Risk of Severe COVID-19 in Prevalent Users of Alpha-1 Adrenergic Receptor Antagonists: A National Case-Control Study of Medicare Beneficiaries

BACKGROUND

Alpha-1 adrenergic receptor antagonists prevent cytokine storm in mouse sepsis models. This led to the hypothesis that alpha-1 blockers may prevent severe coronavirus disease 2019 (COVID-19), which is characterized by hypercytokinemia and progressive respiratory failure.

METHODS

We performed an observational case-control study in male Medicare beneficiaries aged 65 years or older, with or without benign prostatic hyperplasia (BPH), and treated with alpha-1 receptor blockers or 5-alpha reductase inhibitors. Adjusted odds ratios (aOR) and 95% confidence intervals (CI) were estimated for outcomes of uncomplicated and severe COVID-19 hospitalization (intensive care unit admission, invasive mechanical ventilation, or death).

RESULTS

There were 20,963 cases of hospitalized COVID-19 matched to 101,161 controls on calendar date and neighborhood of residence. In the primary analysis (males with BPH), there was no difference in risk of uncomplicated COVID-19 hospitalization (aOR 1.08, 95% CI 0.996-1.17) or hospitalization with severe complications (aOR 0.97, 95% CI 0.88-1.08). In the secondary analysis (males with or without BPH), the corresponding aORs were 1.02 (95% CI, 0.96-1.09) (uncomplicated) and 0.99 (95% CI, 0.91-1.07) (complicated), respectively. Subgroup and sensitivity analyses yielded similar results. Of note, there was no difference in risk of severe COVID-19 hospitalization when comparing non-selective vs selective alpha-1 blocker use (aOR 0.98, 95% CI 0.86-1.10), higher- vs lower-dose alpha-1 blocker use (aOR 0.96, 95% CI 0.86-1.08), or current vs remote alpha-1 blocker use (aOR 1.04, 95% CI 0.91-1.18).

CONCLUSIONS

Prevalent use of alpha-1 receptor blockers was not associated with a protective or harmful effect on risk of uncomplicated or severe hospitalized COVID-19.

Overview of Cancer Control in Armenia and Policy Implications

Cancer is the second leading cause of death in Armenia. Over the past two decades, the country has seen a significant rise in cancer morbidity and mortality. This review aims to provide up-to-date info about the state of cancer control in Armenia and identify priority areas of research. The paper analyzes published literature and local and international statistical reports on Armenia and similar countries to put numbers into context. While cancer detection, diagnosis, and treatment are improving, the prevalence of risk factors is still quite high and smoking is widespread. Early detection rates are low and several important screening programs are absent. Diagnosis and treatment methods are not standardized; there is a lack of treatment accessibility due to insufficient government coverage and limited availability of essential medicines. Overall, there is room for improvement in this sector, as research is limited and multidisciplinary approaches to the topic are rare.

Risk of Covid-19-Related Hospitalization and More Severe Outcomes in Medicare Beneficiaries Treated with Renin-Angiotensin-Aldosterone System Inhibitors for Hypertension

BACKGROUND

There are theoretical concerns that angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) could increase the risk of severe Covid-19.

OBJECTIVE

To determine if ACEIs and ARBs are associated with an increased risk of Covid-19 hospitalization overall, or hospitalization involving intensive care unit (ICU) admission, invasive mechanical ventilation, or death.

DESIGN

Observational case-control study.

PARTICIPANTS

Medicare beneficiaries aged ≥ 66 years with hypertension, treated with ACEIs, ARBs, calcium channel blockers (CCBs), or thiazide diuretics.

MAIN MEASURES

Adjusted odds ratios (OR) and 95% confidence intervals (CI) for the outcomes of Covid-19 hospitalization, or hospitalization involving ICU admission, invasive mechanical ventilation, or death.

RESULTS

A total of 35,300 cases of hospitalized Covid-19 were matched to 228,228 controls on calendar date and neighborhood of residence. The median age of cases was 79 years, 57.4% were female, and the median duration of hospitalization was 8 days (interquartile range 5-12). ACEIs and ARBs were associated with a slight reduction in Covid-19 hospitalization risk compared with treatment with other first-line antihypertensives (OR for ACEIs 0.95, 95% CI 0.92-0.98; OR for ARBs 0.94, 95% CI 0.90-0.97). Similar results were obtained for hospitalizations involving ICU admission, invasive mechanical ventilation, or death. There were no meaningful differences in risk for ACEIs compared with ARBs. In an analysis restricted to monotherapy with a first-line agent, CCBs were associated with a small increased risk of Covid-19 hospitalization compared with ACEIs (OR 1.09, 95% CI 1.04-1.14), ARBs (OR 1.10, 95% CI 1.05-1.15), or thiazide diuretics (OR 1.11, 95% CI 1.03-1.19).

