Sub-lingual administration of a polyvalent mechanical bacterial lysate (PMBL) in patients with moderate, severe, or very severe chronic obstructive pulmonary disease (COPD) according to the GOLD spirometric classification: A multicentre, double-blind, randomised, controlled, phase IV study (AIACE study: Advanced Immunological Approach in COPD Exacerbation)

Exploring the journey: A comprehensive review of vaccine development against Klebsiella pneumoniae

Klebsiella pneumoniae, a prominent nosocomial pathogen, poses a critical global health threat due to its multidrug-resistant (MDR) and hypervirulent strains. This comprehensive review focuses into the complex approaches undertaken in the development of vaccines against K. pneumoniae. Traditional methods, such as whole-cell and ribosomal-based vaccines, are compared with modern strategies, including DNA and mRNA vaccines, and extracellular vesicles (EVs), among others. Each method presents unique advantages and challenges, emphasising the complexity of developing an effective vaccine against this pathogen. Significant advancements in computational tools and artificial intelligence (AI) have revolutionised antigen identification and vaccine design, enhancing the precision and efficiency of developing multiepitope-based vaccines. The review also highlights the potential of glycomics and immunoinformatics in identifying key antigenic components and elucidating immune evasion mechanisms employed by K. pneumoniae. Despite progress, challenges remain in ensuring the safety, efficacy, and manufacturability of these vaccines. Notably, EVs demonstrate promise due to their intrinsic adjuvant properties and ability to elicit robust immune responses, although concerns regarding inflammation and antigen variability persist. This review provides a critical overview of the current landscape of K. pneumoniae vaccine development, stressing the need for continued innovation and interdisciplinary collaboration to address this pressing public health issue. The integration of advanced computational methods and AI holds the potential to accelerate the development of effective immunotherapies, paving the way for novel vaccines against MDR K. pneumoniae.

Sublingually administered bacterial lysates: rationale, mechanisms of action and clinical outcomes

This review discusses available evidence on the mechanisms of action of bacterial lysates, and the clinical effects of their sublingual administration. Bacterial lysates act through many immunological effects, including dendritic cell activation, modification of circulating lymphocyte subsets and antibody production. The production of salivary IgA was repeatedly shown to be induced by the sublingual administration of a prototype bacterial lysate containing soluble and corpuscular antigens. Bacterial lysates are a useful tool for the prevention of recurrent respiratory tract infections. Sublingual administration should be the preferred option.

Advances in Bacterial Lysate Immunotherapy for Infectious Diseases and Cancer

Antigenic cell fragments, pathogen-associated molecular patterns, and other immunostimulants in bacterial lysates or extracts may induce local and systemic immune responses in specific and nonspecific paradigms. Based on current knowledge, this review aimed to determine whether bacterial lysate has comparable functions in infectious diseases and cancer treatment. In infectious diseases, including respiratory and urinary tract infections, immune system activation by bacterial lysate can identify and combat pathogens. Commercially available bacterial lysates, including OM-85, Ismigen, Lantigen B, and LW 50020, were effective in children and adults in treating respiratory tract infections, chronic obstructive pulmonary disease, rhinitis, and rhinosinusitis with varying degrees of success. Moreover, OM-89, Uromune, Urovac, Urivac, and ExPEC4V showed therapeutic benefits in controlling urinary tract infections in adults, especially women. Bacterial lysate-based therapeutics are safe, well-tolerated, and have few side effects, making them a good alternative for infectious disease management. Furthermore, a nonspecific immunomodulation by bacterial lysates may stimulate innate immunity, benefiting cancer treatment. "Coley's vaccine" has been used to treat sarcomas, carcinomas, lymphomas, melanomas, and myelomas with varying outcomes. Later, several similar bacterial lysate-based therapeutics have been developed to treat cancers, including bladder cancer, non-small cell lung cancer, and myeloma; among them, BCG for in situ bladder cancer is well-known. Proinflammatory cytokines, including IL-1, IL-6, IL-12, and TNF-α, may activate bacterial antigen-specific adaptive responses that could restore tumor antigen recognition and response by tumor-specific type 1 helper cells and cytotoxic T cells; therefore, bacterial lysates are worth investigating as a vaccination adjuvants or add-on therapies for several cancers.

