Low HDL-c levels at admission are associated with greater severity and worse clinical outcomes in patients with COVID-19 disease.

Background and aims: HDL particles may act to buffer host cells from excessive inflammatory mediators. The aim of this study is to investigate if the lipid profile provides a prognostic biomarker for COVID-19 outcomes. Methods: This was a prospective study of the characteristics of 125 adult COVID-19 patients with a lipid profile performed on the day of admission analyzed with regard to clinical outcomes. Results: Seventy-seven patients (61.2%) were men, with a mean age of 66.3 (15.6) years. 54.1% had bilateral pneumonia. The all-cause mortality rate during hospitalization was 20.8%. We found a direct association between more severe disease assessed by the WHO classification, admission to the ICU and death with more pronounced lymphopenia, higher levels of CRP, ferritin (p < 0.001), D-dímer and lactate dehydrogenase (LDH) all statistically significant. Lower leves of HDL-c and LDL-c were also associated with a worse WHO classification, ICU admission, and death,. HDL-c levels were inversely correlated with inflammatory markers CRP (r = -0.333; p < 0.001), ferritin (r = -0.354; p < 0.001), D-dímer (r = -0.214; p < 0.001), LDH (r = -0.209; p < 0.001. LDL-c levels were significantly associated with CRP (r = -0.320; p < 0.001) and LDH (r = -0.269; p < 0.001). ROC curves showed that HDL [AUC = 0.737(0.586-0.887), p = 0.005] and lymphocytes [AUC = 0.672(0.497-0.847], p < 0.043] had the best prognostic accuracy to predict death. In a multivariate analysis, HDL-c (ß = -0.146(0.770-0.971), p = 0.014) and urea (ß = 0.029(1.003-1.057), p = 0.027) predicted mortality. Conclusion: Hypolipidemia including HDL levels at admission identifies patients with a higher risk of death and worse clinical manifestations who may require more intensive care.

Plasma gelsolin levels are associated with diabetes, sex, race, and poverty.

BACKGROUND: The growing epidemic of the inflammation-related metabolic disease, type 2 diabetes mellitus, presents a challenge to improve our understanding of potential mechanisms or biomarkers to prevent or better control this age-associated disease. A gelsolin isoform is secreted into the plasma as part of the extracellular actin scavenger system which serves a protective role by digesting and removing actin filaments released from damaged cells. Recent data indicate a role for decreased plasma gelsolin (pGSN) levels as a biomarker of inflammatory conditions. Extracellular vesicles (EVs), a heterogeneous group of cell-derived membranous structures involved in intercellular signaling, have been implicated in metabolic and inflammatory diseases including type 2 diabetes mellitus. We examined whether pGSN levels were associated with EV concentration and inflammatory plasma proteins in individuals with or without diabetes. METHODS: We quantified pGSN longitudinally (n = 104) in a socioeconomically diverse cohort of middle-aged African American and White study participants with and without diabetes mellitus. Plasma gelsolin levels were assayed by ELISA. EV concentration (sub-cohort n = 40) was measured using nanoparticle tracking analysis. Inflammatory plasma proteins were assayed on the SomaScan® v4 proteomic platform. RESULTS: pGSN levels were lower in men than women. White individuals with diabetes had significantly lower levels of pGSN compared to White individuals without diabetes and to African American individuals either with or without diabetes. For adults living below poverty, those with diabetes had lower pGSN levels than those without diabetes. Adults living above poverty had similar pGSN levels regardless of diabetes status. No correlation between EV concentrations and pGSN levels was identified (r = - 0.03; p = 0.85). Large-scale exploratory plasma protein proteomics revealed 47 proteins that significantly differed by diabetes status, 19 of which significantly correlated with pGSN levels, including adiponectin. CONCLUSIONS: In this cohort of racially diverse individuals with and without diabetes, we found differences in pGSN levels with diabetes status, sex, race, and poverty. We also report significant associations of pGSN with the adipokine, adiponectin, and other inflammation- and diabetes-related proteins. These data provide mechanistic insights into the relationship of pGSN and diabetes.

Blood-Borne Microparticles Are an Inflammatory Stimulus in Type 2 Diabetes Mellitus.