CONCLUSIONS

ACEIs and ARBs were not associated with an increased risk of Covid-19 hospitalization or with hospitalization involving ICU admission, invasive mechanical ventilation, or death. The finding of a small increased risk of Covid-19 hospitalization with CCBs was unexpected and could be due to residual confounding.

Treatment and Outcomes of Colorectal Cancer in Armenia: A Real-World Experience From a Developing Country

PURPOSE

In Armenia, colorectal cancer (CRC) is one of the most frequently diagnosed cancers. It is in the third place by incidence. The aim of this study was to evaluate treatment and outcomes of CRC in Armenia during the last 9 years.

MATERIALS AND METHODS

For this retrospective hospital-based study, we have collected data from two main oncology centers in Armenia: National Oncology Center and “Muratsan” Hospital of Yerevan State Medical University. The information about patients with CRC who were treated at these two centers between January 1, 2010 and July 1, 2018 was collected from the medical records. Log-rank test and Kaplan-Meier curves were used for survival analysis. Prognostic factors were identified by Cox regression.

RESULTS

A total of 602 patients with CRC were involved in the final analysis. Median follow-up time was 37 months (range, 3-207 months). A total of 8.6% of patients had stage I, 32.9% stage II, 38.0% stage III, and 17.6% stage IV cancer; for 2.7% patients, the stage was unknown. The main independent prognostic factors for overall survival (OS) were tumor stage, grade, and histology. Adjuvant chemotherapy has been shown to improve survival in stage II colon cancer and stage III rectal but not in stage II rectal cancer. Radiotherapy did not yield survival improvement in stage II or III rectal cancer. Three- and 5-year OS rates were 62.9% and 51.8% for all stages combined and 79.7% and 68.5% for stages I-II, 62.5% and 48.4% for stage III, and 24.4% and 17% for stage IV respectively.

CONCLUSION

As seen from our results, our survival rates are lower than those of the developed world. Additional research is needed to identify the underlying reasons and to improve patients’ treatment and outcomes in Armenia.

Application of PD-1/PD-L1 immune checkpoint inhibitors treating lung cancer in Yerevan Armenia: Two-center experience

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Background: Over the past few years PD-1/PD-L1 pathway blockade through immune checkpoint inhibitors appeared to be an effective treatment approach in advanced lung cancer. The current study aims to investigate the utilization of immunotherapy for lung cancer management purposes in Armenia. Methods: For this retrospective, hospital-based cohort study census sampling method was approached. Data was collected on all the patients who were diagnosed with stage III and IV lung cancer and passed treatment in the departments of Adult Solid Tumors in Hematology Center after prof. Yeolyan and Institute of Surgery after Mikaelyan from 01.05.2019 till 12.01.2020. The time period was selected based on the initiation of PD-L1 testing in Armenia. The prevalence of non-small cell (NSCLC) and small cell (SCLC) lung cancer was calculated. The patients’ PD-L1 testing performance, subsequent immunotherapy utilization, and developed adverse effects were evaluated. Results: According to the hospital-based data, during the mentioned time period 60 patients diagnosed with stage III and IV lung cancer received treatment in the two units. In the cohort, the patients’ median age was 65,5 years (range 46 – 88). The male-to-female ratio was 5.6. The prevalence of NSCLC and SCLC was 61.7% and 28.3% respectively. At the time of follow-up on 10.02.2020, 74.4% of NSCLC patients and 64.7% of SCLC patients were alive. Of the 43 NSCLC subjects, only 11 were checked for the PD-L1 status. Among them, 7 were determined to be PD-L1 positive and 5 of them received immunotherapy. For SCLC patients PD-L1 status wasn’t checked. Of 17 SCLC patients, only one has received immunotherapy. Overall only one case of immunotherapy related adverse effect was observed (severe rash and pruritus). At the time of follow-up, one of the six patients who underwent immunotherapy was dead. Conclusions: The presented data demonstrate a lack of PD-L1 test performance and underutilization of immunotherapy treatment. In the future, it is recommended to perform a nationwide study on the current topic to assess the immune checkpoint inhibitors impact on the survival rates of advanced lung cancer patients.

