Background: Direct immunofluorescence (DIF) is a histochemical technique used to detect tissue-bound autoantibodies and diagnose various immune-mediated skin diseases. Objective: This study aimed to evaluate the sensitivity of DIF for each disorder, and the consistency between clinical, histopathological, and DIF results. Methods: A retrospective study was conducted in 194 patients who underwent skin biopsy and DIF testing at our hospital between January 2011 and December 2021. An antibody panel against immunoglobulin G (IgG), IgA, IgM, C3, C1q, and fibrinogen was used. The concordance rate and κ-coefficient between the clinical, histopathological, and DIF results were evaluated. Results: DIF was observed to be positive in 87 cases; 51 cases of immune-mediated bullous diseases, seven cases of connective tissue diseases (CTDs), 25 cases of vasculitis, and four cases of other diseases. The overall sensitivity of DIF for immune-mediated bullous diseases was 71.8%, which was higher than that of histopathology (64.8%). In CTDs and vasculitis, the overall sensitivities of DIF were 30.4% and 65.8%, respectively, which were lower than those of histopathology (73.9% and 84.2%, respectively). In addition, good concordance among the clinical, histological, and DIF results was observed. Conclusion DIF is a useful diagnostic method, especially for immune-mediated bullous diseases, lupus erythematosus, and Henoch-Schonlein purpura. However, in other CTDs and vasculitis cases, the sensitivity of DIF is relatively low. Therefore, the diagnostic value of DIF along with clinical and histopathological findings will be maximized only when the DIF test is performed for appropriate diseases.

Eosinophilic dermatosis of hematological malignancy (EDHM) is a rare condition associated with various hematologic malignancies, characterized by pruritic skin eruptions. We present a case of a 66-year-old woman with follicular lymphoma who developed urticarial and vesicular lesions indicative of EDHM following chemotherapy.The diagnosis was confirmed through histological analysis, revealing eosinophilic infiltration. Treatment included additional chemotherapy sessions and topical corticosteroids, resulting in complete resolution of skin lesions and lymphoma. EDHM requires careful differentiation based on clinical and histological findings. The pathogenesis remains unclear, but addressing underlying hematologic malignancies appears crucial in management. Early recognition of EDHM is essential for appropriate intervention due to its limited therapeutic options.

Purpose: We investigated the consistent efficacy and safety of eflapegrastim, a novel long-acting granulocyte-colony stimulating factor (G-CSF), in Koreans and Asians compared with the pooled population of two global phase 3 trials. Materials and Methods: Two phase 3 trials (ADVANCE and RECOVER) evaluated the efficacy and safety of fixed-dose eflapegrastim (13.2 mg/0.6 mL [3.6 mg G-CSF equivalent]) compared to pegfilgrastim (6 mg based on G-CSF) in breast cancer patients who received neoadjuvant or adjuvant docetaxel/cyclophosphamide. The primary objective was to demonstrate non-inferiority of eflapegrastim compared to pegfilgrastim in mean duration of severe neutropenia (DSN) in cycle 1, in Korean and Asian subpopulations. Results: Among a total of 643 patients randomized to eflapegrastim (n=314) or pegfilgrastim (n=329), 54 Asians (29 to eflapegrastim and 25 to pegfilgrastim) including 28 Koreans (14 to both eflapegrastim and pegfilgrastim) were enrolled. The primary endpoint, DSN in cycle 1 in the eflapegrastim arm was non-inferior to the pegfilgrastim arm in Koreans and Asians. The DSN difference between the eflapegrastim and pegfilgrastim arms was consistent across populations: –0.120 days (95% confidence interval [CI], –0.227 to –0.016), –0.288 (95% CI, –0.714 to 0.143), and –0.267 (95% CI, –0.697 to 0.110) for pooled population, Koreans and Asians, respectively. There were few treatment-related adverse events that caused discontinuation of eflapegrastim (1.9%) or pegfilgrastim (1.5%) in total and no notable trends or differences across patient populations. Conclusion This study may suggest that eflapegrastim showed non-inferior efficacy and similar safety compared to pegfilgrastim in Koreans and Asians, consistently with those of pooled population.

