Cellular Senescence in Immunity against Infections

Immp2l gene knockout induces granulosa cell senescence by activation of cGAS-STING pathway via TFAM-mediated mtDNA leakage

Granulosa cell-produced inflammatory factors may be key contributors to ovarian dysfunction, and Immp2l deficiency accelerates ovarian aging via granulosa cell senescence; however, the role of inflammation in granulosa cell senescence is largely unknown. Therefore, in this study, cGAS-STING-mediated inflammation was explored in Immp2l deficiency-induced granulosa cell senescence. Immp2l deficiency led to senescence-associated secretory phenotype (SASP) and granulosa cell senescence. Immp2l knockout caused mitochondrial dysfunction and mitochondrial DNA (mtDNA) leakage into the cytoplasm. The cytoplasmic mtDNA was recognized by the DNA-sensing molecule cGAS-STING, which activates cGAS-STING and key downstream interferon-stimulated genes (ISGs) and then promotes the secretion of proinflammatory factors, leading to SASP in senescent granulosa cells. Interestingly, the mitochondrial inner membrane pore protein (Cyclophilin D40) CyPD40 and the outer membrane pore protein voltage-dependent-anion channel 1 (VDAC1) were markedly increased in senescent granulosa cells, accompanied by significantly increased expression of the mtDNA stability protein mitochondrial transcription factor A (TFAM). Downregulation of TFAM with siRNA in senescent granulosa cells improved mitochondrial function, significantly decreased mtDNA in the cytoplasm, inhibited the cGAS-STING pathway and markedly decreased CyPD40 and VDAC1 protein levels in TFAM-treated senescent granulosa cells. The SASP phenotype was also alleviated. In addition, senescent granulosa cells were treated with procyanidin B2 (PCB2), which has anti-inflammatory effects, and the TFAM-mediated mtDNA-cGAS-STING pathway was inhibited, accompanied by a markedly reduced SASP phenotype and granulosa cell senescence. In conclusion, Immp2l gene knockout induced granulosa cell senescence by activation of the cGAS-STING pathway via TFAM-mediated mtDNA leakage into the cytoplasm through the CyPD40 and the VDAC1.

Micro nutrients as immunomodulators in the ageing population: a focus on inflammation and autoimmunity

Immunosenescence, the slow degradation of immune function over time that is a hallmark and driver of aging, makes older people much more likely to be killed by common infections (such as flu) than young adults, but it also contributes greatly to rates of chronic inflammation in later life. Such micro nutrients are crucial for modulating effective immune responses and their deficiencies have been associated with dysfunctional immunity in the elderly. In this review, we specifically focused on the contribution of major micro nutrients (Vitamins A, D and E, Vitamin C; Zinc and Selenium) as immunomodulators in ageing population especially related to inflame-ageing process including autoimmunity. This review will cover these hologenomic interactions, including how micro nutrients can modulate immune cell function and/or cytokine production to benefit their hosts with healthy mucous-associated immunity along with a sustainable immunologic homeostasis. For example, it points out the modulatory effects of vitamin D on both innate and adaptive immunity, with a specific focus on its ability to suppress pro-inflammatory cytokines synthesis while enhancing regulatory T-cell function. In the same context, also zinc is described as important nutrient for thymic function and T-cell differentiation but exhibits immunomodulatory functions by decreasing inflammation. In addition, the review will go over how micro nutrient deficiencies increase systemic chronic low-grade inflammation and, inflammaging as well as actually enhance autoimmune pathologies in old age. It assesses the potential role of additional targeted nutritional supplementation with micro nutrients to counteract these effects, promoting wider immune resilience in older adults. This review collates the current evidence and highlights the role of adequate micro nutrient intake on inflammation and autoimmunity during ageing, providing plausible origins for nutritional interventions to promote healthy immune aging.

Genetic origins, regulators, and biomarkers of cellular senescence

This review comprehensively examines the molecular biology and genetic origins of cellular senescence. We focus on various cellular stressors and pathways leading to senescence, including recent advances in the understanding of the genetic influences driving senescence, such as telomere attrition, chemotherapy-induced DNA damage, pathogens, oncogene activation, and cellular and metabolic stress. This review also highlights the complex interplay of various signaling and metabolic pathways involved in cellular senescence and provides insights into potential therapeutic targets for aging-related diseases. Furthermore, this review outlines future research directions to deepen our understanding of senescence biology and develop effective interventions targeting senescent cells (SnCs).

