Role of thymosin α1 in restoring immune response in immunological nonresponders living with HIV.

BACKGROUND: Immunological nonresponders (INRs) living with HIV are at increased risk of co-infection and multiple tumors, with no effective strategy currently available to restore their T-cell immune response. This study aimed to explore the safety and efficacy of thymosin α1 in reconstituting the immune response in INRs. METHODS: INRs with CD4 + T cell counts between 100 and 350 cells/µL were enrolled and received two-staged 1.6 mg thymosin α1 subcutaneous injections for 24 weeks (daily in the first 2 weeks and biweekly in the subsequent 22 weeks) while continuing antiretroviral therapy. T cell counts and subsets, the expression of PD-1 and TIM-3 on T cells, and signal joint T cell receptor excision circles (sjTREC) at week 24 were evaluated as endpoints. RESULTS: Twenty three INRs were screened for eligibility, and 20 received treatment. The majority were male (19/20), with a median age of 48.1 years (interquartile range: 40.5-57.0) and had received antiretroviral therapy for 5.0 (3.0, 7.3) years. Multiple comparisons indicated that CD4 + T cell count and sjTREC increased after initiation of treatment, although no significant differences were observed at week 24 compared to baseline. Greatly, levels of CD4 + T cell proportion (17.2% vs. 29.1%, P < 0.001), naïve CD4 + and CD8 + T cell proportion (17.2% vs. 41.1%, P < 0.001; 13.8% vs. 26.6%, P = 0.008) significantly increased. Meanwhile, the proportion of CD4 + central memory T cells of HIV latent hosts (42.7% vs. 10.3%, P < 0.001) significantly decreased. Moreover, the expression of PD-1 on CD4 + T cells (14.1% vs. 6.5%, P < 0.001) and CD8 + T cells (8.5% vs. 4.1%, P < 0.001) decreased, but the expression of TIM-3 on T cellsremained unaltered at week 24. No severe adverse events were reported and HIV viral loads kept stable throughout the study. CONCLUSIONS: Thymosin α1 enhance CD4 + T cell count and thymic output albeit as a trend rather than an endpoint. Importantly, it improves immunosenescence and decreases immune exhaustion, warranting further investigation. TRIAL REGISTRATION: This single-arm prospective study was registered with ClinicalTrials.gov (NCT04963712) on July 15, 2021.

Comprehensive Review of the Safety and Efficacy of Thymosin Alpha 1 in Human Clinical Trials.

Objective: This study aims to assess the safety and efficacy of Thymosin Alpha 1 (Tα1) through a comprehensive narrative review of clinical studies involving over 11 000 human subjects in more than 30 trials. The focus was on Tα1's application in COVID-19, autoimmune conditions, and cancer treatment, with implications for future considerations. Methods: We systematically searched articles relevant to critical studies on COVID-19, infectious diseases, cancer, and autoimmune diseases indexed on Pubmed, Google Scholar, and Cochrane Library. Our focus was on evaluating the safety and efficacy of Tα1 in human subjects. Clinical trials conducted worldwide involving diverse populations were analyzed to assess the safety and effectiveness of Tα1. The review examines explicit outcomes in over 11 000 human subjects, emphasizing its role in addressing COVID-19, autoimmune conditions, and cancer treatment. Results: Contrary to the FDA's restriction on Tα1 and 21 additional peptides in 2023, our analysis reveals consistent evidence of Tα1's safety and efficacy. The peptide has demonstrated significant effectiveness in treating various conditions, including COVID-19, autoimmune disorders, and cancer. This review summarizes conclusions drawn from a comprehensive examination of clinical trials worldwide. Conclusions: Based on substantial evidence from clinical trials, Tα1 emerges as a well-tolerated and effective immune modulator. The FDA>s restriction appears unfounded, as Tα1 has shown safety and efficacy beyond the initially specified conditions. Urgent attention and intervention are warranted to ensure the continued availability of this life-saving peptide through prescription. Therefore, it is recommended that the FDA permits 503A compounding pharmacies to compound Tα1, considering its potential to treat a variety of conditions effectively.

A Pilot Trial of Thymalfasin (Thymosin-α-1) to Treat Hospitalized Patients With Hypoxemia and Lymphocytopenia Due to Coronavirus Disease 2019 Infection.