The proinflammatory state associated with diabetes mellitus (DM) remains poorly understood. We found patients with DM have 3- to 14-fold elevations of blood-borne microparticles (MPs) that bind phalloidin (Ph; Ph positive [+] MPs), indicating the presence of F-actin on their surface. We hypothesized that F-actin-coated MPs were an unrecognized cause for DM-associated proinflammatory status. Ph+MPs, but not Ph-negative MPs, activate human and murine (Mus musculus) neutrophils through biophysical attributes of F-actin and membrane expression of phosphatidylserine (PS). Neutrophils respond to Ph+MPs via a linked membrane array, including the receptor for advanced glycation end products and CD36, PS-binding membrane receptors. These proteins in conjunction with TLR4 are coupled to NO synthase 1 adaptor protein (NOS1AP). Neutrophil activation occurs because of Ph+MPs causing elevations of NF-κB and Src kinase (SrcK) via a concurrent increased association of NO synthase 2 and SrcK with NOS1AP, resulting in SrcK S-nitrosylation. We conclude that NOS1AP links PS-binding receptors with intracellular regulatory proteins. Ph+MPs are alarmins present in normal human plasma and are increased in those with DM and especially those with DM and a lower-extremity ulcer.

Adjunctive Recombinant Human Plasma Gelsolin for Severe Coronavirus Disease 2019 Pneumonia.

Background: Excessive inflammation contributes to the morbidity and mortality of severe coronavirus disease 2019 (COVID-19) pneumonia. Recombinant human plasma gelsolin (rhu-pGSN) improves disease outcomes in diverse experimental models of infectious and noninfectious inflammation. Methods: In a blinded, randomized study, 61 subjects with documented COVID-19 pneumonia having a World Health Organization (WHO) Severity Score of 4 to 6 and evidence of a hyperinflammatory state were treated with standard care and either adjunctive rhu-pGSN 12 mg/kg or an equal volume of saline placebo given intravenously at entry, 12 hours, and 36 hours. The prespecified coprimary outcomes were survival without major respiratory, hemodynamic, or renal support on Day 14 and the incidence of serious adverse events (SAEs) during the 90-day study period. Results: All subjects receiving ≥1 dose of study drug were analyzed. Fifty-four of 61 subjects (88.5%) were WHO severity level 4 at entry. The proportions of subjects alive without support on Day 14 were 25 of 30 rhu-pGSN recipients (83.3%) and 27 of 31 placebo recipients (87.1%). Over the duration of the study, WHO Severity Scores improved similarly in both treatment groups. No statistically significant differences were observed between treatment groups at any time point examined. Two subjects died in each group. Numerically fewer subjects in the rhu-pGSN group had SAEs (5 subjects; 16.7%) or ≥ Grade 3 adverse events (5 subjects; 16.7%) than in the placebo group (8 subjects [25.8%] and 9 subjects [29.0%], respectively), mostly involving the lungs. Three rhu-pGSN recipients (10.0%) were intubated compared to 6 placebo recipients (19.4%). Conclusions: Overall, subjects in this study did well irrespective of treatment arm. When added to dexamethasone and remdesivir, no definitive benefit was demonstrated for rhu-pGSN relative to placebo. Safety signals were not identified after the administration of 3 doses of 12 mg/kg rhu-pGSN over 36 hours. The frequencies of SAEs and intubation were numerically fewer in the rhu-pGSN group compared with placebo.

Association of plasma gelsolin with frailty phenotype and mortality among octogenarian community-dwelling men: a cohort study.

BACKGROUND: Biomarkers are needed for frailty, a common phenotype often associated with muscle loss in older people. Plasma gelsolin (pGSN) is a protein largely synthesized and secreted by skeletal muscle. AIMS: To investigate whether pGSN could be a biomarker of the frailty phenotype and predict mortality. METHODS: A homogenous cohort of males (born 1919-1934, baseline n = 3490) has been followed since the 1960s. In 2010/11, frailty phenotypes by modified Fried criteria were assessed. pGSN was measured in a convenience subset (n = 469, mean age 83) and re-measured in survivors (n = 127) in 2017. Mortality through December 31, 2018 was retrieved from national registers. Regression models were used for analyses. RESULTS: Of 469 males, 152 (32.4%) were robust, 284 (60.6%) prefrail, and 33 (7.0%) frail in 2010/11. There was a graded (p = 0.018) association between pGSN (mean 58.1 ug/mL, SD 9.3) and frailty. After multivariable adjustment, higher pGSN levels were associated with lower odds of having contemporaneous phenotypic prefrailty (OR per 1 SD 0.73, 95% CI 0.58-0.92) and frailty (OR per 1 SD 0.70, 95% CI 0.44-1.11). By 2018, 179 males (38.2%) had died, and higher baseline pGSN predicted a lower 7-year mortality rate (HR per 1 SD 0.85, 95% CI 0.72-1.00). pGSN concentrations in 2010/11 and 2017 were correlated (n = 127, r = 0.34, p < 0.001). DISCUSSION: Higher baseline pGSN concentrations were associated with a persistently robust phenotype and lower mortality rate over 7 years in a cohort of octogenarian males with high socioeconomic status and may be a promising laboratory biomarker for the development of a frailty phenotype.

