Scott Commins

Polyethylene glycol (PEG) is frequently used in various protein and nanomedicine therapeutics. However, various studies have shown that select PEGylated therapeutics can induce production of anti-PEG antibodies (APA), potentially culminating in rapid clearance from the systemic circulation, loss of efficacy and possibly increased risks of allergic reactions. Although IgE is a frequent cause of immediate hypersensitivity reactions (IHR), the role of IgE APA in PEG-related IHR is not well understood, due in part to a lack of standardized assays for measuring IgE APA. Here, we developed a rigorous competitive ELISA method to measure the concentrations of various APA isotypes, including IgE, with picomolar sensitivities. In a small number of serum samples from patients with known PEG allergy, the assay allowed us to detect a strong correlation between IgG and IgE APA in individuals with history of allergic …

BackgroundAlpha-gal syndrome (AGS) is an allergy to galactose-α-1,3-galactose (alpha-gal), a carbohydrate found in most mammals. Evidence indicates that AGS develops following a tick bite, and in the United States, AGS is most associated with bites from Amblyomma americanum (lone star tick); however, not all persons bitten by ticks develop clinical AGS.ObjectiveThis study investigated intrinsic risk factors associated with the development of AGS.MethodsWe performed a case-control study among adults presenting for diagnosis or management of AGS at an allergy clinic in North Carolina during 2019–2020 and compared them to controls enrolled from two nearby internal medicine clinics. A questionnaire gathered epidemiologic and tick exposure data and blood was obtained for alpha-gal specific IgE (sIgE) and other testing.ResultsThe 82 enrolled case patients and 191 controls did not differ significantly by …

The recent recognition of a syndrome of tick‐acquired mammalian meat allergy has transformed the previously held view that mammalian meat is an uncommon allergen. The syndrome, mediated by IgE antibodies against the oligosaccharide galactose‐alpha‐1,3‐galactose (alpha‐gal), can also involve reactions to visceral organs, dairy, gelatin and other products, including medications sourced from non‐primate mammals. Thus, fittingly, this allergic disorder is now called the alpha‐gal syndrome (AGS). The syndrome is strikingly regional, reflecting the important role of tick bites in sensitization, and is more common in demographic groups at risk of tick exposure. Reactions in AGS are delayed, often by 2–6 h after ingestion of mammalian meat. In addition to classic allergic symptomatology such as urticaria and anaphylaxis, AGS is increasingly recognized as a cause of isolated gastrointestinal morbidity and alpha …

IntroductionAlpha-Gal Syndrome (AGS) is a delayed allergic reaction due to specific IgE antibodies targeting galactose-α-1,3-galactose (α-gal), a carbohydrate found in red meat. This condition has gained significant attention globally due to its increasing prevalence, with more than 450,000 cases estimated just in the United States alone. Previous research has established a connection between AGS and tick bites, which sensitize individuals to α-gal antigens and elevate the levels of specific IgE. However, the precise mechanism by which tick bites influence the host’s immune system and contribute to the development of AGS remains poorly understood. This study investigates various factors related to ticks and the host associated with the development of AGS following a tick bite, using mice with a targeted disruption of alpha-1,3-galactosyltransferase (AGKO) as a model organism.MethodsLone-star tick (Amblyomma americanum) and gulf-coast tick (Amblyomma maculatum) nymphs were used to sensitize AGKO mice, followed by pork meat challenge. Tick bite site biopsies from sensitized and non-sensitized mice were subjected to mRNA gene expression analysis to assess the host immune response. Antibody responses in sensitized mice were also determined.ResultsOur results showed a significant increase in the total IgE, IgG1, and α-gal IgG1 antibodies titers in the lone-star tick-sensitized AGKO mice compared to the gulf-coast tick-sensitized mice. Pork challenge in Am. americanum -sensitized mice led to a decline in body temperature after the meat challenge. Gene expression analysis revealed that Am. americanum bites direct mouse …

