1.Development and Application of a Cell-Based Assay for Detecting Anti-Agrin Antibodies Associated With Myasthenia Gravis
Seon Hui KIM ; Hye Yoon CHUNG ; MinGi KIM ; Seung Woo KIM ; Ha Young SHIN
Journal of Clinical Neurology 2025;21(2):105-112
Background:
and Purpose Anti-agrin antibodies (agrin Abs) have recently been identified in patients with myasthenia gravis (MG), sometimes in conjunction with antibodies (Abs) to the acetylcholine receptor (AChR), muscle-specific tyrosine kinase (MuSK), or low-density lipoprotein receptor-related protein 4. This study aimed to develop an in-house cell-based assay (CBA) for detecting agrin Abs, and to test its application to serum samples collected from individuals diagnosed with MG.
Methods:
Agrin complementary DNA as cloned into a pCMV6-AC-GFP vector, which was subsequently transfected into human embryonic kidney 293T (HEK293T) cells. Transfected HEK293T cells were incubated with patient serum and antihuman immunoglobulin G Ab conjugated with a red fluorescent dye. Agrin Ab levels were measured using the CBA in 389 serum samples: 340 from patients with MG, 36 from patients with other neuromuscular diseases, and 13 from healthy controls. The presence of agrin Ab was determined based on the fluorescence intensity and colocalization using fluorescence microscopy.
Results:
The expression levels of agrin mRNA and protein in transfected HEK293T cells were confirmed using the reverse-transcription polymerase chain reaction and Western blotting, respectively. Agrin expression in cells was further confirmed by immunocytochemistry.Two (0.6%) of the 340 patients with MG tested positive for agrin Ab: 1 of 191 AChR-positive patients and 1 of 54 MuSK-positive patients.
Conclusions
We have developed and validated a novel CBA for detecting agrin Abs. This CBA was successfully applied to detect agrin Abs in serum samples obtained from individuals with MG.
2.Development and Application of a Cell-Based Assay for Detecting Anti-Agrin Antibodies Associated With Myasthenia Gravis
Seon Hui KIM ; Hye Yoon CHUNG ; MinGi KIM ; Seung Woo KIM ; Ha Young SHIN
Journal of Clinical Neurology 2025;21(2):105-112
Background:
and Purpose Anti-agrin antibodies (agrin Abs) have recently been identified in patients with myasthenia gravis (MG), sometimes in conjunction with antibodies (Abs) to the acetylcholine receptor (AChR), muscle-specific tyrosine kinase (MuSK), or low-density lipoprotein receptor-related protein 4. This study aimed to develop an in-house cell-based assay (CBA) for detecting agrin Abs, and to test its application to serum samples collected from individuals diagnosed with MG.
Methods:
Agrin complementary DNA as cloned into a pCMV6-AC-GFP vector, which was subsequently transfected into human embryonic kidney 293T (HEK293T) cells. Transfected HEK293T cells were incubated with patient serum and antihuman immunoglobulin G Ab conjugated with a red fluorescent dye. Agrin Ab levels were measured using the CBA in 389 serum samples: 340 from patients with MG, 36 from patients with other neuromuscular diseases, and 13 from healthy controls. The presence of agrin Ab was determined based on the fluorescence intensity and colocalization using fluorescence microscopy.
Results:
The expression levels of agrin mRNA and protein in transfected HEK293T cells were confirmed using the reverse-transcription polymerase chain reaction and Western blotting, respectively. Agrin expression in cells was further confirmed by immunocytochemistry.Two (0.6%) of the 340 patients with MG tested positive for agrin Ab: 1 of 191 AChR-positive patients and 1 of 54 MuSK-positive patients.
Conclusions
We have developed and validated a novel CBA for detecting agrin Abs. This CBA was successfully applied to detect agrin Abs in serum samples obtained from individuals with MG.
3.Development and Application of a Cell-Based Assay for Detecting Anti-Agrin Antibodies Associated With Myasthenia Gravis
Seon Hui KIM ; Hye Yoon CHUNG ; MinGi KIM ; Seung Woo KIM ; Ha Young SHIN
Journal of Clinical Neurology 2025;21(2):105-112
Background:
and Purpose Anti-agrin antibodies (agrin Abs) have recently been identified in patients with myasthenia gravis (MG), sometimes in conjunction with antibodies (Abs) to the acetylcholine receptor (AChR), muscle-specific tyrosine kinase (MuSK), or low-density lipoprotein receptor-related protein 4. This study aimed to develop an in-house cell-based assay (CBA) for detecting agrin Abs, and to test its application to serum samples collected from individuals diagnosed with MG.
