University of Arkansas for Medical Sciences

Prevalence of Adverse Drug Reactions: Comparing Crotalidae Immune Polyvalent Antivenoms F(ab') and F(ab) in a Galactose-alpha-1,3-galactose (alpha-gal) Endemic Area.

North American pit viper antivenoms, CroFab® and ANAVIP®, contain galactose-α-1,3-galactose (α-GAL) oligosaccharide. We compared adverse drug reactions, including presumed anaphylaxis, following administration of these antivenoms and investigated biological plausibility of these antivenoms leading to anaphylaxis in α-GAL-immunoglobulin (Ig) E-sensitized individuals. We performed 2 studies. A retrospective chart review from the Arkansas Poison Center (May 2021 to July 2023) identified adverse drug reactions and presumed anaphylaxis in patients treated with crotaline antivenom. Two allergists (JK, LM), blinded to the antivenom used, adjudicated presumed anaphylaxis cases. To assess whether antivenoms could activate basophils from α-GAL-IgE-sensitized individuals, basophil activation tests were performed on blood from 5 α-GAL-IgE-sensitized participants with a history of mammalian meat allergy. Basophil activation was assessed by %CD63 upregulation. Adverse drug reactions without presumed anaphylaxis occurred in 7 out of 171 (4.1%) Fab recipients versus 8 out of 37 (21.6%) F(ab') recipients (Δ=17.5%, 95% confidence interval [CI] [4.0 to 31.0]). Presumed anaphylaxis was observed in 3 out of 171 (1.8%) for Fab and 6/37 (16.2%) for F(ab') (Δ=14.3%, 95% CI 2.5 to 26.2). In the basophil activation tests, the mean EC for basophil CD63 activation was 144-fold higher for Fab (mean, [standard deviation]; 647 μg/mL of antivenom [627]) compared to F(ab') (4.48 μg/mL of antivenom [2.75]). We demonstrate a substantial incidence of adverse drug reactions and presumed anaphylaxis to crotaline antivenoms in an α-GAL endemic region, with F(ab') antivenom associated with more reactions than F(ab). Clinicians in α-GAL endemic regions should be cautious in the use of antivenoms, especially for patients with α-GAL allergy.

UB-221, an antibody that neutralizes IgE and downregulates the CD23 receptor: a potential treatment for the alpha-gal syndrome.

Analysis of Acute Hypersensitivity Reactions by Antivenom Type and Geographic Location in the North American Snake Bite Registry (NASBR).

Evidence regarding acute hypersensitivity reactions (AHRs) to the snakebite antivenoms Crotalidae Polyvalent Immune Fab (ovine) (Fab) and Crotalidae Immune F(ab') (equine) (Fab2) supports no differences. However, larger studies may not account for geographic differences. Recent data suggest a correlation with alpha-gal syndrome (AGS). This study investigates the incidence of AHRs in patients receiving Fab2, Fab, or both, with a focus on U.S. states with higher AGS prevalence. This is an analysis of native pit viper envenomations reported to the Toxicology Investigators Consortium (ToxIC) North American Snakebite Registry (NASBR) between January 1, 2018, and December 31, 2023. Patients administered Fab2 or Fab on index hospitalization were included. High-AGS and low-AGS regions were defined according to epidemiologic data. The primary outcome was incidence of AHRs after administration of antivenom overall and in high-AGS vs. low-AGS states. Bivariate statistical tests and 95% confidence intervals (CI) for proportions were computed. A total of 1051 patients were identified. Fab2 was administered in 439 cases, and Fab was administered in 722 cases for a total of 1161 cases. Fifty AHRs were analyzed. AHRs were more common with Fab2 (6.6%; 95% CI: 4.6%, 9.3%) compared to Fab (2.9%; 95% CI: 1.9%, 4.4%) in the overall NASBR population (p = 0.004). In low-AGS states, there were 25/421 (5.9%; 95% CI: 4.1%, 8.6%) Fab2 AHRs vs. 16/569 (2.8%; 95% CI: 1.7%, 4.5%) Fab AHRs (p = 0.02). In high-AGS states, the Fab2 group had 4/18 (22.2%; 95% CI: 9.0%, 45.2%) AHRs vs. 5/153 (3.3%; 95% CI: 1.4%, 7.4%) in the Fab group (p = 0.008). In this ToxIC NASBR study, administration of Fab2 was associated with a higher incidence of AHRs compared to Fab. The difference was especially notable in states with a higher prevalence of AGS.

The effect of decellularization protocols on characterizations of thermoresponsive and light-curable corneal extracellular matrix hydrogels.