Impact of Senescent Cell-Derived Extracellular Vesicles on Innate Immune Cell Function

Extracellular vesicles (EVs) are components of the senescence-associated secretory phenotype (SASP) that influence cellular functions via their cargo. Here, the interaction between EVs derived from senescent (SEVs) and non-senescent (N-SEVs) fibroblasts and the immune system is investigated. Via endocytosis, SEVs are phagocytosed by monocytes, neutrophils, and B cells. Studies with the monocytic THP-1 cell line find that pretreatment with SEVs results in a 32% (p < 0.0001) and 66% (p < 0.0001) increase in lipopolysaccharide (LPS)-induced tumor necrosis factor-alpha (TNF-α) production when compared to vehicle control or N-SEVs respectively. Interestingly, relative to vehicle control, THP-1 cells exposed to N-SEVs exhibit a 20% decrease in TNF-α secretion (p < 0.05). RNA sequencing reveals significant differences in gene expression in THP-1 cells treated with SEVs or N-SEVs, with vesicle-mediated transport and cell cycle regulation pathways featuring predominantly with N-SEV treatment, while pathways relating to SLITS/ROBO signaling, cell metabolism, and cell cycle regulation are enriched in THP-1 cells treated with SEVs. Proteomic analysis also reveals significant differences between SEV and N-SEV cargo. These results demonstrate that phagocytes and B cells uptake SEVs and drive monocytes toward a more proinflammatory phenotype upon LPS stimulation. SEVs may therefore contribute to the more proinflammatory immune response seen with aging.

Relationship of C-reactive Protein/Serum Albumin Ratio and qPitt Bacteremia Score With An All-Cause In-Hospital Mortality in Patients With Bloodstream Infections

BACKGROUND

Bloodstream infections remain a major cause of morbidity and mortality despite notable advances in their diagnosis and treatment. C-reactive protein/serum albumin ratio and the quick Pitt bacteremia score are two useful tools for clinicians to assess severity and predict mortality risk in patients with sepsis attributable to bloodstream infections. This study examined the relationship between C-reactive protein/serum albumin ratio and Q Pitt bacteremia score with all-cause in-hospital mortality in patients with bloodstream infections.

METHODS

Hospitalized adult patients with bacteremic bloodstream infections between January 1, 2020, and December 31, 2021, were retrospectively reviewed. Patients' demographics and clinical and laboratory data were retrieved from patient electronic records. C-reactive protein/albumin ratio was calculated using CRP (mg/L) and serum albumin (g/L) values obtained within 24 hours of blood culture collection and quick Pitt bacteremia score was calculated for each patient with each of the five variables of the score determined within 24 hours of blood culture collection and each patient was assigned a numerical score of 0-5 accordingly. The relationship between C-reactive protein/albumin ratio and quick Pitt bacteremia score with all-cause in-hospital mortality was determined.

RESULTS

A total of 187 hospitalized adult patients with non-repeat bacteremic bloodstream infections were identified. Escherichia coli was the most common Gram-negative blood isolate while Staphylococcus aureus was the predominant Gram-positive isolate. One hundred and five (56.1%) patients were male with a cohort mean age of 56.9 ± 2.7 years. All-cause in-hospital mortality was 27.3%. The mean CRP/albumin ratio (8.6 ±1.7) and mean quick Pitt bacteremia score (2.8 ±0.4) were significantly higher in patients with bloodstream infections who died during their hospitalization compared to those who survived. The all-cause in-hospital mortality was 8%, 12%, 22%, 46%, 93%, and 100% for patients with quick Pitt scores of 0, 1, 2, 3, 4, and 5, respectively.

CONCLUSION

In hospitalized patients with bacteremic bloodstream infections, an incremental increase in quick Pitt bacteremia score and mean C-reactive protein/albumin ratio of >8 was associated with higher mortality.

Immune profiling of age and adjuvant-specific activation of human blood mononuclear cells in vitro

