POL7085 or anti-CCL28 treatment inhibits development of post-paramyxoviral airway disease.

INTRODUCTION: Asthma is major health burden throughout the world, and there are no therapies that have been shown to be able to prevent the development of disease. A severe respiratory paramyxoviral infection early in life has been demonstrated to greatly increase the risk of developing asthma. We have a mouse model of a severe respiratory paramyxoviral infection (Sendai virus, SeV) that mimics human disease, and requires early expression of the cytokine CCL28 to drive the development of post-viral airway disease. The known receptors for CCL28 are CCR3 and CCR10. However, it is not known if blockade of these receptors will prevent the development of post-viral airway disease. The objective of this study was to determine if treatment with a protein epitope mimetic antagonist of CCR10, POL7085, will provide sufficient protection against the development of post-viral airway disease. METHODS: C57BL6 mice were inoculated with SeV or UV inactivated SeV. From day 3-19 post inoculation (PI), mice were subcutaneously administered daily POL7085 or saline, or every other day anti-CCL28 mAb. On days 8, 10, and 12 PI bronchoalveolar cytokines, serum IgE, and lung cellular constituents were measured. At day 21 PI airway hyper-reactivity to methacholine and mucous cell metaplasia was measured. RESULTS: Treatment with either anti-CCL28 or POL7085 significantly reduced development of airway hyper-reactivity and mucous cell metaplasia following SeV infection. The prevention of post-viral airway disease was associated with early reductions in innate immune cells, but did not appear to be due to a reduction in IL-13 or IgE. CONCLUSIONS: Blockade of CCL28 or CCR10 during an acute severe respiratory paramyxoviral infection is sufficient to prevent the development of post-viral airway disease. However, the mechanism of action is unclear and requires further exploration.

Newborn screening for SCID: lessons learned.

INTRODUCTION: Newborn screening (NBS) for Severe combined immunodeficiency (SCID)/severe T cell lymphopenia (sTCL) is being increasingly used worldwide. AREAS COVERED: In this manuscript we will discuss the following: 1) The rationale for screening newborns for SCID/sTCL; 2) The scientific basis for the use of the T cell receptor excision circle (TREC) assay in screening newborns for SCID/sTCL; 3) The published outcomes of current NBS programs. Expert commentary: 4) Some of the ethical dilemmas that occur when screening newborns for SCID. Finally, we will discuss the future directions for expanding NBS to include other primary immunodeficiencies.

Structure-function analysis of CCL28 in the development of post-viral asthma.

CCL28 is a human chemokine constitutively expressed by epithelial cells in diverse mucosal tissues and is known to attract a variety of immune cell types including T-cell subsets and eosinophils. Elevated levels of CCL28 have been found in the airways of individuals with asthma, and previous studies have indicated that CCL28 plays a vital role in the acute development of post-viral asthma. Our study builds on this, demonstrating that CCL28 is also important in the chronic post-viral asthma phenotype. In the absence of a viral infection, we also demonstrate that CCL28 is both necessary and sufficient for induction of asthma pathology. Additionally, we present the first effort aimed at elucidating the structural features of CCL28. Chemokines are defined by a conserved tertiary structure composed of a three-stranded ß-sheet and a C-terminal α-helix constrained by two disulfide bonds. In addition to the four disulfide bond-forming cysteine residues that define the traditional chemokine fold, CCL28 possesses two additional cysteine residues that form a third disulfide bond. If all disulfide bonds are disrupted, recombinant human CCL28 is no longer able to drive mouse CD4+ T-cell chemotaxis or in vivo airway hyper-reactivity, indicating that the conserved chemokine fold is necessary for its biologic activity. Due to the intimate relationship between CCL28 and asthma pathology, it is clear that CCL28 presents a novel target for the development of alternative asthma therapeutics.

Newborn screening for SCID: where are we now?

Newborn screening (NBS) for severe T-cell lymphopenia/severe combined immunodeficiency using the T-cell receptor excision circle assay continues to expand in the USA and worldwide. Here, we will review why severe combined immunodeficiency is an excellent case for NBS, the outcomes of the first 6 years of screening, and dilemmas surrounding screening and management of infants detected by NBS. We will also discuss the future of NBS for primary immunodeficiencies.

Egg baked in product open oral food challenges are safe in selected egg-allergic patients.

Egg allergy is one of the most common food allergies in children. Most egg-allergic children are able to tolerate egg baked in product (EBP) and will likely outgrow his/her egg allergy. By introducing EBP in the diet of an egg-allergic child, diet can be expanded and family stress can be reduced. Recent evidence suggests that children who tolerate EBP and continue to consume it will have quicker resolution of egg allergy than those who strictly avoid EBP; therefore, we aimed to evaluate the egg-allergic children who underwent EBP oral food challenge (OFC) in our allergy clinic to help define any specific predictors to be used in predicting the outcome of such challenges. We performed a retrospective chart review and 43 egg-allergic patients underwent EBP OFC in our outpatient allergy office from January 2011 to December 2012 were excluded. Nine patients who did not have a prior history of symptomatic egg ingestion. Clinical characteristics and laboratory findings of the remaining 34 patients were all recorded and analyzed. Of the remaining 34 patients, 22 (64.7%) were boys. Average age of first reaction to egg was 12.90 months, with average age at EBP OFC of 71.32 months. The average of the most recent skin-prick test wheal size was 10.10 mm and serum-specific IgE to egg white was 3.21 kU/L. Twenty-eight of the 34 patients (82.4%) passed the EBP OFC. Of the six patients who failed, none required epinephrine. After analysis of all of the clinical characteristics and laboratory findings, no risk factors, such as skin-prick test wheal size, were identified to be associated with an increased risk of failing EBP OFC. EBP OFC is a valuable tool to assess tolerance. As seen in our group of patients, the majority of egg-allergic patients pass EBP OFC. Thus, OFC should be considered as a clinical tool to expand a patient's diet and to improve quality of life as early as possible. Because we were unable to determine any clinical or laboratory predictors helpful to select egg-allergic patients who are likely to pass EBP OFC, additional prospective studies are necessary to determine the ideal egg-allergic patient who is likely to pass EBP OFC.