Can bacterial lysates be useful in prevention of viral respiratory infections in childhood? The results of experimental OM-85 studies.

Respiratory tract infections (RTI) are mainly viral in origin and among the leading cause of childhood morbidity globally. Associated wheezing illness and asthma are still a clear unmet medical need. Despite the continuous progress in understanding the processes involved in their pathogenesis, preventive measures and treatments failed to demonstrate any significant disease-modifying effect. However, in the last decades it was understood that early-life exposure to microbes, may reduce the risk of infectious and allergic disorders, increasing the immune response efficacy. These results suggested that treatment with bacterial lysates (BLs) acting on gut microbiota, could promote a heterologous immunomodulation useful in the prevention of recurrent RTIs and of wheezing inception and persistence. This hypothesis has been supported by clinical and experimental studies showing the reduction of RTI frequency and severity in childhood after oral BL prophylaxis and elucidating the involved mechanisms. OM-85 is the product whose anti-viral effects have been most extensively studied in vitro, animal, and human cell studies and in translational animal infection/disease models. The results of the latter studies, describing the potential immune training-based activities of such BL, leading to the protection against respiratory viruses, will be reported. In response to human rhinovirus, influenza virus, respiratory syncytial virus and severe acute respiratory coronavirus-2, OM-85 was effective in modulating the structure and the functions of a large numbers of airways epithelial and immune cells, when administered both orally and intranasally.

Microbiota profiles in pre-school children with respiratory infections: Modifications induced by the oral bacterial lysate OM-85.

To describe microbiota profiles considering potential influencing factors in pre-school children with recurrent respiratory tract infections (rRTIs) and to evaluate microbiota changes associated with oral bacterial lysate OM-85 treatment, we analyzed gut and nasopharynx (NP) microbiota composition in patients included in the OM-85-pediatric rRTIs (OMPeR) clinical trial (https://www.clinicaltrialsregister.eu/ctr-search/trial/2016-002705-19/IT). Relative percentage abundance was used to describe microbiota profiles in all the available biological specimens, grouped by age, atopy, and rRTIs both at inclusion (T0) and at the end of the study, after treatment with OM-85 or placebo (T1). At T0, Firmicutes and Bacteriodetes were the predominant genera in gut and Proteobacteria, Firmicutes, and Actinobacteria were the predominant genera in NP samples. Gut microbiota relative composition differed with age (<2 vs. ≥2 years) for Firmicutes, Proteobacteria, Actinobacteria (phyla) and Bifidobacterium, Ruminococcus, Lachnospiraceae (genera) (p < 0.05). Moraxella was more enriched in the NP of patients with a history of up to three RTIs. Intra-group changes in relative percentage abundance were described only for patients with gut and NP microbiota analysis available at both T0 and T1 for each study arm. In this preliminary analysis, the gut microbiota seemed more stable over the 6-month study in the OM-85 group, whose mean age was lower, as compared to the placebo group (p = 0.004). In this latter group, the relative abundance of Bacteroides decreased significantly in children ≥2 years. Some longitudinal significant differences in genera relative abundance were also detected in children of ≥2 years for NP Actinobacteria, Haemophilus, and Corynebacterium in the placebo group only. Due to the small number of patients in the different sub-populations, we could not identify significant differences in the clinical outcome and therefore no associations with microbiota changes were searched. The use of bacterial lysates might play a role in microbiota rearrangement, but further data and advanced analysis are needed to prove this in less heterogeneous populations with higher numbers of samples considering the multiple influencing factors such as delivery method, age, environment, diet, antibiotic use, and type of infections to ultimately show any associations with prevention of rRTIs.

Alarmins and innate lymphoid cells 2 activation: A common pathogenetic link connecting respiratory syncytial virus bronchiolitis and later wheezing/asthma?

