Asthma status and waning of measles antibody concentrations after measles immunization

Characteristics of Anti-Measles Immunity in Lung Transplant Candidates

Measles has not yet been eradicated; therefore, its outbreaks are still reported throughout the world. Like any infection, measles is dangerous for immunocompromised patients. Levels of anti-measles IgG antibodies were measured in 157 patients aged 17 to 72, who were placed on the lung transplant waiting list. Measurements were undertaken by enzyme-linked immunosorbent assay (ELISA) using the VectoMeasles-IgG kit (Russia). The proportion of patients seronegative for measles was 19% (30/157). Correlation was detected between patients' age and their levels of anti-measles antibodies, with higher proportions of patients having undetectable titers (25.5-28.9%) or low antibody levels (38.3-44.4%) in the young age groups (17-29 and 30-39 years old). There were no differences between male and female patients in levels of anti-measles antibodies or in the proportion of seronegative individuals. Analyses of antibody levels with regard to type of disease revealed the highest rate of seronegative results in cystic fibrosis patients (34.4%, 11/32). Overall, 19% of lung transplant candidates, mostly young people and cystic fibrosis patients, did not have protective immunity against measles.

Measles vaccination of special risk groups

Measles is an important vaccine preventable disease with significant morbidity and mortality. Although measles vaccine is a safe and effective vaccine available worldwide for more than 50 years, still immunization efforts have not successfully reached the WHO goal of 95% vaccination coverage. Hesitancy is especially increased amongst parents of children with chronic conditions. Contraindications for measles-containing vaccines are well defined and include history of anaphylactic reactions to neomycin, history of severe allergic reaction to previous vaccination, pregnancy, and severe immunosuppression. Concurrently, precautions for measles-containing vaccines include amongst other, history of thrombocytopenia or thrombocytopenic purpura and personal or family history of seizures of any etiology. This article aims to address misconceptions on measles vaccine safety and review data on adverse events among special groups of subjects at increased risk following measles immunization.

Establishing an expert consensus for the operational definitions of asthma-associated infectious and inflammatory multimorbidities for computational algorithms through a modified Delphi technique

BACKGROUND

A subgroup of patients with asthma has been reported to have an increased risk for asthma-associated infectious and inflammatory multimorbidities (AIMs). To systematically investigate the association of asthma with AIMs using a large patient cohort, it is desired to leverage a broad range of electronic health record (EHR) data sources to automatically identify AIMs accurately and efficiently.

METHODS

We established an expert consensus for an operational definition for each AIM from EHR through a modified Delphi technique. A series of questions about the operational definition of 19 AIMS (11 infectious diseases and 8 inflammatory diseases) was generated by a core team of experts who considered feasibility, balance between sensitivity and specificity, and generalizability. Eight internal and 5 external expert panelists were invited to individually complete a series of online questionnaires and provide judgement and feedback throughout three sequential internal rounds and two external rounds. Panelists' responses were collected, descriptive statistics tabulated, and results reported back to the entire group. Following each round the core team of experts made iterative edits to the operational definitions until a moderate (≥ 60%) or strong (≥ 80%) level of consensus among the panel was achieved.

RESULTS

Response rates for each Delphi round were 100% in all 5 rounds with the achievement of the following consensus levels: (1) Internal panel consensus: 100% for 8 definitions, 88% for 10 definitions, and 75% for 1 definition, (2) External panel consensus: 100% for 12 definitions and 80% for 7 definitions.

CONCLUSIONS

The final operational definitions of AIMs established through a modified Delphi technique can serve as a foundation for developing computational algorithms to automatically identify AIMs from EHRs to enable large scale research studies on patient's multimorbidities associated with asthma.

Risk, Mechanisms and Implications of Asthma-Associated Infectious and Inflammatory Multimorbidities (AIMs) among Individuals With Asthma: a Systematic Review and a Case Study

