Racial and Socioeconomic Disparities Exist in Patients Pursuing Peanut Oral Immunotherapy.

BACKGROUND: Oral immunotherapy (OIT) is a promising treatment for food allergy. Prior studies demonstrate significant differences among food-allergic individuals across race, ethnicity, and socioeconomic groups. Disparities in OIT have not been evaluated. OBJECTIVE: We assessed disparities in the use of OIT in patients with peanut allergy based on race, ethnicity, and socioeconomic status at a single academic medical center. METHODS: We identified 1028 peanut-allergic patients younger than 18 years receiving care in the University of Michigan food allergy clinics. Of these, 148 patients who underwent peanut OIT (treatment group) were compared with the 880 patients who avoided peanut (control group). Pertinent demographic and socioeconomic characteristics were compared. RESULTS: There were no differences in gender or ethnicity between the OIT and control groups. However, Black patients comprised 18% of the control group but only 4.1% of the OIT treatment group (P < .0001). The proportion of patients with private insurance was significantly higher in the treatment group compared with the control group (93.2% vs 82.2%, P = .0004). Finally, the neighborhood affluence index, a census-based measure of the relative socioeconomic prosperity of a neighborhood, was significantly higher in the OIT group than the control group (0.51 ± 0.18 vs 0.47 ± 0.19, P = .015), whereas the neighborhood disadvantage index, a census-based measure of the relative socioeconomic disadvantage of a neighborhood, was significantly lower (0.082 ± 0.062 vs 0.10 ± 0.093, P = .020). CONCLUSIONS: Significant racial and economic disparities exist at our institution between peanut-allergic individuals who receive OIT and those who do not. Efforts to understand the basis for these disparities are important to ensure that patients have equitable access to OIT.

Transepidermal water loss rises before food anaphylaxis and predicts food challenge outcomes.

BACKGROUNDFood allergy (FA) is a growing health problem requiring physiologic confirmation via the oral food challenge (OFC). Many OFCs result in clinical anaphylaxis, causing discomfort and risk while limiting OFC utility. Transepidermal water loss (TEWL) measurement provides a potential solution to detect food anaphylaxis in real time prior to clinical symptoms. We evaluated whether TEWL changes during an OFC could predict anaphylaxis onset.METHODSPhysicians and nurses blinded to the TEWL results conducted and adjudicated the results of all 209 OFCs in this study. A study coordinator measured TEWL throughout the OFC and had no input on the OFC conduct. TEWL was measured 2 ways in 2 separate groups. First, TEWL was measured using static, discrete measurements. Second, TEWL was measured using continuous monitoring. Participants who consented provided blood samples before and after the OFCs for biomarker analyses.RESULTSTEWL rose significantly (2.93 g/m2/h) during reactions and did not rise during nonreacting OFCs (-1.00 g/m2/h). Systemic increases in tryptase and IL-3 were also detected during reactions, providing supporting biochemical evidence of anaphylaxis. The TEWL rise occurred 48 minutes earlier than clinically evident anaphylaxis. Continuous monitoring detected a significant rise in TEWL that presaged positive OFCs, but no rise was seen in the OFCs that resulted in no reaction, providing high predictive specificity (96%) for anaphylaxis against nonreactions 38 minutes prior to anaphylaxis onset.CONCLUSIONSDuring OFCs, a TEWL rise anticipated a positive clinical challenge. TEWL presents a monitoring modality that may predict food anaphylaxis and facilitate improvements in OFC safety and tolerability.

Wild-type SARS-CoV-2 neutralizing immunity decreases across variants and over time but correlates well with diagnostic testing.

Importance: The degree of immune protection against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) variants provided by infection versus vaccination with wild-type virus remains unresolved, which could influence future vaccine strategies. The gold-standard for assessing immune protection is viral neutralization; however, few studies involve a large-scale analysis of viral neutralization against the Omicron variant by sera from individuals infected with wild-type virus. Objectives: 1) To define the degree to which infection versus vaccination with wild-type SARS-CoV-2 induced neutralizing antibodies against Delta and Omicron variants.2) To determine whether clinically available data, such as infection/vaccination timing or antibody status, can predict variant neutralization. Methods: We examined a longitudinal cohort of 653 subjects with sera collected three times at 3-to-6-month intervals from April 2020 to June 2021. Individuals were categorized according to SARS-CoV-2 infection and vaccination status. Spike and nucleocapsid antibodies were detected via ADVIA Centaur® (Siemens) and Elecsys® (Roche) assays, respectively. The Healgen Scientific® lateral flow assay was used to detect IgG and IgM spike antibody responses. Pseudoviral neutralization assays were performed on all samples using human ACE2 receptor-expressing HEK-293T cells infected with SARS-CoV-2 spike protein pseudotyped lentiviral particles for wild-type (WT), B.1.617.2 (Delta), and B.1.1.529 (Omicron) variants. Results: Vaccination after infection led to the highest neutralization titers at all timepoints for all variants. Neutralization was also more durable in the setting of prior infection versus vaccination alone. Spike antibody clinical testing effectively predicted neutralization for wild-type and Delta. However, nucleocapsid antibody presence was the best independent predictor of Omicron neutralization. Neutralization of Omicron was lower than neutralization of either wild-type or Delta virus across all groups and timepoints, with significant activity only present in patients that were first infected and later immunized. Conclusions: Participants having both infection and vaccination with wild-type virus had the highest neutralizing antibody levels against all variants and had persistence of activity. Neutralization of WT and Delta virus correlated with spike antibody levels against wild-type and Delta variants, but Omicron neutralization was better correlated with evidence of prior infection. These data help explain why 'breakthrough' Omicron infections occurred in previously vaccinated individuals and suggest better protection is observed in those with both vaccination and previous infection. This study also supports the concept of future SARS-CoV-2 Omicron-specific vaccine boosters.