BACKGROUND: Thymosin-α-1 (Tα1) may be a treatment option for coronavirus disease 2019 (COVID-19), but efficacy and safety data remain limited. METHODS: Prospective, open-label, randomized trial assessing preliminary efficacy and safety of thymalfasin (synthetic form of Tα1), compared with the standard of care, among hospitalized patients with hypoxemia and lymphocytopenia due to COVID-19. RESULTS: A total of 49 patients were included in this analysis. Compared with control patients, the incidence of clinical recovery was higher for treated patients with either baseline low-flow oxygen (subdistribution hazard ratio, 1.48 [95% confidence interval, .68-3.25]) or baseline high-flow oxygen (1.28 [.35-4.63]), although neither difference was significant. Among patients with baseline low-flow oxygen, treated patients, compared with control patients, had an average difference of 3.84 times more CD4+ T cells on day 5 than on day 1 (P = .01). Nine serious adverse events among treated patients were deemed not related to Tα1. CONCLUSIONS: Tα1 increases CD4+ T-cell count among patients with baseline low-flow oxygen support faster than the standard of care and may have a role in the management of hospitalized patients with hypoxemia and lymphocytopenia due to COVID-19. CLINICAL TRIALS REGISTRATION: NCT04487444.

The efficacy of thymosin alpha-1 therapy in moderate to critical COVID-19 patients: a systematic review, meta-analysis, and meta-regression.

BACKGROUND: Effort to search for the optimal COVID-19 treatment has continuously been attempted. Thymosin alpha-1 have immunomodulatory properties which may be beneficial in case of viral infection. This study's goal is to determine whether thymosin alpha-1 is effective in treating people with moderate-to-severe COVID-19. METHODS: We searched for literature in 4 database: Scopus, Europe PMC, Medline, ClinicalTrials.gov, and Cochrane Library until March 25th, 2023. If those articles have data on the efficacy of thymosin alpha-1 therapy on COVID-19, they would be included. Risk ratio (RR) and Mean Difference (MD) along with their 95% confidence intervals were used to pool the results of dichotomous and continuous variables, respectively. RESULTS: Pooled data from 8 studies indicated that moderate to critical Covid-19 patients who were receiving thymosin alpha-1 therapy had significantly lower mortality from COVID-19 (RR 0.59; 95% CI 0.37-0.93, p = 0.02, I2 = 84%), but without any difference in the needs for mechanical ventilation (RR 0.83; 95% CI 0.48-1.44, p = 0.51, I2 = 74%) and hospital length of stay (MD 2.32; 95% CI - 0.93, 5.58, p = 0.16, I2 = 94%) compared to placebo. The benefits of thymosin alpha-1 on the mortality rate were significantly affected only by sample size (p = 0.0000) and sex (p = 0.0117). CONCLUSION: Our study suggests that treatment with thymosin alpha-1 may reduce mortality rate in moderate to critical COVID-19 patients. Randomized clinical trials (RCTs) are still required to verify the findings of our study.

Clinical effect of Xuebijing combined with thymosinα1 on patients with severe pneumonia complicated with sepsis and its effect on serum inflammatory factors.

This study aimed to research the clinical effect of Xuebijing combined with thymosin α1 on patients with severe pneumonia complicated with sepsis, and its effect on serum inflammatory factors. For this purpose, 81 cases of severe pneumonia complicated with sepsis were collected. All patients were given early treatments. 41 cases who received Xuebijing injection by intravenous drip were selected as the control group. 40 cases who were treated through subcutaneous injection of thymosin α1 based on Xuebijing injection by intravenous drip were selected as the study group. The body temperature, respiration, heart rate, leukocytes, other general conditions, blood gas indexes, serum IL-6, TNF-α and CRP levels, bacterial clearance rate and therapy effect were recorded and compared before and after treatment. Results showed that after treatment, the body temperature, respiration, heart rate, leukocytes and other general conditions of the study group were lower than those in the control group (all p<0.05). The blood gas indexes pH and PaCO2 levels of the study group were lower than those of the control group. The levels of serum interleukin-6 (IL-6), serum tumor necrosis factor α (TNF-α) and C-reactive protein (CRP) in the study group were lower than those in the control group (all p<0.05). The bacterial clearance rate of the study group was lower than that of the control group (all p<0.05). The total effective rate of treatment of patients in the study group was higher than that of patients in the control group (all p<0.05). In general, Thymosin α1 and Xuebijing injection can improve the therapy effect of severe pneumonia complicated with sepsis, improve the hemorheology condition of patients, effectively remove bacteria and reduce the expression level of serum CRP, TNF-α, IL-6, IL-8 and other inflammatory factors in patients, which is worthy of clinical promotion.