Breast cancer pathology patterns in Armenia

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Background: Breast cancer (BC) is the most common malignancy among the women in Armenia (AM). Currently there is a knowledge gap regarding the morphology distribution of the BC in AM. Methods: The data on patients with BC diagnosed in 2015-2016 in the pathology lab “Davidyants Labs” in AM were retrospectively reviewed. Pts with Her2+ results by IHC were excluded from the study, due to unavailability to perform FISH or CISH analyses. Overall 361 pathology reports were evaluated. Results: The median age was 54 years; range [19-82]. Histopathological subtypes were defined for 305 pts, from which lobular carcinoma 57.4% of cases (175/305), ductal carcinoma 26.9% (82/305), mucinous carcinoma 2.6% (8/305), mixed type carcinoma (lobular and ductal) 2.6% (8/305), DCIS 2% (n = 6/305), non specified carcinoma 2% (6/305), medullary carcinoma 1% (n = 3/305) and others 5.6% (17/305). Within the cohort 8.5% (23/270) were grade 1, 65.9% grade 2 (178/270); 25.6% grade 3 (n = 69/270). Vascular or lymphatic invasion was present in 59.5% (50/84) and 64.7% (55/85), respectively. Staging distribution, based on pT pN data for 92 pts who went to primary surgery, was: 0 stage 7.6% (7/92), I stage 22.8% (21/92), II stage 41.3% (38/92), III stage 28.3% (26/92). Staging distribution based on ypT ypN data for 27 pts who went to surgery after neoadjuvant chemo was 0 stage 25.9% (7/27), I stage 18.5% (5/27), II stage 29.6% (8/27), III stage 25.9% (7/27). ER and PR were defined for 244 patients. ER positive 89.8% (219/244) of cases, PR pos. 73% (178/244), ER/PR pos. 72.5% (177/244) cases. Her receptor was defined for 237 patients. Her3+ 16.9% (40/237); Her2+ 12.7% (30/237); Her1+ 38% (90/237); Her0 32.5% (n = 77/237). We could not evaluate Her2+ status by FISH or CISH, so these results were excluded from the analysis. Ki67 was low (≤20) in 42.1% (101/240) of cases and high ( > 20) in 57.9% (139/240). Within the group Luminal A type was 41.4% (84/203); Luminal B 32.5% (66/203); Her positive 19.7% (40/203) and triple negative 6.4% (13/203). p53 and perineural invasion (Pn) was present in 32% (16/50) and 52% (26/50), respectively. Tumor leukocyte infiltration was determined for 16 patients. Leukocyte infiltration was positive in 43.7% (7/16) cases, negative in 25% (4/16) cases, minimal in 31.3% cases (5/16). Conclusions: BC in Armenian women presents with different epidemiological characteristics in comparison with other ethnicities. Lobular type BC is the most frequent type among Armenian women, however, differential diagnosis between lobular/ductal carcinomas was done without IHC (E-Cadherin), which rises the need for further studies on that regard.

Treatment of colorectal cancer in Armenia: A retrospective hospital-based study from a developing world

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Background: In Armenia colorectal cancer (CRC) is on the third place by incidence. Every year around 700 new cases are diagnosed with 60% diagnosed in 3rd and 4th stages. Methods: For this retrospective hospital-based study we have collected data from two main oncology centers in Armenia: National Oncology Center and Muratsan Hospital Complex of Yerevan state medical university. The information about patients with CRC who were treated at these two centers during 01/01/2010 - 07/01/2018 period was collected from the medical records. Results: 602 patients with CRC treated during mentioned period in these two hospitals were involved in final analysis. From them 51.8% were female. Median age at diagnosis was 58. Median follow up time was 37 months (range 3-207). 26.1% had right sided, 30.9% left sided and 43.0% rectum cancer. 8.6% of patients had stage 1, 32.9% stage 2, 38.0% stage 3, 17.6% stage 4 CRC and for 2.7% patients stage was unknown. The median survival was not reached for the entire cohort ( > 37 months). Median survival was > 66.5 months for 1st, > 48.5 months for 2nd, > 35 months for 3rd and 19 months for 4th stages. Tumor stage, grade and histology were the main independent prognostic factors by univariate and multivariate Cox regression analysis. For stage 2 CRC patients (198) we found significant difference regarding overall survival (OS) (p = 0.024) and disease free survival (DFS) (p = 0.006) for those who received adjuvant chemotherapy after surgery compared to those who didn’t receive adjuvant chemotherapy. For stage 2 and 3 rectum cancer patients, our study failed to show OS (2nd stage: p = 0.961; 3rd stage: p = 0.348) or DFS (2nd stage: p = 0.719; 3rd stage: p = 0.983) advantage for those who received radiotherapy (RT) compared with those who didn’t receive RT. In our study population 28.3% of stage 4 patients received chemotherapy combined with Bevacizumab while 70% were treated with chemotherapy only. Median OS between these two groups wasn’t significantly different (21 months in Chemo+Bevacizumab group and 18.5 months in chemo only group (p = 0.382)). 3 and 5-year survival rates were 62.9% and 51.8% for all stages combined and 79.7% and 68.5% for stages 1-2, 62.5% and 48.4% for stage 3, 24.4% and 17% for stage 4 respectively. Conclusions: As seen from our results our survival rates are inferior compared to that of developed world. The reasons for that could be compromise in surgery and RT, poor pathological assessment, unavailability of some molecular markers, poor availability of new targeted drugs and absence of national treatment guidelines.

