Background: and Purpose This study evaluated the diagnostic utility of an anti-signal-recognition particle 54 (anti-SRP54) antibody-based enzyme-linked immunosorbent assay (ELISA) as well as the clinical, serological, and pathological characteristics of patients with SRP immune-mediated necrotizing myopathy (IMNM). Methods: We evaluated 87 patients with idiopathic inflammatory myopathy and 107 healthy participants between January 2002 and December 2023. The sensitivity and specificity of the ELISA for anti-SRP54 antibodies were assessed, and the clinical profiles of patients with antiSRP54 antibodies were determined. Results: The ELISA for anti-SRP54 antibodies had a sensitivity and specificity of 88% and 99%, respectively, along with a test–retest reliability of 0.92 (p<0.001). The 32 patients diagnosed with anti-SRP IMNM using a line-blot immunoassay included 28 (88%) who tested positive for anti-SRP54 antibodies using the ELISA, comprising 12 (43%) males and 16 (57%) females whose median ages at symptom onset and diagnosis were 43.0 years and 43.5 years, respectively. Symptoms included proximal muscle weakness in all 28 (100%) patients, neck weakness in 9 (32%), myalgia in 15 (54%), dysphagia in 5 (18%), dyspnea in 4 (14%), dysarthria in 2 (7%), interstitial lung disease in 2 (7%), and myocarditis in 2 (7%). The median serum creatine kinase (CK) level was 7,261 U/L (interquartile range: 5,086–10,007 U/L), and the median anti-SRP54 antibody level was 2.0 U/mL (interquartile range: 1.0–5.6 U/mL). The serum CK level was significantly higher in patients with coexisting anti-Ro-52 antibodies. Conclusions This study has confirmed the reliability of the ELISA for anti-SRP54 antibodies and provided insights into the clinical, serological, and pathological characteristics of South Korean patients with anti-SRP IMNM.

Background: and Purpose This study evaluated the diagnostic utility of an anti-signal-recognition particle 54 (anti-SRP54) antibody-based enzyme-linked immunosorbent assay (ELISA) as well as the clinical, serological, and pathological characteristics of patients with SRP immune-mediated necrotizing myopathy (IMNM). Methods: We evaluated 87 patients with idiopathic inflammatory myopathy and 107 healthy participants between January 2002 and December 2023. The sensitivity and specificity of the ELISA for anti-SRP54 antibodies were assessed, and the clinical profiles of patients with antiSRP54 antibodies were determined. Results: The ELISA for anti-SRP54 antibodies had a sensitivity and specificity of 88% and 99%, respectively, along with a test–retest reliability of 0.92 (p<0.001). The 32 patients diagnosed with anti-SRP IMNM using a line-blot immunoassay included 28 (88%) who tested positive for anti-SRP54 antibodies using the ELISA, comprising 12 (43%) males and 16 (57%) females whose median ages at symptom onset and diagnosis were 43.0 years and 43.5 years, respectively. Symptoms included proximal muscle weakness in all 28 (100%) patients, neck weakness in 9 (32%), myalgia in 15 (54%), dysphagia in 5 (18%), dyspnea in 4 (14%), dysarthria in 2 (7%), interstitial lung disease in 2 (7%), and myocarditis in 2 (7%). The median serum creatine kinase (CK) level was 7,261 U/L (interquartile range: 5,086–10,007 U/L), and the median anti-SRP54 antibody level was 2.0 U/mL (interquartile range: 1.0–5.6 U/mL). The serum CK level was significantly higher in patients with coexisting anti-Ro-52 antibodies. Conclusions This study has confirmed the reliability of the ELISA for anti-SRP54 antibodies and provided insights into the clinical, serological, and pathological characteristics of South Korean patients with anti-SRP IMNM.

Background: and Purpose This study evaluated the diagnostic utility of an anti-signal-recognition particle 54 (anti-SRP54) antibody-based enzyme-linked immunosorbent assay (ELISA) as well as the clinical, serological, and pathological characteristics of patients with SRP immune-mediated necrotizing myopathy (IMNM). Methods: We evaluated 87 patients with idiopathic inflammatory myopathy and 107 healthy participants between January 2002 and December 2023. The sensitivity and specificity of the ELISA for anti-SRP54 antibodies were assessed, and the clinical profiles of patients with antiSRP54 antibodies were determined. Results: The ELISA for anti-SRP54 antibodies had a sensitivity and specificity of 88% and 99%, respectively, along with a test–retest reliability of 0.92 (p<0.001). The 32 patients diagnosed with anti-SRP IMNM using a line-blot immunoassay included 28 (88%) who tested positive for anti-SRP54 antibodies using the ELISA, comprising 12 (43%) males and 16 (57%) females whose median ages at symptom onset and diagnosis were 43.0 years and 43.5 years, respectively. Symptoms included proximal muscle weakness in all 28 (100%) patients, neck weakness in 9 (32%), myalgia in 15 (54%), dysphagia in 5 (18%), dyspnea in 4 (14%), dysarthria in 2 (7%), interstitial lung disease in 2 (7%), and myocarditis in 2 (7%). The median serum creatine kinase (CK) level was 7,261 U/L (interquartile range: 5,086–10,007 U/L), and the median anti-SRP54 antibody level was 2.0 U/mL (interquartile range: 1.0–5.6 U/mL). The serum CK level was significantly higher in patients with coexisting anti-Ro-52 antibodies. Conclusions This study has confirmed the reliability of the ELISA for anti-SRP54 antibodies and provided insights into the clinical, serological, and pathological characteristics of South Korean patients with anti-SRP IMNM.