Value of Thymosin α1 Combined With Blood Purification to Increase Successful Rescues of Shock Patients.

Context: Septic shock (SS) can pose a high risk of death if rescue efforts in an emergency room aren't started in a timely manner. Thus, rapid and efficient treatment is of great significance to the SS patients' survival. T-α1 can enhance the cellular immune function of patients, and blood purification (BP) can improve the hemodynamics of SS patients by clearing inflammatory mediators in the blood. Objective: The study intended to explore the effects of Thymosin α1 (T-α1) plus blood purification (BP) on SS patients under the emergency green channel (GC), a fast and efficient service system that hospitals provide for acutely and critically ill patients. Design: The research team designed a randomized controlled study. Setting: The study took place in the Emergency Department at the Second Affiliated Hospital of Xi'an Jiaotong University in Xi'an, Shaanxi, China. Participants: Participants were 86 SS patients who came to the hospital for treatment between June 2019 and January 2021. Intervention: The research team numbered the patients in sequence according to the admission time of the patients, and then randomly numbered them by the computer, and assigned participants to an intervention or a control group, with 43 participants in the intervention group receiving T-α1 plus BP therapy and 43 participants in the control group receiving BP treatment only. Outcome Measures: The study measured preparation time before treatment, symptom-onset-to-door (SOTD), duration of shock, length of stay in the intensive care unit (ICU), and incidence of adverse reactions. The study also assessed changes between baseline and postintervention in inflammatory cytokines (ICs), immunological function, and myocardial-function markers. Finally, the research team conducted a one-year follow-up to determine participants' prognostic survival. Results: The groups showed no significant differences in the preparation time before treatment, SOTD, rescue success rate, and incidence of adverse events (P > .05), while the intervention group showed a significantly shorter duration of shock and length stay in the ICU and a significantly higher overall response rate (P < .05). The research team observed significant improvements in the T-lymphocyte subsets, ICs, and myocardial function in both groups postintervention, but the changes in the intervention group were significantly greater (P < .05). Follow-up results showed no significant differences in overall survival between the intervention and control groups (P > .05), but the average LC was significantly higher in the intervention group (P < .05). Conclusions: For SS patients, the combination of T-α1 and BP under the emergency GC can effectively improve their immunological and myocardial function, reduce inflammatory reaction, and prolong their LCs, which provides a greater guarantee of the effectiveness of treatment for SS patients in the future.

The right immune-modulation at the right time: thymosin α1 for prevention of severe COVID-19 in cancer patients.

We presented the rationale for the use of thymosin α1 as prophylaxis of severe COVID-19 in cancer patients undergoing active treatment, constituting the background for the PROTHYMOS study, a prospective, multicenter, open-label, Phase II randomized study, currently in its start-up phase (Eudract no. 2020-006020-13). We aim to offer new hope for this incurable disease, especially to frail patient population, such as patients with cancer. The hypothesis of an effective prophylactic approach to COVID-19 would have immediate clinical relevance, especially given the lack of curative approaches. Moreover, in the 'COVID-19 vaccine race era' both clinical and biological results coming from the PROTHYMOS trials could even support the rationale for future combinatorial approaches, trying to rise vaccine efficacy in frail individuals.

Dysfunctional Inflammation in Cystic Fibrosis Airways: From Mechanisms to Novel Therapeutic Approaches.

Cystic fibrosis (CF) is an inherited disorder caused by mutations in the gene encoding for the cystic fibrosis transmembrane conductance regulator (CFTR) protein, an ATP-gated chloride channel expressed on the apical surface of airway epithelial cells. CFTR absence/dysfunction results in defective ion transport and subsequent airway surface liquid dehydration that severely compromise the airway microenvironment. Noxious agents and pathogens are entrapped inside the abnormally thick mucus layer and establish a highly inflammatory environment, ultimately leading to lung damage. Since chronic airway inflammation plays a crucial role in CF pathophysiology, several studies have investigated the mechanisms responsible for the altered inflammatory/immune response that, in turn, exacerbates the epithelial dysfunction and infection susceptibility in CF patients. In this review, we address the evidence for a critical role of dysfunctional inflammation in lung damage in CF and discuss current therapeutic approaches targeting this condition, as well as potential new treatments that have been developed recently. Traditional therapeutic strategies have shown several limitations and limited clinical benefits. Therefore, many efforts have been made to develop alternative treatments and novel therapeutic approaches, and recent findings have identified new molecules as potential anti-inflammatory agents that may exert beneficial effects in CF patients. Furthermore, the potential anti-inflammatory properties of CFTR modulators, a class of drugs that directly target the molecular defect of CF, also will be critically reviewed. Finally, we also will discuss the possible impact of SARS-CoV-2 infection on CF patients, with a major focus on the consequences that the viral infection could have on the persistent inflammation in these patients.