ImportanceTick-borne diseases (TBDs) other than Lyme disease, such as spotted fever group rickettsiosis, ehrlichiosis, and galactose-α-1,3-galactose (α-gal) syndrome, are an emerging public health issue. Long-term sequelae secondary toEhrlichiaorRickettsiainfection are uncommon; however, musculoskeletal symptoms are often attributed to prior tick exposure.ObjectiveTo evaluate the potential associations between prior exposure to TBDs and musculoskeletal symptoms, including radiographic osteoarthritis.Design, Setting, and ParticipantsThis cross-sectional study analyzed serum samples from the fourth visit (2017-2018) of the Johnston County Osteoarthritis (JoCo OA) project, an ongoing longitudinal, population-based study in Johnston County, North Carolina. Biospecimen testing and analysis were performed between May 2022 and November 2023. Participants in the JoCo OA project are …

MethodsThis is a retrospective cohort study at the UNC Medical Center (UNCMC) and Allergy Partners (AP). Chart review was performed on a subset to collect symptom frequency, maximum eosinophil count, EGD data, medications, dietary elimination, and SCIT content. Our cohort includes children and adults of age 0-99.ResultsWe found 936 patients at AP with EoE on SCIT and 72 patients at UNCMC from 2008 to 2023. Symptom duration prior to diagnosis of EoE was shorter in the EoE group as compared to the EoE on SCIT (7.3 vs 13.8 years). Grass pollens were the most common allergens included in SCIT. Patients with EoE on SCIT had a higher rate of atopic disease. Any topical steroid use was similar in both groups (42% and 47%). Histological response was also similar. No increase adverse effects were noted in the EoE on SCIT cohorts.ConclusionsWe report the largest number of patients with EoE and …

Alpha-Gal Syndrome (AGS) is a delayed allergic reaction triggered by IgE antibodies targeting galactose-α-1,3-galactose (α-gal), prevalent in red meat. Its global significance has increased, with over 450,000 estimated cases in the United States alone. AGS is linked to tick bites, causing sensitization and elevated α-gal specific IgE levels. However, the precise mechanisms and tick intrinsic factors contributing to AGS development post-tick bites remain unclear. This study aims to characterize the alpha-gal conjugated lipid antigens in Amblyomma americanum (Am. americanum) salivary glands and saliva. Nanospray ionization mass spectrometry (NSI-MS) analysis revealed the identification of α-gal bound lipid antigens in Am. americanum saliva. Additionally, activation of basophils by isolated alpha-gal bound lipids and proteins provides evidence of their antigenic capabilities.

MethodsAlpha-gal knockout (AGKO) mice were infested with Aa and Am ticks and assessed for the production of total and alpha-gal specific IgE and IgG1. Mice were challenged with pork kidney homogenate (PKH) and hypersensitivity responses were measured as a drop in body temperature> 3 C. RNA was isolated from the tick attachment site and subjected to Nanostring gene expression analysis.ResultsAa-infested mice had robust production of total IgE, total IgG1 and α-gal sIgG1. In contrast, infestation of mice with Am (not linked to AGS), resulted in a small but insignificant increase in total IgE, total IgG1 and α-gal sIgG1. Notably, mice infested with Aa but not Am ticks developed anaphylaxis following oral challenge with PKH. Inflammatory genes such as Tlr2, Tlr6, IL-1beta, NLPR3 and TNF-alpha were induced following the initial tick infestation. Repeated infestation led to induction of Treg transcription factor …

Methods:We pooled and analyzed symptoms and demographics of patients from two prospective cohorts of patients with a diagnosis of alpha-gal allergy who reacted after eating mammalian meat under observation. We compared the characteristics of patients who demonstrated GI-isolated symptoms on a challenge with those who exhibited symptoms outside the GI tract (skin, respiratory, and circulatory).Results:Among the 91 children and adult alpha-gal allergic patients who exhibited symptoms after oral challenge with mammalian meat, 72.5% experienced GI distress with one or more GI symptoms, which was the most frequent class of symptoms, compared with skin changes in 57.1% and respiratory distress in 5.5%. The most common GI symptoms were abdominal pain (71%) and vomiting (22.0%). GI-isolated symptoms occurred in 37 patients (40.7%) who reacted, and those patients reacted more quickly than …

MethodsThe NC population includes 488 individuals from the 2017–2018 Johnston County Osteoarthritis Project, a population-based cohort. The SC population includes 743 individuals from 2022-2023 ALL-IN, a statewide COVID-19 study involving minority, marginalized, and rural communities. Plasma was tested for alpha-gal sIgE utilizing a positive threshold of≥ 0.2 IU/mL. Descriptive statistics and multivariate models were performed.ResultsIn NC, 15.8% tested seropositive, with 17.2% reporting a tick bite in the preceding 5 years. The NC median age is 73 years, 68.9% are female, and 33.0% identify as Black. In SC, 3.5% tested seropositive, the median age is 48 years, and 62.7% are female. A higher proportion identify as Black or African American (67.5% among a broader ALL-IN cohort). In NC, self-identifying as Black was associated (p= 0.0026) with 60% lower odds of seropositivity, unadjusted OR 0.40 (95 …

