Journal of Microbiology Immunology and Infection最新文献

Background: Healthcare workers (HCWs) have increased risks of active tuberculosis, yet there are limited reports of incidence and risk factors of latent tuberculosis infection (LTBI) among HCWs.

Methods: HCWs were enrolled from four medical centers in Taiwan. Quantiferon-TB Gold Plus Test (QFT-Plus) was performed initially and 9-12 months afterwards. The prevalence, incidence, and clinical factors associated with LTBI, and willingness to receive LTBI treatment were explored.

Results: Among 297 HCWs, the prevalence rate of LTBI was 10.8 %. The independent factors associated with prevalent LTBI were age >40 years old (aOR 3.52, 95 % CI 1.46-8.45), health professionals (aOR 3.99, 95 % CI 1.02-15.65), and working in intensive care units (ICUs) (aOR 4.06, 95 % CI 1.28-12.86). Having all three factors escalated the risk of prevalent LTBI (aOR 13.81, 95 % CI 3.16-60.37). Of 129 LTBI-free HCWs undergoing 2nd QFT-Plus, seven (5.4 %) had positive conversion, indicating incident LTBI, among which four had TB contacts without wearing N95 mask. Two had a TB2-TB1 value > 0.6 IU/ml. 40.6 % prevalent LTBI patients refused LTBI preventive therapy.

Conclusions: More advanced age, health professionals, and working in ICUs were independent factors associated with prevalent LTBI. Most healthcare workers with incident LTBI cases had TB contacts without wearing N95 masks.

Background: Type 1 diabetes mellitus (T1D) is an autoimmune disorder characterized by immune-mediated destruction of pancreatic β-cells, resulting in lifelong insulin dependence. Interleukin-17A (IL-17A), associated with T1D progression and complications, can mobilize and activate neutrophils to release lytic enzymes, reactive oxygen species, and cytokines, thereby promoting systemic inflammation and cell destruction; such neutrophil-driven responses have also been implicated in autoimmune diseases, including diabetes. This study aimed to compare the clinical characteristics and neutrophil stress of IL-17A-positive and -negative T1D patients.

Methods: 37 patients were enrolled between May 2023 and April 2024 at Department of Pediatric Endocrinology, Changhua Christian Children's Hospital. In addition to clinical characteristics, peripheral blood neutrophils were isolated to analyze antioxidant-related protein, autophagy, and respiratory bursts. Serum cytokine profiles were also assessed.

Results: 27 patients were IL-17A-positive. At disease onset, they were younger and had lower absolute neutrophil counts. Years later, they showed higher LDL, with HDL declining over time and TG trending upward. All participants were Vitamin D insufficiency, and IL-17A levels correlated positively with vitamin D levels. Neutrophils in the peripheral blood displayed reduced xCT, GPX4, and HO-1, increased LC3II/LC3I ratios with decreased p62, and greater ROS production upon stimulation. Serum IL-5 levels were significantly higher, with eotaxin trending higher.

Conclusion: IL-17A-positive T1D is associated with earlier onset. As the disease progresses, it leads to an increased risk of dyslipidemia and the development of type 2 inflammation. Furthermore, the neutrophils in these patients suggestive of ferroptosis, defining a distinct phenotype for potential targeted therapy.

Background: Since coronavirus disease 2019 (COVID-19) pandemic, its variants have challenged vaccine effectiveness and immunity, particularly among high-risk individuals. Assessment of the risk of severe COVID-19 in these populations is crucial for informed therapeutic decisions. We aim to correlate early quantitative SARS-CoV-2 spike antibody (S ab) levels in SARS-CoV-2 infections with the risk of severe COVID-19.

Methods: We conducted a retrospective cohort study of hospitalized patients with early-stage COVID-19 and S ab titers between April 2021 and June 2022. S ab titers were stratified into four categories: <500 units/milliliter (U/mL), 500 to <1500 U/mL, 1500 to <5000 U/mL and ≥5000 U/mL, and their effects on the risk of severe COVID-19 were analyzed. Severe COVID-19 was defined as the development of pneumonia requiring oxygen supplementation, intensive care unit (ICU) admission, or death.

Results: Among the 1665 patients with early-stage COVID-19, 61(3.66 %) developed severe COVID-19. S ab titers were significantly lower in patients who developed severe COVID-19; 72.13 % of these patients had titers below 500 U/mL, whereas 24.19 % of the patients in the non-severe group (P < 0.01) had titers below 500 U/mL during the Delta and Omicron periods. Patients with S ab titers ≥5000 U/mL had an adjusted odds ratio of 0.12 (95 % CI: 0.05-0.33, P < 0.01) for severe COVID-19 compared with those with titers <500 U/mL, independent of vaccination status, variant period, and comorbidities.

Conclusion: S ab titers less than 500 U/mL are associated with an increased risk of severe COVID-19. The quantitative S ab titer may serve as a practical surrogate for SARS-CoV-2 immunity.