Immunoglobulin A nephropathy (IgAN) is a major cause of end-stage kidney disease (ESKD). The International IgA Nephropathy Prediction Tool (IIgAN-PT) predicts IgAN prognosis, but improvement in the prediction performance using machine learning (ML)-based methods is needed. Methods: We analyzed 4,425 biopsy-confirmed patients with IgAN and ≥6 months of follow-up from nine tertiary university hospitals in Korea. The study population was divided into development and validation cohorts. Using the collected 87 clinicodemographic and pathological variables, ML-based prediction models for ESKD or estimated glomerular filtration rate decline (50% reduction or <15 mL/min/1.73 m2 ) were constructed: 1) the conventional CatBoost model, 2) the optimized CatBoost model with Cox proportional hazards, 3) the deep Cox proportional hazards model, and 4) the deep Cox mixture model. The area under the curve (AUC) and calibration plots were used to investigate the discriminative and calibration performance of the models, which were then compared with those of the IIgAN-PT full model. Results: The full model showed excellent performance (AUC [95% confidence interval] for 5-year outcome, 0.896 [0.853–0.940]), with acceptable calibration results. The ML-based models showed good performance in predicting adverse kidney outcomes and revealed acceptable discrimination performance in the external validation (AUC [95% confidence interval] for the 5-year outcome: 1) 0.829 [0.791–0.866]; 2) 0.847 [0.804–0.890]; 3) 0.823 [0.784–0.862]; and 4) 0.832 [0.794–0.870]), although the models showed underestimation in calibration analysis of the external validation cohort. With the validation data, the overall performance of the IIgAN-PT was non-inferior to that of the ML-based model. Conclusions: Our ML-based models showed good performance in predicting adverse kidney outcomes in patients with IgAN but they did not outperform the IIgAN-PT.

Background: Dipeptidyl peptidase-4 (DPP4) inhibitors are frequently prescribed for patients with type 2 diabetes; however, their cost can pose a significant barrier for those with impaired kidney function. This study aimed to estimate the economic benefits of substituting non-renal dose-adjusted (NRDA) DPP4 inhibitors with renal dose-adjusted (RDA) DPP4 inhibitors in patients with both impaired kidney function and type 2 diabetes. Methods: This retrospective cohort study was conducted from January 1, 2012 to December 31, 2018, using data obtained from common data models of five medical centers in Korea. Model 1 applied the prescription pattern of participants with preserved kidney function to those with impaired kidney function. In contrast, model 2 replaced all NRDA DPP4 inhibitors with RDA DPP4 inhibitors, adjusting the doses of RDA DPP4 inhibitors based on individual kidney function. The primary outcome was the cost difference between the two models. Results: In total, 67,964,996 prescription records were analyzed. NRDA DPP4 inhibitors were more frequently prescribed to patients with impaired kidney function than in those with preserved kidney function (25.7%, 51.3%, 64.3%, and 71.6% in patients with estimated glomerular filtration rates [eGFRs] of ≥60, <60, <45, and <30 mL/min/1.73 m2, respectively). When model 1 was applied, the cost savings per year were 7.6% for eGFR <60 mL/min/1.73 m2 and 30.4% for eGFR <30 mL/min/1.73 m2. According to model 2, 15.4% to 51.2% per year could be saved depending on kidney impairment severity. Conclusion Adjusting the doses of RDA DPP4 inhibitors based on individual kidney function could alleviate the economic burden associated with medical expenses.