Severe respiratory syncytial virus (RSV) infection in infancy is associated with increased risk of recurrent wheezing in childhood. Both acute and long-term alterations in airway functions are thought to be related to inefficient antiviral immune response. The airway epithelium, the first target of RSV, normally acts as an immunological barrier able to elicit an effective immune reaction but may also be programmed to directly promote a Th2 response, independently from Th2 lymphocyte involvement. Recognition of RSV transcripts and viral replication intermediates by bronchial epithelial cells brings about release of TSLP, IL-33, HMGB1, and IL-25, dubbed "alarmins." These epithelial cell-derived proteins are particularly effective in stimulating innate lymphoid cells 2 (ILC2) to release IL-4, IL-5, and IL-13. ILC2, reflect the innate counterparts of Th2 cells and, when activate, are potent promoters of airway inflammation and hyperresponsiveness in RSV bronchiolitis and childhood wheezing/asthma. Long-term epithelial progenitors or persistent epigenetic modifications of the airway epithelium following RSV infection may play a pathogenetic role in the short- and long-term increased susceptibility to obstructive lung diseases in response to RSV in the young. Additionally, ILC2 function may be further regulated by RSV-induced changes in gut microbiota community composition that can be associated with disease severity in infants. A better understanding of the alarmin-ILC interactions in childhood might provide insights into the mechanisms characterizing these immune-mediated diseases and indicate new targets for prevention and therapeutic interventions.

Respiratory syncytial virus and airway microbiota - A complex interplay and its reflection on morbidity.

The immunopathology of respiratory syncytial virus (RSV) infection varies considerably, severe disease occurring only in a minority of the affected children. The variability of the clinical presentation is in part explained by viral and environmental factors but, in infants and young children, disease severity is certainly linked to the physiologic immaturity of the innate and adaptive immune system. There is evidence that the maturation of the host immune response is positively influenced by the composition of the nasopharyngeal microbiome that, promoting an efficient reaction, can counteract the predisposition to develop viral respiratory infections and lower the risk of disease severity. However, interaction between the nasopharyngeal microbiota and respiratory viruses can be bidirectional since microbial dysbiosis may also represent a reflection of the disease-induced alterations of the local milieu. Moreover, viruses like RSV can also increase the virulence of potential pathogens in nasopharynx, a main reservoir of bacteria, and therefore promote their spread to the lower airways causing superinfection. Moreover, if negative changes in microbial community composition in early life may constitute a heightened risk toward severe RSV respiratory infection, on the contrary specific groups of microorganisms seem to be associated with protection. A better understanding into the potential negative and positive role of the different nasopharyngeal bacterial species on RSV infection may improve primary prevention and possibly care of this highly contagious disorder.

Dysbiosis in Pediatrics Is Associated with Respiratory Infections: Is There a Place for Bacterial-Derived Products?

Respiratory tract infections (RTIs) are common in childhood because of the physiologic immaturity of the immune system, a microbial community under development in addition to other genetic, physiological, environmental and social factors. RTIs tend to recur and severe lower viral RTIs in early childhood are not uncommon and are associated with increased risk of respiratory disorders later in life, including recurrent wheezing and asthma. Therefore, a better understanding of the main players and mechanisms involved in respiratory morbidity is necessary for a prompt and improved care as well as for primary prevention. The inter-talks between human immune components and microbiota as well as their main functions have been recently unraveled; nevertheless, more is still to be discovered or understood in the above medical conditions. The aim of this review paper is to provide the most up-to-date overview on dysbiosis in pre-school children and its association with RTIs and their complications. The potential role of non-harmful bacterial-derived products, according to the old hygiene hypothesis and the most recent trained-innate immunity concept, will be discussed together with the need of proof-of-concept studies and larger clinical trials with immunological and microbiological endpoints.

Viral infections and wheezing-asthma inception in childhood: is there a role for immunomodulation by oral bacterial lysates?

Severe and recurrent infections of the respiratory tract in early childhood constitute major risk factors for the development of bronchial hyper-responsiveness and obstructive respiratory diseases in later life. In the first years of life, the vast majority of respiratory tract infections (RTI) leading to wheezing and asthma are of a viral origin and severity and recurrence are the consequence of a greater exposure to infectious agents in a period when the immune system is still relatively immature. Therefore, boosting the efficiency of the host immune response against viral infections seems to be a rational preventative approach. In the last decades it has been demonstrated that living in farm environments, i.e. early-life exposure to microbes, may reduce the risk of allergic and infectious disorders, increasing the immune response efficacy. These findings have suggested that treatment with bacterial lysates could promote a nonspecific immunomodulation useful in the prevention of recurrent RTIs and of wheezing inception and persistence. Experimental and clinical studies showing the reduction of RTI frequency and severity in childhood and elucidating the involved mechanisms can support this hypothesis.

