Background: Apolipoprotein A-I (ApoA-I), the major protein component of high-density lipoprotein, is increasingly recognized for its immunomodulatory roles beyond lipid transport, including antimicrobial and anti-inflammatory functions. Although ApoA-I can modulate immune cell activity, its effect on eosinophils remains poorly understood. Objective: This study aimed to determine whether ApoA-I could modulate human eosinophil activation and survival during fungal stimulation and to elucidate the underlying mechanisms. Methods: Human eosinophils were isolated and stimulated with Alternaria alternata or β-glucan in the presence or absence of recombinant ApoA-I. Eosinophil degranulation was assessed by measuring eosinophil-derived neurotoxin (EDN) release using an enzyme-linked immunosorbent assay. Surface CD11b expression and cell viability were evaluated using flow cytometry. Dose-response experiments and comparisons with apolipoprotein A-II (ApoA-II) and interleukin-5 (IL-5) were also conducted. Results: ApoA-I markedly increased EDN secretion and upregulated CD11b expression upon fungal stimulation. It also improved eosinophil viability, with effects comparable to those of IL-5. These responses were specific to ApoA-I, as ApoA-II did not elicit similar effects. Conclusion ApoA-I enhanced eosinophil activation and survival following fungal stimulation. These findings underscore the context-dependent immunomodulatory role of ApoA-I and its potential as a regulator of antifungal immunity.

Background: Omalizumab, a monoclonal antibody targeting immunoglobulin E (IgE), is approved for adults and adolescents (12 years or older) with chronic spontaneous urticaria (CSU) that does not respond to high-dose antihistamines. In Korea, there is limited research on predictive biomarkers for omalizumab response in CSU patients. Objective: This retrospective, single-institution study aimed to identify clinical parameters predicting omalizumab response in Korean CSU patients. Methods: We analyzed records of CSU patients aged 19 or older starting omalizumab between January 2017 and October 2019. Omalizumab efficacy was assessed using the Urticaria Activity Score summed over 7 days (UAS7), categorized as well-controlled, mild, moderate, or severe.Ninety CSU patients participated in this study. Results: Among these, improvements in UAS7 categories from baseline to 12 weeks of treatment were observed in 78 patients, while 12 patients showed no significant efficacy. The present study identified potential biomarkers that could predict a patient’s response to omalizumab, including disease duration and total serum IgE levels (p=0.022, p=0.046). Notably, a significant correlation was observed between higher detection rates in multiple antigen simultaneous test (MAST) food testing and lower treatment responses (p=0.033). Conclusion Shorter disease duration of CSU and elevated initial serum total IgE level may serve as potential predictive biomarkers for the responsiveness to omalizumab. Furthermore, a higher MAST food detection rate seemed to correlate with a less favorable treatment response, suggesting patients with a high MAST food detection rate might benefit from a food evaluation in addition to omalizumab treatment.

Porocarcinoma is a malignancy of the eccrine sweat gland. It may arise de novo or develop from pre-existing poroma and hidroacanthoma simplex. A 56-year-old woman was presented with a pinkish plaque on her left posterior thigh. She was diagnosed with hidroacanthoma simplex 6 years ago, and the same lesion had changed in size and shape. Histopathology revealed intraepidermal proliferation of small-sized basaloid cells, continuing to the proliferation of large polygonal tumor cells. This malignant transformation was consistent with the change in p53 expression pattern. The patient underwent wide excision with clear resection margin, and no evidence of recurrence was noted. We highlight this case in that the transition from hidroacanthoma simplex to porocarcinoma in situ was confirmed in the same tissue, as demonstrated by immunohistochemical staining.