Pharmacological and Genomic Approaches in Management of Cystic Fibrosis.

Cystic fibrosis (CF) is an inherited recessive autosomal disorder that affects the lungs, the digestive system, and secretory glands. It is a lethal condition caused by a mutation in the gene cystic-fibrosis-transmembrane-conductance- regulator (CFTR), which leads to defects in ion channels and results in obstruction of mucus in airway channels. Unbalanced ion exchange causes impaired water transport and accumulation of viscous mucus in the air way leads to bacterial colonization, for example, with Staphylococcus aureus. The most common mutation is the deletion of nucleotides in epithelial membrane; hence, it is a multiple-organ-defective disease that mostly effects the lungs. Researchers are working on gene therapy that aims to introduce a normal CFTR gene copy into the epithelial cells of lungs. Several approaches have been designed to improve transepithelial ion transport in CF patients. Normal CFTR gene delivery has been performed using viral and nonviral vectors, but these approaches are not more efficient against the cell barriers. Enzymes may be used that inhibit the sphingolipid to provide proper microenvironment for the CFTR gene product. Thymosin alpha-1 has also been reported as a potential corrector in treatment of CF.

The clinical efficacy and adverse effects of Entecavir plus Thymosin alpha-1 combination therapy versus Entecavir Monotherapy in HBV-related cirrhosis: a systematic review and meta-analysis.

BACKGROUND: Previous studies have demonstrated the benefits of thymosin alpha-1 (Tα1) in anti-virus, immunological enhancement and anti-inflammation. However, it is controversial about the efficacy and safety of entecavir (ETV) plus Tα1 combination therapy versus ETV monotherapy in cirrhotic patients with hepatitis B virus (HBV) infection. METHODS: The systematic review and meta-analysis of randomized clinical trials (RCTs) were performed to evaluate the efficacy and safety of ETV plus Tα1 combination therapy versus ETV monotherapy in HBV-related patients with cirrhosis. We performed a systematic literature search via PubMed, Web of Science, Cochrane Central Register of Controlled Trials (CENTRAL), EMBASE, China National Knowledge Infrastructure (CNKI), Chinese Science and Technology Journals Database (VIP), and Chinese Biological Medicine database (CBM). Relative risk (RR) and standardized mean difference (SMD) with a fixed- or random- effect model were calculated. Heterogeneity was assessed through a Cochrane Q-test and I2 values. RESULTS: Seven RCTs involving 1144 subjects were included in the systematic review and meta-analysis. Compared with ETV monotherapy, ETV plus Tα1 combination therapy led to a higher complete response (RR = 1.18; 95% CI, 1.07-1.30). In post treatment for 24 weeks, the HBV DNA undetectable rate and HBeAg loss rate were higher in ETV plus Tα1 group than in ETV alone group (RR = 1.91; 95% CI, 1.56-2.35; RR = 2.05; 95% CI, 1.62-2.60). However, after 48 and 52 weeks of treatment, there was no significant difference between the combination therapy and ETV monotherapy (RR = 1.07; 95% CI, 0.96-1.18; RR = 1.17; 95% CI, 0.89-1.55). At week 52 of treatment, the HBsAg loss rate of ETV plus Tα1 group was no significance with that of ETV alone group (RR = 1.03; 95% CI, 0.15-7.26). In comparison with ETV alone, the some biochemical parameters and liver fibrosis were obviously improved by ETV plus Tα1, and there was significant heterogeneity. In addition, the number of adverse events was significantly reduced by ETV plus Tα1, compared to ETV alone (RR = 0.48; 95% CI, 0.24-0.95). CONCLUSIONS: ETV plus Tα1 might lead to a higher clinical response and a lower comprehensive adverse reaction rate in HBV-related patients with cirrhosis, compared to ETV alone. However, the whole patients included in this meta-analysis were from Chinese mainland, so that more worldwide RCTs with a larger sample size are needed to verify the current findings.

