fish extracts revealed 26 protein bands in the range of about 11 to >175 kD, while the cooked extracts produced fewer protein bands. Immunoblotting demonstrated 17 IgE-binding bands, ranging in molecular weight from 11 to 151 kD. Two components with molecular weight of about ~50 and 42 kD showed the highest frequency of IgE-binding (62.2 and 51.4% respectively) and were identified as the major allergens of this fish allergy. Other IgE-binding proteins including a protein at ~12 kD which was equivalent in size to parvalbumin were identified as the minor allergens.
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 pANCA (87.3%) was the more common ANCA pattern and 40.9% of IF positive samples were positive for PR3- and MPOANCA.
Introduction: Systemic lupus erythematosus (SLE) has a broad spectrum of clinical presentations. The diagnosis of SLE remains a challenge and largely depends on the presence of several serum autoantibodies including anti-nuclear antibody (ANA), anti-double-stranded DNA antibody (anti-dsDNA) and anti-Smith antibody (anti-Sm). ANA, a highly sensitive but not specific marker is used for SLE screening Anti-dsDNA and anti-Sm are SLE-specific biomarkers but has lower sensitivity of 80% and 30% for SLE, respectively. However, it is noted that there are SLE patients who are persistently negative for SLE-specific autoantibodies. Anti-dsDNA and anti-Sm were reported to be negative in up to 51.2% and 62.4% of SLE, respectively. This limitation can lead to misdiagnosis and halter proper treatment to SLE patients. Previous studies have suggested that cell membrane DNA (cmDNA) can act as a specific target for the autoantibodies in SLE patients. Autoantibodies towards cmDNA (anti-cmDNA) were reported to have promis-ing value as a reliable biomarker for SLE. In this study, we would like to determine the usefulness of anti-cmDNA in diagnosing SLE as compared to the standard SLE-specific autoantibodies. Methods: Serum samples from 83 SLE patients, 86 other connective tissue diseases and 61 healthy subjects were included in this study. The other connec-tive tissue diseases include samples from 10 Sjogren’s syndrome, 56 rheumatoid arthritis, 12 scleroderma and eight mixed connected tissues disease (MCTD) patients. All samples were analysed by indirect immunofluorescence (IIF) technique using Raji cells as substrate to detect the presence of anti-cmDNA. Anti-cmDNA was reported as positive if there was presence of a fluorescent ring, either continuous or punctate. Sera from SLE patients were also tested for anti-dsDNA and anti-Sm antibodies by using enzyme-immunoassays. Results: Anti-cmDNA positivity was highest in SLE (55.4%) than in other connective tissue diseases (9.3%) and healthy subjects (0%). Anti-cmDNA was 100% spe-cific at differentiating SLE from healthy subjects and 90.7% specific at differentiating SLE from other connective tissue diseases. There was no difference in the sensitivity (55.4%) of anti-cmDNA at differentiating SLE from both groups. Anti-cmDNA were present in 46 SLE samples negative for standard SLE-specific autoantibodies. It was detected in 11 (42.3%) of anti-dsDNA, 23 (63.9%) of anti-Sm and 8 (12.9%) of both anti-Sm and anti-dsDNA negative samples. Conclusion: The high specificity of anti-cmDNA detection using IIF method makes it an excellent diagnostic tool for SLE. Anti-cmDNA is potentially a very useful biomarker for SLE with negative anti-dsDNA or/and anti-Sm antibodies.
Introduction: Diabetes-associated autoantibodies (DAA) is the hallmark of T1DM and LADA which are frequently tested in young diabetes patients. It was noted that up to 10-15% of patients with initial diagnosis of T2DM also exhibit DAA. Regardless of the classification, the presence of DAA suggests an underlying islet autoimmunity which lead to progressive pancreatic β-cell failure. There is limited data reported on DAA in young diabetes patients in Malaysia. This study aims to determine the frequency of DAA positivity and its association with demographic and clinical characteristics among this cohort. Methods: A retrospective study using secondary data obtained from Al- lergy and Immunology Research Centre, Institute for Medical Research, Malaysia. This study included 194 diabetes patients who were diagnosed before the age of 40 years old and tested for GADA, ICA, IA2A and IAA. Results: From 194 patients, 91 (46.9%) were positive for least one of the following DAA: ICA (79, 40.7%), GADA (61, 31.4%), IA2A (37, 19.1%) and IAA (9, 4.6%). Multiple positivity was higher (73.6%) compared to single positivity. Highest com- bination of double positivity was ICA+GADA (54, 59.3%) and triple positivity was ICA+GADA+IA2A (25, 27.5%). Simultaneous positivity of four autoantibodies was seen in only one (1.1%) patient. ICA, GADA and IA2A were asso- ciated with age group and ethnicity (all p < 0.001). Only IA2A was associated with gender (p = 0.012). Conclusions: GADA, ICA ad IA2A are more significant in young Malaysian diabetes patients. IAA has a very low frequency in this studied population.
The longtail tuna (Thunnus tonggol) is widely consumed in Asia. Parvalbumin, the main major allergen of fish, has been well identified in multiple fish species, yet little is known about the allergenic proteins in T. tonggol. Thus, the aim of this study was to characterize the major allergens of T. tonggol using a proteomics approach.