Background: Programmed cell death 1/programmed cell death ligand 1 (PD-1/PD-L1) inhibitors are effective treatments for non-small cell lung cancer (NSCLC), but their use can lead to severe pneumonitis. This study aims to evaluate the utility of Krebs von den Lungen-6 (KL-6) for predicting and diagnosing PD-1/PD-L1 inhibitor-related pneumonitis in NSCLC patients. Methods: We conducted a prospective observational study at a university-affiliated tertiary hospital in Korea from February 2022 to June 2023. Baseline KL-6 levels were measured immediately before initiating PD-1/PD-L1 inhibitor therapy. In patients who developed pneumonitis, KL-6 levels were monitored every 1–2 weeks from the onset of pneumonitis. For patients without pneumonitis, KL-6 levels were measured every 6 weeks. We compared clinical characteristics and serial KL-6 levels between the pneumonitis and non-pneumonitis groups. Results: Eighteen patients were enrolled, with 11 developing pneumonitis. Baseline KL-6 levels did not significantly differ between the two groups (261 U/mL in the pneumonitis group vs. 373 U/mL in the non-pneumonitis group, p=0.375). In the pneumonitis group, KL-6 levels generally showed an upward trend, with a median of 412 U/mL at pneumonitis onset. Conversely, KL-6 levels in the non-pneumonitis group showed no clear overall change. Conclusion In this pilot study, baseline KL-6 was not clearly linked to PD-1/PD-L1 inhibitor-related pneumonitis in NSCLC patients. However, increases in KL-6 levels post-baseline were more frequently observed in patients who developed pneumonitis, including cases of all-cause pneumonitis.

Background/Aims: Biliary tract cancer (BTC) is a rare malignancy with poor prognosis. We investigated genomic determinants of clinical benefit from gemcitabine, cisplatin, and nab-paclitaxel (GAP) versus gemcitabine and cisplatin (GC) in advanced BTC. Methods: Clinical and genomic data using TruSight Oncology 500 were analyzed from patients treated with GAP (N=198) or GC (N=89) as first-line therapy. Results: With a median follow-up of 33.0 months, GAP modestly improved progression-free survival (PFS) (hazard ratio [HR] 0.764; 95% confidence interval [CI] 0.591–0.989) without significant overall survival (OS) difference compared to GC. Genomic profiling revealed frequent alterations in TP53 (35.2%), KRAS (16.4%), SMAD4 (10.5%), and TNFRSF14 (10.5%), involving RTK/RAS (44.3%), TP53 (41.8%), and PI3K (20.2%) pathways. Single-gene mutations did not predict treatment benefit. However, pathway-level analysis identified PI3K pathway activation as significantly associated with inferior PFS (HR 2.148; 95% CI 1.478–3.124) and OS (HR 2.096; 95% CI 1.413–3.109) in patients receiving GAP, an effect not observed with GC. Importantly, GAP conferred clinical benefit only in patients without PI3K pathway activation, while no survival advantage was seen in those with such alterations (Pinteraction=0.023 for PFS, Pinteraction=0.003 for OS). Similar results were obtained in the independent validation cohort treated with GAP (N=103) or GC (N=64) for BTC. Conclusions Genomic profiling using next-generation sequencing identified PI3K pathway activation as key molecular determinant that differentiates patient outcomes between GAP and GC treatments in advanced BTC.

The brain-derived neurotrophic factor (BDNF) plays a crucial role in neuroprotection, and we have previously demonstrated BDNF-mediated neuroprotective effects in mesenchymal stromal cells (MSCs). The present study aimed to investigate whether BDNF-overexpressing MSCs enhance the therapeutic efficacy of naïve MSCs in a preclinical model of severe neonatal intraventricular hemorrhage (IVH). We exposed primary rat neuronal cells to 40 U of thrombin overnight in vitro. Subsequently, the neuronal cells were co-cultured with either naïve MSCs or BDNF-overexpressing MSCs (1×105 cells in 1 mL media) for 24 hours. Next, 300 μL of maternal blood was injected into bilateral ventricles on postnatal day (P)4 to induce severe IVH in newborn Sprague-Dawley male rats. At P6, either naïve MSCs or BDNF-overexpressing MSCs (1×105 cells in 10 μL saline) were transplanted intraventricularly. Behavioral function tests, including passive avoidance, followed by endpoint analyses of brain tissue and cerebrospinal fluid were performed at P35. BDNF-overexpressing MSCs enhanced the effects of naïve MSCs against cell death, cytotoxicity, and oxidative stress in vitro. Notably, naïve and BDNF-overexpressing MSCs did not attenuate post-hemorrhagic ventricular dilatation, neuronal cell death, or gliosis. However, BDNF-overexpressing MSCs attenuated microglial activation.Furthermore, inflammatory cytokine (interleukin [IL]-1α, IL-1β, IL-6, and tumor necrosis factor-α) levels and memory function assessed using a passive avoidance test significantly improved in the BDNF-overexpressing MSC transplanted group compared with the naïve MSC transplanted group. Our data suggest that BDNF-overexpressing MSCs may offer superior protective effects to naïve MSCs in a neonatal IVH model.