Background: Chronic cough is a common symptom encountered by healthcare practitioners.The global prevalence of chronic cough is 9.6%, with a female predominance. The aim of our study is to reveal the sex differences in prevalence and severity of chronic cough in South Korea, stratified by age and etiology. Methods: This study included adult patients with chronic cough who were recruited from 19 respiratory centers in South Korea. Patients completed the cough numeric rating scale (NRS) and COugh Assessment Test (COAT) questionnaire to assess the severity and multidimensional impact of cough. Results: Among the 625 patients, 419 (67.0%) were females, with a male-to-female ratio of 1:2.03. The mean age was 49.4 years, and the median duration of cough was 12 weeks. The mean NRS and COAT scores were 5.5 ± 1.8 and 9.5 ± 3.6, respectively. Female patients were older (45.3 ± 15.4 vs. 51.6 ± 15.2, P < 0.001) and more likely to have asthma/cough variant asthma (CVA) (26.7% vs. 40.8%, P = 0.001) than male patients. There was no difference in the duration or severity of cough between sexes, regardless of the cause. The male-tofemale ratio was lower for upper airway cough syndrome (UACS), asthma/CVA, and gastroesophageal reflux disease (GERD), but not for eosinophilic bronchitis (EB) or unexplained cough. The mean age of female patients was higher in UACS and asthma/CVA, but not in EB, GERD, or unexplained cough. The majority (24.2%) fell within the age category of 50s. The proportion of females with cough increased with age, with a significant rise in the 50s, 60s, and 70–89 age groups. The severity of cough decreased in the 50s, 60s, and 70–89 age groups, with no significant sex differences within the same age group. Conclusion The sex disparities in prevalence and severity of cough varied significantly depending on the age category and etiology. Understanding the specific sex-based difference could enhance comprehension of cough-related pathophysiology and treatment strategies.

Background: Acromegaly leads to various skeletal complications, and fragility fractures are emerging as a new concern in patients with acromegaly. Therefore, this study investigated the risk of fractures in Korean patients with acromegaly. Methods: We used the Korean nationwide claims database from 2009 to 2019. A total of 931 patients with acromegaly who had never used an osteoporosis drug before and were treated with surgery alone were selected as study participants, and a 1:29 ratio of 26,999 age- and sex-matched osteoporosis drug-naïve controls without acromegaly were randomly selected from the database. Results: The mean age was 46.2 years, and 50.0% were male. During a median follow-up of 54.1 months, there was no difference in the risks of all, vertebral, and non-vertebral fractures between the acromegaly and control groups. However, hip fracture risk was significantly higher (hazard ratio [HR], 2.73; 95% confidence interval [CI], 1.32 to 5.65), and non-hip and non-vertebral fractures risk was significantly lower (HR, 0.40; 95% CI, 0.17 to 0.98) in patients with acromegaly than in controls; these results remained robust even after adjustment for socioeconomic status and baseline comorbidities. Age, type 2 diabetes mellitus, cardio-cerebrovascular disease, fracture history, recent use of acid-suppressant medication, psychotropic medication, and opioids were risk factors for all fractures in patients with acromegaly (all P<0.05). Conclusion Compared with controls, patients surgically treated for acromegaly had a higher risk of hip fractures. The risk factors for fracture in patients with acromegaly were consistent with widely accepted risk factors in the general population.

Pancreatitis, panniculitis, and polyarthritis (PPP) syndrome is a rare but critical disease with a high mortality rate. The diagnostic dilemma of PPP syndrome is the fact that symptoms occur unexpectedly. A 48-year-old man presented with fever and painful swelling of the left foot that was initially mistaken for cellulitis and gouty arthritis. The diagnosis of PPP syndrome was made based on the abdominal CT findings and elevated pancreatic enzyme levels, lobular panniculitis with ghost cells on a skin biopsy, and polyarthritis on a bone scan. The pancreatitis and panniculitis disappeared spontaneously over time, but the polyarthritis followed its own course despite the use of anti-inflammatory agents. In addition to this case, 30 cases of PPP syndrome in the English literature were reviewed. Most of the patients had initial symptoms other than abdominal pain, leading to misdiagnosis. About one-third of them were finally diagnosed with a pancreatic tumor, of which pancreatic acinar cell carcinoma was the most dominant. They showed a mortality rate of 32.3%, associated mainly with the pancreatic malignancy. Therefore, PPP syndrome should be considered when cutaneous or osteoarticular manifestations occur in patients with pancreatitis. Active investigation and continued observations are needed for patients suspected of PPP syndrome.
Abdominal Pain ; Anti-Inflammatory Agents ; Arthritis ; Arthritis, Gouty ; Biopsy ; Carcinoma, Acinar Cell ; Cellulitis ; Diagnosis ; Diagnostic Errors ; Fever ; Foot ; Humans ; Middle Aged ; Mortality ; Pancreatic Neoplasms ; Pancreatitis ; Panniculitis ; Skin ; Tomography, X-Ray Computed