Background: During the coronavirus disease 2019 (COVID-19) pandemic, patients with myasthenia gravis (MG) were more susceptible to poor outcomes owing to respiratory muscle weakness and immunotherapy. Several studies conducted in the early stages of the COVID-19 pandemic reported higher mortality in patients with MG compared to the general population. This study aimed to investigate the clinical course and prognosis of COVID-19 in patients with MG and to compare these parameters between vaccinated and unvaccinated patients in South Korea. Methods: This multicenter, retrospective study, which was conducted at 14 tertiary hospitals in South Korea, reviewed the medical records and identified MG patients who contracted COVID-19 between February 2022 and April 2022. The demographic and clinical characteristics associated with MG and vaccination status were collected. The clinical outcomes of COVID-19 infection and MG were investigated and compared between the vaccinated and unvaccinated patients. Results: Ninety-two patients with MG contracted COVID-19 during the study. Nine (9.8%) patients required hospitalization, 4 (4.3%) of whom were admitted to the intensive care unit. Seventy-five of 92 patients were vaccinated before contracting COVID-19 infection, and 17 were not. During the COVID-19 infection, 6 of 17 (35.3%) unvaccinated patients were hospitalized, whereas 3 of 75 (4.0%) vaccinated patients were hospitalized (P < 0.001). The frequencies of ICU admission and mechanical ventilation were significantly lower in the vaccinated patients than in the unvaccinated patients (P = 0.019 and P = 0.032, respectively). The rate of MG deterioration was significantly lower in the vaccinated patients than in the unvaccinated patients (P = 0.041). Logistic regression after weighting revealed that the risk of hospitalization and MG deterioration after COVID-19 infection was significantly lower in the vaccinated patients than in the unvaccinated patients. Conclusion This study suggests that the clinical course and prognosis of patients with MG who contracted COVID-19 during the dominance of the omicron variant of COVID-19 may be milder than those at the early phase of the COVID-19 pandemic when vaccination was unavailable. Vaccination may reduce the morbidity of COVID-19 in patients with MG and effectively prevent MG deterioration induced by COVID-19 infection.

Background: As the coronavirus disease (COVID-19) pandemic continues, wearing masks has become a daily routine. As the mask-wearing time increased, the mask-covered skin was more likely to be influenced. Objective: This study aimed to identify face mask-wearing behaviors and their effects on patients with facial skin diseases. Methods: Patients with facial skin disease were surveyed at two institutions. The patterns of mask use, mask-associated skin problems, and the Dermatology Life Quality Index (DLQI) were investigated. Results: A total of 174 participants were enrolled and the mean age was 42.2 years. Rosacea (35.6%) was the most common condition, followed by acne (25.3%) and contact dermatitis (17.2%). Ninety-four subjects (54.0%) reported that they wore masks for less than 6 hours a day, and 96 subjects (55.2%) wore masks to fit tightly against the face. Regarding the mask type, KF-99, 94, and 80 (62.6%) were the most common. Nearly three-quarters (n=128, 73.6%) of patients complained of mask-associated skin problems. Pimples were the most common symptom (59.4%), and the cheek was the most commonly affected area (67.2%). The mean DLQI score was 9.90. Conclusion We investigated the current patterns of mask use in patients with facial skin diseases. Moreover, it is necessary to recognize newly encountered relationships and seek strategies for relevant patients.

Background: Alopecia areata (AA) is common non-scarring hair loss disease. Sleep distrubance has been regarded as a triggering or aggravating factor for AA. However, objective evaluation of sleep disturbance and its clinical effect on AA has not been clearly demonstrated. Objective: This study investigated objective sleep evaluation tool for AA patients and their clinical correlation. Methods: Patients presenting with new-onset AA or recurrences of pre-existing AA were included, and those who reported sleep disturbance in the preliminary survey were designated as the sleep disturbance group (SD group). Sleep quality was investigated for them using three self-administered questionnaires: Pittsburgh Sleep Quality Index (PSQI), Insomnia Severity Index (ISI), and Epworth Sleep Scale (ESS). Demographic information and clinical features of AA were analyzed according to sleep quality. Results: A total of 400 participants were enrolled, and 53 were categorized into the SD group. The incidence of stressful events was significantly higher in the SD group (54.7%) than in the non-SD group (25.1%) (p<0.001). Based on the PSQI, 77.3% of participants were objective poor sleepers (score of 5 or more), and they showed a significantly higher incidence of stressful events compared to good sleepers (p=0.019). The proportion of poor sleepers was significantly lower in patients with mild AA (S1) than in those with moderate to severe AA (S2~S5) (p=0.045). Conclusion This study demonstrated a positive correlation among stress, SD, and AA. The degree of SD was objectively represented by the PSQI score, showing different scores according to AA severity.