To compare the effects of two decellularization protocols on the characteristics of fabricated COrnea Matrix (COMatrix) hydrogels. Porcine corneas were decellularized with Detergent (De) or Freeze-Thaw (FT)-based protocols. DNA remnant, tissue composition and α-Gal epitope content were measured. The effect of α-galactosidase on α-Gal epitope residue was assessed. Thermoresponsive and light-curable (LC) hydrogels were fabricated from decellularized corneas and characterized with turbidimetric, light-transmission and rheological experiments. The cytocompatibility and cell-mediated contraction of the fabricated COMatrices were assessed. Both protocols reduced the DNA content to < 0.1 µg/mg (native, > 0.5 µg/mg), and preserved the collagens and glycosaminoglycans. The α-Gal epitope remnant decreased by > 50% following both decellularization methods. We observed more than 90% attenuation in α-Gal epitope after treatment with α-galactosidase. The thermogelation half-time of thermoresponsive COMatrices derived from De-Based protocol (De-COMatrix) was 18 min, similar to that of FT-COMatrix (21 min). The rheological characterizations revealed significantly higher shear moduli of thermoresponsive FT-COMatrix (300.8 ± 22.5 Pa) versus De-COMatrix 178.7 ± 31.3 Pa, p < 0.01); while, this significant difference in shear moduli was preserved after fabrication of FT-LC-COMatrix and De-LC-COMatrix (18.3 ± 1.7 vs 2.8 ± 2.6 kPa, respectively, p < 0.0001). All thermoresponsive and light-curable hydrogels have similar light-transmission to human corneas. Lastly, the obtained products from both decellularization methods showed excellent in vitro cytocompatibility. We found that FT-LC-COMatrix was the only fabricated hydrogel with no significant cell-mediated contraction while seeded with corneal mesenchymal stem cells (p < 0.0001). The significant effect of decellularization protocols on biomechanical properties of hydrogels derived from porcine corneal ECM should be considered for further applications.

Novel Case Presentation of Abulia After Lone Star Tick Bite As Evidenced by Raised Titers of Alpha-Gal Specific IgM Immunoglobulin and a Possibility of Alpha-Gal Driven Hypothalamic Dysfunction As the Pathomechanism.

Galactose-α-1,3-galactose, an oligosaccharide epitope better acknowledged as α-Gal, is present in non-primate mammal meat, tick bites, microorganisms, and vaccines as a glycoprotein or glycolipid moiety. This can manifest hyperimmune reactions as it enters the human body, known as α-Gal syndrome (AGS). AGS and Guillain-Barré syndrome share cognate immunogenic pathomechanism via conquering immune tolerance further speculating galactose navigated neurological sequel. Unusual symptomatic presentation of abulia in our case, with incidental finding of high titers of α-Gal specific IgE immunoglobulin further supported by temporal resolution of symptoms on abstinence of meat products, raises a high degree of suspicion of neuro-psychiatric manifestation in sensitized α-Gal patients. The pathomechanism is blurry, and an absence of an objective diagnostic tool makes the neurological diagnosis challenging. α-Gal driven immune-related hypothalamic dysfunction could be a possibility that needs further exploration and is a topic of research.

Incidence and Management of Olaratumab Infusion-Related Reactions.

Olaratumab is a human monoclonal immunoglobulin G1 antibody against platelet-derived growth factor receptor-α. We report the nature and frequency of infusion-related reactions (IRRs) with olaratumab in clinical trials and postmarketing reports. Data from patients exposed to olaratumab across nine clinical trials were reviewed for IRRs. Blood samples were also analyzed for pre-existing immunoglobulin E anti-galactose-α-1,3-galactose (anti-α-Gal) antibodies. In the clinical trials, IRRs were identified in 70 of 485 patients (14.4%). The most frequent symptoms included flushing, fever or chills, and dyspnea. For 68 of 70 patients (97.1%), the first IRR occurred during the first two cycles of treatment. Grade 3 or worse IRRs were reported in 11 patients (2.3%), all during the first infusion and usually within 15 minutes of the start of the infusion. One IRR-related fatality (0.2%) occurred in a nonpremedicated patient with grade 3 or worse cardiac comorbidities. There was an association between grade 3 or worse IRRs and pre-existing anti-α-Gal antibodies, with a trend toward higher IRR rates in US geographies known to have a higher prevalence of anti-α-Gal antibodies. IRRs in postmarketing reports were consistent in nature and severity with those in the clinical trials. Premedication with corticosteroids and antihistamines should occur in all patients before olaratumab infusion, as indicated in labels in the United States and the European Union. Patients receiving olaratumab should be monitored for IRRs in a setting where resuscitation equipment is available for the treatment of IRRs.