Unlocking the power of postbiotics: A revolutionary approach to nutrition for humans and animals

Postbiotics, which comprise inanimate microorganisms or their constituents, have recently gained significant attention for their potential health benefits. Extensive research on postbiotics has uncovered many beneficial effects on hosts, including antioxidant activity, immunomodulatory effects, gut microbiota modulation, and enhancement of epithelial barrier function. Although these features resemble those of probiotics, the stability and safety of postbiotics make them an appealing alternative. In this review, we provide a comprehensive summary of the latest research on postbiotics, emphasizing their positive impacts on both human and animal health. As our understanding of the influence of postbiotics on living organisms continues to grow, their application in clinical and nutritional settings, as well as animal husbandry, is expected to expand. Moreover, by substituting postbiotics for antibiotics, we can promote health and productivity while minimizing adverse effects. This alternative approach holds immense potential for improving health outcomes and revolutionizing the food and animal products industries.

Postbiotics as potential new therapeutic agents for sepsis

Sepsis is the main cause of death in critically ill patients and gut microbiota dysbiosis plays a crucial role in sepsis. On the one hand, sepsis leads to the destruction of gut microbiota and induces and aggravates terminal organ dysfunction. On the other hand, the activation of pathogenic gut flora and the reduction in beneficial microbial products increase the susceptibility of the host to sepsis. Although probiotics or fecal microbiota transplantation preserve gut barrier function on multiple levels, their efficacy in sepsis with intestinal microbiota disruptions remains uncertain. Postbiotics consist of inactivated microbial cells or cell components. They possess antimicrobial, immunomodulatory, antioxidant and antiproliferative activities. Microbiota-targeted therapy strategies, such as postbiotics, may reduce the incidence of sepsis and improve the prognosis of patients with sepsis by regulating gut microbial metabolites, improving intestinal barrier integrity and changing the composition of the gut microbiota. They offer a variety of mechanisms and might even be superior to more conventional 'biotics' such as probiotics and prebiotics. In this review, we present an overview of the concept of postbiotics and summarize what is currently known about postbiotics and their prospective utility in sepsis therapy. Overall, postbiotics show promise as a viable adjunctive therapy option for sepsis.

Immunostimulants versus placebo for preventing exacerbations in adults with chronic bronchitis or chronic obstructive pulmonary disease

BACKGROUND

Individuals with chronic obstructive pulmonary disease (COPD) or chronic bronchitis may experience recurrent exacerbations, which negatively impact prognosis and quality of life, and can impose a significant socioeconomic burden on the individual and wider society. Immunostimulants are a broad category of therapies that may theoretically enhance non-specific immunity against several respiratory insults, thereby reducing exacerbation risk and severity. However, evidence to date for their use in this population is limited.

OBJECTIVES

To determine the efficacy of immunostimulants in preventing respiratory exacerbations in adults with chronic obstructive pulmonary disease, chronic bronchitis, or both.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest literature search was conducted on 25 January 2022.  SELECTION CRITERIA: We included parallel randomised controlled trials (RCTs) that compared immunostimulant therapy, administered by any method and with the intention of preventing (rather than treating) exacerbations, with placebo for a minimum treatment duration of one month in adults with chronic bronchitis or COPD, or both. We excluded participants with other respiratory conditions.  DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcomes were number of participants with no exacerbations during the study period and all-cause mortality, secondary outcomes were respiratory-related mortality, quality of life, number of participants requiring antibiotics, exacerbation duration, respiratory-related hospitalisation duration and adverse events/side effects. We used GRADE to assess certainty of evidence for each outcome.