The prevalence of small bowel cancer is relatively low. The abdominal pain that patients with small bowel cancer present as a symptom is non-specific and often interpreted as a normal finding on radiographic studies. To prevent delayed diagnosis of small bowel cancer, practitioners must maintain a certain level of suspicion. We report a case of delayed diagnosis of jejunal cancer as it was misdiagnosed as gastroparesis. A 69-year-old woman complained of recurrent nausea and vomiting. At the beginning of her hospitalization, we could not diagnose mechanical obstruction through esophagogastroduodenoscopy and abdominal computed tomography. A gastric emptying study revealed delayed gastric emptying. Although the patients received treatments, including administration of prokinetics and botulinum toxin injection, for gastroparesis, her symptoms aggravated. Subsequently, plain radiography of the abdomen revealed a double-bubble sign. Abdominal computed tomography was performed under the suspicion of small bowel obstruction; however, the diagnosis was not clear. Consequently, exploratory laparoscopy was performed. She underwent surgical management, including small bowel segmental resection and duodenojejunostomy, due to the jejunal mass with involvement of the stomach, pancreatic head, and mesentery of the transverse colon. The postoperative pathological results revealed a moderately differentiated adenocarcinoma of the jejunum.
Abdomen ; Abdominal Pain ; Adenocarcinoma ; Aged ; Botulinum Toxins ; Colon, Transverse ; Delayed Diagnosis ; Diagnosis ; Endoscopy, Digestive System ; Female ; Gastric Emptying ; Gastroparesis ; Head ; Hospitalization ; Humans ; Jejunal Neoplasms ; Jejunum ; Laparoscopy ; Mesentery ; Nausea ; Prevalence ; Radiography ; Stomach ; Vomiting

Pancreatitis, panniculitis, and polyarthritis (PPP) syndrome is a rare but critical disease with a high mortality rate. The diagnostic dilemma of PPP syndrome is the fact that symptoms occur unexpectedly. A 48-year-old man presented with fever and painful swelling of the left foot that was initially mistaken for cellulitis and gouty arthritis. The diagnosis of PPP syndrome was made based on the abdominal CT findings and elevated pancreatic enzyme levels, lobular panniculitis with ghost cells on a skin biopsy, and polyarthritis on a bone scan. The pancreatitis and panniculitis disappeared spontaneously over time, but the polyarthritis followed its own course despite the use of anti-inflammatory agents. In addition to this case, 30 cases of PPP syndrome in the English literature were reviewed. Most of the patients had initial symptoms other than abdominal pain, leading to misdiagnosis. About one-third of them were finally diagnosed with a pancreatic tumor, of which pancreatic acinar cell carcinoma was the most dominant. They showed a mortality rate of 32.3%, associated mainly with the pancreatic malignancy. Therefore, PPP syndrome should be considered when cutaneous or osteoarticular manifestations occur in patients with pancreatitis. Active investigation and continued observations are needed for patients suspected of PPP syndrome.
Abdominal Pain ; Anti-Inflammatory Agents ; Arthritis ; Arthritis, Gouty ; Biopsy ; Carcinoma, Acinar Cell ; Cellulitis ; Diagnosis ; Diagnostic Errors ; Fever ; Foot ; Humans ; Middle Aged ; Mortality ; Pancreatic Neoplasms ; Pancreatitis ; Panniculitis ; Skin ; Tomography, X-Ray Computed

