Evaluation of the TEST 1 erythrocyte sedimentation rate system and intra- and inter-laboratory quality control using new latex control materials.

BACKGROUND: The erythrocyte sedimentation rate (ESR) test has been considered to be a simple procedure, not requiring quality control (QC). However, QC is essential for accuracy and precision. We evaluated the TEST 1 ESR system and performed QC procedures using newly developed latex control materials in three hospitals. METHODS: Using tripotassium ethylenediaminetetraacetic acid blood samples (n=184), we compared TEST 1 ESR values with Westergren ESR data and evaluated intra-assay precision. Three levels of latex control materials were used to assess inter-assay precision. Reference range assessment was done using samples from 220 healthy individuals. Inter-laboratory QC with latex control materials in three hospitals was performed. RESULTS: Correlation between TEST 1 ESR and Westergren ESR results was good (p<0.001). Intra-assay precision [coefficients of variation (CV) 6.6%-21.7%] with patient samples and inter-assay precision (CV 0.0%-6.8%) with latex control materials were satisfactory. The reference ranges of 2-10 mm/h for males and 2-19 mm/h for females were established. Inter-laboratory QC data with latex control materials in three hospitals demonstrated good accuracy and satisfactory precision (CV 0.0%-14.4%). CONCLUSIONS: Our results demonstrate that the TEST 1 QC is reliable and the latex control materials are valuable for inter-laboratory proficiency testing.

Increased plasma viscosity in plasma cell dyscrasia and whole blood viscosity in polycythemia vera.

BACKGROUND: Although hyperviscosity syndrome in plasma cell dyscrasia (PCD) and thrombosis in myeloproliferative neoplasm (MPN) are major causes of morbidity and mortality, blood viscosity measurements are often underutilized. OBJECTIVE: This study aimed to characterize whether whole blood viscosity (WBV) or plasma viscosity (PV) could be predictive of hyperviscosity syndrome in PCD and could be elevated in subgroups of MPN. METHODS: A total of 75 patients with hematologic diseases: PCD (n = 26), MPN (n = 25) including polycythemia vera (P. vera) and lymphoma (n = 24) were enrolled along with 104 healthy controls. Both WBV and PV were measured using a capillary tube viscometer. Hyperviscosity syndrome was defined as having 2 or more hyperviscosity symptoms. RESULTS: Patients with PCD showed significantly higher PVs at high and low shear rates when compared to healthy controls, especially in those with hyperviscosity syndrome. The sensitivity and specificity of WBV and PV in detecting hyperviscosity syndrome were 28.6% and 94.1%, and 71.4% and 66.7%, respectively. Patients with P. vera exhibited high WBV and RBC counts compared to healthy controls. CONCLUSION: PV is predictive of hyperviscosity syndrome in PCD and WBV is elevated in patients with P. vera. It suggests that hemorheologic disturbances exist in patients with PCD and MPN and that tests of viscosity may be helpful in detecting hemorheological disturbances.

Correlation between plasma activity of ADAMTS-13 and coagulopathy, and prognosis in disseminated intravascular coagulation.

INTRODUCTION: In disseminated intravascular coagulation (DIC), widespread activation of intravascular coagulation accompanied with florid endothelial activation results in release of unusually large von Willebrand factor (ULvWF) from endothelium. Circulating a disintegrin-like and metalloprotease with thrombospondin type 1 repeats (ADAMTS)-13 may be consumed through the ongoing cleavage of ULvWF, resulting in a secondary deficiency of ADAMTS-13 in DIC. We determined whether ADAMTS-13 activity showed a significant correlation with the activation status of the coagulation system and hospital mortality in DIC. MATERIALS AND METHODS: ADAMTS-13 activity was assayed by fluorescence resonance energy transfer assay in 97 patients who were clinically suspected to have DIC. RESULTS: ADAMTS-13 activity gradually decreased based on the DIC score and D-dimer levels and was correlated with the antithrombin level, representing the consumption of ADAMTS-13 during the ongoing coagulation process. There were no correlation between ADAMTS-13 activity and neutrophil CD64 expression as a neutrophil activation marker and circulating IL-6 level as an inflammatory marker. Patients with a low activity of ADAMTS-13 (< or = 56.4%) had a poor survival rate compared to patients with a high activity of ADAMTS-13. CONCLUSIONS: We conclude that ADAMTS-13 activity is strongly correlated with the severity of coagulopathy and hospital mortality. ADAMTS-13 may serve as a diagnostic and prognostic marker of DIC.

Prognostic value of immature platelet fraction and plasma thrombopoietin in disseminated intravascular coagulation.

Although platelet count is a good parameter for the diagnosis of disseminated intravascular coagulation (DIC), a single measurement of platelet is not enough to reflect the ongoing platelet consumption because of compensatory synthesis of circulating platelet number. Increased thrombopoiesis owing to peripheral destruction is expected in patients with DIC. Reticulated platelet, measured as immature platelet fraction (IPF), and plasma thrombopoietin (TPO) are markers of platelet production. We investigated the potential usefulness of circulating IPF and TPO in 222 patients suspected of having DIC. Both IPF and TPO levels were significantly increased in overt DIC patients and well correlated with DIC score. IPF also correlated with fibrin-related marker such as fibrinogen degradation product and D-dimer. Both IPF and TPO showed better mortality prediction than platelet count with the multivariate logistic regression and Kaplan-Meier survival analysis. These results suggest that IPF and TPO are new potential candidates to detect the severity of DIC and to predict DIC mortality.

Erythrocyte sedimentation rate measurements by TEST 1 better reflect inflammation than do those by the Westergren method in patients with malignancy, autoimmune disease, or infection.

We compared the TEST 1 (Alifax, Padova, Italy) and Westergren methods of measuring the erythrocyte sedimentation rate (ESR) to assess inflammation. The ESR was measured by both methods in 154 blood samples from patients with malignancy (n = 69), autoimmune disease (n = 44), or infection (n = 41). Total protein, albumin, and C-reactive protein (CRP) levels were measured in each plasma sample, and albumin and alpha(1)-, alpha(2)-, beta(1)-, beta(2)-, and gamma-globulin fractions were measured by capillary electrophoresis. TEST 1 ESR values were significantly lower than the Westergren values, by 10.9 mm/h. We found that the correlations of TEST 1 ESR values with inflammatory protein levels (total protein, globulin, CRP, and alpha(1)-, alpha(2)-, beta(2)-, and gamma-globulin) were better than those obtained using the Westergren method. These findings indicate that ESR measurements by TEST 1 reflect inflammation better than do those by the Westergren method in patients with malignancy, autoimmune disease, or infection.