MAIN RESULTS

This review included 36 studies involving 6192 participants. Studies were published between 1981 and 2015. Duration ranged from three to 14 months. The mean age of study participants varied between 35.2 and 82 years. Twelve studies examined participants with COPD only. Seventeen studies reported baseline lung function values; most indicated a moderate-to-severe degree of airflow limitation. Nineteen studies indicated inclusion of participants with a mean baseline exacerbation frequency of two or more in the preceding year. Immunostimulants investigated were OM-85, AM3, RU41740 (Biostim), Ismigen, Diribiotine CK, thymomodulin, pidotimod, D53 (Ribomunyl), Lantigen B, Symbioflor, and hyaluronan; routes of administration were oral, sublingual, and subcutaneous. The risk of bias of the included studies was mostly low or unclear. Participants receiving immunostimulants for a mean duration of six months were slightly more likely to be free of exacerbations during that time (odds ratio (OR) 1.48, 95% confidence interval (CI) 1.15 to 1.90; 15 RCTs, 2961 participants; moderate-certainty evidence). The overall number needed to treat with immunostimulants for a mean of six months, to prevent one participant from experiencing an exacerbation, was 11 (95% CI 7 to 29). This outcome was associated with a moderate degree of unexplained heterogeneity (I2 = 53%). Type of immunostimulant, baseline lung function, baseline exacerbation frequency, treatment duration, and follow-up duration did not modify the effect size, although due to heterogeneity and limited study and participant numbers within some subgroups, the validity of the subgroup treatment effect estimates were uncertain. Immunostimulants probably result in little to no difference in all-cause mortality (OR 0.64, 95% CI 0.37 to 1.10; 5 RCTs, 1558 participants; moderate-certainty evidence) and respiratory-related mortality (OR 0.40, 95% CI 0.15 to 1.07; 2 RCTs, 735 participants; low-certainty evidence) compared to placebo; however, the effects were imprecise and data quality limited the certainty of these results.  There was a small improvement in health-related quality of life, as measured by the St George's Respiratory Questionnaire (SGRQ), with immunostimulant compared to placebo (mean difference -4.59, 95% CI -7.59 to -1.59; 2 RCTs, 617 participants; very-low certainty evidence). The effect estimate just met the minimum clinically important difference (MCID) score of 4 units; however, the CI width means the possibility of a non-meaningful difference cannot be excluded. The pooled result from five studies indicated that immunostimulants likely reduce the number of participants requiring antibiotics over a mean duration of six months (OR 0.34, 95% CI 0.18 to 0.63; 542 participants; moderate-certainty evidence). This outcome had a low-to-moderate degree of heterogeneity (I2 = 38%), but the direction of effect was consistent across all studies. There was no evidence of a difference in the odds of experiencing an adverse event with immunostimulant compared to placebo, over a mean duration of six months (OR 1.01, 95% CI 0.84 to 1.21; 20 RCTs, 3780 participants; high-certainty evidence). The CI limits for the associated risk ratio (RR) did not cross thresholds for appreciable harm or benefit (RR 1.02, 95% CI 0.92 to 1.13). An additional seven studies reported no events rates in either study arm. Meta-analyses were not performed for the outcomes of exacerbation duration and respiratory-related hospitalisation duration, due to high levels of heterogeneity across the included studies (exacerbation duration: I2 = 92%; respiratory-related hospitalisation duration: I2 = 83%). Results from an effect direction plot and binomial probability test for exacerbation duration indicated that a significant proportion of studies (94% (95% CI 73% to 99%); P = 0.0002) favoured intervention, possibly indicating that immunostimulants are efficacious in reducing the mean exacerbation duration compared to placebo. However, the degree of uncertainty associated with this estimate remained high due to data quality and heterogeneity. Three studies reported mean duration of respiratory-related hospitalisation, two of which demonstrated a direction of effect that favoured immunostimulant over placebo.

AUTHORS' CONCLUSIONS

In participants with chronic bronchitis or COPD, we are moderately confident that treatment with immunostimulants is associated with a small reduction in the likelihood of having an exacerbation and a moderate reduction in the requirement for antibiotics. Low numbers of events limit interpretation of the effect of immunostimulants on all-cause and respiratory-related mortality. We are uncertain whether immunostimulants improve quality of life, and whether they are associated with a reduction in exacerbation and respiratory-related hospitalisation durations, although immunostimulants were generally associated with a positive effect direction in the studies that examined these outcomes. Immunostimulants appear to be safe and well-tolerated, and are not associated with an increased risk of adverse events.