Vaccination reduces morbidity and mortality due to infections, but efficacy may be limited due to distinct immunogenicity at the extremes of age. This raises the possibility of employing adjuvants to enhance immunogenicity and protection. Early IFNγ production is a hallmark of effective vaccine immunogenicity in adults serving as a biomarker that may predict effective adjuvanticity. We utilized mass cytometry (CyTOF) to dissect the source of adjuvant-induced cytokine production in human blood mononuclear cells (BMCs) from newborns (~39-week-gestation), adults (~18-63 years old) and elders (>65 years of age) after stimulation with pattern recognition receptors agonist (PRRa) adjuvants. Dimensionality reduction analysis of CyTOF data mapped the BMC compartment, elucidated age-specific immune responses and profiled PRR-mediated activation of monocytes and DCs upon adjuvant stimulation. Furthermore, we demonstrated PRRa adjuvants mediated innate IFNγ induction and mapped NK cells as the key source of TLR7/8 agonist (TLR7/8a) specific innate IFNγ responses. Hierarchical clustering analysis revealed age and TLR7/8a-specific accumulation of innate IFNγ producing γδ T cells. Our study demonstrates the application of mass cytometry and cutting-edge computational approaches to characterize immune responses across immunologically distinct age groups and may inform identification of the bespoke adjuvantation systems tailored to enhance immunity in distinct vulnerable populations.

Tumor-Associated Senescent Macrophages, Their Markers, and Their Role in Tumor Microenvironment

Tumor-associated macrophages (TAMs) are an important component of the tumor microenvironment (TME) and the most abundant population of immune cells infiltrating a tumor. TAMs can largely determine direction of anti-tumor immune response by promoting it or, conversely, contribute to formation of an immunosuppressive TME that allows tumors to evade immune control. Through interactions with tumor cells or other cells in the microenvironment and, as a result of action of anti-cancer therapy, macrophages can enter senescence. In this review, we have attempted to summarize information available in the literature on the role of senescent macrophages in tumors. With the recent development of senolytic therapeutic strategies aimed at removing senescent cells from an organism, it seems important to discuss functions of the senescent macrophages and potential role of the senolytic drugs in reprogramming TAMs to enhance anti-tumor immune response and improve efficacy of cancer treatment.

The Impact of Immune System Aging on Infectious Diseases

Immune system aging is becoming a field of increasing public health interest because of prolonged life expectancy, which is not paralleled by an increase in health expectancy. As age progresses, innate and adaptive immune systems undergo changes, which are defined, respectively, as inflammaging and immune senescence. A wealth of available data demonstrates that these two conditions are closely linked, leading to a greater vulnerability of elderly subjects to viral, bacterial, and opportunistic infections as well as lower post-vaccination protection. To face this novel scenario, an in-depth assessment of the immune players involved in this changing epidemiology is demanded regarding the individual and concerted involvement of immune cells and mediators within endogenous and exogenous factors and co-morbidities. This review provides an overall updated description of the changes affecting the aging immune system, which may be of help in understanding the underlying mechanisms associated with the main age-associated infectious diseases.

T-cell immunity against senescence: potential role and perspectives

The development of age-associated diseases is related to the accumulation of senescent cells in the body. These are old non-functional cells with impaired metabolism, which are unable to divide. Such cells are also resistant to programmed cell death and prone to spontaneous production of some inflammatory factors. The accumulation of senescent cells is related to the age-associated dysfunction of organs and tissues as well as chronic inflammation that enhances with age. In the young organism, senescent cells are removed with the innate immunity system. However, the efficiency of this process decreases with age. Nowadays, more and more evidences are accumulating to support the involvement of specific immunity and T-lymphocytes in the fight against senescent cells. It has great physiological importance since the efficient elimination of senescent cells requires a high diversity of antigen-recognizing receptors to cover the entire spectrum of senescent-associated antigens with high precision and specificity. Developing the approaches of T-cell immunity stimulation to generate or amplify a physiological immune response against senescent cells can provide new perspectives to extend active longevity. In this mini-review, the authors summarize the current understanding of the role of T-cell immunity in the fight against senescent cells and discuss the prospects of stimulating adaptive immunity for combating the accumulation of senescent cells that occurs with age.

Transcriptomic analysis of mRNAs in human whole blood identified age-specific changes in healthy individuals

Older age is one of the most important shared risk factors for multiple chronic diseases, increasing the medical burden to contemporary societies. Current research focuses on identifying aging biomarkers to predict aging trajectories and developing interventions aimed at preventing and delaying the progression of multimorbidity with aging. Here, a transcriptomic changes analysis of whole blood genes with age was conducted. The age-related whole blood gene-expression profiling datasets were downloaded from the Gene Expression Omnibus (GEO) database. We screened the differentially expressed genes (DEGs) between healthy young and old individuals and performed functional enrichment analysis. Cytoscape with Cytohubba and MCODE was used to perform an interaction network of DEGs and identify hub genes. In addition, ROC curves and correlation analysis were used to evaluate the accuracy of hub genes. In total, we identified 29 DEGs between young and old samples that were enriched mainly in immunoglobulin binding and complex, humoral immune response, and immune response-activating signaling pathways. In combination with the PPI network and topological analysis, 4 hub genes (IGLL5, Jchain, POU2AF1, and Bach2) were identified. Pearson analysis showed that the expression changes of these hub genes were highly correlated with age. Among them, 3 hub genes (IGLL5, POU2AF1, and Bach2) were identified with good accuracy (AUC score > 0.7), indicating that these genes were the best indicators of age. Together, our results provided potential biomarkers IGLL5, POU2AF1, and Bach2 to identify individuals at high early risk of age-related disease to be targeted for early interventions and contribute to understanding the molecular mechanisms in the progression of aging.