Our prior work and the work of others have demonstrated that asthma increases the risk of a broad range of both respiratory (e.g., pneumonia and pertussis) and non-respiratory (e.g., zoster and appendicitis) infectious diseases as well as inflammatory diseases (e.g., celiac disease and myocardial infarction [MI]), suggesting the systemic disease nature of asthma and its impact beyond the airways. We call these conditions asthma-associated infectious and inflammatory multimorbidities (AIMs). At present, little is known about why some people with asthma are at high-risk of AIMs, and others are not, to the extent to which controlling asthma reduces the risk of AIMs and which specific therapies mitigate the risk of AIMs. These questions represent a significant knowledge gap in asthma research and unmet needs in asthma care, because there are no guidelines addressing the identification and management of AIMs. This is a systematic review on the association of asthma with the risk of AIMs and a case study to highlight that 1) AIMs are relatively under-recognized conditions, but pose major health threats to people with asthma; 2) AIMs provide insights into immunological and clinical features of asthma as a systemic inflammatory disease beyond a solely chronic airway disease; and 3) it is time to recognize AIMs as a distinctive asthma phenotype in order to advance asthma research and improve asthma care. An improved understanding of AIMs and their underlying mechanisms will bring valuable and new perspectives improving the practice, research, and public health related to asthma.

Clinical form of asthma and vaccine immunity in preschoolers

Introduction

Asthma is the most common chronic disease in children. Its exacerbation results from allergic and infectious diseases.

Aim

To assess the influence of a clinical form of asthma on preschoolers’ vaccine immunity following 3 years after the completion of the mandatory vaccination programme.

Material and methods

The study encompassed 172 preschool children with asthma being newly diagnosed, including 140 patients with mild asthma and 32 with moderate asthma, whose vaccine immunity (level of IgG-specific antibodies) was assessed after the mandatory early vaccines had been administered in the early childhood. Monovalent vaccines (HBV + IPV + Hib) along with a three-component combined vaccine (DTwP) and MMR were given to 86 children while a six-component combined vaccine (DTaP + IPV + Hib + HBV) along with a three-component MMR vaccine were administered to the remaining 86 children. The immunity class for particular vaccinations was assessed according to the manufacturers’ instructions.

Results

Children suffering from mild asthma had considerably more frequently vaccinations administered on time (p < 0.001) and the type of vaccines (monovalent or highly-combined) administered did not have a significant influence on the clinical form of asthma in the children examined (p = 0.6951). Apart from the vaccines against hepatitis B and rubella where considerably more frequently a high level of antibodies occurred in children with mild asthma, the antibody levels to other vaccines, namely diphtheria, tetanus, pertussis, Hib and mumps, were not associated with the severity of asthma.

Conclusions

Moderate asthma may have a negative impact on remote vaccine immunity to HBV and rubella.

Serum IgG Concentrations in Adult Patients Experiencing Virus-Induced Severe Asthma Exacerbations

BACKGROUND

Patients experiencing severe asthma exacerbations have a poorer quality of life and an increase in morbidity and mortality. Viruses are frequently involved in asthma exacerbations.

OBJECTIVE

To determine the value of measuring serum IgG concentrations in asthma exacerbations and assess their link with viral infections in patients hospitalized for asthma.

METHODS

Patients hospitalized for asthma exacerbation were included in an observational study from January 1, 2015, to December 31, 2015. Serum IgG concentrations on admission were compared between patients with a positive upper airway viral sample and those with a negative viral sample.

RESULTS

Among the 82 patients included, those with positive viral nasopharyngeal samples (n = 40) presented with lower serum IgG concentrations during exacerbation than those with a negative viral sample (n = 42) (10.1 ± 2.3 g/L vs 11.5 ± 3.6 g/L; P < .05). The median concentration of serum IgG was lower in patients hospitalized for more than 3 days compared with those hospitalized for less than 3 days (10.0 g/L [8.2-12.4] vs 11.4 g/L [10.1-12.8]; P < .05) and in patients who received oral corticosteroid therapy for more than 5 days compared with those treated with oral steroids for less than 5 days (10.1 g/L [8.3-12.2] vs 11.6 g/L [10.0-13.8]; P < .05).

CONCLUSIONS

Serum IgG level was significantly lower when asthma exacerbations were associated with positive viral samples. The patients with lower serum IgG concentrations required longer hospitalizations and longer courses of steroids.