Plasma gelsolin modulates the production and fate of IL-1ß-containing microparticles following high-pressure exposure and decompression.

Plasma gelsolin (pGSN) levels fall in association with diverse inflammatory conditions. We hypothesized that pGSN would decrease due to the stresses imposed by high pressure and subsequent decompression, and repletion would ameliorate injuries in a murine decompression sickness (DCS) model. Research subjects were found to exhibit a modest decrease in pGSN level while at high pressure and a profound decrease after decompression. Changes occurred concurrent with elevations of circulating microparticles (MPs) carrying interleukin (IL)-1ß. Mice exhibited a comparable decrease in pGSN after decompression along with elevations of MPs carrying IL-1ß. Infusion of recombinant human (rhu)-pGSN into mice before or after pressure exposure abrogated these changes and prevented capillary leak in brain and skeletal muscle. Human and murine MPs generated under high pressure exhibited surface filamentous actin (F-actin) to which pGSN binds, leading to particle lysis. In addition, human neutrophils exposed to high air pressure exhibit an increase in surface F-actin that is diminished by rhu-pGSN resulting in inhibition of MP production. Administration of rhu-pGSN may have benefit as prophylaxis or treatment for DCS.NEW & NOTEWORTHY Inflammatory microparticles released in response to high pressure and decompression express surface filamentous actin. Infusion of recombinant human plasma gelsolin lyses these particles in decompressed mice and ameliorates particle-associated vascular damage. Human neutrophils also respond to high pressure with an increase in surface filamentous actin and microparticle production, and these events are inhibited by plasma gelsolin. Gelsolin infusion may have benefit as prophylaxis or treatment for decompression sickness.

Low Plasma Gelsolin Concentrations in Chronic Granulomatous Disease.

Plasma gelsolin (pGSN) is the secreted isoform of an intracellular actin remodeling protein found in high concentrations in human plasma. Clinical studies demonstrate reduced pGSN concentrations in several disease states, including severe trauma, burns, and sepsis. Markedly decreased pGSN concentrations in these conditions precede and predict adverse clinical outcomes. In this study, we measured pGSN in patients with chronic granulomatous disease (CGD), a primary immunodeficiency characterized by recurrent infections and dysregulated inflammation. pGSN was quantified using a sandwich ELISA in plasma from healthy volunteers, clinically stable CGD patients, and X-linked CGD carriers and in sera from 12 CGD patients undergoing bone marrow transplantation. pGSN was also quantified in healthy volunteers challenged with intravenous endotoxin. pGSN concentrations were lower in CGD patients without active infection or systemic inflammation compared with healthy control subjects. In CGD patients undergoing bone marrow transplantation, pGSN concentrations increased significantly following successful transplant. X-linked carriers of CGD had normal pGSN. Despite reduction of pGSN in CGD patients, we did not detect significant changes in pGSN over 24 h following challenge of healthy volunteers with intravenous endotoxin (4 ng/kg) that elicited a febrile response. We describe, for the first time, significantly lower pGSN in clinically stable patients with CGD compared with age- and sex-matched healthy volunteers. Low pGSN levels in CGD patients significantly increased following bone marrow transplantation. X-linked carriers of CGD had normal pGSN. In healthy volunteers challenged with intravenous endotoxin, pGSN is not an acute phase reactant.

An immune-based biomarker signature is associated with mortality in COVID-19 patients.

