Introduction
  The cross-linked fibrin degradation product known as D-dimer, in combination with pretest clinical probability scores, is widely used in deep vein thrombosis（DVT） exclusion diagnosis. However, if the common normal range for D-dimer is taken as the cutoff for all patients, regardless of medical status, the exclusion efficiency is unacceptably low. Therefore, it is necessary to establish optimal cutoffs based on patient population and reagent type. This study retrospectively examined cases in which the LPIA Genesis D-dimer test（LG-DD） was employed.
Methods
  We confirmed optimal D-dimer cutoffs for DVT exclusion diagnosis for each patient background with thrombotic tendencies. The 764 patients tested for lower extremity DVT by ultrasonography were divided into three groups: No DVT, acute DVT, and chronic DVT. D-dimer values were compared among patients over the age of 55, patients with a malignant tumor, post-operative patients, pregnant patients, and other medical conditions.
Results
  Each population, excluding pregnant patients, showed significantly higher values in the acute DVT group than in the no DVT and chronic DVT groups. The optimal D-dimer cutoff for patient characteristics was 1.9 μg/mL in the “other” category and 2.1 μg/mL in the group over 55 years old. The cutoff was as high as 3.4 μg/mL in the malignant tumor patient group and 16.6 μg/mL in the post-operative patient group. In addition, when an age-adjusted cutoff was used, the specificity and positive likelihood ratio were improved, while maintaining high sensitivity.
Conclusion
  The D-dimer measurement using LG-DD is useful in DVT exclusion diagnosis. Effective and efficient DVT exclusion diagnosis can be determined by setting a D-dimer cutoff based on the characteristics of the patient.

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  In recent years, testing equipment located inwards has been managed in a central laboratory, and the same is true for blood gas analyzers. We investigated the time course of blood gas analysis（BGA） using actual samples and attempted to apply it to the inter-instrument difference test of blood gas analyzers. Patients admitted to our hospital between October 2021 and March 2022 with BGA samples taken were analyzed after data collection. 5 mL of blood was collected into a blood collection tube containing heparin sodium, and continuous BGA testing was performed approximately every 2.5 minutes. The reference range for quality control was calculated from （the average） ±2×（standard deviation） of the amount of change obtained in 10 consecutive measurements. While pH and pO₂ increased over time, pCO₂, HCO₃^－, Ca²⁺, and glucose decreased. On the other hand, no obvious changes were observed in Na⁺, K⁺, Cl^－, and Lactate. In continuous BGA using 2 devices, the HCO₃^－ of all 3 patients and the pCO₂ of 2 out of 3 patients decreased beyond the reference range, suggesting differences between the devices, where improvement was observed after the maintenance of the electrode. From the above, the time course of BGA was clarified. Furthermore, it was considered that the present results could be applied to the inter-instrument difference test of blood gas analyzers using actual samples.

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Objective: This study intended to clarify whether serum ferritin levels are a marker for the early detection of glucose intolerance and diabetes in young adults.
Methods: 382 young healthy Japanese individuals aged 22-29 years underwent oral glucose tolerance test （OGTT）. We analyzed the relationship between serum ferritin levels and insulin secretion ability, insulin sensitivity, lipid metabolism markers, and complete blood count.
Results: Among 233 men, ferritin showed a positive correlation with age, HOMA-β, LDL-C, non-HDL-C, Hb, platelet count, and 120-minute post-load plasma glucose and insulin. Ferritin showed a negative correlation with Matsuda and disposition indices. The multivariate analysis revealed that fasting plasma glucose, ferritin, and non- HDL-C are independent predictors of the 120-minute post-load plasma glucose in young men. Among 149 women, ferritin showed a positive correlation with Hb and CRP, and a negative correlation with HbA1c and HDL-C. Men were divided into groups based on ferritin levels above or below the average of 97.8 ng/mL; women were similarly divided at 24.7 ng/mL. Men with higher levels of ferritin showed decreased levels of Matsuda index and disposition index and increased insulin levels at 60 minutes compared to men with lower levels of ferritin. Women with higher ferritin levels showed lower HbA1c, but higher Hb than those with lower ferritin levels.
Conclusion: Among healthy young Japanese men, serum ferritin levels and non-HDL-C independently predict prolonged glucose elevation in the OGTT.

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