Background: Traumatic spinal injuries in children are uncommon and result in different patterns of injuries due to the anatomical characteristics of children’s spines. However, there are only a few epidemiological studies of traumatic spinal injury in children. The purpose of this study was to investigate the characteristics of traumatic spinal injury in children. Methods: We retrospectively reviewed the cases of pediatric patients (age < 18 years) with traumatic spinal injury who were treated at a level 1 trauma center between January 2017 and December 2021. We divided them into three groups according to age and analyzed demographics, injury mechanism, level of injury, and injury pattern. Results: A total of 62 patients (255 fractures) were included, and the mean age was 13.8 ± 3.2 years. There were 5 patients (22 fractures) in group I (0–9 years), 24 patients (82 fractures) in group II (10–14 years), and 33 patients (151 fractures) in group III (15–17 years). Both the Injury Severity Score and the Revised Trauma Score were highest in group I, but there was no statistical difference between the age groups. Fall from height was the most common injury mechanism, of which 63% were suicide attempts. The level of spinal injury was different in each age group, T10–L2 injury being the most common. In all age groups, the number of multilevel continuous injury was larger than that of single-level injury or multilevel noncontinuous injury. Surgical intervention was required in 33.9%, and mortality was 3.2%. Conclusions In our study, fall from height was the most common mechanism of injury, and there were many suicide attempts associated with mental health issues. Thoracolumbar junction injuries were predominant, and the rate of multilevel contiguous injuries was high. The support and interest of the society and families for adolescent children seem crucial in preventing spinal trauma, and image testing of the entire spine is essential when evaluating pediatric spinal injuries.

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare and aggressive lymphoma with an overall incidence of 0.04 cases per 100,000 people. BPDCN is a hematopoietic clonal neoplasm that originates from plasmacytoid dendritic cell precursors. A 63-year-old man presented with multiple erythematous nodules over his whole body, including his face, trunk, and both upper and lower extremities that appeared 1 month ago. Skin biopsy showed diffuse dermal infiltration by monomorphic atypical lymphocytes with large, irregular nuclei and scant cytoplasms. Immunohistochemical staining was positive for CD4, CD56, and CD123. The karyotype test showed abnormalities in male chromosomes 47, XY, ＋8 [2]/46, and XY [25], and mutations in DNMT3A, TET2, SRSF2, and ATRX genes were identified in a next-generation sequencing (NGS)-based acute myeloid leukemia gene panel test. The patient was diagnosed with BPDCN and treated with a KALLA 1406 regimen; however, he died on the 17th day of treatment.

Background: Total cholesterol concentration measurement is important in the diagnosis of dyslipidemia and evaluation of cardiovascular disease risk factors. Measurement reliability for obtaining an accurate total cholesterol concentration requires procedure standardization. We evaluated the standardization status for total cholesterol concentration measurement through Korean external quality assessment (EQA) data analysis. Methods: This study involved 1,670 laboratories that participated in the EQA of total cholesterol concentration measurements in 2019 for 32 products from different manufacturers. The target concentrations of three quality control (QC) materials (samples A, B, and C) were measured using the reference method and compared with EQA data. The performance criteria for total cholesterol concentration measurement were based on the National Cholesterol Education Program guidelines, with ± 3% inaccuracy. Results: The target values and inaccuracies of the QC material based on the reference method measurements were 254.65 ± 7.64, 108.30 ± 3.25, and 256.29 ± 7.69 mg/dL (6.59 ± 0.20, 2.80 ± 0.08, and 6.63 ± 0.20 mmol/L) for samples A, B, and C, respectively.The performance criteria were not met in 42.7% laboratories for sample A, 68.4% of laboratories for sample B, and 38.0% laboratories for sample C. Conclusions Despite significant efforts to accurately measure total cholesterol concentrations, further actions are needed for measurement standardization. Manufacturers reporting values that differ from target values should check calibrator traceability; additional efforts to accurately measure total cholesterol concentrations are required for laboratories that use products from these manufacturers.

External quality assessment (EQA) is important for evaluating clinical laboratories and enhancing their testing quality. EQA schemes are variable; thus, it is crucial that the EQA organizers share their experiences to continuously improve the EQA scheme. The Korean Association of External Quality Assessment Service (KEQAS) has been the leading, authorized EQA institute for the standardization and quality management of laboratory testing in Korean medical institutions since 1976. The EQA scheme underwent a major change in 2016, and the number of EQA programs increased significantly since then. The key changes implemented in EQA scheme include a fully computerized assessment to accelerate feedback and unification of the testing and reporting methods. We provide an overview of the EQA schemes and performance evaluation criteria of the KEQAS and suggest directions for achieving the global harmonization of EQA.