Methods:
Agrin complementary DNA as cloned into a pCMV6-AC-GFP vector, which was subsequently transfected into human embryonic kidney 293T (HEK293T) cells. Transfected HEK293T cells were incubated with patient serum and antihuman immunoglobulin G Ab conjugated with a red fluorescent dye. Agrin Ab levels were measured using the CBA in 389 serum samples: 340 from patients with MG, 36 from patients with other neuromuscular diseases, and 13 from healthy controls. The presence of agrin Ab was determined based on the fluorescence intensity and colocalization using fluorescence microscopy.
Results:
The expression levels of agrin mRNA and protein in transfected HEK293T cells were confirmed using the reverse-transcription polymerase chain reaction and Western blotting, respectively. Agrin expression in cells was further confirmed by immunocytochemistry.Two (0.6%) of the 340 patients with MG tested positive for agrin Ab: 1 of 191 AChR-positive patients and 1 of 54 MuSK-positive patients.
Conclusions
We have developed and validated a novel CBA for detecting agrin Abs. This CBA was successfully applied to detect agrin Abs in serum samples obtained from individuals with MG.
4.Minimizing Radiation Exposure in Neonatal Intensive Care Unit: A Quality Improvement Approach on X-Ray Practices
Jae Hui RYU ; Seung Han SHIN ; Young Hun CHOI ; Ee-Kyung KIM ; Han-Suk KIM
Neonatal Medicine 2024;31(3):56-64
Purpose:
Radiographic examinations are frequently performed for diagnostic and therapeutic purposes in neonatal intensive care units (NICUs). However, concerns are emerging regarding the safety of radiation exposure, especially in vulnerable preterm infants in periods of rapid cellular division. This quality improvement (QI) project aimed to reduce radiation hazards in level-IV NICU.
Methods:
We established an "X-ray prescription protocol" and educated the physicians to ensure that only essential radiographs were obtained. Additionally, we discouraged full-body infantograms and emphasized the prescription of targeted radiographs, such as chest or abdominal radiographs. Furthermore, to reduce the dose-area product (DAP, Gy·cm2) values, which act as a surrogate for radiation exposure, we provided training to radiologic technologists on meticulous collimation for each radiography session. We aimed to achieve a 30% reduction in the average monthly cumulative DAP per patient, which was calculated by dividing the total monthly DAP from radiographs in the NICU by the monthly average of patient admissions. Retrospective baseline data were collected 8 months pre-intervention and prospectively for 4 months post-interventions.
Results:
The average monthly X-ray count per patient was 28.3 in the pre-intervention period (October 2022 to May 2023), which decreased to 25.4 in the post-intervention period (June 2023 to September 2023), reflecting a 10.2% reduction (p=0.109). The average monthly infantogram count per patient showed an 18.0% reduction (25.9% to 21.2%, p=0.016), and the proportion of infantograms in the total X-ray counts decreased from 91.5% to 83.3% (p=0.017). The DAP value per X-ray decreased by 42.6%, from an average of 0.25 to 0.14 (p=0.011). The primary outcome, the average monthly cumulative DAP value per patient, showed a substantial reduction of 48.6%, dropping from 7.00 to 3.60 (p=0.004). The baseline characteristics and short-term morbidities of the patients did not differ significantly between the pre- and post-intervention period.
Conclusion
Our QI approach, which included discouraging excessive prescriptions of infantograms and promoting optimal collimation, significantly reduced the average monthly radiation exposure in the NICU, benefiting both patients and healthcare workers.
5.Growth and Developmental Outcomes of Triplets Preterm Infants according to the Chorionicity: A Retrospective Cohort Study
Eun Woo NAM ; Jae Hui RYU ; Hye Su HWANG ; Ho Jung CHOI ; Seulgi PARK ; Seung Han SHIN ; Ee-Kyung KIM ; Han-Suk KIM
Perinatology 2024;35(2):61-68
Objective:
We elucidated the effect of monochorionicity on neonatal and long-term neurologic outcomes on an individual basis in triplets.
