A population-based characterization study of anti-mitochondrial M2 antibodies and its consistency with anti-mitochondrial antibodies.

OBJECTIVE: This study aims to estimate the prevalence of anti-mitochondrial antibody subtype M2 (AMA-M2) and assess its consistency with AMA in a general population. METHODS: A total of 8954 volunteers were included to screen AMA-M2 using enzyme-linked immunosorbent assay. Sera with AMA-M2 >50 RU/mL were further tested for AMA using an indirect immunofluorescence assay. RESULTS: The population frequency of AMA-M2 positivity was 9.67%, of which 48.04% were males and 51.96% were females. The AMA-M2 positivity in males had a peak and valley value of 7.81% and 16.88% in those aged 40 to 49 and ≥70 years, respectively, whereas it showed a balanced age distribution in females. Transferrin and immunoglobulin M were the risk factors for AMA-M2 positivity and exercise was the only protective factor. Of 155 cases with AMA-M2 >50 RU/mL, 25 cases were AMA-positive, with a female-to-male ratio of 5.25:1. Only 2 people, with very high AMA-M2 of 760 and >800 RU/mL, met the diagnostic criteria of primary biliary cholangitis (PBC), making the prevalence of PBC 223.36 per million in southern China. CONCLUSION: We found that AMA-M2 has a low coincidence rate with AMA in the general population. A new decision-making point for AMA-M2 is needed to improve consistency with AMA and diagnostic accuracy.

Performance Evaluation of Antiphospholipid Antibodies on INOVA Quanta Flash System.

BACKGROUND: The diagnosis of antiphospholipid syndrome (APS) relies predominantly on the laboratory measurement of antiphospholipid antibodies (aPLs). We attempt to verify the analytical performance of anticardiolipin antibodies (aCL) IgA/IgG/IgM and anti-ß2-glycoprotein I antibodies (aß2GPI) IgA/IgG/IgM on a high-throughput automated immunoassay platform. METHODS: Limit of blank (LOB), limit of detection (LOD), imprecision, and linearity were calculated according to the corresponding Clinical and Laboratory Standards Institute (CLSI) guidelines protocols. The biological reference intervals (RIs) were verified in healthy individuals. RESULTS: The LoB of aCL IgA/IgG/IgM and aß2GPI IgA/IgG/IgM were 0.000, 1.200, 0.200, and 0.400, 1.250, 0.100, respectively. The LoD were 0.093, 1.715, 0.337 and 0.547, 2.174, 0.185 CU, respectively. All the within-run CVs and total CVs were less than the criterion at 10%. The linear analysis showed a good correlation between the predictive values and observed values with correlation coefficients greater than 0.99. CONCLUSIONS: The BIO-FLASH automated chemiluminescent analyzer performed well in measuring aPLs.

[Isolation and characterization of human rheumatoid arthritis fibroblast-like synoviocytes].

OBJECTIVE: To isolate and characterize human rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLSs). METHODS: The synovial membrane tissues were obtained from 4 RA patients, 1 chondroma patient and 1 healthy subject and FLS were isolated by means of tissue culture. The cell morphology was observed by phase-contrast microscope and the cell surface markers were detected by flow cytometry. RESULTS: The FLSs were successfully cultured from the synovial membrane tissues with good cell homogeneity after the third passage. The FLSs of the 3rd to 7th passages were stable and proliferated actively, followed by slow proliferation and aging since the 8th passage. Flow cytometry showed that the 4th-passage FLSs from the RA patients contained 99.04% CD90(+) cells, 2.73% CD3(+) cells, 0.29% CD3(-)CD19(+) cells, 2.81% CD3(-)CD16(+)CD56(+) cells, 5.89% CD14(+) cells, and 54.17% CD55(+) cells. The presence of interleukin-1 receptor type I (IL-1RI, 158.63-/+20.32 pg/ml) and IL-1beta (4.67-/+0.82 pg/ml) were detected in the cell culture supernatant of the 4th-passage FLSs from the RA patients by enzyme-linked immunosorbent assay ELISA. CONCLUSION: FLSs from RA patients can be effectively culture by means of tissue culture, and the cultured FLSs show high expressions of CD90, IL-1RI and IL-1beta.