Abstract
Context
Long COVID is an emerging syndrome affecting 50% to 70% of COVID-19 survivors that still lacks predicting factors.
Objective
Due to the extraskeletal effects of vitamin D, we ...retrospectively assessed the association between 25(OH) vitamin D levels and long COVID in COVID-19 survivors 6 months after hospitalization.
Methods
Long COVID was defined according to NICE guidelines. Fifty long COVID and 50 non–long-COVID subjects matched on a 1:1 basis were enrolled from an outpatient clinic post-COVID cohort seen from August to November 2020. Therapies/comorbidities affecting calcium/vitamin D/bone metabolism, and/or admission to the intensive care unit during hospitalization were exclusion criteria. 25(OH) Vitamin D was measured at hospital admission and 6 months after discharge.
Results
We observed lower 25(OH) vitamin D levels, evaluated at follow-up, in subjects with long COVID than those without (20.1 vs 23.2 ng/mL, P = .03). Regarding the affected health areas evaluated in the entire cohort, we observed lower 25(OH) vitamin D levels in those with neurocognitive symptoms at follow-up (n = 7) than those without (n = 93) (14.6 vs 20.6 ng/mL, P = .042). In patients presenting vitamin D deficiency (<20 ng/mL), both at admission and at follow-up (n = 42), those affected by long COVID (n = 22) presented lower 25(OH) vitamin D levels at follow-up than those not affected (n = 20) (12.7 vs 15.2 ng/mL, P = .041). In multiple regression analyses, lower 25(OH) vitamin D levels at follow-up were the only variable significantly associated with long COVID in our cohort (P = .008, OR 1.09, CI 1.01-1.16).
Conclusion
COVID-19 survivors with long COVID have lower 25(OH) vitamin D levels than matched patients without long COVID. Our data suggest that vitamin D levels should be evaluated in COVID-19 patients after hospital discharge. The role of vitamin D supplementation as a preventive strategy of COVID-19 sequelae should be tested in randomized controlled trials.
Summary
A single protein, HMGB1, directs the triggering of inflammation, innate and adaptive immune responses, and tissue healing after damage. HMGB1 is the best characterized damage‐associated ...molecular pattern (DAMP), proteins that are normally inside the cell but are released after cell death, and allow the immune system to distinguish between antigens that are dangerous or not. Notably, cells undergoing severe stress actively secrete HMGB1 via a dedicated secretion pathway: HMGB1 is relocated from the nucleus to the cytoplasm and then to secretory lysosomes or directly to the extracellular space. Extracellular HMGB1 (either released or secreted) triggers inflammation and adaptive immunological responses by switching among multiple oxidation states, which direct the mutually exclusive choices of different binding partners and receptors. Immune cells are first recruited to the damaged tissue and then activated; thereafter, HMGB1 supports tissue repair and healing, by coordinating the switch of macrophages to a tissue‐healing phenotype, activation and proliferation of stem cells, and neoangiogenesis. Inevitably, HMGB1 also orchestrates the support of stressed but illegitimate tissues: tumors. Concomitantly, HMGB1 enhances the immunogenicity of mutated proteins in the tumor (neoantigens), promoting anti‐tumor responses and immunological memory. Tweaking the activities of HMGB1 in inflammation, immune responses and tissue repair could bring large rewards in the therapy of multiple medical conditions, including cancer.
Regulatory T cells and skeletal muscle regeneration Schiaffino, Stefano; Pereira, Marcelo G.; Ciciliot, Stefano ...
The FEBS journal,
February 2017, 2017-02-00, 20170201, Letnik:
284, Številka:
4
Journal Article
Recenzirano
Odprti dostop
Skeletal muscle regeneration results from the activation and differentiation of myogenic stem cells, called satellite cells, located beneath the basal lamina of the muscle fibers. Inflammatory and ...immune cells have a crucial role in the regeneration process. Acute muscle injury causes an immediate transient wave of neutrophils followed by a more persistent infiltration of M1 (proinflammatory) and M2 (anti‐inflammatory/proregenerative) macrophages. New studies show that injured muscle is also infiltrated by a specialized population of regulatory T (Treg) cells, which control both the inflammatory response, by promoting the M1‐to‐M2 switch, and the activation of satellite cells. Treg cells accumulate in injured muscle in response to specific cytokines, such as IL‐33, and promote muscle growth by releasing growth factors, such as amphiregulin. Muscle repair during aging is impaired due to reduced number of Treg cells and can be enhanced by IL‐33 supplementation. Migration of Treg cells could also contribute to explain the effect of heterochronic parabiosis, whereby muscle regeneration of aged mice can be improved by a parabiotically linked young partners. In mdx dystrophin‐deficient mice, a model of human Duchenne muscular dystrophy, muscle injury, and inflammation is mitigated by expansion of the Treg‐cell population but exacerbated by Treg‐cell depletion. These findings support the notion that immunological mechanisms are not only essential in the response to pathogenic microbes and tumor cells but also have a wider homeostatic role in tissue repair, and open new perspectives for boosting muscle growth in chronic muscle disease and during aging.