NLRP3 inhibitors: Unleashing their therapeutic potential against inflammatory diseases

The NOD-like receptor pyrin domain-containing protein 3 (NLRP3) inflammasome has been linked to the release of pro-inflammatory cytokines and is essential for innate defence against infection and danger signals. These secreted cytokines improve the inflammatory response caused by tissue damage and associated inflammation. Consequently, the development of NLRP3 inflammasome inhibitors are viable option for the treatment of diverse inflammatory disorders. The significant anti-inflammatory effects of the NLRP3 inhibitors have severe side effects. Hence, the application of NLRP3 inhibitors against inflammatory disease has not yet been understood and most of the developed inhibitors are unsuccessful in clinical trials. The processes behind the NLRP3 complex, priming, and activation are the main emphasis of this review, which also covers therapeutical inhibitors of the NLRP3 inflammasome and potential therapeutic strategies for directing the NLRP3 inflammasome towards clinical development.

Contribution of viral and bacterial infections to senescence and immunosenescence

Cellular senescence is a key biological process characterized by irreversible cell cycle arrest. The accumulation of senescent cells creates a pro-inflammatory environment that can negatively affect tissue functions and may promote the development of aging-related diseases. Typical biomarkers related to senescence include senescence-associated β-galactosidase activity, histone H2A.X phosphorylation at serine139 (γH2A.X), and senescence-associated heterochromatin foci (SAHF) with heterochromatin protein 1γ (HP-1γ protein) Moreover, immune cells undergoing senescence, which is known as immunosenescence, can affect innate and adaptative immune functions and may elicit detrimental effects over the host's susceptibility to infectious diseases. Although associations between senescence and pathogens have been reported, clear links between both, and the related molecular mechanisms involved remain to be determined. Furthermore, it remains to be determined whether infections effectively induce senescence, the impact of senescence and immunosenescence over infections, or if both events coincidently share common molecular markers, such as γH2A.X and p53. Here, we review and discuss the most recent reports that describe cellular hallmarks and biomarkers related to senescence in immune and non-immune cells in the context of infections, seeking to better understand their relationships. Related literature was searched in Pubmed and Google Scholar databases with search terms related to the sections and subsections of this review.

Temporal trends, sex differences, and age-related disease influence in Neutrophil, Lymphocyte count and Neutrophil to Lymphocyte-ratio: results from InCHIANTI follow-up study

BACKGROUND

Neutrophils and lymphocytes represent the larger percentage of all white blood cells, they vary with age, with a progressive increase of the ratio in the first years of life, and then tend to remain at similar levels in steady state condition during adult age. Neutrophils to lymphocytes-ratio (NL-ratio) was proposed as an effective and low-cost marker to monitor and predict the evolution of several clinical conditions. The main objective of the study is to analyze its temporal trend variation, over twenty years' follow-up, according to age, sex, and main clinical diagnosis, in a large representative Italian population.

METHODS

The InCHIANTI study enrolled representative samples from the registry list of two towns in Tuscany, Italy. Baseline data were collected in 1998, and last follow-up visits were made in 2015-18. 1343 out of the 1453 participants enrolled were included, and consented to donate a blood sample. All subjects were assessed and followed for life-style, clinical condition, physical performance, and underwent an instrumental diagnostic session.

RESULTS

The NL-ratio showed a statistically significant interaction between birth-cohort and time of the study (p-value = 0.005). A gender dimorphism was recognized in the neutrophils absolute count and in the NL-ratio. Moreover, in female participants only, those who reported CHF had lower neutrophil-count and NL-ratio; whereas an increase in creatinine clearance was directly associated with NL-ratio. In male subjects, an increase of BMI was inversely associated with both NL-ratio and neutrophils-count during the follow-up; a similar association but in the opposite direction was observed in female participants.

