Background: Three phenotypic identification systems (MicroScan, VITEK 2, and Crystal GP) were evaluated for their accuracy to identify coagulase-negative staphylococci (CNS). A total of 120 clinical isolates confirmed to be CNS via 16S rRNA sequencing and analysis with the MicroSeq 500 v2.0 database were assessed. Results: The MicroScan, VITEK 2, and Crystal GP systems correctly identified 82.5%, 87.5%, and 67.5% of the isolates, respectively. Misidentification was the main problem in MicroScan (10.8%) and Crystal GP (23.3%) systems, whereas the main problem of VITEK 2 was low-level discrimination (7.5%). Conclusion: None of the 3 phenotypic systems tested could accurately and reliably identify CNS at the species level. Further verifications such as biochemical testing or 16S rRNA sequencing together with analysis using a comparable database might be helpful in this regard.

Objective: The incidence rate of Parkinson’s disease (PD) is growing rapidly owing to the ageing population. We investigated the mortality rates and causes of death in South Korean patients with PD. Design: We investigated a national cohort using the nationwide insurance database. Setting: Korean Health Insurance Review and Assessment Service—National Sample Cohort database. Participants: We included 3510 participants ≥60 years of age who were diagnosed with PD between 2002 and 2013, as well as 14 040 matched controls. Interventions: None Primary and secondary outcome measures: A stratified Cox proportional hazards model was used to evaluate patients with PD who were matched 1:4 with non-PD control subjects adjusted for age, sex, income and region of residence. The causes of death were grouped into 12 classifications. Results: The adjusted HR for mortality in the PD group was 2.09 (95% CI 1.94 to 2.24, p<0.001). Subgroup analysis according to age (<70 years, 70–79 years, and ≥80 years) and sex revealed that patients with PD showed higher adjusted HRs for mortality across all subgroups. Mortalities caused by metabolic, mental, neurologic, circulatory, respiratory, and genitourinary diseases, as well as trauma, were more common in the PD group than in the control group, with the highest OR observed in patients with neurologic disease. Conclusions: We demonstrated that PD in South Korean patients ≥60 years of age was associated with increased mortality in both sexes regardless of age.

Background: The use of laboratory reference intervals based on younger populations is of questionable validity in older populations. We established reference intervals for 16 complete blood count (CBC) parameters in healthy elderly Koreans aged ≥60 years and compared them to those of individuals aged 20–59 years. Methods: Among 64,532 individuals (39,609 men and 24,923 women) aged ≥20 years who underwent medical checkups, 8151 healthy subjects (12.6%, 5270 men and 2881 women, including 675 and 511, respectively, who were ≥60 years of age) were enrolled based on stringent criteria including laboratory, imaging and endoscopy results; previous medical history; and medication history. CBC parameters were measured using an Advia2120i instrument. Results: Overall, healthy individuals aged ≥60 years did not require separate reference intervals from those aged <60 years except for red cell distribution width (RDW) and mean corpuscular hemoglobin (MCH) in women. However, subjects aged ≥60 years still required sex-specific reference intervals for red blood cell count, hemoglobin, hematocrit, MCH, monocytes and eosinophils. Separate reference intervals were required for MCH, eosinophils and basophils for certain age subgroups of men aged ≥60 years, and for MCH and RDW in certain age subgroups of women aged ≥60 years, compared to counterparts <60 years of age. Conclusions: Healthy elderly Koreans can use the same reference intervals as younger populations. Thus, abnormal CBC results may not necessarily be attributable to physiologic changes but possible underlying diseases that should be investigated.

Mikyoung Park, M.D., Ph.D., Jihyang Lim, M.D., Ph.D., Ari Ahn, M.D., Ph.D., Eun-Jee Oh, M.D., Ph.D., Jaewoo Song, M.D., Ph.D., Kyeong-Hee Kim, M.D., Ph.D., Jin-Yeong Han, M.D., Ph.D., Hyun-Woo Choi, M.D., Ph.D., Joo-Heon Park, M.D., Kyung-Hwa Shin, M.D., Ph.D., Hyerim Kim, M.D., Ph.D., Miyoung Kim, M.D., Ph.D., Sang-Hyun Hwang, M.D., Ph.D., Hyun-Young Kim, M.D., Ph.D., Duck Cho, M.D., Ph.D., and Eun-Suk Kang, M.D., Ph.D.. Ann Lab Med 2024;44:222-34. https://doi.org/10.3343/alm.2023.0298

Objectives Automated haematology analysers measure various parameters of relevance to clinical research along with routine complete blood count (CBC)-related components. We aimed to establish ethnicity-specific and sex-specific reference intervals for 26 research-specific parameters as well as 18 routinely reported components using a large cohort of healthy Korean adults. The necessity of requiring separate sex-specific reference intervals for each parameter was also examined. Design A retrospective database review. Setting Single tertiary-care hospital of approximately 375 physicians and 530 nurses. Participants This study included 1383 reference individuals (840 men and 543 women). Primary and secondary outcome measures Following the Clinical and Laboratory Standards Institute guidelines for establishing reference intervals, routine CBCs as well as research parameters were measured using an ADVIA 2120i instrument. Results All the routine components except for mean platelet volume and per cent lymphocytes differed significantly between men and women. Most research parameters also differed between the sexes; the exceptions were large platelets, platelet dry mass distribution width, per cent basophil saturation, per cent peroxidase saturation and per cent abnormal peroxidase absorption. Despite these differences, separate reference intervals for men and women were required only for two research-specific parameters: ‘percentage high cellular haemoglobin’ and ‘percentage of hyperchromic red blood cells (RBCs)’. Conclusion Even though most parameters showed significant differences between men and women, none of the evaluated parameters except two RBC-related factors required separate reference intervals for each sex.

Purpose: Minimal residual disease (MRD)-guided therapy is the global standard treatment for pediatric acute lymphoblastic leukemia (ALL). We assessed the impact of MRD-driven intensification along with protocol-defined risk groups in pediatric ALL treatment. Methods: This retrospective analysis included 209 patients with ALL (treated between January 2013 to June 2023). MRD was assessed using six- to eight-color flow cytometry at the end of each phase before the maintenance phase. Post-induction treatment was determined based on early response, National Cancer Institute risk, and cytogenetics. High-risk (HR) patients followed the Korean HR or CCG-1882 protocols and standard-risk (SR) patients followed the modified COG-AALL0331 protocol. Treatment was intensified if flow-MRD ≥ 0.1% was identified. Results: Overall, 103 and 106 patients were classified as having SR and HR, respectively. The 5-year overall survival (OS) and event-free survival (EFS) were 92.5% and 84.3%, respectively. Thirty SR and 18 HR patients received intensified chemotherapy. Treatment intensification significantly improved EFS in patients with high MRD (94.2% vs. 75.5%, p = 0.04), particularly in post-induction patients with high MRD (90.0% vs. 19.0%, p = 0.035). The difference in survival between rapid early responder (RER) and slow early responder (SER) groups was eliminated after MRD-based intensification. The implementation rates of treatment intensification varied over time (9.1% before 2015, 28.6% during 2016–2019, and 13.9% during 2020–2023), reflecting improved risk stratification and therapy selection. Conclusion: MRD-guided therapy intensification markedly improved survival outcomes in patients with pediatric ALL when combined with risk-based protocols, highlighting the importance of MRD monitoring for optimizing risk-adapted treatment strategies.