The epidemiological status of African swine fever in domestic swine herds in the Tavush Province region, Armenia

KEEN The factors associated with the spread and persistence of African swine fever (ASF) in the Caucasus region remain to be fully identified. It is assumed that large naive populations of domestic free-ranging and wild pigs are critical to disease transmission and maintenance. Nonetheless, 11 years since its epidemic introduction into the region in 2007, ASF virus (ASFV) is still circulating, suggesting that an endemic cycle has been established based on contact between free-ranging domestic pigs and wild pigs, and that native Ornithodoros ticks probably serve as reservoirs for the virus. Therefore, research is required to gather information on the epidemiological status of ASF in the Caucasus region, focusing particularly on understanding modes of ASFV spread and persistence in this new virus environment. The authors established an ASFV survey targeting domestic pigs in the Tavush province of northern Armenia, an area of the country considered to be at high risk of disease incursion/occurrence. All tested samples collected for this survey were negative for ASF. The probability of observing no reactors by antibody enzyme-linked immunosorbent assay in a sample of this size (n = 1,506) from a population with an estimated disease prevalence of 1% is very low (< 0.0001). Therefore, it is possible but very unlikely for ASFV to be present among domestic pigs in the Tavush province region.

Denosumab treatment for progressive skull base giant cell tumor of bone in a 14 year old female - a case report and literature review

Background

Giant cell tumor of bone (GCT) is a rare primary bone tumor, which can metastasize and undergo malignant transformation. The standard treatment of GCT is surgery. In patients with unresectable or metastatic disease, additional therapeutic options are available. These include blocking of the receptor activator of NF-kappa B ligand (RANKL) signaling pathway, which plays a role in the pathogenesis of GCT of bone, via the anti-RANKL monoclonal antibody denosumab.

Case Presentation

Herein we report on a female teenager who presented in a very poor clinical condition (cachexia, diplopia, strabismus, dysphonia with palsy of cranial nerves V, VI, VIII, IX, X, XI and XII) due to progressive disease, after incomplete resection and adjuvant radiotherapy, of a GCT which affected the cervical spine (C1 and C2) as well as the skull base; and who had an impressive clinical response to denosumab therapy. To the best of our knowledge, this is the youngest patient ever reported with a skull base tumor treated with denosumab.

Conclusion

In situations when surgery can be postponed and local aggressiveness of the tumor does not urge for acute surgical intervention, upfront use of denosumab in order to reduce the tumor size might be considered. Principally, the goal of denosumab therapy is to reduce tumor size as much as possible, with the ultimate goal to make local surgery (or as in our case re-surgery) amenable. However, improvement in quality of life, as demonstrated in our patient, is also an important aspect of such targeted therapies.

Electronic supplementary material

The online version of this article (doi:10.1186/s13052-017-0353-0) contains supplementary material, which is available to authorized users.

Treating Adults with Hodgkin Lymphoma in the Developing World: a Hospital-Based Cohort Study from Armenia

BACKGROUND

With advances in diagnostics and treatment approaches, patients with Hodgkin's lymphoma (HL) in developed countries can nowadays expect to have excellent outcomes. However, information about the characteristics and outcomes in the developing world is very scarce, and this is important given the fact that there are several reports about differences of disease characteristics depending on geographic location and the development level of the country.