Evidence that a primary anti-viral stimulation of the immune response by OM-85 reduces susceptibility to a secondary respiratory bacterial infection in mice.

BACKGROUND: Viral respiratory infections may promote bacterial super-infection decreasing the host immune response efficiency. However, using a mice model we recently demonstrated that preventive treatment with the bacterial extract OM-85 reduces the susceptibility to a secondary Streptococcus (S.) pneumoniae infection after influenza virus (I.V.) challenge. METHODS: To better characterize the efficacy of OM-85 against S. pneumoniae super-infection, a post-hoc analysis was conducted, comparing efficacy (survival) and morbidity signs (clinical score, body temperature and weight loss) in the OM-85 and the control (BLANC) groups of mice after: a) I.V. infection; b) primary S. pneumoniae infection and c) post-I.V. S. pneumoniae super-infection. RESULTS: After a sublethal I.V. dose, all mice stayed alive at day 5 and no differences in morbidity signs were detected between the OM-85 and the BLANC groups. However, OM-85 pretreatment led to a significantly reduction of the viral load in the lung on day 5 post viral infection and, on day 10, reduced neutrophilic inflammation while increasing influenza-specific CD8 + T-cell proportion in the airways. Conversely to viral infection, exposure to S. pneumoniae induced a dramatic reduction of survival, with no mice surviving on day 3 post infection in the BLANC group, whereas a partial protective effect was observed in OM-85 pre-treated mice (20% of mice surviving at day 3, and 10% at day 4 and 5). The morbidity data substantiated the survival results. Interestingly, in the "super-infection" study, when mice were exposed to a sublethal I.V. dose followed by a secondary S. pneumoniae infection, all mice died by day 4 in the BLANC group. In contrast, in the OM-85 treated group, the survival rate was 70% at day 4 and still 50% at day 5, with positive effects on the clinical scores and on the body temperature already detectable at days 1 and 2. CONCLUSIONS: The efficacy of OM-85 pre-treatment against S. pneumoniae super-infection reflects a strong and immediate immune reaction from the host, an event that can be explained in part by a "non-specific" activation of the immune system, a positive "immune effect" of the general OM-85- induced immune response against I.V.

Social and economic burden of recurrent urinary tract infections and quality of life: a patient web-based study (GESPRIT).

BACKGROUND: Uncomplicated lower urinary tract infections (UTIs) occur in approximately 50% of women, and 20-30% experience recurrent UTI. Data on UTIs and quality of life (QoL) in Europe are limited. METHODS: This was an anonymous, self-administered web-based survey conducted in 5 countries (Germany, Switzerland, Poland, Russia and Italy), on adult women who had experienced recurrent UTI and were affected by acute UTI currently or within 4 weeks of study entry. Questions covered disease course; management; social and economic burden; education, income, and health insurance status. QoL was evaluated using the SF-12v2. RESULTS: Participants reported a mean of 5.15 UTI symptoms, ranging from 4.85 - 5.38 in Russia and Germany. There was a mean of 2.78 doctor visits per year (1.74 - 3.71 in Russia and Germany; p < 0.0001). 80.3% of participants had been treated with antibiotics, mean prescriptions ranged from 2.17 (Poland) to 3.36 (Germany) per person per year. A mean of 3.09 days sick leave due to UTIs, and 3.45 days of limited activities, were reported. Although 73.8% of participants had tried prophylaxis recurrence was common and associated with mental stress for a high proportion of women. CONCLUSIONS: Our results indicate that recurrent UTIs have a significant impact on QoL of women in Europe.

Adjuvant treatment with the bacterial lysate (OM-85) improves management of atopic dermatitis: A randomized study.

