Posts

Maternal psychological distress during pregnancy affects wheezing in preschool children

Mechanisms such as social, behavioral, and environmental factors during pregnancy that may affect the risk of childhood asthma have been studied, but only few studies have assessed the relationship between maternal psychological distress and childhood wheezing.  Guxens et al performed a population-based study among children from birth to 6 years of age while assessing maternal and paternal psychological distress during pregnancy ( J Allergy Clin Immunol 2014; 133(1): 59-67 ) .  This large study of 4,848 children was embedded within the Generation R study, a population-based prospective cohort from fetal life onwards in Rotterdam, The Netherlands.  Maternal and paternal distress data was collected at 20 weeks gestation and again at 2 and 6 months, and 3 years after delivery by using the Brief Symptom Inventory questionnaire. Wheezing was annually assessed in the children up to 4 years of age. Physician diagnosed ever asthma was reported by parents at age 6 years.  The...

Implications of race and ethnicity on genetic profiles for personalized medicine

It is well known that frequencies and severity of disease can differ among races.  The mixing of African, European, and Native American ancestries has resulted in a variety of different ethnic groups with varied diversity. There is robust evidence from various clinical trials that different ethnic groups have variable responses to specific therapeutic agents.  The study of pharmacogenetics is used to personalize therapies specific to individuals from different ethnic or racial groups and it has historically been composed of mostly non-Hispanic whites of European descent.  Ortega and Meyers summarize the genetic and epidemiologic basis for the variable genetic backgrounds observed between different, recently admixed ethnic groups such as African American or Hispanic ( J Allergy Clin Immunol 2014; 133(1): 16-26 ). Rare genetic variants appear to be more frequent among individuals of African ancestry and could account for inter-ethnic differences in drug responses especially...

Treatment of peanut allergy with omalizumab

Peanut allergy is a well known food allergy estimated to include 3-4% of the US population and accounts for a disproportionate number of severe allergic reactions. The vast majority of food allergy death is related to peanut allergy and is often ingested accidentally despite strict food avoidance. Peanut allergy sensitivity often fails to diminish over time compared to other food allergens causing a lifetime of anxiety and food avoidance for patients and families. The only effective treatment option for this epidemic other than food avoidance is ready access to injectable epinephrine.  Recent clinical trials using double blind, placebo controlled food challenges (DBPCFC) have reported success with allergen immunotherapy and desensitization with common food allergens including peanut. Although long term tolerance can be achieved with daily intake, most patients experienced mild to severe symptoms including anaphylaxis which occurred in up to 25% of patients with a high peanut specif...

Atopic disease and the herpes microbiome

Unlike bacteria or fungi, herpes viruses establish life-long infection in the human host through latent genomic persistence within the host cells nuclei and are thus considered part of the human microbiome. The ability of the virus to interact with the human genome influences allergic and atopic disease due to the bias these patients have towards a Th2 profile. Dr. David Dreyfus examined the role of common human herpes viruses on the microbiome of atopic patients, who have more severe and atypical disease when infected ( J Allergy Clin Immunol 2013; 132(6): 1278-1286 ). The herpes virus Epstein Barr (EBV or mononucleosis) expresses latency in lymphocytes and has co-evolved with humans long enough to encode for a protein that resembles the cytokine IL-10, as well as other cytokines by activating host transcription factors. The author explains that EBV and other herpes viruses encode for microRNAs that cause immunomodulation of distant cells. This lead to studies suggesting that EBV infe...

Rhinovirus infection causes steroid resistance in airway epithelium through nuclear factor кB and c-Jun N-terminal kinase activation

Inhaled glucocorticoids are often highly effective in treating symptoms of asthma exacerbations, however they are ineffective at treating and preventing exacerbations brought on by rhinovirus infection, especially in children.  Glucocorticoids act by binding to glucocorticoid receptors (GR) α which become activated and translocate to the nucleus, leading to the activation of down-stream anti-inflammatory pathways.  Papi et al sought to determine the mechanistic actions of glucocorticoids during rhinovirus infection by studying factors in these anti-inflammatory pathways ( J Allergy Clin Immunol 2013; 132(5): 1075-1085 ). Using a variety of assays and human bronchial epithelial cells, the authors determined that the rhinovirus RV-16 reduces the ability of dexamethasone to inhibit the pro-inflammatory cytokine IL-1β induction of the chemokine CXCL8.  They went on to show that there is an RV-16 dependent impairment of dexamethasone-induced GRα nuclear translocation that is m...

Predictors of response to tiotropium versus salmeterol in asthmatic adults

The severity of asthma symptoms is well known to be attenuated by inhaled corticosteroid (ICS) due to their anti-inflammatory effect.  Long-acting β-agonists (LABA) and long acting muscarinic antagonists (LAMA) are current treatment options for patients that do not respond well to low dose ICSs.  Using data from the double-blind, 3-way, crossover National Heart, Lung, and Blood Institute’s Asthma Clinical Research Network’s Tiotropium Bromide as an Alternative to Increased Inhaled Glucocorticoid in Patients Inadequately Controlled on a Lower Dose of Inhaled Corticosteroid, Peters et al sought to determine individual and differential responses of asthmatic patients to salmeterol (LABA) and tiotropium (LAMA) when added to an inhaled corticosteroid, as well as predictors of a positive clinical response to the end points FEV₁, morning peak expiratory flow (PEF), and asthma control days (ACDs) ( J Allergy Clin Immunol 2013; 132(5):1068-1074 ) . In the attempt to personalize the bes...

Exhaled NO levels and blood eosinophil counts independently associate with wheeze and asthma events

Eosinophils and exhaled Nitric Oxide (NO) levels are prominent features of asthma.  It is known that both exhaled NO and blood eosinophil counts (B-Eos) are markers of local and systemic eosinophil inflammation respectively, and are elevated in patients with the disease. However, little is known about the association of these markers with wheeze and asthma events.  Malinovschi et al [ J Allergy Clin Immunol 2013; 132(4):821-827 ] examined subjects from National Health and Nutrition Examination Survey 2007-2008 and 2009-2010 to determine individual and independent B-Eos and Fraction of Exhaled Nitric Oxide (FENO) levels in relation to wheeze, asthma diagnosis, and asthma events. From the cross sectional study, 12,408 subjects ranging from 6-80 years old were selected who had FENO measurements and blood differential counts.  The authors report that the prevalence of current asthma and wheeze increased progressively with FENO values and B-Eos values.  Furthermore, ther...