BackgroundSiglec-3 (CD33) is a major Siglec expressed on human mast cells and basophils and engagement of CD33 leads to inhibition of cellular signaling via immunoreceptor tyrosine-based inhibitory motifs (ITIMs).ObjectiveWe sought to inhibit human basophil degranulation by simultaneously recruiting inhibitory CD33 to the IgE-FcεRI complex using monoclonal anti-IgE directly conjugated to CD33 ligand (CD33L).MethodsDirect and indirect basophil activation tests (BAT) were used to assess both antigen-specific (peanut) and antigen non-specific (polyclonal anti-IgE) stimulation. Whole blood from allergic donors was used for direct BAT, whereas non-food allergic donor blood was passively sensitized with peanut-allergic plasma in the indirect BAT. Blood was incubated with anti-IgE-CD33L or controls for one hour or overnight, then stimulated with peanut, polyclonal anti-IgE, or N-formylmethionyl-leucyl …

Background Alpha‐gal syndrome (AGS) is an IgE‐mediated allergy to galactose‐alpha‐1,3‐galactose. Clinical presentation ranges from hives to anaphylaxis; episodes typically occur 2–6 h after exposure to alpha‐gal‐containing products. In the United States, lone star tick bites are associated with the development of AGS. To characterize features of AGS, we evaluated a cohort of patients presenting for care at the University of North Carolina, focusing on symptoms, severity, and identifying features unique to specific alpha‐gal‐containing product exposures. Methods We performed a chart review and descriptive analysis of 100 randomly selected patients with AGS during 2010–2019. Results Median age at onset was 53 years, 56% were female, 95% reported White race, 86% reported a history of tick bite, and 75% met the criteria for anaphylaxis based on the involvement of ≥2 organ systems. Those reporting …

Background The incidence of ehrlichiosis, spotted fever rickettsioses (SFR), and Alpha-gal syndrome (AGS) is high in North Carolina (NC). Post-infectious sequelae secondary to ehrlichiosis or SFR are uncommon, however patients often attribute persistent musculoskeletal symptoms, including arthralgia, to prior tick-borne exposure. It is uncertain if these symptoms represent long-term complications from SFR or ehrlichiosis, or non-anaphylactic AGS via the development of IgE to galactose alpha-1,3-galactose (alpha-gal IgE). Utilizing a population-based cohort, we sought to examine the potential association between prior exposure to Ehrlichia, Rickettsia and alpha-gal, and chronic musculoskeletal symptoms. Methods A total of 488 Individuals from the 2017–2018 Johnston County Osteoarthritis study – a longitudinal, probability-based cohort – completed questionnaires …

The Consortium of Eosinophilic Gastrointestinal Diseases (CEGIR) and The International Gastrointestinal Eosinophil Researchers (TIGERs) organized a day-long symposium at the 2022 Annual Meeting of the American Academy of Allergy, Asthma & Immunology. The symposium featured a review of recent discoveries in the basic biology and pathogenesis of eosinophilic gastrointestinal diseases (EGIDs) in addition to advances in our understanding of the clinical features of EGIDs. Diagnostic and management approaches were reviewed and debated, and clinical trials of emerging therapies were highlighted. Herein, we briefly summarize the breakthrough discoveries in EGIDs.

BackgroundThe disaccharide galactose-α-1,3-galactose (alpha-gal) is expressed in mammals other than humans, apes, and old-world monkeys. In humans, elevated immunoglobulin E (IgE) antibodies specific for alpha-gal can result in allergic hypersensitivity known as alpha-gal syndrome (AGS). Case reports and series suggest that tick bites can induce alpha-gal–specific IgE (sIgE) antibodies.ObjectiveTo evaluate tick exposure as a risk factor for AGS and elevated alpha-gal sIgE level.MethodsWe conducted a case-control study comparing patients with AGS from a North Carolina allergy clinic with controls who were patients at a nearby internal medicine clinic. Cases and controls were administered a questionnaire to obtain information about demographics, home environment, outdoor activities, and recollection of tick bite. Serum samples taken at the time of enrollment were tested for total IgE, alpha-gal sIgE …