CONCLUSION

NL-ratio is a more reliable predictor of healthy aging than absolute lymphocytes and/or neutrophils counts. It is associated with the changes induced by disease, lifestyle, and environmental challenges in the immune system. NL-ratio confirms the gender dimorphism in the occurrence of inflammation-driven diseases, thus providing additional evidence for the necessity of tailored sex-specific measures to prevent and treat such diseases.

Temporal trends, sex differences, and age-related disease influence in Neutrophil, Lymphocyte count and Neutrophil to Lymphocyte-ratio. Results from InCHIANTI follow-up study

Background Neutrophils and lymphocytes represent the larger percentage of all white bloodcells, they vary with age, with a progressive increase of the ratio in the first years of life, and then tend to remain at similar levels in steady state condition during adult age. Neutrophils to lymphocytes-ratio (NL-ratio) was proposed as an effective and low-cost marker to monitor and predict the evolution of severalclinical conditions. The main objective of the study is to analyze its temporal trend variation, over twenty years' follow-up, according to age, sex, and main clinical diagnosis, in a large representative Italian population. Methods The InCHIANTI study enrolled representative samples from the registry list of two towns in Tuscany, Italy. Baseline data were collected in 1998, and last follow-up visits were made in 2015-18. 1343 out of the 1453 participants enrolled were included, and consented to donate a blood sample. All subjects were assessed and followed for life-style, clinical condition, physical performance, and underwent an instrumental diagnostic session. Results The NL-ratio showed a statistically significant interaction between birth-cohort and time of the study (p-value=0.005). A gender dimorphism was recognized in the neutrophils absolute count and in the NL-ratio. Moreover, in female participants only, those who reported CHF had lower neutrophil-count and NL-ratio; whereas an increase in creatinine clearance was directly associated with NL-ratio. In male subjects, an increase of BMI was inversely associated with both NL-ratio and neutrophils-count during the follow-up; a similar association but in the opposite direction was observed in female participants. Conclusion NL-ratio is a more reliable predictor of healthy aging than absolute lymphocytes and/or neutrophils counts. It is associated with the changes induced by disease, lifestyle, and environmental challenges in the immune system. NL-ratio confirms the gender dimorphism in the occurrence of inflammation-driven diseases, thus providing additional evidence for the necessity of tailored sex-specific measures to prevent and treat such diseases.

Temporal trends, sex differences, and age-related disease influence in Neutrophil, Lymphocyte count and Neutrophil to Lymphocyte-ratio. Results from InCHIANTI follow-up study

Background Neutrophils and lymphocytes represent the larger percentage of all white bloodcells, they vary with age, with a progressive increase of the ratio in the first years of life, and then tend to remain at similar levels in steady state condition during adult age. Neutrophils to lymphocytes-ratio (NL-ratio) was proposed as an effective and low-cost marker to monitor and predict the evolution of severalclinical conditions. The main objective of the study is to analyze its temporal trend variation, over twenty years' follow-up, according to age, sex, and main clinical diagnosis, in a large representative Italian population. Methods The InCHIANTI study enrolled representative samples from the registry list of two towns in Tuscany, Italy. Baseline data were collected in 1998, and last follow-up visits were made in 2015-18. 1343 out of the 1453 participants enrolled were included, and consented to donate a blood sample. All subjects were assessed and followed for life-style, clinical condition, physical performance, and underwent an instrumental diagnostic session. Results The NL-ratio showed a statistically significant interaction between birth-cohort and time of the study (p-value=0.005). A gender dimorphism was recognized in the neutrophils absolute count and in the NL-ratio. Moreover, in female participants only, those who reported CHF had lower neutrophil-count and NL-ratio; whereas an increase in creatinine clearance was directly associated with NL-ratio. In male subjects, an increase of BMI was inversely associated with both NL-ratio and neutrophils-count during the follow-up; a similar association but in the opposite direction was observed in female participants. Conclusion NL-ratio is a more reliable predictor of healthy aging than absolute lymphocytes and/or neutrophils counts. It is associated with the changes induced by disease, lifestyle, and environmental challenges in the immune system. NL-ratio confirms the gender dimorphism in the occurrence of inflammation-driven diseases, thus providing additional evidence for the necessity of tailored sex-specific measures to prevent and treat such diseases.

Chronic inflammation and the hallmarks of aging

BACKGROUND

Recently, the hallmarks of aging were updated to include dysbiosis, disabled macroautophagy, and chronic inflammation. In particular, the low-grade chronic inflammation during aging, without overt infection, is defined as "inflammaging," which is associated with increased morbidity and mortality in the aging population. Emerging evidence suggests a bidirectional and cyclical relationship between chronic inflammation and the development of age-related conditions, such as cardiovascular diseases, neurodegeneration, cancer, and frailty. How the crosstalk between chronic inflammation and other hallmarks of aging underlies biological mechanisms of aging and age-related disease is thus of particular interest to the current geroscience research.

