Comparison of different algorithms for lupus anticoagulant detection: a single-center experience.

Background: The laboratory tests for lupus anticoagulant (LA) detection comprise complex and multistep coagulation testing procedures. There is no established gold standard assay or direct comparison of algorithms as recommended by different guidelines. Objectives: This study aimed to evaluate and compare the LA detection performance of different laboratory algorithms suggested by the existing guidelines. Methods: The routine LA test data of 1801 plasma samples, including 188 LA-positive and 1613 LA-negative samples, were re-evaluated by applying the algorithms recommended by existing guidelines and were interpreted using various methods. Diagnostic performance indices for each LA detection algorithm were compared with those of the other algorithms. The efficacies of the different interpretation methods were analyzed to determine a suitable interpretation methodology for each assay. Results: The diagnostic performance for detecting LA varied by the algorithm and method of interpretation used. All laboratory algorithms displayed exceptional diagnostic performance with all diagnostic parameters of >90.0%. Nearly perfect agreement was observed in all algorithms when compared to the Clinical and Laboratory Standards Institute 2014 guideline interpreted by normalized screen-to-confirm ratio (NSCR) and mixing test-specific cutoff (MTC), as a reference assay (Cohen's kappa coefficient, >0.90 [range, 0.94-1.00]). A combination of the index of circulating anticoagulant and NSCR was optimal for interpreting the activated partial thromboplastin time-based test, whereas a combination of the MTC and NSCR was suitable for the diluted Russell's viper venom time-based test. Conclusion: All laboratory algorithms showed equivalent diagnostic performance. Establishing the best method of interpretation for each assay is recommended to improve LA detection performance.

Association between HLA class II Polymorphism and Knee Osteoarthritis in a Thai Population.

BACKGROUND: Osteoarthritis (OA) is a degenerative joint disease commonly found among elderly populations. Multiple risk factors, including non-clinical and genetic factors, contribute to the etiology and pathogenesis of OA. This study aimed to investigate the association between the human leukocyte antigen (HLA) class II alleles and knee OA occurrence in a Thai population. METHODS: HLA-DRB1 and -DQB1 alleles in 117 patients with knee OA and 84 controls were determined using the PCR with sequence-specific primer (PCR-SSP) method. The association between knee OA and the presence of certain HLA class II alleles was investigated. RESULTS: DRB1*07 and DRB1*09 frequencies increased, while DRB1*14, DRB1*15, and DRB1*12 decreased among patients compared with controls. DQB1*03 (DQ9) and DQB1*02 frequencies increased, while DQB1*05 decreased among patients. Notably, the DRB1*14 allele significant decreased (5.6% vs. 11.3%, p = 0.039, OR = 0.461, 95% CI: 0.221 - 0.963), while the DQB1*03 (DQ9) allele significantly increased among patients compared with controls (14.1% vs. 7.1%, p = 0.032, OR = 2.134, 95% CI: 1.067 - 4.265). Moreover, the DRB1*14-DQB1*05 haplotype showed a significant protective effect on knee OA (p = 0.039, OR = 0.461, 95% CI: 0.221 - 0.963). A contrary effect of HLA-DQB1*03 (DQ9) and HLA-DRB1*14 was observed, wherein the presence of HLA-DQB1*03 (DQ9) seemed to promote disease susceptibility, whereas HLA-DRB1*14 appeared to protect against knee OA. CONCLUSIONS: Knee OA was more pronounced among females than males, especially those aged  60 years. In addition, a contrary effect was found regarding HLA-DQB1*03 (DQ9) and HLA-DRB1*14, in whom the presence of HLA-DQB1*03 (DQ9) seems to promote disease susceptibility, whereas HLA-DRB1*14 appears to be a protective factor against knee OA. However, further study with a larger sample size is suggested.

Serum proteomic profiling reveals MTA2 and AGO2 as potential prognostic biomarkers associated with disease activity and adverse outcomes in multiple myeloma.

Multiple myeloma (MM) is an incurable plasma cell malignancy accounting for approximately 10% of hematological malignancies. Identification of reliable biomarkers for better diagnosis and prognosis remains a major challenge. This study aimed to identify potential serum prognostic biomarkers corresponding to MM disease activity and evaluate their impact on patient outcomes. Serum proteomic profiles of patients with MM and age-matched controls were performed using LC-MS/MS. In the verification and validation phases, the concentration of the candidate biomarkers was measured using an ELISA technique. In addition, the association of the proposed biomarkers with clinical outcomes was assessed. We identified 23 upregulated and 15 downregulated proteins differentially expressed in newly diagnosed and relapsed/refractory MM patients compared with MM patients who achieved at least a very good partial response to treatment (≥VGPR). The top two candidate proteins, metastasis-associated protein-2 (MTA2) and argonaute-2 (AGO2), were selected for further verification and validation studies. Both MTA2 and AGO2 showed significantly higher levels in the disease-active states than in the remission states (p < 0.001). Regardless of the patient treatment profile, high MTA2 levels were associated with shorter progression-free survival (p = 0.044; HR = 2.48; 95% CI, 1.02 to 6.02). Conversely, high AGO2 levels were associated with IgG and kappa light-chains isotypes and an occurrence of bone involvement features (p < 0.05) and were associated with prolonged time to response (p = 0.045; HR = 3.00; 95% CI, 1.03 to 8.76). Moreover, the analytic results using a publicly available NCBI GEO dataset revealed that AGO2 overexpression was associated with shorter overall survival among patients with MM (p = 0.032, HR = 1.60, 95% CI, 1.04 to 2.46). In conclusion, MTA2 and AGO2 proteins were first identified as potential biomarkers that reflect disease activity, provide prognostic values and could serve as non-invasive indicators for disease monitoring and outcome predicting among patients with MM.

Validation of high concentrated thrombin time assay for unfractionated heparin monitoring.

BACKGROUND: The high concentrated thrombin time (hcTT), a thrombin time modified by increasing the thrombin concentration, is a possible alternative assay to activated partial thromboplastin time (aPTT) in unfractionated heparin (UFH) monitoring. This study aimed to determine the optimal thrombin concentration used in the hcTT assay for UFH monitoring. METHODS: A total of 30 blood samples obtained from healthy volunteers were included in this study. Thrombin concentrations of 10.0, 15.0, 20.0, and 25.0 IU/ml were used in the hcTT assay. The consistency between the hcTT and anti-FXa assays was evaluated. To validate the hcTT assay, linearity, repeatability, reproducibility, and diagnostic performance of the assay were assessed. RESULTS: The hcTT assay using thrombin concentration of 15.0 IU/ml showed a strong correlation to the anti-FXa assay with R2 of 0.72 and the Spearman's correlation coefficient (rs ) of 0.97 (95% CI, 0.96-0.98). Within-run and day-to-day run variabilities of the assay were satisfactory (all coefficients of variation <10%). We found an excellent correlation between the results which were measured using different reagents with intra- or inter-laboratory instruments. Notably, as compared to the aPTT assay, the hcTT assay showed a significantly better performance in identifying the samples which contain UFH at the supratherapeutic level, with an AUC of 0.97 vs. 0.91, p = 0.049. CONCLUSION: The hcTT assay can be used as an alternative assay for UFH therapy monitoring. A further study using clinical samples is recommended to confirm the appropriateness of the hcTT assay for clinical application.