Methods:
We retrospectively reviewed the perinatal outcomes and development and growth at 18 to 24 months corrected age (CA) of triplets born alive between 24 and 32 weeks of gestational age (GA) between 2009 and 2021 from the Seoul National University Hospital database. Neurodevelopmental impairment (NDI) was defined as any delay among the Bayley-III domains (motor and language), cerebral palsy, hearing impairment, or visual loss and was performed at a CA of 18 to 24 months.
Results:
We included 40 sets of triplets (120 infants), comprising 26, 10, and 4 sets of trichorionic (TC), dichorionic (DC), and monochorionic (MC) triplets, respectively. Ten infants, unaffected by monochorionicity out of 30 DC infants, were included in the non-MC group. Eighty-eight infants were included in the non-MC group, and 32 infants were affected by monochorionicity. In vitro fertilization-embryo transfer was more frequent in the non-MC group (P<0.05), and twin-to-twin transfusion syndrome affected only the MC group (P<0.01). At 24 months of CA, a combined delay of language and cognition in Bayley-III was evident in the MC group (P<0.05). Although NDI did not significantly differ between the 2 groups (P=0.059), the composite outcome of NDI+ postnatal death was significantly different (P<0.05). NDI+ postnatal death correlated with GA, Z-score of birth weight, brain injury, and monochorionicity in the univariate analysis (P<0.05). Multivariate analysis revealed a significant correlation between monochorionicity and NDI+ postnatal death. (P<0.05).
Conclusion
Monochorionicity is associated with adverse long-term neurodevelopmental out comes.
6.Minimizing Radiation Exposure in Neonatal Intensive Care Unit: A Quality Improvement Approach on X-Ray Practices
Jae Hui RYU ; Seung Han SHIN ; Young Hun CHOI ; Ee-Kyung KIM ; Han-Suk KIM
Neonatal Medicine 2024;31(3):56-64
Purpose:
Radiographic examinations are frequently performed for diagnostic and therapeutic purposes in neonatal intensive care units (NICUs). However, concerns are emerging regarding the safety of radiation exposure, especially in vulnerable preterm infants in periods of rapid cellular division. This quality improvement (QI) project aimed to reduce radiation hazards in level-IV NICU.
Methods:
We established an "X-ray prescription protocol" and educated the physicians to ensure that only essential radiographs were obtained. Additionally, we discouraged full-body infantograms and emphasized the prescription of targeted radiographs, such as chest or abdominal radiographs. Furthermore, to reduce the dose-area product (DAP, Gy·cm2) values, which act as a surrogate for radiation exposure, we provided training to radiologic technologists on meticulous collimation for each radiography session. We aimed to achieve a 30% reduction in the average monthly cumulative DAP per patient, which was calculated by dividing the total monthly DAP from radiographs in the NICU by the monthly average of patient admissions. Retrospective baseline data were collected 8 months pre-intervention and prospectively for 4 months post-interventions.
Results:
The average monthly X-ray count per patient was 28.3 in the pre-intervention period (October 2022 to May 2023), which decreased to 25.4 in the post-intervention period (June 2023 to September 2023), reflecting a 10.2% reduction (p=0.109). The average monthly infantogram count per patient showed an 18.0% reduction (25.9% to 21.2%, p=0.016), and the proportion of infantograms in the total X-ray counts decreased from 91.5% to 83.3% (p=0.017). The DAP value per X-ray decreased by 42.6%, from an average of 0.25 to 0.14 (p=0.011). The primary outcome, the average monthly cumulative DAP value per patient, showed a substantial reduction of 48.6%, dropping from 7.00 to 3.60 (p=0.004). The baseline characteristics and short-term morbidities of the patients did not differ significantly between the pre- and post-intervention period.
Conclusion
Our QI approach, which included discouraging excessive prescriptions of infantograms and promoting optimal collimation, significantly reduced the average monthly radiation exposure in the NICU, benefiting both patients and healthcare workers.
7.Growth and Developmental Outcomes of Triplets Preterm Infants according to the Chorionicity: A Retrospective Cohort Study
Eun Woo NAM ; Jae Hui RYU ; Hye Su HWANG ; Ho Jung CHOI ; Seulgi PARK ; Seung Han SHIN ; Ee-Kyung KIM ; Han-Suk KIM
Perinatology 2024;35(2):61-68
Objective:
We elucidated the effect of monochorionicity on neonatal and long-term neurologic outcomes on an individual basis in triplets.