BACKGROUND: Environmental factors play a major role on atopic dermatitis (AD) which shows a constant rise in prevalence in western countries over the last decades. The Hygiene Hypothesis suggesting an inverse relationship between incidence of infections and the increase in atopic diseases in these countries, is one of the working hypothesis proposed to explain this trend. OBJECTIVE: This study tested the efficacy and safety of oral administration of the bacterial lysate OM-85 (Broncho-Vaxom®, Broncho-Munal®, Ommunal®, Paxoral®, Vaxoral®), in the treatment of established AD in children. METHODS: Children aged 6 months to 7 years, with confirmed AD diagnosis, were randomized in a double-blind, placebo-controlled trial to receive, in addition to conventional treatment with emollients and topical corticosteroids, 3.5mg of the bacterial extract OM-85 or placebo daily for 9 months. The primary end-point was the difference between groups in the occurrence of new flares (NF) during the study period, evaluated by Hazard Ratio (HR) derived from conditional Cox proportional hazard regression models accounting for repeated events. RESULTS: Among the 179 randomized children, 170 were analysed, 88 in the OM-85 and 82 in the placebo group. As expected most children in both treatment groups experienced at least 1 NF during the study period (75 (85%) patients in the OM-85 group and 72 (88%) in the placebo group). Patients treated with OM-85 as adjuvant therapy had significantly fewer and delayed NFs (HR of repeated flares = 0.80; 95% confidence interval (CI): 0.67-0.96), also when potential confounding factors, as family history of atopy and corticosteroids use, were taken into account (HR = 0.82; 95% CI: 0.69-0.98). No major side effect was reported, with comparable and good tolerability for OM-85 and placebo. CONCLUSIONS: Results show an adjuvant therapeutic effect of a well standardized bacterial lysate OM-85 on established AD.

A randomized, double-blind, placebo-controlled, clinical study on the efficacy and safety of calcium dobesilate in the treatment of chronic venous insufficiency.

OBJECTIVE: To show the superiority of 500 mg calcium dobesilate vs. placebo in reduction of edema of the lower limbs in patients with chronic venous insufficiency, Clinical, Etiological, Anatomical and Pathophysiological classes C3/C4. METHODS: A total of 351 patients were randomized (n = 174 calcium dobesilate, n = 177 placebo). Active treatment was 500 mg calcium dobesilate, three times daily for 12 weeks, with a 12-week follow-up. RESULTS: At the end of treatment, the relative volume change in the most pathological leg was -0.6 ± 4.8% with calcium dobesilate compared to -0.3 ± 3.3% with placebo (p = 0.09). At the end of follow-up, this was -1.01 ± 5.4% for calcium dobesilate vs. -0.08 ± 3.5% for placebo (p = 0.002). CONCLUSIONS: Calcium dobesilate treatment resulted in no significant volume change in the most pathological leg between baseline and end of treatment. However, the calcium dobesilate group showed a significantly greater volume decrease in the most pathological leg at the end of follow-up. Calcium dobesilate was well-tolerated, with a safety profile consistent with previously published data.

Non-traditional systemic treatments for diabetic retinopathy: an evidence-based review.

The rapid escalation in the global prevalence diabetes, with more than 30% being afflicted with diabetic retinopathy (DR), means it is likely that associated vision-threatening conditions will also rise substantially. This means that new therapeutic approaches need to be found that go beyond the current standards of diabetic care, and which are effective in the early stages of the disease. In recent decades several new pharmacological agents have been investigated for their effectiveness in preventing the appearance and progression of DR or in reversing DR; some with limited success while others appear promising. This up-to-date critical review of non-traditional systemic treatments for DR is based on the published evidence in MEDLINE spanning 1980-December 2014. It discusses a number of therapeutic options, paying particular attention to the mechanisms of action and the clinical evidence for the use of renin-angiotensin system blockade, fenofibrate and calcium dobesilate monohydrate in DR.

A Randomized, Double-Blind, Parallel-Group, Multicenter Clinical Study of Escherichia coli-Lyophilized Lysate for the Prophylaxis of Recurrent Uncomplicated Urinary Tract Infections.

BACKGROUND: One strategy for managing recurrent uncomplicated urinary tract infections (UTIs) is prevention. This study tested OM-89S, a lyophilized lysate of 18 Escherichia coli strains manufactured using a modified lytic process. METHODS: This was a randomized, double-blind trial in 451 female subjects with recurrent uncomplicated UTIs. Period 1 of the study tested 6 mg of OM-89S versus placebo (3 months), plus a 3-month observation. Period 2 of the study was a 3-month treatment period (each monthly cycle consisted of 6 mg of OM-89S daily for 10 days and placebo for 20 days, vs. 50 mg nitrofurantoin daily for 30 days), plus a 3-month observation. RESULTS: There was no difference in the mean rate of UTI episodes between the OM-89S (0.66 ± 0.93) and placebo groups (0.63 ± 0.86; p = 0.95) in period 1. Similar findings were obtained for period 2. OM-89S was well-tolerated. CONCLUSIONS: Our results did not demonstrate a preventive effect of OM-89S compared to placebo. This may be due to the low number of UTIs that occurred during the study, the high number of protocol violations, and/or the modified manufacturing process used for OM-89S.

