Objectives: To investigate antibody production in asymptomatic and mild COVID-19 patients. Methods: Sera from asymptomatic to severe COVID-19 patients were collected. Microneutralization (MN), fluorescence immunoassay (FIA), and enzyme-linked immunosorbent assay (ELISA) were performed. Results: A total of 70 laboratory-confirmed COVID-19 patients were evaluated, including 15 asymptomatic/anosmia, 49 mild symptomatic, and 6 pneumonia patients. The production of the neutralizing antibody was observed in 100% of pneumonia, 93.9% of mild symptomatic, and 80.0% of asymptomatic/anosmia groups. All the patients in the pneumonia group showed high MN titer (≥1:80), while 36.7% of mild symptomatic and 20.0% of asymptomatic/anosmia groups showed high titer (p < 0.001). Anti-SARS-CoV-2 antibodies could be more sensitively detected by FIA IgG (98.8%) and ELISA (97.6%) in overall. For the FIA IgG test, all patients in the pneumonia group exhibited a high COI value (≥15.0), while 89.8% of mild symptomatic and 73.3% of asymptomatic/anosmia groups showed a high value (p = 0.049). For the ELISA test, all patients in the pneumonia group showed a high optical density (OD) ratio (≥3.0), while 65.3% of mild symptomatic and 53.3% of asymptomatic/anosmia groups showed a high ratio (p = 0.006). Conclusions: Most asymptomatic and mild COVID-19 patients produced the neutralizing antibody, although the titers were lower than pneumonia patients. ELISA and FIA sensitively detected anti-SARS-CoV-2 antibodies.

Calcitonin gene-related peptide (CGRP) has been reported as elevated in chronic migraine. We aimed to validate the role of interictal serum CGRP concentration in peripheral blood samples as a biomarker of chronic migraine. We prospectively recruited patients with episodic and chronic migraine and normal controls (NCs) in the Samsung Medical Center between August 2015 and May 2016. Blood samples were collected interictally from antecubital veins per prespecified protocol. Serum CGRP measurement was performed in the central laboratory by a single experienced technician blinded to clinical information. Migraine subtype, headache days in the previous month, and the presence and characteristics of headache at ±2 days of measurement were evaluated at every visit. A total of 156 migraineurs (106 episodic and 50 chronic) and 27 NCs were recruited in this study. Compared to NCs (75.7 ± 20.07 pg/mL) and patients with episodic migraine (67.0 ± 20.70 pg/mL), patients with chronic migraine did not show an interictal elevation of serum CGRP levels (64.9 ± 15.32 pg/mL). Serum CGRP concentration was not associated with headache status (ictal vs. interictal), migraine subtype (migraine with vs. without aura), use of preventive or acute medications, and comorbid medication overuse. Higher serum CGRP concentration did not predict treatment response in patients with chronic migraine. Serum CGRP concentration may not be a feasible biomarker for chronic migraine. Further validation is necessary before CGRP can be used in the clinical practice.

The prognostic effects of tumor infiltrating regulatory T cells and myeloid derived suppressor cells assessed by multicolor flow cytometry in gastric cancer patients

Jeong SY, et al. J Korean Med Sci. 2017 Oct;32(10):1717-1720. https://doi.org/10.3346/jkms.2017.32.10.1717

Choi SR, et al. Pediatr Infect Vaccine. 2018 Dec;25(3):123-131. https://doi.org/10.14776/piv.2018.25.e8