Methods:
We retrospectively reviewed the perinatal outcomes and development and growth at 18 to 24 months corrected age (CA) of triplets born alive between 24 and 32 weeks of gestational age (GA) between 2009 and 2021 from the Seoul National University Hospital database. Neurodevelopmental impairment (NDI) was defined as any delay among the Bayley-III domains (motor and language), cerebral palsy, hearing impairment, or visual loss and was performed at a CA of 18 to 24 months.
Results:
We included 40 sets of triplets (120 infants), comprising 26, 10, and 4 sets of trichorionic (TC), dichorionic (DC), and monochorionic (MC) triplets, respectively. Ten infants, unaffected by monochorionicity out of 30 DC infants, were included in the non-MC group. Eighty-eight infants were included in the non-MC group, and 32 infants were affected by monochorionicity. In vitro fertilization-embryo transfer was more frequent in the non-MC group (P<0.05), and twin-to-twin transfusion syndrome affected only the MC group (P<0.01). At 24 months of CA, a combined delay of language and cognition in Bayley-III was evident in the MC group (P<0.05). Although NDI did not significantly differ between the 2 groups (P=0.059), the composite outcome of NDI+ postnatal death was significantly different (P<0.05). NDI+ postnatal death correlated with GA, Z-score of birth weight, brain injury, and monochorionicity in the univariate analysis (P<0.05). Multivariate analysis revealed a significant correlation between monochorionicity and NDI+ postnatal death. (P<0.05).
Conclusion
Monochorionicity is associated with adverse long-term neurodevelopmental out comes.
8.Minimizing Radiation Exposure in Neonatal Intensive Care Unit: A Quality Improvement Approach on X-Ray Practices
Jae Hui RYU ; Seung Han SHIN ; Young Hun CHOI ; Ee-Kyung KIM ; Han-Suk KIM
Neonatal Medicine 2024;31(3):56-64
Purpose:
Radiographic examinations are frequently performed for diagnostic and therapeutic purposes in neonatal intensive care units (NICUs). However, concerns are emerging regarding the safety of radiation exposure, especially in vulnerable preterm infants in periods of rapid cellular division. This quality improvement (QI) project aimed to reduce radiation hazards in level-IV NICU.
Methods:
We established an "X-ray prescription protocol" and educated the physicians to ensure that only essential radiographs were obtained. Additionally, we discouraged full-body infantograms and emphasized the prescription of targeted radiographs, such as chest or abdominal radiographs. Furthermore, to reduce the dose-area product (DAP, Gy·cm2) values, which act as a surrogate for radiation exposure, we provided training to radiologic technologists on meticulous collimation for each radiography session. We aimed to achieve a 30% reduction in the average monthly cumulative DAP per patient, which was calculated by dividing the total monthly DAP from radiographs in the NICU by the monthly average of patient admissions. Retrospective baseline data were collected 8 months pre-intervention and prospectively for 4 months post-interventions.
Results:
The average monthly X-ray count per patient was 28.3 in the pre-intervention period (October 2022 to May 2023), which decreased to 25.4 in the post-intervention period (June 2023 to September 2023), reflecting a 10.2% reduction (p=0.109). The average monthly infantogram count per patient showed an 18.0% reduction (25.9% to 21.2%, p=0.016), and the proportion of infantograms in the total X-ray counts decreased from 91.5% to 83.3% (p=0.017). The DAP value per X-ray decreased by 42.6%, from an average of 0.25 to 0.14 (p=0.011). The primary outcome, the average monthly cumulative DAP value per patient, showed a substantial reduction of 48.6%, dropping from 7.00 to 3.60 (p=0.004). The baseline characteristics and short-term morbidities of the patients did not differ significantly between the pre- and post-intervention period.
Conclusion
Our QI approach, which included discouraging excessive prescriptions of infantograms and promoting optimal collimation, significantly reduced the average monthly radiation exposure in the NICU, benefiting both patients and healthcare workers.