Postbiotics and Kidney Disease

Chronic kidney disease (CKD) is projected to become the fifth global cause of death by 2040 as a result of key shortcomings in the current methods available to diagnose and treat kidney diseases. In this regard, the novel holobiont concept, used to describe an individual host and its microbial community, may pave the way towards a better understanding of kidney disease pathogenesis and progression. Microbiota-modulating or -derived interventions include probiotics, prebiotics, synbiotics and postbiotics. As of 2019, the concept of postbiotics was updated by the International Scientific Association of Probiotics and Prebiotics (ISAPP) to refer to preparations of inanimate microorganisms and/or their components that confer a health benefit to the host. By explicitly excluding purified metabolites without a cellular biomass, any literature making use of such term is potentially rendered obsolete. We now review the revised concept of postbiotics concerning their potential clinical applications and research in kidney disease, by discussing in detail several formulations that are undergoing preclinical development such as GABA-salt for diet-induced hypertension and kidney injury, sonicated Lactobacillus paracasei in high fat diet-induced kidney injury, GABA-salt, lacto-GABA-salt and postbiotic-GABA-salt in acute kidney injury, and O. formigenes lysates for hyperoxaluria. Furthermore, we provide a roadmap for postbiotics research in kidney disease to expedite clinical translation.

Promising Immunomodulatory Effects of Bacterial Lysates in Allergic Diseases

In light of an escalating prevalence of allergic disorders, it is crucial to fully comprehend their pathophysiology and etiology. Such knowledge would play a pivotal role in the search for new therapeutic approaches concerning not only diseases’ symptoms, but also their underlying causes. The hygiene hypothesis indicates a high correlation between limited exposure to pathogens in early childhood and the risk of developing allergic disorders. Bearing in mind the significance of respiratory and digestive systems’ mucous membrane’s first-line exposure to pathogens as well as its implications on the host’s immune response, a therapy targeted at aforesaid membranes could guarantee promising and extensive treatment outcomes. Recent years yielded valuable information about bacterial lysates (BLs) known for having immunomodulatory properties. They consist of antigen mixtures obtained through lysis of bacteria which are the most common etiologic agents of respiratory tract infections. They interact with dendritic cells located in the mucous membranes of the upper respiratory tract and the gastrointestinal tract by toll-like receptors. The dendritic cells present acquired antigens resulting in innate immune response development on the release of chemokines, both stimulating monocytes and NK cells maturation and promoting polymorphonuclear neutrophil migration. Moreover, they influence the adaptive immune system by stimulating an increase of specific antibodies against administered bacterial antigens. The significance of BLs includes not only an anti-inflammatory effect on local infections but also restoration of Th1/Th2 balance, as demonstrated mainly in animal models. They decrease Th2-related cytokine levels (IL-4, IL-13) and increase Th1-related cytokine levels (IFN-γ). The reestablishment of the balance of the immune response leads to lowering atopic reactions incidence which, in addition to reduced risk of inflammation, provides the alleviation and improvement of clinical manifestations of allergic disorders. In this review, we hereby describe mechanisms of BLs action, considering their significant immunomodulatory role in innate immunity. The correlation between local, innate, and adaptive immune responses and their impact on the clinical course of allergic disorders are discussed as well. To conclude our review, we present up-to-date literature regarding the outcomes of BLs implemented in atopic dermatitis, allergic rhinitis, and asthma prevention and treatment, especially in children.

A Meta-Analysis on the Efficacy and Safety of Bacterial Lysates in Chronic Obstructive Pulmonary Disease

Background

Chronic obstructive pulmonary disease (COPD) is a common and frequently encountered disease of respiratory apparatus and is vulnerable to infection. Increasing studies reveal that bacterial lysates play an encouraging role in preventing exacerbations in these patients. We here investigated the efficacy and safety of bacterial lysates in COPD.