Relationship between asthma status and antibody response pattern to 23-valent pneumococcal vaccination

Objective: Asthma poses an increased risk for serious pneumococcal disease, but little is known about the influence of asthma status on the 23-valent serotype-specific pneumococcal antibody response. We examined differences in antibody titers between pre- and post-vaccination with 23-valent pneumococcal polysaccharide vaccine (PPSV-23) in relation to asthma status. Methods: Asthma status was retrospectively ascertained by the Predetermined Asthma Criteria in an existing vaccine cohort through comprehensive medical record review. Twenty-three serotype-specific pneumococcal antibody titers measured at baseline and 4-6 weeks post-vaccination were analyzed. Vaccine responses to PPSV-23 were calculated from pre- to post-vaccine titers for each of the serotypes. Results: Of the 64 eligible and enrolled subjects, 18 (28%) had asthma. Controls (i.e., subjects without asthma) demonstrated a statistically significant fold change response compared to their baseline for all serotypes, while those with asthma did not mount a significant response to serotypes 7F, 22F, and 23F. The overall vaccine response as measured by fold change over baseline was lower in subjects with asthma than controls. Conclusions: Poorer humoral immune responses to PPSV-23 as measured by fold change were more likely to be observed in subjects with asthma compared to controls. We recommend the consideration of asthma status when interpreting vaccine response for immune competence workup through larger studies. Further studies are warranted to replicate these findings.

Allergic airway sensitization impairs antibacterial IgG antibody responses during bacterial respiratory tract infections

BACKGROUND

Mycoplasma pneumoniae, an atypical human pathogen, has been associated with asthma initiation and exacerbation. Asthmatic patients have been reported to have higher carriage rates of M pneumoniae compared with nonasthmatic subjects and are at greater risk for invasive respiratory infections.

OBJECTIVE

We sought to study whether prior allergen sensitization affects the host response to chronic bacterial infection.

METHODS

BALB/cJ and IL-4 receptor α^-/- mice were sensitized with ovalbumin (OVA) and then infected with M pneumoniae or Streptococcus pneumoniae. Immune parameters were analyzed at 30 days postinfection and included cellular profiles in bronchoalveolar lavage fluid (BALF) and serum IgG and IgE antibody levels to whole bacterial lysate, recombinant P1 adhesin, and OVA. Total lung RNA was examined for transcript levels, and BALF was examined for cytokine protein profiles.

RESULTS

Anti-M pneumoniae antibody responses were decreased in allergen-sensitized, M pneumoniae-infected animals compared with control animals, but OVA-specific IgG responses were unaffected. Similar decreases in anti-S pneumoniae antibody levels were found in OVA-sensitized animals. However, M pneumoniae, but not S pneumoniae, infection augmented anti-OVA IgE antibody responses. Loss of IL-4 receptor signaling partially restored anti-M pneumoniae antibody responses in IgG_2a and IgG_2b subclasses. Inflammatory cytokine levels in BALF from OVA-sensitized, M pneumoniae-infected or S pneumoniae-infected animals were reduced compared with those in uninfected OVA-sensitized control animals. Unexpectedly, airway hyperreactivity to methacholine was essentially ablated in M pneumoniae-infected, OVA-sensitized animals.

CONCLUSIONS

An established type 2-biased host immune response impairs the host immune response to respiratory bacterial infection in a largely pathogen-independent manner. Some pathogens, such as M pneumoniae, can augment ongoing allergic responses and inhibit pulmonary type 2 cytokine responses and allergic airway hyperreactivity.

Asthma and risk of breakthrough varicella infection in children

BACKGROUND

We recently reported a more rapid waning of vaccine-induced humoral immunity (measles vaccine) in children with asthma. It is unknown if asthma affects susceptibility to vaccine-preventable diseases.

OBJECTIVE

To determine whether asthma is associated with an increased risk of vaccine-preventable disease, e.g., breakthrough varicella infection.

METHODS

This was a retrospective population-based case-control study that examined cases of breakthrough varicella among children between 2005 and 2011. Children with a diagnosis of breakthrough varicella infection in Olmsted County, Minnesota (infection of >42 days after vaccination) between 2005 and 2011 and two age- and sex-matched controls were enrolled for each case. Asthma status was determined by using predetermined criteria. Conditional logistic regression models were used to calculate matched odds ratios (OR) and their corresponding 95% confidence intervals (CI).

RESULTS

Of the 165 cases and their 330 matched controls, 48% were boys and the mean (standard deviation) age at the index date was 6.6 ± 3.5 years for both cases and controls. Of the 330 controls, 80 (24%) had two doses of the varicella vaccine compared with only 23 (14%) of the 165 cases (OR 0.29 [95% CI, 0.14-0.61]; p = 0.001). Children with a history of asthma ever had a higher risk of developing breakthrough varicella compared with those without a history of asthma (adjusted OR 1.63 [95% CI, 1.04-2.55]; p = 0.032) when adjusting for elapsed time since the first varicella vaccination and the number of varicella vaccine doses.