9.Growth and Developmental Outcomes of Triplets Preterm Infants according to the Chorionicity: A Retrospective Cohort Study
Eun Woo NAM ; Jae Hui RYU ; Hye Su HWANG ; Ho Jung CHOI ; Seulgi PARK ; Seung Han SHIN ; Ee-Kyung KIM ; Han-Suk KIM
Perinatology 2024;35(2):61-68
Objective:
We elucidated the effect of monochorionicity on neonatal and long-term neurologic outcomes on an individual basis in triplets.
Methods:
We retrospectively reviewed the perinatal outcomes and development and growth at 18 to 24 months corrected age (CA) of triplets born alive between 24 and 32 weeks of gestational age (GA) between 2009 and 2021 from the Seoul National University Hospital database. Neurodevelopmental impairment (NDI) was defined as any delay among the Bayley-III domains (motor and language), cerebral palsy, hearing impairment, or visual loss and was performed at a CA of 18 to 24 months.
Results:
We included 40 sets of triplets (120 infants), comprising 26, 10, and 4 sets of trichorionic (TC), dichorionic (DC), and monochorionic (MC) triplets, respectively. Ten infants, unaffected by monochorionicity out of 30 DC infants, were included in the non-MC group. Eighty-eight infants were included in the non-MC group, and 32 infants were affected by monochorionicity. In vitro fertilization-embryo transfer was more frequent in the non-MC group (P<0.05), and twin-to-twin transfusion syndrome affected only the MC group (P<0.01). At 24 months of CA, a combined delay of language and cognition in Bayley-III was evident in the MC group (P<0.05). Although NDI did not significantly differ between the 2 groups (P=0.059), the composite outcome of NDI+ postnatal death was significantly different (P<0.05). NDI+ postnatal death correlated with GA, Z-score of birth weight, brain injury, and monochorionicity in the univariate analysis (P<0.05). Multivariate analysis revealed a significant correlation between monochorionicity and NDI+ postnatal death. (P<0.05).
Conclusion
Monochorionicity is associated with adverse long-term neurodevelopmental out comes.
10.Minimizing Radiation Exposure in Neonatal Intensive Care Unit: A Quality Improvement Approach on X-Ray Practices
Jae Hui RYU ; Seung Han SHIN ; Young Hun CHOI ; Ee-Kyung KIM ; Han-Suk KIM
Neonatal Medicine 2024;31(3):56-64
Purpose:
Radiographic examinations are frequently performed for diagnostic and therapeutic purposes in neonatal intensive care units (NICUs). However, concerns are emerging regarding the safety of radiation exposure, especially in vulnerable preterm infants in periods of rapid cellular division. This quality improvement (QI) project aimed to reduce radiation hazards in level-IV NICU.
Methods:
We established an "X-ray prescription protocol" and educated the physicians to ensure that only essential radiographs were obtained. Additionally, we discouraged full-body infantograms and emphasized the prescription of targeted radiographs, such as chest or abdominal radiographs. Furthermore, to reduce the dose-area product (DAP, Gy·cm2) values, which act as a surrogate for radiation exposure, we provided training to radiologic technologists on meticulous collimation for each radiography session. We aimed to achieve a 30% reduction in the average monthly cumulative DAP per patient, which was calculated by dividing the total monthly DAP from radiographs in the NICU by the monthly average of patient admissions. Retrospective baseline data were collected 8 months pre-intervention and prospectively for 4 months post-interventions.
Results:
The average monthly X-ray count per patient was 28.3 in the pre-intervention period (October 2022 to May 2023), which decreased to 25.4 in the post-intervention period (June 2023 to September 2023), reflecting a 10.2% reduction (p=0.109). The average monthly infantogram count per patient showed an 18.0% reduction (25.9% to 21.2%, p=0.016), and the proportion of infantograms in the total X-ray counts decreased from 91.5% to 83.3% (p=0.017). The DAP value per X-ray decreased by 42.6%, from an average of 0.25 to 0.14 (p=0.011). The primary outcome, the average monthly cumulative DAP value per patient, showed a substantial reduction of 48.6%, dropping from 7.00 to 3.60 (p=0.004). The baseline characteristics and short-term morbidities of the patients did not differ significantly between the pre- and post-intervention period.
Conclusion
Our QI approach, which included discouraging excessive prescriptions of infantograms and promoting optimal collimation, significantly reduced the average monthly radiation exposure in the NICU, benefiting both patients and healthcare workers.

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