Immune and inflammatory responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) contribute to disease severity of coronavirus disease 2019 (COVID-19). However, the utility of specific immune-based biomarkers to predict clinical outcome remains elusive. Here, we analyzed levels of 66 soluble biomarkers in 175 Italian patients with COVID-19 ranging from mild/moderate to critical severity and assessed type I IFN-, type II IFN-, and NF-κB-dependent whole-blood transcriptional signatures. A broad inflammatory signature was observed, implicating activation of various immune and nonhematopoietic cell subsets. Discordance between IFN-α2a protein and IFNA2 transcript levels in blood suggests that type I IFNs during COVID-19 may be primarily produced by tissue-resident cells. Multivariable analysis of patients' first samples revealed 12 biomarkers (CCL2, IL-15, soluble ST2 [sST2], NGAL, sTNFRSF1A, ferritin, IL-6, S100A9, MMP-9, IL-2, sVEGFR1, IL-10) that when increased were independently associated with mortality. Multivariate analyses of longitudinal biomarker trajectories identified 8 of the aforementioned biomarkers (IL-15, IL-2, NGAL, CCL2, MMP-9, sTNFRSF1A, sST2, IL-10) and 2 additional biomarkers (lactoferrin, CXCL9) that were substantially associated with mortality when increased, while IL-1α was associated with mortality when decreased. Among these, sST2, sTNFRSF1A, IL-10, and IL-15 were consistently higher throughout the hospitalization in patients who died versus those who recovered, suggesting that these biomarkers may provide an early warning of eventual disease outcome.

Recombinant Human Plasma Gelsolin Improves Survival and Attenuates Lung Injury in a Murine Model of Multidrug-Resistant Pseudomonas aeruginosa Pneumonia.

BACKGROUND: Plasma gelsolin (pGSN) is an abundant circulating protein quickly consumed by extensive tissue damage. Marked depletion is associated with later poor outcomes in diverse clinical circumstances. Repletion with recombinant human (rhu)-pGSN in animal models of inflammation lessens mortality and morbidity. METHODS: Neutropenic mice were treated with different meropenem doses ±12 mg of rhu-pGSN commencing 1 day before an intratracheal challenge with multidrug-resistant Pseudomonas aeruginosa. Survival, bacterial counts, and pulmonary pathology were compared between corresponding meropenem groups with and without rhu-pGSN. RESULTS: Overall survival was 35/64 (55%) and 46/64 (72%) in mice given meropenem without and with rhu-pGSN, respectively (Δ = 17%; 95% CI, 1-34). In control mice receiving meropenem 1250 mg/kg/d where the majority died, the addition of rhu-pGSN increased survival from 5/16 (31%) to 12/16 (75%) (Δ = 44%; 95% CI, 13-75). Survival with minor lung injury was found in 26/64 (41%) mice receiving only meropenem, vs 38/64 (59%) in mice given meropenem plus rhu-pGSN (Δ = 19%; 95% CI, 2-36). CONCLUSIONS: In a series of dose-ranging experiments, both mortality and lung injury were reduced by the addition of rhu-pGSN to meropenem against carbapenem-resistant P. aeruginosa. Rhu-pGSN offers a novel candidate therapy for antibiotic-resistant pneumonia.

Safety and Pharmacokinetics of Recombinant Human Plasma Gelsolin in Patients Hospitalized for Nonsevere Community-Acquired Pneumonia.

There remains an unmet need to address the substantial morbidity and mortality associated with severe community-acquired pneumonia (sCAP). Recombinant human plasma gelsolin (rhu-pGSN) improves disease outcomes in diverse animal models of infectious and noninfectious inflammation. This blinded dose-escalation safety study involved non-intensive care unit (ICU) patients admitted for mild CAP and randomized 3:1 to receive adjunctive rhu-pGSN or placebo intravenously. Thirty-three subjects were treated: 8 in the single-dose phase and 25 in the multidose phase. For the single-dose phase, rhu-pGSN at 6 mg/kg of body weight was administered once. For the multidose phase, a daily rhu-pGSN dose of 6, 12, or 24 mg/kg was given on 3 consecutive days. Adverse events (AEs) were generally mild in both treatment groups irrespective of dose. The only serious AE (SAE) in the single-dose phase was a non-drug-related pneumonia in a rhu-pGSN recipient who died after institution of comfort care. One single-dose placebo recipient had a drug-related AE (maculo-papular rash). In the multidose phase, there were 2 SAEs in 1 placebo recipient, including a fatal pulmonary embolism. In the 18 rhu-pGSN recipients in the multidose phase, there were no serious or drug-related AEs, and nausea and increased blood pressure were each reported in 2 patients. The median rhu-pGSN half-life exceeded 17 h with all dosing regimens, and supraphysiologic levels were maintained throughout the 24-h dosing interval in the 2 highest dosing arms. Rhu-pGSN was well tolerated overall in CAP patients admitted to non-ICU beds, justifying a larger proof-of-concept trial in an ICU population admitted with sCAP. (This study has been registered at ClinicalTrials.gov under identifier NCT03466073.).