Methods

We performed systematic research on PubMed, EMBASE, the Cochrane Library (CENTRAL), and Web of Science by using the keywords and their synonyms for studies published before January 11, 2022. Two researchers screened the studies of literature independently according to the inclusion and exclusion criteria and extracted data from the included studies. Another two researchers assessed the risk of bias of each included using the Cochrane risk-of-bias tool. Meta-analysis was conducted using R (version 4.1.1, The R Foundation for Statistical Computing) and Review Manager (version 5.4.0, The Cochrane Collaboration).

Results

A total of 12 studies were included in this meta-analysis, and the pooled results showed that bacterial lysates were effective to reduce exacerbation rate (overall: relative risk [RR] = 0.83, 95% confidence interval [CI] 0.72-0.96; alkaline bacterial lysate subgroup [OM-85]: RR = 0.87, 95% CI 0.77-0.98; mechanical bacterial lysate subgroup [Ismigen]: RR = 0.70, 95% CI 0.41-1.20) and mean number of exacerbations (overall: MD = -0.42, 95% CI -0.75 to -0.08; alkaline bacterial lysate subgroup [OM-85]: MD = -0.72, 95% CI -1.35 to -0.09; mechanical bacterial lysate subgroup [Ismigen]: MD = -0.02, 95% CI -0.21 to 0.17). Bacterial lysates were also found beneficial in alleviating symptoms. The side effects were acceptable and slight.

Conclusion

Bacterial lysates can benefit patients with COPD by reducing exacerbations and alleviating symptoms. OM-85 is the preferable product based on the existing evidence. Further studies are needed to validate these findings.

Systematic Review Registration

[www.crd.york.ac.uk/prospero/], identifier [CRD42022299420].

Microbiome Modulation as a Novel Strategy to Treat and Prevent Respiratory Infections

Acute and chronic lower airway disease still represent a major cause of morbidity and mortality on a global scale. With the steady rise of multidrug-resistant respiratory pathogens, such as Pseudomonas aeruginosa and Klebsiella pneumoniae, we are rapidly approaching the advent of a post-antibiotic era. In addition, potentially detrimental novel variants of respiratory viruses continuously emerge with the most prominent recent example being severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). To this end, alternative preventive and therapeutic intervention strategies will be critical to combat airway infections in the future. Chronic respiratory diseases are associated with alterations in the lung and gut microbiome, which is thought to contribute to disease progression and increased susceptibility to infection with respiratory pathogens. In this review we will focus on how modulating and harnessing the microbiome may pose a novel strategy to prevent and treat pulmonary infections as well as chronic respiratory disease.

Current Stage in the Development of Klebsiella pneumoniae Vaccines

Klebsiella pneumoniae is a bacterium capable of colonizing mucous membranes, causing serious infections. Widespread antibiotic resistance in K. pneumoniae—either through intrinsic mechanisms or via acquisition from different species, especially in hospital environments—limits the therapeutic options against this pathogen, further aggravating the disease burden. To date, there are no vaccines available against K. pneumoniae infection. Although formulations based on capsular polysaccharides have been proposed, the high variability in capsular serotypes limits vaccine coverage. Recombinant vaccines based on surface exposed bacterial antigens are a promising alternative owing to their conservation among different serotypes and accessibility to the immune system. Many vaccine candidates have been proposed, some of which have reached clinical trials. The present review summarizes the current status of K. pneumoniae vaccine development. Different strategies including whole cell vaccines, outer membrane vesicles (OMVs), ribosome, polysaccharide, lipopolysaccharide (LPS), and protein-based formulations are discussed. The contribution of antibody and cell-mediated responses is also presented. In summary, K. pneumoniae vaccines are feasible and a promising strategy to prevent infections and to reduce the antimicrobial resistance burden worldwide.