SCOPE OF REVIEW

This review integrates the cellular and molecular mechanisms of age-associated chronic inflammation with the other eleven hallmarks of aging. Extra discussion is dedicated to the hallmark of "altered nutrient sensing," given the scope of Molecular Metabolism. The deregulation of hallmark processes during aging disrupts the delicate balance between pro-inflammatory and anti-inflammatory signaling, leading to a persistent inflammatory state. The resultant chronic inflammation, in turn, further aggravates the dysfunction of each hallmark, thereby driving the progression of aging and age-related diseases.

MAIN CONCLUSIONS

The crosstalk between chronic inflammation and other hallmarks of aging results in a vicious cycle that exacerbates the decline in cellular functions and promotes aging. Understanding this complex interplay will provide new insights into the mechanisms of aging and the development of potential anti-aging interventions. Given their interconnectedness and ability to accentuate the primary elements of aging, drivers of chronic inflammation may be an ideal target with high translational potential to address the pathological conditions associated with aging.

Anti-Inflammatory Klotho Protein Serum Concentration Correlates with Interferon Gamma Expression Related to the Cellular Activity of Both NKT-like and T Cells in the Process of Human Aging

Klotho is a beta-glucuronidase that reveals both anti-inflammatory and anti-oxidative properties that have been associated with mechanisms of aging. The study aimed to analyze the relationships between the serum concentration of soluble α-Klotho and cellular activity of two populations of lymphocytes; T and NKT-like cells corresponding to the level of cytokine secretion; i.e., IFN-γ, TNF-α, and IL-6. The studied population comprised three age groups: young individuals ('young'), seniors aged under 85 ('old'), and seniors aged over 85 ('oldest'). Both NKT-like and T cells were either non-cultured or cultured for 48 h and stimulated appropriately with IL-2, LPS or PMA with ionomycin to compare with unstimulated control cells. In all studied age groups non-cultured or cultured NKT-like cells revealed higher expressions of TNF-α, IL-6, and IFN-γ than T cells. α-Klotho concentration in serum decreased significantly in the process of aging. Intriguingly, only IFN-γ expression revealed a positive correlation with α-Klotho protein serum concentration in both non-cultured and cultured T and NKT-like cells. Since IFN-γ is engaged in the maintenance of immune homeostasis, the observed relationships may indicate the involvement of α-Klotho and cellular IFN-γ expression in the network of adaptive mechanisms developed during the process of human aging.

Immunoglobulin G production in COVID-19 - associations with age, outcome, viral persistence, inflammation and pro-thrombotic markers

Age represents the major risk factor for fatal disease outcome in coronavirus disease (COVID-19) due to age-related changes in immune responses. On the one hand lymphocyte counts continuously decline with advancing age, on the other hand somatic hyper-mutations of B-lymphocytes and levels of class-switched antibodies diminish, resulting in lower neutralizing antibody titers. To date the impact of age on immunoglobulin G (IgG) production in response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is unknown. Therefore, we investigated the impact of age on the onset of IgG production and its association with outcome, viral persistence, inflammatory and thrombotic markers in consecutive, hospitalized COVID-19 patients admitted to the Clinic Favoriten (Vienna, Austria) between April and October 2020 that fulfilled predefined inclusion criteria. Three different IgGs against SARS-CoV-2 (spike protein S1, nucleocapsid (NC), and the spike protein receptor binding domain (RBD)) were monitored in plasma of 97 patients upon admission and three times within the first week followed by weekly assessment during their entire hospital stay. We analyzed the association of clinical parameters including C-reactive protein (CRP), D-dimer levels and platelet count as well as viral persistence with the onset and concentration of different anti-SARS-CoV-2 specific IgGs. Our data demonstrate that in older individuals anti-SARS-CoV-2 IgG production increases earlier after symptom onset and that deceased patients have the highest amount of antibodies against SARS-CoV-2 whereas intensive care unit (ICU) survivors have the lowest titers. In addition, anti-SARS-CoV-2 IgG concentrations are not associated with curtailed viral infectivity, inflammatory or thrombotic markers, suggesting that not only serological memory but also other adaptive immune responses are involved in successful viral killing and protection against a severe COVID-19 infection.