PURPOSE: With the emergence of next-generation sequencing (NGS) technology, profiling a wide range of genomic alterations has become a possibility resulting in improved implementation of targeted cancer therapy. In Asian populations, the prevalence and spectrum of clinically actionable genetic alterations has not yet been determined because of a lack of studies examining high-throughput cancer genomic data. MATERIALS AND METHODS: To address this issue, 1,071 tumor samples were collected from five major cancer institutes in Korea and analyzed using targeted NGS at a centralized laboratory. Samples were either fresh frozen or formalin-fixed, paraffin embedded (FFPE) and the quality and yield of extracted genomic DNA was assessed. In order to estimate the effect of sample condition on the quality of sequencing results, tissue preparation method, specimen type (resected or biopsied) and tissue storage time were compared. RESULTS: We detected 7,360 non-synonymous point mutations, 1,164 small insertions and deletions, 3,173 copy number alterations, and 462 structural variants. Fifty-four percent of tumors had one or more clinically relevant genetic mutation. The distribution of actionable variants was variable among different genes. Fresh frozen tissues, surgically resected specimens, and recently obtained specimens generated superior sequencing results over FFPE tissues, biopsied specimens, and tissues with long storage duration. CONCLUSION: In order to overcome, challenges involved in bringing NGS testing into routine clinical use, a centralized laboratory model was designed that could improve the NGS workflows, provide appropriate turnaround times and control costs with goal of enabling precision medicine.
Academies and Institutes ; Asian Continental Ancestry Group ; DNA ; Humans ; Korea ; Methods ; Paraffin ; Point Mutation ; Precision Medicine ; Prevalence

BACKGROUND: Calcium pyrophosphate dihydrate deposition disease (CPDD) is a rare disease in the temporomandibular joint (TMJ) space. It forms a calcified crystal mass and induces a limitation of joint movement. CASE PRESENTATION: The calcified mass in our case was occupied in the left TMJ area and extended to the infratemporal and middle cranial fossa. For a complete excision of this mass, we performed a vertical ramus osteotomy and resected the mass around the mandibular condyle. The calcified mass in the infratemporal fossa was carefully excised, and the segmented mandible was anatomically repositioned. Scanning electronic microscopy (SEM)/energy-dispersive X-ray spectroscopy (EDS) microanalysis was performed to evaluate the calcified mass. The result of SEM/EDS showed that the crystal mass was completely composed of calcium pyrophosphate dihydrate. This result strongly suggested that the calcified mass was CPDD in the TMJ area. CONCLUSIONS: CPDD in the TMJ is a rare disease and is difficult to differentially diagnose from other neoplasms. A histological examination and quantitative microanalysis are required to confirm the diagnosis. In our patient, CPDD in the TMJ was successfully removed via the extracorporeal approach. SEM/EDS microanalysis was used for the differential diagnosis.
Calcium Pyrophosphate ; Calcium ; Chondrocalcinosis ; Cranial Fossa, Middle ; Diagnosis ; Diagnosis, Differential ; Humans ; Joints ; Mandible ; Mandibular Condyle ; Microscopy ; Osteotomy ; Rare Diseases ; Spectrum Analysis ; Temporomandibular Joint

OBJECTIVE: The objective of this study was to investigate changes in the posterior cranial fossa in patients with symptomatic Chiari malformation type I (CMI) compared to a control group. METHODS: We retrospectively reviewed clinical and radiological data from 12 symptomatic patients with CMI and 24 healthy control subjects. The structures of the brain and skull base were investigated using magnetic resonance imaging. RESULTS: The length of the clivus had significantly decreased in the CMI group than in the control group (p=0.000). The angle between the clivus and the McRae line (p<0.024), as the angle between the supraocciput and the McRae line (p<0.021), and the angle between the tentorium and a line connecting the internal occipital protuberance to the opisthion (p<0.009) were significantly larger in the CMI group than in the control group. The mean vertical length of the cerebellar hemisphere (p<0.003) and the mean length of the coronal and sagittal superoinferior aspects of the cerebellum (p<0.05) were longer in the CMI group than in the control group, while the mean length of the axial anteroposterior aspect of the cerebellum (p<0.001) was significantly shorter in the CMI group relative to control subjects. CONCLUSION: We elucidate the transformation of the posterior cranial fossa into the narrow funnel shape. The sufficient cephalocaudal extension of the craniectomy of the posterior cranial fossa has more decompression effect than other type extension of the craniectomy in CMI patients.
Arnold-Chiari Malformation ; Brain ; Cerebellum ; Congenital Abnormalities ; Cranial Fossa, Posterior* ; Decompression ; Decompressive Craniectomy ; Embryology ; Humans ; Magnetic Resonance Imaging ; Retrospective Studies ; Skull Base