The efficacy of clarithromycin-containing triple therapy (TT) against Helicobacter pylori has declined in Korea, with recent first-line eradication rates falling below 70%. Clarithromycin resistance exceeded 30%, undermining the standard regimen for H. pylori. These trends necessitate a change in the treatment strategy. This review analyzed the shift proposed in the draft of the 2025 Korean H. pylori guidelines. We examined the rationale for abandoning TT as a first-line empirical therapy and the establishment of a new dual-pillar strategy: 1) the declining role of clarithromycin-containing TT as a first-line treatment and 2) polymerase chain reaction (PCR)-based tailored therapy as the recommended precision approach. We explored the 1) emergence of new empirical regimen options, 2) application of tailored therapy, and 3) adoption of potassium-competitive acid blockers (P-CABs). Empirical regimens have shifted toward four-drug combinations to achieve higher cure rates. Concomitant therapy (proton-pump inhibitor [PPI] or P-CAB+amoxicillin+clarithromycin+metronidazole) offers high efficacy but raises concerns about antibiotic overuse. As a compromise, bismuth-augmented triple regimens (adding bismuth to TT) are now recommended; these modified quadruple therapies (e.g., PACB: PPI+amoxicillin+clarithromycin+bismuth, or PAMB: PPI+amoxicillin+metronidazole+bismuth) significantly improve eradication rates without requiring a third antibiotic class. Regarding tailored therapy, PCR-based domestic clinical research data consistently achieves ≥90% cure rates in first-line treatment—markedly higher than empirical TT in Korea. Economic analyses supported the cost-effectiveness of this approach. The guideline algorithm for salvage therapy was clarified. Bismuth quadruple therapy has been confirmed as the standard second-line treatment. For third-line therapy, we analyzed the efficacy of levofloxacin-based regimens, rifabutin-based therapy, and bismuth add-on therapy with two previously unused antibiotics. The 2025 Korean guidelines establish quadruple therapies as the new standard through a dual strategy: pragmatic empirical treatment and PCR-guided tailored therapy, with P-CABs and bismuth-based regimens as key components.

Purpose: To evaluate the clinical characteristics, etiologies, and treatment outcomes of pediatric macular holes (MHs). Methods: The medical records of pediatric patients under 18 years of age diagnosed with MHs at Severance Hospital between January 2005 and December 2022 were retrospectively reviewed. Data regarding etiology, MH diameter, treatment methods, and both visual and anatomical outcomes were analyzed. Results: Among 15 patients (16 eyes), traumatic MHs were identified in 7 cases (46.7%), while non-traumatic causes included Stargardt disease, familial exudative vitreoretinopathy, and vitreomacular traction. No statistically significant differences were observed between the traumatic and non-traumatic groups in terms of age, MH diameter, or initial and final best-corrected visual acuity (BCVA). However, there was a significant difference in sex distribution, with all traumatic cases occurring in males, whereas only 3 of the 9 non-traumatic eyes were male (p = 0.01). Surgical intervention was performed in 13 eyes, achieving anatomical closure in 62.5% (10 eyes). The three eyes without closure (37.5%) were all non-traumatic cases. BCVA (logMAR) significantly improved from a median of 1.00 preoperatively to 0.70 postoperatively (p = 0.013). Among the three eyes that did not undergo surgery, one demonstrated spontaneous closure, and another achieved closure following medical treatment. Conclusions Pediatric MHs may arise from various ocular conditions beyond trauma. Surgical intervention was effective, particularly for traumatic MHs, while non-traumatic cases demonstrated a lower closure rate. In some instances, spontaneous or medically induced closure occurred without surgical management. Further multicenter studies with larger cohorts are warranted to establish definitive management guidelines for pediatric MHs.

Background: Laser procedures are integral to dermatologic practice, yet safety measures- particularly regarding ocular protection and plume control- are poorly studied in real-world settings. Objective: To evaluate current practices in eye protection, infection control, and occupational risk awareness among Korean dermatologists performing laser treatments. Methods: A cross-sectional survey was conducted among board-certified dermatologists at the 2024 Korean Society for Dermatologic Laser Surgery meeting. The questionnaire covered demographics, laser frequency, use of goggles and masks, infection control strategies, ophthalmologic monitoring, and history of warts or cancer. Results: Seventy-nine respondents completed the survey. All reported using protective goggles, but only 26.6% and 22.8% did so for CO 2 and erbium-doped yttrium aluminium garnet lasers, respectively. Only 24.1% underwent regular eye exams, and 13.9% reported eye conditions after starting laser practice. While 89.9% used masks, 40.8% used dental masks, which are inadequate for plume protection. Suction devices were used by 94.9%, though performance specifications were unclear. Warts were reported by 46.8% of respondents; two reported cancer diagnoses after initiating laser work. Conclusion Despite high overall adherence to basic safety practices, critical gaps remain. Our findings highlight the need for standardized guidelines and long-term occupational health monitoring to ensure safe laser practice.