MATERIALS AND METHODS

In this retrospective study we assessed the features of 36 adult (≥18 years old) patients with HL and their diagnosis and treatment and outcomes in the Clinic of Chemotherapy of Muratsan University Hospital of Yerevan State Medical University, Armenia, between 2008- 2014.

RESULTS

All patients had classic HL and among them 19 (53%) had nodular sclerosis subtype, 8 (22%) mixed cellularity and 9 (25%) lymphocyte-rich. 16 (44.5%) patients were at stage II, 13 (36%) stage III and 7 (19.5%) stage IV. Median follow-up time was 24.5 months (range 1-71 months) and during the whole follow- up period only two relapses (early) were documented and there were no deaths. Twenty-three (64%) patients received a BEACOPP (bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone) regimen, and 13 (36%) ABVD (doxorubicin, bleomycin, vinblastine and dacarbazine) regimen. A total of 25 (69.5%) patients received radiation in addition to chemotherapy.

CONCLUSIONS

Although the number of patients involved in the study is small and the median follow-up time was just two years, this retrospective study shows that treatment of HL can be successfully organized in a resource-limited setting.

Chart-confirmed guillain-barre syndrome after 2009 H1N1 influenza vaccination among the Medicare population, 2009-2010

Given the increased risk of Guillain-Barré Syndrome (GBS) found with the 1976 swine influenza vaccine, both active surveillance and end-of-season analyses on chart-confirmed cases were performed across multiple US vaccine safety monitoring systems, including the Medicare system, to evaluate the association of GBS after 2009 monovalent H1N1 influenza vaccination. Medically reviewed cases consisted of H1N1-vaccinated Medicare beneficiaries who were hospitalized for GBS. These cases were then classified by using Brighton Collaboration diagnostic criteria. Thirty-one persons had Brighton level 1, 2, or 3 GBS or Fisher Syndrome, with symptom onset 1-119 days after vaccination. Self-controlled risk interval analyses estimated GBS risk within the 6-week period immediately following H1N1 vaccination compared with a later control period, with additional adjustment for seasonality. Our results showed an elevated risk of GBS with 2009 monovalent H1N1 vaccination (incidence rate ratio = 2.41, 95% confidence interval: 1.14, 5.11; attributable risk = 2.84 per million doses administered, 95% confidence interval: 0.21, 5.48). This observed risk was slightly higher than that seen with previous seasonal influenza vaccines; however, additional results that used a stricter case definition (Brighton level 1 or 2) were not statistically significant, and our ability to account for preceding respiratory/gastrointestinal illness was limited. Furthermore, the observed risk was substantially lower than that seen with the 1976 swine influenza vaccine.

Prenatal allergen exposures prevent allergen-induced sensitization and airway inflammation in young mice

BACKGROUND

Immune-modulation such as tolerance induction appears to be an upcoming concept to prevent development of atopic diseases. Pregnancy might present a critical period for preventing allergic sensitization of the progeny. We investigated the effect of maternal allergen exposures during pregnancy on allergen-induced sensitization and airway inflammation in the offspring in a murine model.

METHODS

BALB/c mice were exposed to aerosolized ovalbumin (OVA) three times per week from day 7 of pregnancy until delivery (day 0). Offspring were systemically sensitized by six intraperitoneal injections with OVA between postnatal days 21 and 35, prior to airway allergen challenges on days 48, 49, and 50. Analyses were performed on day 52. To examine long-lasting effects of maternal OVA exposures some offspring were sensitized between days 115 and 129; analyses took place on day 147.

RESULTS

Compared to maternal placebo exposures, maternal OVA exposures suppressed OVA-specific IgE serum levels and inhibited development of allergen-induced airway inflammation in the OVA-sensitized offspring on both days 52 and 147. This protective effect was associated with a shift from a predominant Th2 immune response toward a predominant production of the cytokines IFN-γ and IL-10. Further, maternal OVA exposures were associated with development of CD25(+) Foxp3(+) regulatory T cells (T(regs)) in the OVA-sensitized offspring. Depletion of T(regs) or neutralization of IL-10 prior to allergen sensitization re-established OVA-induced sensitization and eosinophilic airway inflammation in the OVA-sensitized offspring.

CONCLUSIONS

In our model, maternal allergen exposures during pregnancy prevented later allergen-mediated sensitization and airway inflammation by allergen-specific tolerance induction in the offspring.

