Functional testing of humoral immunity in the Prevnar 20 era.

Humoral immune disorders such as common variable immunodeficiency and specific antibody deficiency are prevalent in clinical practice and require accurate functional testing of humoral immunity for diagnosis and to guide treatment approach. Traditionally, the 23-valent pneumococcal polysaccharide vaccine (PPSV23) has been used to assess polysaccharide antibody responses by measuring pre- and post-vaccination pneumococcal titers. However, the recent introduction of pneumococcal conjugate vaccines (PCVs), such as PCV13, PCV15, and PCV20, into the childhood and adult vaccine schedules has significantly reduced the number of unique serotypes available for testing and in turn has complicated the evaluation process.

Disparities in Diagnosis, Access to Specialist Care and Treatment for Inborn Errors of Immunity.

Inborn errors of immunity represent a rapidly expanding group of genetic disorders of the immune system. Significant advances have been made in recent years in diagnosis, including using genetic testing and newborn screening; treatment, including precision therapies, gene therapy and hematopoietic stem cell transplant; and development of patient registries to inform prevalence, understand morbidity of these disorders and guide the development of clinical trials. However, significant disparities due to age, race, ethnicity, socioeconomic status, or geographic location exist in all aspects of care of patients with inborn errors of immunity, beginning with delays in diagnosis and further compounded by impaired access to specialist care and treatment, leading to a notable impact on outcomes including morbidity and mortality.

Impaired Response to Polysaccharide Vaccine in Selective IgE Deficiency.

Purpose: Immunoglobulin E deficiency (IgED) (defined as IgE < 2 IU/mL) is enriched in patients with primary antibody deficiency (PAD). We hypothesized that selective IgED (sIgED) is a more sensitive predictor of the development of PAD than declining IgG, as IgE production typically requires two class switch recombination (CSR) events in contrast to IgG. Thus, the inability of patients with sIgED to mount an appropriate antibody response to a T-cell independent antigen or evidence of aberrant induction of ɛ germ line (ɛGL) or IgE heavy chain (IgEHC) transcripts in vitro would support the concept that sIgED is a biomarker for emerging PAD.

Further evidence of a type 2 inflammatory signature in chronic obstructive pulmonary disease or emphysema.

Background: There is increasing recognition of a type 2 (T2) inflammatory pattern in a subset of patients with chronic obstructive pulmonary disease (COPD) or emphysema, characterized by blood and airway eosinophilia. The mechanism underlying this is not well established. The recognition that CD125 (interleukin [IL]-5 receptor alpha) is expressed on some lung neutrophils and eosinophils in patients with asthma led us to speculate that CD125 may also be expressed on lung neutrophils in patients with COPD or emphysema.

Over-expression of CRTH2 indicates eosinophilic inflammation and poor prognosis in recurrent nasal polyps.

Background: Chronic rhinosinusitis with nasal polyps (CRSwNP) is often characterized by recurrent nasal polyp (NP) growth following surgical removal, but the mechanisms are still not clear. This study aimed to investigate the expression of chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2) receptor on NP and the role it plays in eosinophil inflammation and polyp recurrence.

Methods: Forty-one CRSwNPs patients and seventeen controls were enrolled in this study.

Monogenic early-onset lymphoproliferation and autoimmunity: Natural history of STAT3 gain-of-function syndrome.

Background: In 2014, germline signal transducer and activator of transcription (STAT) 3 gain-of-function (GOF) mutations were first described to cause a novel multisystem disease of early-onset lymphoproliferation and autoimmunity.

Objective: This pivotal cohort study defines the scope, natural history, treatment, and overall survival of a large global cohort of patients with pathogenic STAT3 GOF variants.

Methods: We identified 191 patients from 33 countries with 72 unique mutations.

Navigating diagnostic options for inborn errors of immunity in children: a case-based illustration.

Purpose Of Review: In recent years, there has been a dramatic increase in the number of recognized inborn errors of immunity (IEI), many of which present in childhood. This review discusses diagnostic approaches for some of the more common presentations of IEI in childhood.

Recent Findings: Implementation of newborn screening (NBS) using the T cell receptor excision circle (TREC) assay has led to the timely identification of patients with severe combined immunodeficiency (SCID) as well as both syndromic and nonsyndromic forms of T cell lymphopenia, including DiGeorge syndrome.

Specific antibody deficiency: pearls and pitfalls for diagnosis.

Objective: To summarize the pitfalls associated with defining exactly what constitutes an "impaired" antibody response to polysaccharide antigens and the importance of documenting actual pyogenic infections before making a diagnosis of an immune deficiency. Specific antibody deficiency is an immune deficiency defined by the presence of normal quantitative levels of immunoglobulins, but impaired antibody responses to polysaccharide antigens, in patients presenting with frequent otosinopulmonary infections with pyogenic bacteria.

Data Sources: PubMed review using the following keywords: specific antibody deficiency, pneumococcal vaccination, Salmonella vaccination, infectious sinusitis.

Lower viral loads in subjects with rhinovirus-challenged allergy despite reduced innate immunity.

Background: Viral infections, especially those caused by rhinovirus, are the most common cause of asthma exacerbations. Previous studies have argued that impaired innate antiviral immunity and, as a consequence, more severe infections contribute to these exacerbations.

Objective: These studies explored the innate immune response in the upper airway of volunteers with allergic rhinitis and asthma in comparison to healthy controls and interrogated how these differences corresponded to severity of infection.

Interleukin-5 receptor alpha (CD125) expression on human blood and lung neutrophils.

Background: Our previous studies revealed the presence of interleukin-5 (IL-5) receptor alpha chain (IL-5Rα, CD125) on neutrophils in a murine model of influenza and in the lung fluid of children with severe asthma.

Objective: To further evaluate the functional characteristics and effects of clinical factors and inflammatory variables on neutrophil surface IL-5Rα abundance in lung fluid and blood.

Methods: IL-5Rα expression was quantified by flow cytometry performed on purified neutrophils from blood and bronchoalveolar lavage fluid samples obtained from healthy controls and individuals with asthma.

A Toolkit and Framework for Optimal Laboratory Evaluation of Individuals with Suspected Primary Immunodeficiency.

Knowledge related to the biology of inborn errors of immunity and associated laboratory testing methods continues to expand at a tremendous rate. Despite this, many patients with inborn errors of immunity suffer for prolonged periods of time before identification of their underlying condition, thereby delaying appropriate care. Understanding that test selection and optimal evaluation for patients with recurrent infections or unusual patterns of inflammation can be unclear, we present a document that distills relevant clinical features of immunologic disease due to inborn errors of immunity and related appropriate and available test options.

Novel Treatment-Refractory Preschool Wheeze Phenotypes Identified by Cluster Analysis of Lung Lavage Constituents.

Background: Preschool children with treatment-refractory wheeze often require unscheduled acute care. Current guidelines advise treatment of persistent wheeze with inhaled corticosteroids. Alternative treatments targeting structural abnormalities and specific inflammatory patterns could be more effective.

Bronchoalveolar lavage cytokine patterns in children with severe neutrophilic and paucigranulocytic asthma.

Background: Asthma is a complex heterogeneous disease occurring in adults and children that is characterized by distinct inflammatory patterns. While numerous studies have been performed in adults, little is known regarding the heterogeneity of severe asthma in children, particularly inflammatory signatures involving the air spaces.

Objective: We sought to determine the relationship of bronchoalveolar lavage (BAL) cytokine/chemokine expression patterns in children with severe therapy-resistant asthma stratified according to neutrophilic versus nonneutrophilic BAL inflammatory cell patterns.