Skeletal muscle can regenerate after injury as a result of the activation of myogenic stem cells. Inflammatory and immune cells are also required for muscle regeneration, both by removing necrotic tissue and by promoting the proliferation and differentiation of muscle stem cells. Recent studies highlight a specific role of a specialized population of regulatory T cells, whose depletion is responsible for the impaired regeneration of aging muscle.
Background
Platelet activation and thrombotic events characterizes COVID‐19.
Objectives
To characterize platelet activation and determine if SARS‐CoV‐2 induces platelet activation.
Patients/Methods
...We investigated platelet activation in 119 COVID‐19 patients at admission in a university hospital in Milan, Italy, between March 18 and May 5, 2020. Sixty‐nine subjects (36 healthy donors, 26 patients with coronary artery disease, coronary artery disease, and seven patients with sepsis) served as controls.
Results
COVID‐19 patients had activated platelets, as assessed by the expression and distribution of HMGB1 and von Willebrand factor, and by the accumulation of platelet‐derived (plt) extracellular vesicles (EVs) and HMGB1+ plt‐EVs in the plasma. P‐selectin upregulation was not detectable on the platelet surface in a fraction of patients (55%) and the concentration of soluble P‐selectin in the plasma was conversely increased. The plasma concentration of HMGB1+ plt‐EVs of patients at hospital admission remained in a multivariate analysis an independent predictor of the clinical outcome, as assessed using a 6‐point ordinal scale (from 1 = discharged to 6 = death). Platelets interacting in vitro with SARS‐CoV‐2 underwent activation, which was replicated using SARS‐CoV‐2 pseudo‐viral particles and purified recombinant SARS‐CoV‐2 spike protein S1 subunits. Human platelets express CD147, a putative coreceptor for SARS‐CoV‐2, and Spike‐dependent platelet activation, aggregation and granule release, release of soluble P‐selectin and HMGB1+ plt‐EVs abated in the presence of anti‐CD147 antibodies.
Conclusions
Hence, an early and intense platelet activation, which is reproduced by stimulating platelets in vitro with SARS‐CoV‐2, characterizes COVID‐19 and could contribute to the inflammatory and hemostatic manifestations of the disease.
Objective
To evaluate whether the initial chest X-ray (CXR) severity assessed by an AI system may have prognostic utility in patients with COVID-19.
Methods
This retrospective single-center study ...included adult patients presenting to the emergency department (ED) between February 25 and April 9, 2020, with SARS-CoV-2 infection confirmed on real-time reverse transcriptase polymerase chain reaction (RT-PCR). Initial CXRs obtained on ED presentation were evaluated by a deep learning artificial intelligence (AI) system and compared with the Radiographic Assessment of Lung Edema (RALE) score, calculated by two experienced radiologists. Death and critical COVID-19 (admission to intensive care unit (ICU) or deaths occurring before ICU admission) were identified as clinical outcomes. Independent predictors of adverse outcomes were evaluated by multivariate analyses.
Results
Six hundred ninety-seven 697 patients were included in the study: 465 males (66.7%), median age of 62 years (IQR 52–75). Multivariate analyses adjusting for demographics and comorbidities showed that an AI system-based score ≥ 30 on the initial CXR was an independent predictor both for mortality (HR 2.60 (95% CI 1.69 − 3.99;
p
< 0.001)) and critical COVID-19 (HR 3.40 (95% CI 2.35–4.94;
p
< 0.001)). Other independent predictors were RALE score, older age, male sex, coronary artery disease, COPD, and neurodegenerative disease.