A Convalescent of COVID-19 with RT-PCR Test Continues Positive in Stool.

BACKGROUND: Coronavirus disease (COVID-19) has affected more than 100 countries worldwide and the discharge criteria of patients with COVID-19 vary across different countries. In China, patients with two negative respiratory viral RNA tests taken at least one day apart can be discharged with no further quarantine required. Currently, PCR testing of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in fecal sample is not routinely performed. METHODS: We present a patient with COVID-19, whose respiratory swabs became negative but fecal sample remained positive for SARS-CoV-2 RNA. RESULTS: Stool sample collected on 27th of February was still positive for SARS-CoV-2 RNA, 24 days after the first negative respiratory swab. CONCLUSIONS: Based on the experience from the 2003 SARS epidemic, we recommend that fecal RNA testing of SARS-CoV-2 should be incorporated into the discharge criteria to minimize the risk of transmission from the gastrointestinal tract.

The severe COVID-19: A sepsis induced by viral infection? And its immunomodulatory therapy.

COVID-19 is known for its magical infectivity, fast transmission and high death toll based on the large number of infected people. From the perspective of the clinical manifestation, autopsy examination and pathophysiology, the essence of COVID-19 should be viewed as a sepsis induced by viral infection, and has the essential characteristics as sepsis induced by other pathogens. Therefore, in addition to etiological and supportive treatment, immunomodulatory therapy is also appropriate to severe COVID-19. Although there is still a lack of consensus on immunotherapy for sepsis so far, relatively rich experiences have been accumulated in the past decades, which will help us in the treatment of severe COVID-19. This article will elaborate immunotherapy of sepsis, though it may not be consistent.

Immune-Enhancing Treatment among Acute Necrotizing Pancreatitis Patients with Metabolic Abnormalities: A Post Hoc Analysis of a Randomized Clinical Trial.

Background/Aims: Metabolic syndrome is common in patients with acute pancreatitis and its components have been reported to be associated with infectious complications. In this post hoc analysis, we aimed to evaluate whether metabolic abnormalities impact the effect of immune-enhancing thymosin alpha-1 (Tα1) therapy in acute necrotizing pancreatitis (ANP) patients. Methods: All data were obtained from the database for a multicenter randomized clinical trial that evaluated the efficacy of Tα1 in ANP patients. Patients who discontinued the Tα1 treatment prematurely were excluded. The primary outcome was 90-day infected pancreatic necrosis (IPN) after randomization. Three post hoc subgroups were defined based on the presence of hyperglycemia, hypertriglyceridemia, or both at the time of randomization. In each subgroup, the correlation between Tα1 and 90-day IPN was assessed using the Cox proportional-hazards regression model. Multivariable propensity-score methods were used to control potential bias. Results: Overall, 502 participants were included in this post hoc analysis (248 received Tα1 treatment and 254 received matching placebo treatment). Among them, 271 (54.0%) had hyperglycemia, 371 (73.9%) had hypertriglyceridemia and 229 (45.6%) had both. Tα1 therapy was associated with reduced incidence of IPN among patients with hyperglycemia (18.8% vs 29.7%: hazard ratio, 0.80; 95% confidence interval, 0.37 to 0.97; p=0.03), but not in the other subgroups. Additional multivariate regression models using three propensity-score methods yielded similar results. Conclusions: Among ANP patients with hyperglycemia, immune-enhancing Tα1 treatment was associated with a reduced risk of IPN (ClinicalTrials.gov, Registry number: NCT02473406).

Evaluation of the efficacy and safety of a precise thymalfasin-regulated PRaG regimen for advanced refractory solid tumours: protocol for the open-label, prospective, multicentre study (PRaG5.0 study).