Lipocalin2 protects against airway inflammation and hyperresponsiveness in a murine model of allergic airway disease

BACKGROUND

Allergen-induced bronchial asthma is a chronic airway disease that involves the interplay of various genes with environmental factors triggering different inflammatory pathways.

OBJECTIVE

The aim of this study was to identify possible mediators of airway inflammation (AI) in a model of allergic AI via microarray comparisons and to analyse one of these mediators, Lipocalin2 (Lcn2), for its role in a murine model of allergic airway disease.

METHODS

Gene microarrays were used to identify genes with at least a twofold increase in gene expression in the lungs of two separate mouse strains with high and low allergic susceptibility, respectively. Validation of mRNA data was obtained by Western blotting, followed by functional analysis of one of the identified genes, Lcn2, in mice with targeted disruption of specific gene expression. Epithelial cell cultures were undertaken to define induction requirements and possible mechanistic basis of the results observed in the Lcn2 knock-out mice.

RESULTS

Lcn2 was up-regulated upon allergen sensitization and airway challenges in lung tissues of both mouse strains and retraced on the protein level in bronchoalveolar lavage fluids. Functional relevance was assessed in mice genetically deficient for Lcn2, which showed enhanced airway resistance and increased AI associated with decreased apoptosis of lung inflammatory cells, compared with wild-type controls. Similarly, application of Lcn2-blocking antibodies before airway challenges resulted in increased inflammation and reduced apoptosis.

CONCLUSION

These data indicate a protective role for Lcn2 in allergic airway disease, suggesting a pro-apoptotic effect as the underlying mechanism.

Gastrointestinal nematode infection interferes with experimental allergic airway inflammation but not atopic dermatitis

BACKGROUND

Some helminth infections are negatively associated with the prevalence of allergic disorders, arguing for a modulation of allergic reactions by the parasites, depending on the worm species, intensity and phase of infection and the type of disease.

OBJECTIVE

The aim of this study was to analyse the influence of a chronic infection with the gastrointestinal nematode Heligmosomoides polygyrus, in a murine model of allergic airway disease and of atopic dermatitis (AD), respectively.

METHODS

Mice were infected with H. polygyrus and systemically sensitized with the model allergen ovalbumin. Subsequently, the animals were challenged with the allergen either via the airways for induction of airway disease, or via skin patches for induction of dermatitis.

RESULTS

Mice concomitantly infected with H. polygyrus showed diminished eosinophil and lymphocyte recruitment into the lungs and decreased allergen-specific IgE levels when compared with sensitized and airway challenged controls. In addition, animals showed a trend towards reduced airway hyper-reactivity. In contrast, no significant differences in the severity of eczematous skin lesions were observed between infected and control animals in the AD model. Although H. polygyrus infection reduced CD8+ and CD4+ T-cell infiltration into the skin and production of allergen-specific IgE, mast cell recruitment was significantly increased in worm-infected mice in the dermatitis model. The worm infection was associated with significantly elevated numbers of Foxp3+ regulatory T cells (Treg) in peribronchial lymph nodes in H. polygyrus-infected sensitized and airway challenged mice. In contrast, Treg cells were basically absent in eczematous skin and their number was not increased in skin-draining lymph nodes of mice with experimental dermatitis.

CONCLUSION

Infection with the gastrointestinal nematode used in our study leads to significant inhibition of mucosa-associated but not cutaneous allergic reactions, pointing to a site specificity of the immunomodulation exerted by helminths. This finding might be an important aspect for future considerations of helminths for treatment of allergic diseases.

Intranasal delivery of whole influenza vaccine prevents subsequent allergen-induced sensitization and airway hyper-reactivity in mice

BACKGROUND

Infection with influenza virus has been associated with seemingly opposing effects on the development of asthma. However, there are no data about the effects of mucosal vaccination with inactivated influenza on the inception of allergic asthma.

OBJECTIVE

To assess the immunological effects of inhaled inactivated influenza vaccine, using two different types of flu vaccines, on the inception of allergic sensitization and allergen-mediated airway disease in a mouse model.

METHODS

BALB/c mice were intranasally or intratracheally vaccinated with whole or split influenza virus vaccine (days -1 or -1, 27) before systemic sensitization with ovalbumin (OVA) (days 1, 14) and repeated airway allergen challenges (days 28-30). Allergen sensitization (IgE serum levels), airway inflammation (differential cells in bronchoalveolar lavage fluid) and airway hyper-reactivity (AHR) (in vivo lung function) were analysed.