Vaccination counseling with and without excipient skin testing in patients with suspected allergic reactions to mRNA COVID-19 vaccines and patients with atopy.

Background: Allergic reactions have been reported with mRNA vaccines for COVID-19 prevention. Patients perceived to be at higher risk for a reaction may be referred to an allergist, although evaluation strategies may differ between allergists. Objective: Our aim was to determine outcomes of COVID-19 vaccinations in patients evaluated by an allergist using different approaches. Methods: We conducted a retrospective case series evaluation of 98 patients seen at the University of Michigan Allergy Clinic for concerns regarding COVID-19 vaccination. Of these 98 patients, 34 underwent skin testing with polyethylene glycol (PEG) 2000 with or without PEG 3350/polysorbate 80 testing. Results: Of the 34 patients on whom skin testing was performed, 16 underwent testing before vaccination and 18 underwent testing after a reported vaccine-related event. One patient had a positive skin testing result in response to PEG 3350 following a vaccination reaction and natural infection and was advised against a second dose. One patient with a significant history concerning of anaphylaxis in response to PEG had positive results of testing to identify allergy to PEG 2000, PEG 3350, and polysorbate 80 and was advised against vaccination. Of the 98 patients, 63 (64%) tolerated COVID-19 vaccination without complication after evaluation by an allergist. Conclusion: No significant differences were found between vaccination counseling with and without skin testing to excipients. Patients who presented before the first dose of vaccination were more likely to proceed with COVID-19 vaccination and tolerate vaccination without complication.

Pathophysiology of Eosinophilic Esophagitis.

Eosinophilic esophagitis is an emerging disease that is distinguished from gastroesophageal reflux disease by the expression of a unique esophageal transcriptome and the interplay of early life environmental factors with distinct genetic susceptibility elements at 5q22 (TSLP) and 2p23 (CAPN14). Rare genetic syndromes have uncovered the contribution of barrier disruption, mediated in part by defective desmosomes and dysregulated transforming growth factor beta production and signaling, to eosinophilic esophagitis pathophysiology. Experimental modeling has defined a cooperative role of activated eosinophils, mast cells, and the cytokines IL-5 and IL-13, mediated by allergic sensitization to multiple foods. Understanding these processes is opening the way to better treatment based on disrupting allergic inflammatory and type 2 cytokine-mediated responses, including anti-cytokine therapeutics and dietary therapy.

Immune Activity of BCG Infected Mouse Macrophages Treated with a Novel Recombinant Mouse Lactoferrin.

Lactoferrin has been investigated for its adjuvant action to boost the BCG vaccine. Previous studies demonstrated that lactoferrin (LF) enhanced efficacy of the Bacillus Calmette-Guérin (BCG) vaccine to protect mice against the virulent Erdman Mycobacterium tuberculosis challenge. The studies here investigate the hypothesis that a novel CHO-derived recombinant mouse LF can modify cytokine production and antigen presentation molecules on macrophages. The mouse LF (rmLF) was examined for effects on bone marrow derived macrophage (BMM) activities when cultured with BCG. Comparisons were made to CHO-derived recombinant human LF (rhLF). Inflammatory cytokine responses were investigated, as were antigen presentation and associated co-stimulatory molecules. Cytokine responses were subsequently measured when these cells were co-cultured with naïve or BCG sensitized CD4+ lymphocytes. While overall responses were similar between mouse, human, and bovine forms, the homologous rmLF treated infected BMMs showed unique activation patterns of cytokine production. These results indicate that species-specific LF can have different effects on mouse macrophages exposed to BCG, thus potentially affecting adjuvant activity when used in models of vaccination in mice.

Disrupted pulmonary artery cyclic guanosine monophosphate signaling in mice with hyperoxia-induced pulmonary hypertension.

Pulmonary hypertension (PH) occurs in 25 to 35% of premature infants with significant bronchopulmonary dysplasia (BPD). Neonatal mice exposed to 14 days of hyperoxia develop BPD-like lung injury and PH. To determinne the impact of hyperoxia on pulmonary artery (PA) cyclic guanosine monophosphate (cGMP) signaling in a murine model of lung injury and PH, neonatal C57BL/6 mice were placed in room air, 75% O2 for 14 days (chronic hyperoxia [CH]) or 75% O2 for 24 hours, followed by 13 days of room air (acute hyperoxia with recovery [AHR]) with or without sildenafil. At 14 days, mean alveolar area, PA medial wall thickness (MWT), right ventricular hypertrophy (RVH), and vessel density were assessed. PA protein was analyzed for cGMP, soluble guanylate cyclase, and PDE5 activity. CH and AHR mice had RVH, but only CH mice had increased alveolar area and MWT and decreased vessel density. In CH and AHR PAs, soluble guanylate cyclase activity was decreased, and PDE5 activity was increased. In CH mice, sildenafil attenuated MWT and RVH but did not improve mean alveolar area or vessel density. In CH and AHR PAs, sildenafil decreased PDE5 activity and increased cGMP. Our results indicate that prolonged hyperoxia leads to lung injury, PH, RVH, and disrupted PA cGMP signaling. Furthermore, 24 hours of hyperoxia causes RVH and disrupted PA cGMP signaling that persists for 13 days. Sildenafil reduced RVH and restored vascular cGMP signaling but did not attenuate lung injury. Thus, hyperoxia can rapidly disrupt PA cGMP signaling in vivo with sustained effects, and concurrent sildenafil therapy can be protective.