Polyvalent Bacterial Lysate Protects Against Pneumonia Independently of Neutrophils, IL-17A or Caspase-1 Activation

Polyvalent bacterial lysates have been in use for decades for prevention and treatment of respiratory infections with reported clinical benefits. However, besides claims of broad immune activation, the mode of action is still a matter of debate. The lysates, formulated with the main bacterial species involved in respiratory infections, are commonly prepared by chemical or mechanical disruption of bacterial cells, what is believed influences the biological activity of the product. Here, we prepared two polyvalent lysates with the same composition but different method of bacterial cell disruption and evaluated their biological activity in a comparative fashion. We found that both bacterial lysates induce NF-kB activation in a MyD88 dependent manner, suggesting they work as TLR agonists. Further, we found that a single intranasal dose of any of the two lysates, is sufficient to protect against pneumococcal pneumonia, suggesting that they exert similar biological activity. We have previously shown that protection against pneumococcal pneumonia can also be induced by prior S. pneumoniae sub lethal infection or therapeutic treatment with a TLR5 agonist. Protection in those cases depends on neutrophil recruitment to the lungs, and can be associated with increased local expression of IL-17A. Here, we show that bacterial lysates exert protection against pneumococcal pneumonia independently of neutrophils, IL-17A or Caspase-1/11 activation, suggesting the existence of redundant mechanisms of protection. Trypsin-treated lysates afford protection to the same extent, suggesting that just small peptides suffice to exert the protective effect or that the molecules responsible for the protective effect are not proteins. Understanding the mechanism of action of bacterial lysates and deciphering the active components shall allow redesigning them with more precisely defined formulations and expanding their range of action.

The International Scientific Association of Probiotics and Prebiotics (ISAPP) consensus statement on the definition and scope of postbiotics

In 2019, the International Scientific Association for Probiotics and Prebiotics (ISAPP) convened a panel of experts specializing in nutrition, microbial physiology, gastroenterology, paediatrics, food science and microbiology to review the definition and scope of postbiotics. The term 'postbiotics' is increasingly found in the scientific literature and on commercial products, yet is inconsistently used and lacks a clear definition. The purpose of this panel was to consider the scientific, commercial and regulatory parameters encompassing this emerging term, propose a useful definition and thereby establish a foundation for future developments. The panel defined a postbiotic as a "preparation of inanimate microorganisms and/or their components that confers a health benefit on the host". Effective postbiotics must contain inactivated microbial cells or cell components, with or without metabolites, that contribute to observed health benefits. The panel also discussed existing evidence of health-promoting effects of postbiotics, potential mechanisms of action, levels of evidence required to meet the stated definition, safety and implications for stakeholders. The panel determined that a definition of postbiotics is useful so that scientists, clinical triallists, industry, regulators and consumers have common ground for future activity in this area. A generally accepted definition will hopefully lead to regulatory clarity and promote innovation and the development of new postbiotic products.

Bacterial Lysates as Immunotherapies for Respiratory Infections: Methods of Preparation

Bacterial lysates, prepared from the microorganisms most frequently involved in human Respiratory Tract Infections (RTIs) have been in the market for several decades, and at present, several different brands are available in many countries worldwide. They all claimed to exert local and systemic immunomodulatory effects but different clinical trials show disparate results between them. The lack of consistency of predicted therapeutic effects has undermined their clinical use and hampered licensing in several countries. One explanation for such lack of consistency in the results is that their methods of preparation are also very different. Here, we review the available literature describing methods of preparation of bacterial lysates, including patent disclosure documents. We found a great variety of methodologies of preparation and a lack of standardized procedures among them. The main conclusion of our study is that there is a clear need for standardized protocols of production to obtain comparable results in clinical trials worldwide.

Immunoactive preparations and regulatory responses in the respiratory tract: potential for clinical application in chronic inflammatory airway diseases