MethodsCharacterization of alpha α-gal was determined via ELISA, Western and IHC assays. The various food products evaluated included bacon, ham, and dietary supplements (collagen, whey, and pepsin). Porcine a-gal knockout (devoid of a-gal aka GalSafe) derived tissue or products served as negative controls.ResultsAnalytical analysis indicated presence of alpha-gal in all products from standard mammalian sources (pigs and cows) with relative concentrations exceeding 10 million epitopes per mg. Alpha-gal is undetectable in the negative control (porcine alpha-gal knockout).ConclusionsAlpha-gal persist at very high concentrations in all mammalian derived food products evaluated. Products sourced from alpha gal knockout pigs had no detectable levels of alpha gal.

MethodsQuantitation of the alpha gal epitope was determined via an indirect ELISA assay. In addition, IHC further confirmed the presence of alpha-α-gal in potential source material using AGS patient’s serum. The various products evaluated included bone powder, immunoglobulin isolates, thyroid derived therapeutic drugs, and heparin. Porcine a-gal knockout (devoid of a-gal) derived tissue or demineralized bone powder served as negative controls.ResultsELISA and IHC data indicates presence of alpha-gal in all bovine/porcine derived products irrespective of their source/preparation/form. The relative amount of alpha gal present in these products exceeded 10,000,000 epitopes per mg.ConclusionsAlpha-gal persist at very high concentrations in all commercially available therapeutic products that were evaluated that may cause adverse reactions after exposure. More studies must be done to elucidate potential …

MethodsWe performed a case-control study with patients aged≥ 18 years presenting for diagnosis or management of AGS at an allergy clinic in North Carolina during 2018–2020 and compared them to controls enrolled at a nearby internal medicine clinic. An interviewer-administered questionnaire gathered epidemiologic and tick exposure data in the year prior to AGS onset (case-patients) or time of enrollment (controls), and blood was obtained for alpha-gal-specific IgE (sIgE) testing.ResultsEighty-two case-patients (98% positive for alpha-gal sIgE≥ 0.1 kU/L positive) and 191 controls (33% positive for alpha-gal sIgE) were enrolled; they did not differ by age or sex, but case-patients were less likely to report Black race (2% vs. 14%; OR [95% CI]: 0.2 [0.04–0.6]). Nearly all case-patients (94%) reported tick bite in the year before AGS onset compared to 54% of controls (OR [95% CI]: 12.7 [5.0–32.0]); 71% of case …

METHODS:We performed a cross-sectional study of participants who underwent a screening colonoscopy at our center between 2013 and 2015. We quantified serum alpha-gal immunoglobulin E antibodies in participants who were prospectively enrolled at screening colonoscopy and compared diet intake and lower GI symptoms reported in standardized questionnaires among those with elevated versus no alpha-gal IgE antibodies.RESULTS:Alpha-gal IgE antibodies were common—31.4% of screening colonoscopy participants (127 of 404) had elevated serum alpha-gal IgE> 0.1 kU/L. Alpha-gal–sensitized participants endorsed similar rates of abdominal pain compared with those without alpha-gal antibodies (33% vs 38%, adjusted odds ratio 0.9, 95% confidence interval 0.7–1.3). Mammalian meat consumption did not differ based on alpha-gal sensitization status (average 1.43 servings/d in sensitized subjects …

MethodsB cells were enriched by negative selection and mixed with PBMCs in a 1: 1 ratio from the individual alpha-gal allergic and control subjects. The cells were labeled with 17 BD AbSeq oligo-conjugated antibodies and libraries were prepared for BD AbSeq as well as BD Rhapsody Targeted Human Immune Response Panel (399 genes) supplemented with 20 custom selected genes. Cell subsets were defined based on canonical protein and mRNA markers identified from the sequencing data and were subjected to differential gene expression using Seurat.ResultsWe were able to define B cell populations such as naïve, non-switched and switched memory, plasmablast, IL7R+ CD4 cells, NK cells and monocytes. We detected all 17 AbSeq as well as 417 of 419 genes. Immunologically-related cells clustered and we observed an increase in CXCL8 (8.9-fold) and XBP1 genes, notably, among others …