CONCLUSIONS

A history of asthma might be an unrecognized risk factor for breakthrough varicella infection. Children with asthma should follow the two-dose varicella vaccine policy.

Asthma as a risk factor for zoster in adults: A population-based case-control study

BACKGROUND

We recently reported an increased risk of herpes zoster (shingles or zoster) in children with asthma, but little is known about whether the same is true for adults with asthma.

OBJECTIVE

We determined whether asthma is associated with an increased risk of zoster in adults.

METHODS

This study was designed as a population-based case-control study. Zoster cases during the study period were identified among adults (aged ≥50 years) who resided in Olmsted County, Minnesota. We compared the frequency of asthma between zoster cases and birthday- and sex-matched control subjects (1:2 matching) without a history of zoster. Asthma status was ascertained based on predetermined criteria. A conditional logistic regression model was used to assess the association of asthma with risk of zoster.

RESULTS

A total of 371 zoster cases and their 742 matched control subjects were enrolled. Of the 371 cases, 246 (66%) were female, 348 (94%) were white, and the mean ± SD age was 66.8 ± 10.7 years. Twenty-three percent (n = 87) of zoster cases had a history of asthma compared with 15% (n = 114) of control subjects. Controlling for pertinent covariates and confounders, there was a significant association between a history of asthma and risk of zoster (adjusted odds ratio, 1.70; 95% CI, 1.20-2.42; P = .003). The population attributable risk percentage for asthma was about 10%.

CONCLUSIONS

Asthma is an unrecognized risk factor for zoster in adults. Consideration should be given to immunizing adults with asthma aged more than 50 years as a target group.

Risk of herpes zoster in children with asthma

BACKGROUND

There is literature that indicates the association of asthma with an increased risk of common and serious microbial infections. We recently reported an increased risk of vaccine-preventable diseases, e.g., herpes zoster (HZ) among children with asthma, defined by predetermined asthma criteria. Little is known about whether this association is persistent if the asthma status is defined by different asthma criteria, e.g., the Asthma Predictive Index, given the heterogeneity of asthma.

OBJECTIVE

To assess the consistency of the association between asthma and the risk of HZ in children.

METHODS

This is a population-based case-control study based on all pediatric patients with HZ between 1996 and 2001 in Olmsted County, Minnesota, and 1:1 age- and sex-matched controls without a history of HZ who were enrolled in our previous study. The original Asthma Predictive Index criteria was operationalized by two or more wheezing episodes in a year for the first 3 years of life plus one of the major (physician-diagnosed asthma for a parent or physician-diagnosed eczema for a patient) or two of the minor criteria (physician-diagnosed allergic rhinitis for a patient, wheezing apart from cold, or eosinophilia [≥4%]). Data were fit to traditional logistic regression models to calculate odds ratios and 95% confident intervals.

RESULTS

Of the original cohort (n = 554), 95 (17%) did not meet the enrollment criteria for this study, which left 459. Of the 221 patients, 53% were female, with a mean (standard deviation) age of 9.7 ± 4.2 years. The risk of HZ was increased in children with asthma defined by the API controlling for a varicella vaccine history and atopic status (adjusted odds ratio 2.56 [95% confidence interval, 1.08-6.56]).

CONCLUSIONS

The association between asthma and increased risk of HZ in children and adolescents is consistent, independent of asthma definitions. Asthma might be an important clinical condition to be considered in HZ vaccine studies.

Risks for infection in patients with asthma (or other atopic conditions): is asthma more than a chronic airway disease?

Most of the research effort regarding asthma has been devoted to its causes, therapy, and prognosis. There is also evidence that the presence of asthma can influence patients' susceptibility to infections, yet research in this aspect of asthma has been limited. There is additional debate in this field, with current literature tending to view the increased risk of infection among atopic patients as caused by opportunistic infections secondary to airway inflammation, especially in patients with severe atopic diseases. However, other evidence suggests that such risk and its underlying immune dysfunction might be a phenotypic or clinical feature of atopic conditions. This review argues (1) that improved understanding of the effects of asthma or other atopic conditions on the risk of microbial infections will bring important and new perspectives to clinical practice, research, and public health concerning atopic conditions and (2) that research efforts into the causes and effects of asthma must be juxtaposed because they are likely to guide each other.