Introduction: The prevalence of chronic inflammatory airway diseases is rising. Their treatment with corticosteroids increases infection risk, while overuse of antimicrobial agents may increase morbidity and antimicrobial resistance. Nonspecific immunomodulatory compounds alter immune responses to both infectious and atopic challenges. These compounds may offer an alternative approach for symptom reduction and prophylaxis against both infections and exacerbations in chronic inflammatory airway disease.Areas covered: We assessed the available data on the efficacy of nonspecific immunomodulators including bacterial lysates, synthetic compounds, and vaccines in chronic rhinosinusitis (CRS); allergic and non-allergic rhinitis; chronic obstructive pulmonary disease (COPD), and asthma. A search of PubMed was carried out using the 'Clinical Trials' filter for each condition and immunomodulatory product detailed below, where available, data from meta-analyses were reported.Expert opinion: Pre-clinical data has revealed a coherent mechanistic path of action for oral immunomodulators on the respiratory immune system, principally via the gut-lung immune axis. In patients with asthma, allergic rhinitis, CRS, and COPD immunomodulatory therapy reduces symptoms, exacerbations, hospitalizations, and drug consumption. However, data are heterogeneous, and study quality remains limited. A lack of high-quality recent trials remains the major unmet research need in the field.

Immunostimulants in respiratory diseases: focus on Pidotimod

Usefulness of Pidotimod and its role as immunostimulant, has been discussed, we know, for several decades. Nevertheless, there is still much to know. Understanding its mechanisms and its potential usefulness in airway infections and its prevention, asthma both Th2 and non Th2 type, bronchiectasis, as adjuvant in vaccination and in allergen immunotherapy still remains to clearly unveil. The aim of this paper was to provide a useful updated review of the role of the main available immunostimulants, giving particular focus on Pidotimod use and its potentials utility in respiratory diseases. Pidotimod showed its usefulness in reducing need for antibiotics in airway infections, increasing the level of immunoglobulins (IgA, IgM, IgG) and T-lymphocyte subsets (CD3+, CD4+) endowed with immunomodulatory activity that affect both innate and adaptive immune responses. Higher expression of TLR2 and of HLA-DR molecules, induction of dendritic cell maturation and release of pro-inflammatory molecules, stimulation of T lymphocyte proliferation and differentiation toward a Th1 phenotype, as well as an increase of the phagocytosis have been demonstrated to be associated with Pidotimod in in vitro studies. All these activities are potentially useful for several respiratory conditions such as asthma, COPD, and recurrent respiratory tract infections.

The Challenges of Precision Medicine in COPD

Pheno-/endotyping chronic obstructive pulmonary disease (COPD) is really important because it provides patients with precise and personalized medicine. The central concept of precision medicine is to take individual variability into account when making management decisions. Precision medicine should ensure that patients get the right treatment at the right dose at the right time, with minimum harmful consequences and maximum efficacy. Ideally, we should search for genetic and molecular biomarker-based profiles. Given the clinical complexity of COPD, it seems likely that a panel of several biomarkers will be required to characterize pathogenetic factors and their course over time. The need for biomarkers to guide the clinical care of individuals with COPD and to enhance the possibilities of success in drug development is clear and urgent, but biomarker development is tremendously challenging and expensive, and translation of research efforts to date has been largely ineffective. Furthermore, the development of personalized treatments will require a much more detailed understanding of the clinical and biological heterogeneity of COPD. Therefore, we are still far from being able to apply precision medicine in COPD and the treatable traits and FEV₁-free approaches are attempts to precision medicine in COPD that must be considered still quite unsophisticated.

Treatment options for moderate-to-very severe chronic obstructive pulmonary disease

INTRODUCTION

The appropriate drug management of COPD is still based on the use of bronchodilators, possibly associated with an anti-inflammatory agent. However, there are still fundamental questions that require clarification to optimise their use and major unmet clinical needs that must be addressed.

AREAS COVERED

The advances obtained with the pharmacological options currently consolidated and the different approaches that are often used in an attempt to respond to unmet therapeutic needs are reviewed Expert opinion: In view of the unsatisfactory status of current treatments for COPD, there is an urgent need for alternative and more effective therapeutic approaches that will help to relieve patient symptoms and affect the natural course of COPD, inhibiting chronic inflammation and reversing the disease process or preventing its progression. However, new pharmacologic options have proved difficult to develop. Therefore, it is mandatory to optimize the use of the treatment options at our disposal. However, there are still fundamental questions regarding their use, including the step-up and step-down pharmacological approach, that require clarification to optimise the use of these drugs. It is likely that phenotyping COPD patients would help in identifying the right treatment for each COPD patient and improve the effectiveness of therapies.