Recurrent Lower Urinary Tract Infections Have a Detrimental Effect on Patient Quality of Life: a Prospective, Observational Study.

INTRODUCTION: This study investigated the effects of recurrent urinary tract infections (rUTI) and the impact of prophylaxis on rUTI and patients' quality of life (QoL). METHODS: Altogether, 575 patients affected by rUTI were included in a 6-month observational study. QoL was assessed using the Hospital Anxiety and Depression (HAD) and the Leicester scales. Statistical analyses were performed using SAS® Version 8.2 software (SAS Institute Inc., Cary, NC, USA). The significance level was set at 5%. Spearman correlation was used to assess the degree of correlation between infectious episodes and HAD and Leicester scores. For each parameter, the comparison between Day 0 and Day 180 was performed using Wilcoxon signed-rank test for quantitative data. RESULTS: In total, 61.9% of patients suffering from rUTI exhibited some degree of depression at baseline (Day 0). Alternative oral non-antimicrobial prophylactic treatment for rUTI [Escherichia coli lyophilized bacterial lysate (OM-89)] was administered to 94.4% of patients (1 capsule a day for 90 days), followed by a 3-month treatment-free period. At the end of the study (Day 180), the mean number of UTI decreased by 59.3% (P ≤ 0.0001), the total HAD score decreased by 32.1% (P ≤ 0.0001), and the mean Leicester score decreased by 44.0% (P ≤ 0.0001) from baseline. There was a correlation trend between the reduction in the numbers of UTI at the end of the study compared to the 6 months prior to study entry and the reduction in the anxiety, depression, total HAD scores, activity, feeling, and total Leicester scores registered from Day 0 to Day 180, suggesting a lessening of emotional problems, and social and functional handicaps with decreasing UTI incidence. CONCLUSIONS: This study showed that rUTI had a negative impact on patients' QoL and that effective alternative prophylaxis significantly improved their QoL.

Immunostimulation in chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS): a one-year prospective, double-blind, placebo-controlled study.

PURPOSE: Inflammation/immunological dysfunction are discussed etiological causes of chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS). OM-89 is an orally immunostimulating agent. We performed a phase three multicentre, randomized, double-blind, placebo-controlled, long-term (12 months) study with OM-89 produced with a different lysis process in patients with moderate-to-severe CP/CPPS type III. METHODS: Patients were randomized to OM-89 or placebo. Primary efficacy variable was difference of responders at the end of treatment (month 9) in patients receiving OM-89 versus placebo. RESULTS: Two hundred and three patients were screened, 185 patients (47.8 ± 8.4 years) (90 % of CP/CPPS type IIIb) were enrolled in 30 centers and included in the safety set. Ninety-four were randomized to OM-89, 91 to placebo. One hundred and seventy-six patients were subjected to the full analysis (FAS), 150 to the per protocol set (PPS). Baseline NIH-CPSI score in FAS was 21.8 ± 3.8 (OM-89) and 23.0 ± 5.6 (placebo). At primary efficacy endpoint (month 9), in the OM-89 group, 67.0 % in FAS (PPS 72.7 %) and in the placebo group, 64.3 % in FAS (PPS 64.4 %) were responders [FAS: OR 1.19, p = 0.59; PPS: p = 0.19]. Mean relative decrease in NIH-CPSI was 40.5 and 44.0 % in the FAS. Treatment-related adverse events were low: 8.5 % with OM-89 and 5.5 % with placebo. Because of small numbers, no conclusion could be drawn regarding the potential benefit of OM-89 in CP/CPPS IIIa. CONCLUSIONS: This placebo-controlled study evaluating OM-89 in patients with CP/CPPS showed a significant and long-lasting (12 months) favorable response with OM-89, but also with placebo. OM-89 was safe and well tolerated. EUDRACT: 2007-004609-85.