Min-Seung Park, M.D., Hyun-Young Kim, M.D., Jae Joon Lee, M.D., Duck Cho, M.D., Chul Won Jung, M.D., Hee-Jin Kim, M.D., and Sun-Hee Kim, M.D.. Ann Lab Med 2023;43:310-4. https://doi.org/10.3343/alm.2023.43.3.310

Rationale: Plasminogen plays an important role in fibrinolysis and is encoded by the PLG gene. The missense variant PLG Ala620Thr is the major cause of dysplasminogenemia in East Asian countries, including Korea. Although dysplasminogenemia was first reported in a Japanese patient with recurrent venous thromboembolism (VTE), subsequent studies have not demonstrated any clear association between the PLG Ala620Thr variant and the risk of VTE. To the best of our knowledge, this is the first report of a homozygous PLG Ala620Thr variant case from Korea. Patient concerns: Here, we report a Korean family with PLG Ala620Thr mutation. The proband was a 34-year-old man who presented with multiple thrombotic arterial embolism and cardiac myxoma. Interventions: Laboratory workup, including coagulation profile and PLG gene sequencing, was carried out for the affected family. Diagnosis and Outcome: The proband carried a heterozygous PLG Ala620Thr variant with decreased plasminogen activity of 65%. His 53-year-old mother, who had no reported history of VTE, was homozygous for the PLG Ala620Thr variant with decreased plasminogen activity of just 25%. Decreased plasminogen activity indicates dysplasminogenemia. Lessons: We believe that this clinically silent homozygous case supports the previous findings that isolated PLG Ala620Thr variant does not confer a significant risk of VTE.

Conventional diagnostic methods (CDMs) for lower respiratory infections (LRIs) have limitations in detecting causative pathogens. This study evaluates the utility of shotgun metagenomic sequencing (SMS) as a complementary diagnostic tool using bronchoalveolar lavage (BAL) fluid. Sixteen BAL fluid samples from pneumonia patients with positive CDM results—including bacterial/fungal cultures; PCR for Mycobacterium tuberculosis or cytomegalovirus; and the BioFire^® FilmArray^® Pneumonia Panel (BioFire Diagnostics LLC, Salt Lake City, UT, USA)—underwent 10 Gb SMS on the Illumina NovaSeq 6000 platform (Illumina, San Diego, CA, USA). Reads were aligned to the NCBI RefSeq database; with fungal identification further supported by internal transcribed spacer (ITS) analysis. Antibiotic resistance genes (ARGs) were annotated using the Comprehensive Antibiotic Resistance Database. Microbial reads accounted for 0.00002–0.04971% per sample. SMS detected corresponding bacteria in 63% of cases, increasing to 69% when subdominant taxa were included. Fungal reads were low; however, Candida species were identified in four samples via ITS. No viral reads were detected. ARGs meeting perfect match criteria were found in two cases. This is the first real-world study comparing SMS with CDMs, including semiquantitative PCR, in BAL fluid for LRI. SMS shows promise as a supplementary diagnostic method, with further research needed to optimize its performance and cost-effectiveness.

Ha-eun Cho, M.D., Yujin Han, M.D., Ph.D., Jae Joon Lee, M.D., Ph.D., Kyung Sun Park, M.D., Ph.D., Young Jin Kim, M.D., Ph.D., Sun Young Cho, M.D., Ph.D., Hoi Soo Yoon, M.D., Ph.D., Woo-In Lee, M.D., Ph.D., and Tae Sung Park, M.D., Ph.D.. Ann Lab Med 2022;42:485-7. https://doi.org/10.3343/alm.2022.42.4.485

Hyun-Young Kim, M.D., Ph.D., Jae Joon Lee, M.D., Ph.D., Min-Seung Park, M.D., Ph.D., Chang-Hun Park, M.D., Ph.D., Taek Kyu Park, M.D., Ph.D., Sung-A Chang, M.D., Ph.D., and Hee-Jin Kim, M.D., Ph.D.. Ann Lab Med -0001;0:. https://doi.org/10.3343/alm.2025.0543