Background: Rosacea is a chronic inflammatory skin disorder characterized by erythema, papules, ocular symptoms, and heightened sensitivity. Patients with neurogenic symptoms such as burning or stinging remain particularly difficult to manage. Current guidelines often underrepresent energy-based devices (EBDs), pigmentary sequelae, psychosocial burden, and ocular comorbidities. Objective: To examine Korean dermatologists’ expert perspectives on rosacea management, focusing on skin sensitivity, neurogenic symptoms, pigmentary changes, psychosocial impact, ocular involvement, and EBD use. Methods: A web-based, 29-item survey was administered to 25 board-certified Korean dermatologists (May–June 2025). Quantitative and qualitative responses were analyzed. Results: Erythematotelangiectatic and papulopustular phenotypes with sensitivity skin predominated. EBDs (pulsed dye laser, intense pulsed light) were frequently used but limited by cost and sensitivity issues. Neurogenic symptoms were recognized but rarely treated with neuromodulators. Post-inflammatory hyperpigmentation was infrequent, yet monitoring was inconsistent.Psychosocial and ocular aspects were acknowledged but seldomly systematically addressed.Respondents expressed interest in emerging adjunctive treatments such as cold plasma, skin boosters, and holistic care approaches. Conclusion Korean dermatologists adopt individualized strategies for rosacea, yet practice gaps remain regarding neurogenic symptoms, pigmentary complications, and psychosocial and ocular comorbidities. Findings support the need for updated multidisciplinary, phenotype-driven guidelines aligned with real-world practice.

Purpose: Persistent hypercalcemia after parathyroidectomy (PTx) remains a significant concern in patients with tertiary hyperparathyroidism (THPT) following kidney transplant (KT). Complete resection of hyperfunctioning glands is challenging due to ectopic or intrathyroidal glands. This study evaluated whether intraoperative parathyroid hormone (ioPTH) monitoring during PTx in KT patients with THPT reduces the surgical failure rate. Methods: We retrospectively analyzed 111 patients with THPT who underwent PTx at a single tertiary center. Patients were divided into 2 groups: those without ioPTH monitoring (n=98) and those with ioPTH monitoring (n=13). Surgical procedures included less than subtotal, subtotal, or total PTx with autotransplantation. Surgical failure was defined as persistent hypercalcemia (serum calcium ≥10.3 mg/dL and intact parathyroid hormone [PTH] >65 pg/mL) on postoperative day 1 (POD1) or at ≥6 months postoperatively. Results: The ioPTH group demonstrated a significantly lower mean PTH level on POD1 (21±15.3 pg/mL vs. 39±39 pg/mL; P=0.006). Although not statistically significant, the ioPTH group showed a higher biochemical cure rate at 3 months (53.8% vs. 30.6%) and no cases of persistent hyperparathyroidism, compared to 15.3% in the non-ioPTH group.Despite adequate intraoperative PTH reduction, some patients in both groups exhibited isolated PTH elevation without hypercalcemia. Conclusion Although ioPTH monitoring did not significantly reduce the surgical failure rate in PTx for THPT, the use of ioPTH may meaningfully improve surgical completeness and reduce the risk of persistent or recurrent hyperparathyroidism, suggesting its substantial potential value as an intraoperative.

Objective: Thoracic pedicle screw fixation is technically demanding because of the natural variability in pedicle anatomy, a challenge that is further exacerbated in patients with spinal tumors who often have compromised pedicles. The L-point entry, juxtapedicular, and endplate-parallel trajectory (L-JET) technique was developed to provide a uniform entry point, a predictable screw trajectory, and the capacity to accommodate larger-diameter screws at levels T3–10. This study aimed to evaluate the safety and feasibility of the L-JET technique in comparison with the conventional transpedicular method. Methods: A comparative analysis of consecutively collected data was performed to evaluate outcomes associated with the L-JET technique in patients undergoing surgery for thoracic extradural spinal tumors. The L-point was defined as the intersection of a vertical line along the lateral margin of the facet joint and a horizontal line along the upper edge of the transverse process. The screw trajectory was planned with 30° of medial convergence in the axial plane, creating a juxtapedicular path, and a straightforward trajectory in the sagittal plane. Primary outcome measures included screw diameter, screw length, cortical breach rate, and the need for revision surgery, as assessed using computed tomography scans and medical records. Results: A total of 108 screws were placed in 22 patients using the L-JET technique, while 98 screws were placed in 18 patients using the conventional technique. The L-JET group used significantly larger-diameter screws (6.06±0.65 mm) than the conventional group (5.74±0.80 mm, p=0.02), with no significant difference observed in screw length between groups. Medial cortical breach occurred in one screw in each group, and no supra- or infrapedicular breaches were identified. No screw-related neurovascular complications or revision surgeries occurred in either group. Conclusion The L-JET technique enables consistent screw placement with larger-diameter screws, even in compromised pedicles associated with thoracic spinal tumors, without increasing the risk of complications or the need for revision surgery.