INTRODUCTION: The PRaG regimen, which consists of hypofractionated radiotherapy combined with a programmed cell death-1/programmed cell death ligand-1 (PD-1/PD-L1) inhibitor and granulocyte-macrophage colony stimulating factor (GM-CSF), has been demonstrated to have a survival benefit in patients with advanced solid tumours who have failed at least two lines of treatment. Nonetheless, lymphopenia poses an impediment to the enduring efficacy of PD-1/PD-L1 inhibitor therapy. Adequate lymphocyte reserves are essential for the efficacy of immunotherapy. Coupling the PRaG regimen with immunomodulatory agents that augment the number and functionality of lymphocytes may yield further survival benefits in this cohort of patients. OBJECTIVE: The aim of this study is to investigate the effectiveness and safety of a meticulously thymalfasin-controlled PRaG regimen in patients with advanced and chemotherapy-resistant solid tumours. METHODS AND ANALYSIS: The study has a prospective, single-arm, open-label, multicentre design and aims to recruit up to 60 patients with histologically confirmed advanced solid tumours that have relapsed or metastasised. All eligible patients will receive a minimum of two cycles of the PRaG regimen comprising thymalfasin followed by maintenance treatment with a PD-1/PD-L1 inhibitor and thymalfasin for 1 year or until disease progression. Patients will be monitored according to the predetermined protocol for a year or until disease progression after initiation of radiotherapy. ETHICS AND DISSEMINATION: The study protocol was approved by the Ethics Committee of the Second Affiliated Hospital of Soochow University, on 25 November 2022 (JD-LK-2022-151-01) and all other participating hospitals. Findings will be disseminated through national and international conferences. We also plan to publish our findings in high-impact peer-reviewed journal. TRIAL REGISTRATION NUMBER: NCT05790447.

PD-1 inhibitor combined with SBRT, GM-CSF, and thymosin alpha-1 in metastatic breast cancer: A case report and literature review.

RATIONALE: Triple-negative breast cancer is characterized by a worse prognosis compared with other breast cancer subtypes, especially in the case of pretreated metastatic triple-negative breast cancer (mTNBC). Because of the limited treatment options and suboptimal response rates, there is a pressing need to explore novel treatment protocols. PATIENT CONCERNS: A 48-year-old female patient diagnosed with mTNBC who had not responded to multiple lines of therapy (including surgery, chemotherapy, and radiotherapy) but demonstrated significant efficacy and abscopal effects after enrolling in our clinical trial. DIAGNOSES: Triple-negative breast cancer with lung metastases. INTERVENTIONS: The clinical trial combined stereotactic body radiotherapy, immunotherapy, granulocyte-macrophage colony-stimulating factor, and thymosin alpha-1 to treat previously treated metastatic solid cancers. OUTCOMES: This combined treatment regimen implemented in this clinical trial yielded the patient's notable efficacy, accompanied by abscopal effects. The target lesion and the 3 observed lesions achieved a partial response according to the RECIST v1.1 criteria. reevaluation scans after 2 cycles of immunotherapy indicated a regression rate of -78.97% for the target lesion and -56.73% for the observed lesions. Hematological indexes were stable, and there was no apparent myelosuppression. Also, the tumor marker CA-199 exhibited a downward trend. During the course of treatment, the patient experienced a grade 2 skin reaction, which improved after receiving antiallergic treatment. No further adverse effects were observed. LESSONS: This treatment regimen may offer a promising treatment strategy for patients with mTNBC and other metastatic solid cancers.

COVID-19 and beyond: Reassessing the role of thymosin alpha1 in lung infections.

The recent COVID-19 pandemic has catalyzed the attention of the scientific community to the long-standing issue of lower respiratory tract infections. The myriad of airborne bacterial, viral and fungal agents to which humans are constantly exposed represents a constant threat to susceptible individuals and bears the potential to reach a catastrophic scale when the ease of inter-individual transmission couples with a severe pathogenicity. While we might be past the threat of COVID-19, the risk of future outbreaks of respiratory infections is tangible and argues for a comprehensive assessment of the pathogenic mechanisms shared by airborne pathogens. On this regard, it is clear that the immune system play a major role in dictating the clinical course of the infection. A balanced immune response is required not only to disarm the pathogens, but also to prevent collateral tissue damage, thus moving at the interface between resistance to infection and tolerance. Thymosin alpha1 (Tα1), an endogenous thymic peptide, is increasingly being recognized for its ability to work as an immunoregulatory molecule able to balance a derailed immune response, working as immune stimulatory or immune suppressive in a context-dependent manner. In this review, we will take advantage from the recent work on the COVID-19 pandemic to reassess the role of Tα1 as a potential therapeutic molecule in lung infections caused by either defective or exaggerated immune responses. The elucidation of the immune regulatory mechanisms of Tα1 might open a new window of opportunity for the clinical translation of this enigmatic molecule and a potential new weapon in our arsenal against lung infections.

