Autoimmunity against melanoma differentiation-associated gene 5 induces interstitial lung disease mimicking dermatomyositis in mice.

Anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive dermatomyositis (DM) is characterized by amyopathic DM with interstitial lung disease (ILD). Patients with anti-MDA5 antibody-associated ILD frequently develop rapidly progression and present high mortality rate in the acute phase. Here, we established a murine model of ILD mediated by autoimmunity against MDA5. Mice immunized with recombinant murine MDA5 whole protein, accompanied with complete Freund's adjuvant once a week for four times, developed MDA5-reactive T cells and anti-MDA5 antibodies. After acute lung injury induced by intranasal administration of polyinosinic-polycytidylic acid [poly (I:C)] mimicking viral infection, the MDA5-immunized mice developed fibrotic ILD representing prolonged respiratory inflammation accompanied by fibrotic changes 2 wk after poly (I:C)-administration, while the control mice had quickly and completely recovered from the respiratory inflammation. Treatment with anti-CD4 depleting antibody, but not anti-CD8 depleting antibody, suppressed the severity of MDA5-induced fibrotic ILD. Upregulation of interleukin (IL)-6 mRNA, which was temporarily observed in poly (I:C)-treated mice, was prolonged in MDA5-immunized mice. Treatment with anti-IL-6 receptor antibody ameliorated the MDA5-induced fibrotic ILD. These results suggested that autoimmunity against MDA5 exacerbates toll-like receptor 3-mediated acute lung injury, and prolongs inflammation resulting in the development of fibrotic ILD. IL-6 may play a key role initiating ILD in this model.

Pityriasis Rosea With Multiple Herald Patches Resulting in a V-shaped Pattern and a Christmas Tree Distribution.

Pityriasis rosea (PR), a benign and self-limiting skin disorder, typically manifests as a single initial lesion known as the herald patch. The herald patch is commonly followed by the development of secondary erythematous papules and plaques, aligning with Langer's lines to form a specific distribution pattern, resembling a Christmas tree on the back and a V-shaped pattern on the upper chest. Therefore, diagnosing PR may not be difficult based on its typical clinical presentation. In contrast, cases of atypical PR presentation have been reported, encompassing several differential diagnoses. Here, we present a case with multiple herald patches that needed differentiation from ringworm, syphilis, and erythema annular centrifugum. Subsequently, our case was diagnosed with PR, as the patches formed a V-shaped pattern and a Christmas-tree distribution.

Baricitinib Improvement Across Regions in Atopic Dermatitis Patients with Baseline Body Surface Area up to 40% and Severe Itch.

INTRODUCTION: Patients with moderate-to-severe atopic dermatitis (AD) who are most likely to respond to the Janus kinase (JAK) 1/2 inhibitor baricitinib (BARI) are known to have an impacted body surface area (BSA) ≤ 40% and severe itch (numerical rating scale [NRS] ≥ 7], collectively termed 'BARI itch-dominant' patients. Our objective is to build on our previous work by providing a body region-specific, clinical characterization of the BARI itch-dominant patient at baseline and their response to BARI 4 mg. METHODS: BREEZE-AD7 was a phase 3 trial in adults with moderate-to-severe AD receiving placebo or 2 mg or 4 mg BARI in combination with topical corticosteroids. Assessing only data from BARI itch-dominant patients, we summarized the baseline characteristics and conducted body region-specific analyses on Eczema Area and Severity Index (EASI) data in order to report the response to placebo versus BARI 4 mg within this patient subtype. RESULTS: BARI 4 mg was highly effective across all body regions; at week 16, 75% improvement was seen in EASI scores (EASI75), and response rates with BARI 4 mg (head/neck, 58.3%; trunk, 69.2%; upper extremities, 61.5%; lower extremities, 87.5%) all exceeded those with placebo (head/neck: 37.5%; trunk, 40.6%; upper extremities, 18.8%; lower extremities, 40.6%) as well as the overall EASI75 rates of the intent-to-treat (ITT) population (BARI, 48.0%; placebo, 23.0%). At baseline, most BARI itch-dominant patients presented with involvement of all regions (mean regional BSA 22.7%-40.3%), highest in the head and neck, mean EASI region scores of 15.7-24.0, and considerably severe sign ratings (mean EASI sub-scores: 1.4-2.3, out of 3), especially for erythema. CONCLUSION: BARI itch-dominant patients exhibit AD involvement across all body regions and considerable sign severity, especially erythema. In response to BARI 4 mg, EASI quickly improved across regions, substantially more so in this subtype than in the ITT population.

Possible correlation between serum interleukin-8 levels and the activity of myositis in anti-NXP2 antibody-positive dermatomyositis.

Anti-nuclear matrix protein 2 (NXP2) antibody-positive dermatomyositis (DM) is characterized by extensive and severe myositis. In this study, we evaluated which cytokines/chemokines involved with the activity of the myositis. We performed quantitative immunoassays using the MILLIPLEX® Multiplex Assays Using Luminex to evaluate serum levels of interferon-γ, interleukin (IL)-1ß, IL-6, IL-8, IL-12p40, and tumor necrosis factor-α in samples collected over time from a 9-year-old female with anti-NXP2 antibody-positive DM. In our case, the serum level of IL-8 was elevated when the myositis worsened, and decreased in accordance with the improvement of myositis, suggesting that the serum IL-8 levels were correlated with the myositis activity. Serum levels of IL-8 in samples from five patients with anti-NXP2 antibody-positive DM and five patients with anti-transcriptional intermediary factor 1γ (TIF1γ) antibody-positive DM without both interstitial lung disease (ILD) and malignancy before starting treatments, along with five healthy controls, were also evaluate by an enzyme-linked immunosorbent assay. Serum IL-8 levels were significantly elevated in anti-NXP2 or anti-TIF1γ antibody-positive DM patients with myositis but not ILD, than healthy controls. It was suggested that serum levels of IL-8 correlate with the activity of myositis in DM including anti-NXP2 antibody-positive DM.

Development of Conformationally Restricted Negamycin Derivatives for Potent Readthrough Activity.

(+)-Negamycin, which is a dipeptide-like antibiotic containing a hydrazide structure, exhibits readthrough activity, resulting in the restoration of dystrophin in the mdx mouse model of Duchenne muscular dystrophy (DMD). In our previous structure-activity relationship study of negamycin, we found that its natural analogue 3-epi-deoxynegamycin (TCP-107), without antimicrobial activity, showed a higher readthrough activity than negamycin. In this study, we designed and synthesized cyclopropane-based conformationally restricted derivatives of TCP-107 and evaluated their readthrough activity in the cell-based reporter assay against a TGA-type mutation derived from DMD. As a result, a down-cis isomer, TCP-304, showed significant readthrough activity among the four isomers. Moreover, TCP-306, a derivative acylated by l-α-aminoundecanoic acid, possessed approximately 3 times higher activity than TCP-304. These down-cis derivatives showed dose-dependent readthrough activity and were effective for not only TGA but also TAG mutations. These results suggest that the conformational restriction of negamycin derivatives by the introduction of the cyclopropane ring is effective for an exhibition of potent readthrough activity.