Delayed Administration of Recombinant Plasma Gelsolin Improves Survival in a Murine Model of Penicillin-Susceptible and Penicillin-Resistant Pneumococcal Pneumonia.

Therapy to enhance host immune defenses may improve outcomes in serious infections, especially for antibiotic-resistant pathogens. Recombinant human plasma gelsolin (rhu-pGSN), a normally circulating protein, has beneficial effects in diverse preclinical models of inflammation and injury. We evaluated delayed therapy (24-48 hours after challenge) with rhu-pGSN in a mouse model of pneumococcal pneumonia. rhu-pGSN without antibiotics increased survival and reduced morbidity and weight loss after infection with either penicillin-susceptible or penicillin-resistant pneumococci (serotypes 3 and 14, respectively). rhu-pGSN improves outcomes in a highly lethal pneumococcal pneumonia model when given after a clinically relevant delay, even in the setting of antimicrobial resistance.

Delayed administration of recombinant plasma gelsolin improves survival in a murine model of severe influenza.

Background: Host-derived inflammatory responses contribute to the morbidity and mortality of severe influenza, suggesting that immunomodulatory therapy may improve outcomes. The normally circulating protein, human plasma gelsolin, is available in recombinant form (rhu-pGSN) and has beneficial effects in a variety of pre-clinical models of inflammation and injury.   Methods: We evaluated delayed therapy with subcutaneous rhu-pGSN initiated 3 to 6 days after intra-nasal viral challenge in a mouse model of influenza A/PR/8/34. Results: Rhu-pGSN administered starting on day 3 or day 6 increased survival (12-day survival: 62 % vs 39 %, pGSN vs vehicle; p < 0.00001, summary of 18 trials), reduced morbidity, and decreased pro-inflammatory gene expression. Conclusions: Rhu-pGSN improves outcomes in a highly lethal influenza model when given after a clinically relevant delay.

Low Admission Plasma Gelsolin Concentrations Identify Community-acquired Pneumonia Patients at High Risk for Severe Outcomes.

BACKGROUND: Plasma gelsolin (pGSN) is an abundant circulating protein that neutralizes actin exposed by damaged cells, modulates inflammatory responses, and enhances alveolar macrophage antimicrobial activity. We investigated whether adults with low pGSN at hospital admission for community-acquired pneumonia (CAP) were at high risk for severe outcomes. METHODS: Admission pGSN concentrations in 455 adults hospitalized with CAP were measured using enzyme-linked immunosorbent assay. Patients were grouped into the following 4 hierarchical, mutually exclusive categories based on maximum clinical severity experienced during their hospitalization: general floor care without intensive care unit (ICU) admission, invasive respiratory or vasopressor support (IRVS), or death; ICU care without IRVS or death; IRVS without death; or death. Admission pGSN concentrations were compared across these discrete outcome categories. Additionally, outcomes among patients in the lowest quartile of pGSN concentration were compared to those in the upper 3 quartiles. RESULTS: Overall, median (interquartile range) pGSN concentration was 38.1 (32.1, 45.7) µg/mL. Patients with more severe outcomes had lower pGSN concentrations (P = .0001); median values were 40.3 µg/mL for floor patients, 36.7 µg/mL for ICU patients, 36.5 µg/mL for patients receiving IRVS, and 25.7 µg/mL for patients who died. Compared to patients with higher pGSN concentrations, patients in the lowest quartile (pGSN ≤ 32.1 µg/mL) more often required IRVS (21.2% vs 11.7%, P = .0114) and died (8.8% vs 0.9%, P < .0001). CONCLUSIONS: Among adults hospitalized with CAP, lower pGSN concentrations were associated with more severe clinical outcomes. Future studies are planned to investigate possible therapeutic benefits of recombinant human pGSN in this population.

The future of drug development: advancing clinical trial design.

Declining pharmaceutical industry productivity is well recognized by drug developers, regulatory authorities and patient groups. A key part of the problem is that clinical studies are increasingly expensive, driven by the rising costs of conducting Phase II and III trials. It is therefore crucial to ensure that these phases of drug development are conducted more efficiently and cost-effectively, and that attrition rates are reduced. In this article, we argue that moving from the traditional clinical development approach based on sequential, distinct phases towards a more integrated view that uses adaptive design tools to increase flexibility and maximize the use of accumulated knowledge could have an important role in achieving these goals. Applications and examples of the use of these tools--such as Bayesian methodologies--in early- and late-stage drug development are discussed, as well as the advantages, challenges and barriers to their more widespread implementation.