Conclusion
AI- and radiologist-assessed disease severity scores on CXRs obtained on ED presentation were independent and comparable predictors of adverse outcomes in patients with COVID-19.
Trial registration
ClinicalTrials.gov
NCT04318366 (
https://clinicaltrials.gov/ct2/show/NCT04318366
).
Key Points
• AI system–based score ≥ 30 and a RALE score ≥ 12 at CXRs performed at ED presentation are independent and comparable predictors of death and/or ICU admission in COVID-19 patients.
• Other independent predictors are older age, male sex, coronary artery disease, COPD, and neurodegenerative disease.
• The comparable performance of the AI system in relation to a radiologist-assessed score in predicting adverse outcomes may represent a game-changer in resource-constrained settings.
Background
Circulating androgens could have a relevant pathobiological role in clinical outcomes in men with severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection (COVID‐19).
...Objectives
We aimed to assess: (a) circulating sex steroids levels in a cohort of 286 symptomatic men with laboratory‐confirmed COVID‐19 at hospital admission compared to a cohort of 281 healthy men; and (b) the association between serum testosterone levels (tT), COVID‐19, and clinical outcomes.
Materials and Methods
Demographic, clinical, and hormonal values were collected for all patients. Hypogonadism was defined as tT ≤9.2 nmol/l. The Charlson Comorbidity Index (CCI) was used to score health‐significant comorbidities. Severe clinical outcomes were defined as patients either transferred to intensive care unit (ICU) or death. Descriptive statistics and multivariable linear and logistic regression models tested the association between clinical and laboratory variables and tT levels. Univariable and multivariable logistic regression models tested the association between tT and severe clinical outcomes.
Results
Overall, a significantly lower levels of LH and tT were found in patients with COVID‐19 compared to healthy controls (all p < 0.0001); conversely, healthy controls depicted lower values of circulating E2 (p < 0.001). Testosterone levels suggestive for hypogonadism were observed in 257 (89.8%) patients at hospital admission. In as many as 243 (85%) cases, hypogonadism was secondary. SARS‐CoV‐2 infection status was independently associated with lower tT levels (p < 0.0001) and greater risk of hypogonadism (p < 0.0001), after accounting for age, BMI, CCI, and IL‐6 values. Lower tT levels were associated with higher risk of ICU admission and death outcomes (all p ≤ 0.05), after accounting for clinical and laboratory parameters.
Conclusions
We unveil an independent association between SARS‐CoV‐2 infection status and secondary hypogonadism already at hospital admission, with lower testosterone levels predicting the most severe clinical outcomes.
Background
Hypocalcemia has been identified as a major distinctive feature of COVID-19, predicting poor clinical outcomes. Among the mechanisms underlying this biochemical finding, high prevalence of ...vitamin D (VD) deficiency in COVID-19 patients reported so far in several studies was advocated. However, robust data in favor of this hypothesis are still lacking. Therefore, aim of our study was to investigate the role of hypovitaminosis D and parathyroid hormone (PTH) levels in the development of hypocalcemia in COVID-19 patients.
Methods
Patients admitted to IRCCS Ospedale San Raffaele for COVID-19 were enrolled in this study, excluding those with comorbidities and therapies influencing calcium and VD metabolism. Serum levels of total calcium (tCa), ionized calcium (Ca
2+
), 25-OH-VD, and PTH were evaluated at admission. We defined VD deficiency as VD below 20 ng/mL, hypocalcemia as tCa below 2.2 mmol/L or as Ca
2+
below 1.18 mmol/L, and hyperparathyroidism as PTH above 65 pg/mL.
Results
A total of 78 patients were included in the study. Median tCa and Ca
2+
levels were 2.15 and 1.15 mmol/L, respectively. Total and ionized hypocalcemia were observed in 53 (67.9%) and 55 (70.5%) patients, respectively. VD deficiency was found in 67.9% of patients, but secondary hyperparathyroidism was detected in 20.5% of them, only. tCa levels were significantly lower in patients with VD deficiency and regression analyses showed a positive correlation between VD and tCa.
Conclusions
In conclusion, we confirmed a high prevalence of hypocalcemia in COVID-19 patients and we showed for the first time that it occurred largely in the context of marked hypovitaminosis D not adequately compensated by secondary hyperparathyroidism.
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