After anaplastic large-cell lymphoma (ALCL) was first described by Stain in 1985, there have been several histological variants of ALCL reported. There are classified histological subtypes of ALCL, such as lymphohistiocytic, small cell, Hodgkin-like, composite pattern, and other less common variants including neutrophil-rich ALCL. A 63-year-old male patient presented with erythematous exophytic mass on the left lower leg. In the past, his condition had been diagnosed as abdominal primary cutaneous ALCL (pcALCL), which recurred as systemic ALCL (sALCL) in the left bronchus. After treatment, he achieved complete remission. Histopathologic examination showed large-sized pleomorphic, anaplastic mitotic tumor cells, several neutrophils, and a few lymphocytes. Neutrophil-rich ALCL is a rare histological variant of ALCL. It is characterized by the presence of CD30-positive anaplastic tumor cells with numerous neutrophil infiltrations. Neutrophil-rich ALCL responds well to treatment but tends to recur. There were four cases reported to have recurrent neutrophilrich ALCL. All cases were diagnosed with neutrophil-rich pcALCL prior to recurrence.Three cases had local recurrence, and only one case relapsed as sALCL. Herein, we present the first case of neutrophil-rich ALCL recurring as sALCL twice.

Background: With the introduction of Xpert MTB/RIF assay (Xpert), its incorporation into tuberculosis (TB) diagnostic algorithm has become an important issue. The aim of this study was to evaluate the performance of the Xpert assay in comparison with a commercial polymerase chain reaction (PCR) assay. Methods: Medical records of patients having results of both Xpert and AdvanSure TB/NTM real-time PCR (AdvanSure) assays using the same bronchial washing specimens were retrospectively reviewed. Results: Of the 1,297 patients included in this study, 205 (15.8%) were diagnosed with pulmonary TB. Using mycobacterial culture as the reference method, sensitivity of the Xpert assay using smear-positive specimens was 97.5%, which was comparable to that of the AdvanSure assay (96.3%, p=0.193). However, the sensitivity of the Xpert assay using smear-negative specimens was 70.6%, which was significantly higher than that of the AdvanSure assay (52.9%, p=0.018). Usng phenotypic drug susceptibility testing as the reference method, sensitivity and specificity for detecting rifampicin resistance were 100% and 99.1%, respectively. Moreover, a median turnaround time of the Xpert assay was 1 day, which was significantly shorter than 3 days of the AdvanSure assay (p<0.001). Conclusion In comparison with the AdvanSure assay, the Xpert assay had a higher sensitivity using smear-negative specimens, a shorter turnaround time, and could reliably predict rifampin resistance. Therefore, the Xpert assay might be preferentially recommended over TB-PCR in Korean TB diagnostic algorithm.

Background: Biologics-experienced patients are more likely to show a lower response to biologics than that of biologic-naïve patients. However, no consensus on switching biologics exists. Objective: We aimed to investigate the switching patterns and efficacy of the switched biologics in patients with moderate-to-severe psoriasis in actual clinical practice. Methods: This multicenter retrospective study included 37 patients with a history of switching biologics. We analyzed the reasons for switching, the switching patterns, and psoriasis area and severity index (PASI) 75 response rates after switching biologics. We also analyzed the factors affecting the PASI75 response rate to the second biologic. Results: The reasons for switching baseline biologics were primary failure in five patients (13.5%), secondary failure in 28 patients (75.7%), and adverse events in four patients (10.8%). The second biologics prescribed mostly include interleukin (IL)-23 inhibitor in twenty-four patients (64.9%), IL-17 inhibitor in eight patients (21.6%), tumor necrosis factor-α inhibitor in three patients (8.1%), and IL-12/23 inhibitor in two patients (5.4%). A total of 46% of patients (17/37) switched biologics from IL-12/23 inhibitors to IL-23 inhibitors. The PASI75 response rates at the primary endpoint of the second and third biologics were 89.2% and 88.8%, respectively. Our study found that female sex and obesity were associated with the primary failure of the second biologic. Conclusion Secondary failure was the most common reason for switching baseline biologics. Korean dermatologists prefer different classes of biologics while switching. The PASI75 response rates at the primary endpoints of the second and third biologics were relatively satisfactory.