RESULTS

The intranasal instillation of whole influenza vaccine before allergen sensitization significantly reduced the serum levels of total and OVA-specific IgE as well as allergen-induced AHR. Prevention was due to an allergen-specific shift from a predominant T helper (Th)2- towards a Th1-immune response. Application of split influenza vaccine did not show the same preventive effect.

CONCLUSION

Intranasal administration of inactivated whole influenza vaccine reduced subsequent allergen sensitization and prevented allergen-induced AHR. Our results show that the composition of the influenza vaccine has a major influence on subsequent development of allergen-induced sensitization and AHR, and suggest that mucosal inactivated whole influenza vaccination may represent a step towards the development of a preventive strategy for atopic asthma.

Probiotic-induced suppression of allergic sensitization and airway inflammation is associated with an increase of T regulatory-dependent mechanisms in a murine model of asthma

BACKGROUND

Microbial intestinal colonization in early in life is regarded to play a major role for the maturation of the immune system. Application of non-pathogenic probiotic bacteria during early infancy might protect from allergic disorders but underlying mechanisms have not been analysed so far.

OBJECTIVE

The aim of the current study was to investigate the immune effects of oral application of probiotic bacteria on allergen-induced sensitization and development of airway inflammation and airway hyper-reactivity, cardinal features of bronchial asthma.

METHODS

Newborn Balb/c mice received orally 10(9) CFU every second day either Lactobacillus rhamnosus GG or Bifidobacterium lactis (Bb-12) starting from birth for consecutive 8 weeks, during systemic sensitization (six intraperitoneal injections, days 29-40) and airway challenge (days 54-56) with ovalbumin.

RESULTS

The administration of either Bb-12 or LGG suppressed all aspects of the asthmatic phenotype: airway reactivity, antigen-specific immunoglobulin E production and pulmonary eosinophilia (mean: 137 vs. 17 and 13 cellsx10(3)/mL, respectively). Antigen-specific recall proliferation by spleen cells and T-helper type 2 cytokine production (IL-4, IL-5 and IL-10) by mesenteric lymph node cells also showed significant reduction, while TGF production remained unchanged. Oral LGG administration particularly suppressed allergen-induced proliferative responses and was associated with an increase in numbers of TGF-beta-secreting CD4+/CD3+ T cells in mesenteric lymph nodes (6.5, 16.7%) as well as nearly 2-fold up-regulation of Foxp3-expressing cells in peribronchial lymph nodes.

CONCLUSIONS

Neonatal application of probiotic bacteria inhibits subsequent allergic sensitization and airway disease in a murine model of asthma by induction of T regulatory cells associated with increased TGF-beta production.

Common vaccine antigens inhibit allergen-induced sensitization and airway hyperresponsiveness in a murine model

BACKGROUND

Co-vaccination with cellular pertussis vaccine down-regulates allergic sensitization to diphtheria and tetanus antigens. Using a murine model, we investigated whether vaccination with diphtheria/tetanus toxoids, administered separately or simultaneously with the whole cell vaccine of Bordetella pertussis, inhibits subsequent allergen-induced immune and inflammatory responses.

METHODS

BALB/c-mice were vaccinated intracutaneously with a combination of diphtheria and tetanus toxoids or a combination of diphtheria and tetanus toxoids with a whole cell vaccine of B. pertussis (three times, days -21 to -7) prior to systemic sensitization (days 1-14) and repeated airway challenges (days 28-30) with ovalbumin.

RESULTS

Compared with negative controls, systemic sensitization and airway allergen challenges induced high serum levels of allergen-specific IgE, predominant Th2-type cytokine production, airway inflammation and development of in vivo airway hyperreactivity. Vaccination with diphtheria and tetanus toxoids prior to sensitization suppressed IgE formation and development of eosinophilic airway inflammation. Co-vaccination with a whole cell pertussis vaccine inhibited allergen sensitization, airway inflammation and development of in vivo airway hyperreactivity. Prevention was due to an allergen-specific and general shift from a predominant Th2 towards a predominant Th1 immune response.

CONCLUSION

Vaccination with diphtheria and tetanus toxoids alone or in combination with whole cell pertussis vaccine prior to allergen sensitization prevented allergen-induced Th2 immune responses. Vaccine antigens may down-regulate allergic responses to a range of common allergens.