Thymosin α-1 in cancer therapy: Immunoregulation and potential applications.

Thymosin α-1 (Tα-1) is an immunomodulating polypeptide of 28 amino acids, which was the first peptide isolated from thymic tissue and has been widely used for the treatment of viral infections, immunodeficiencies, and especially malignancies. Tα-1 stimulates both innate and adaptive immune responses, and its regulation of innate immune cells and adaptive immune cells varies under different disease conditions. Pleiotropic regulation of immune cells by Tα-1 depends on activation of Toll-like receptors and its downstream signaling pathways in various immune microenvironments. For treatment of malignancies, the combination of Tα-1 and chemotherapy has a strong synergistic effect by enhancing the anti-tumor immune response. On the basis of the pleiotropic effect of Tα-1 on immune cells and the promising results of preclinical studies, Tα-1 may be a favorable immunomodulator to enhance the curative effect and decrease immune-related adverse events of immune checkpoint inhibitors to develop novel cancer therapies.

Thymosin alpha1 use in adult COVID-19 patients: A systematic review and meta-analysis on clinical outcomes.

OBJECTIVE: Thymosin alpha1 (Ta1) is widely used to treat patients with coronavirus disease 2019 (COVID-19), however, its effect remains unclear. This systematic review and meta-analysis aimed to evaluate the effect of Ta1 as a COVID-19 therapy. METHODS: PubMed, EMBASE, the Cochrane library, Web of Science, and the reference lists of relevant articles were searched to identify eligible studies. Assessment of heterogeneity was done using the I-squared (I2) test and random/fixed effect analysis was done to determine the risk ratio (RR). We polled the data related to mortality mainly by using Review Manager 5.4. Predefined subgroup analyses and sensitivity analyses were also performed. RESULTS: A total of 9 studies were included, on a total of 5352 (Ta1 = 1152, control = 4200) patient outcomes. Meta-analysis results indicated that Ta1 therapy had no statistically significant effect on mortality [RR 1.03 (0.60, 1.75), p = 0.92, I2 = 90 %]. Subgroup analyses demonstrated that the beneficial effect in mortality was associated with mean age＞60 years in the Tα1 group [RR 0.68 (0.58, 0.78), p < 0.0000.1, I2 = 0 %], the proportion of female ≤ 40 % in the Tα1 group [RR 0.67 (0.58, 0.77), p < 0.0000.1, I2 = 0 %], and severe/critical COVID-19 patients [RR 0.66 (0.57, 0.76), p < 0.0000.1, I2 = 0 %]. Sensitivity analysis further demonstrated the results to be robust. CONCLUSIONS: The results of this meta-analysis do not support the use of Ta1 in hospitalized adult COVID-19 patients.

Thymosin alpha 1 restores the immune homeostasis in lymphocytes during Post-Acute sequelae of SARS-CoV-2 infection.

The complex alterations of the immune system and the immune-mediated multiorgan injury plays a key role in host response to SARS-CoV-2 infection and in the pathogenesis of COVID-19, being also associated with adverse outcomes. Thymosin alpha 1 (Tα1) is one of the molecules used in the treatment of COVID-19, as it is known to restore the homeostasis of the immune system during infections and cancer. The use of Tα1 in COVID-19 patients had been widely used in China and in COVID-19 patients, it has been shown to decrease hospitalization rate, especially in those with greater disease severity, and reduce mortality by restoring lymphocytopenia and more specifically, depleted T cells. Persistent dysregulation with depletion of naive B and T cell subpopulations and expansion of memory T cells suggest a chronic stimulation of the immune response in individuals with post-acute sequelae of SARS-CoV-2 infection (PASC). Our data obtained from an ex vivo study, showed that in PASC individuals with a chronically altered immune response, Tα1 improve the restoration of an appropriate response, most evident in those with more severe illness and who need respiratory support during acute phase, and in those with specific systemic and psychiatric symptoms of PASC, confirming Tα1 treatment being more effective in compromised patients. The results obtained, along with promising reports on recent trials on Tα1 administration in patients with COVID-19, offer new insights into intervention also for those patients with long-lasting inflammation with post-infectious symptoms, some of which have a delayed onset.