The Development of Hypersensitivity Reactions in the Pediatric Population: A Review

Over the past several years, pediatric allergies have come to the forefront of many studies. Reports of immune-mediated hypersensitivity in younger patients have grown and led to an interest researching the causes of pediatric hypersensitivities. There are various risk factors that have been discussed that may lead to the development of allergies including genetic inheritance, genetic mutation, and environmental sensitization. It is important for all of these factors to be discussed in relation to the function of the immune system and its role in hypersensitivity reactions. If the causes of hypersensitivity reactions could be further studied and understood, treatments might be developed to reduce or eliminate these hypersensitivity reactions in younger pediatric populations. Much research has been done regarding the risk factors for pediatric hypersensitivity reactions and many recommendations have been made to combat this growing phenomenon. It is important to review the mechanisms of hypersensitivity reactions, the risk factors for developing them, and to research the incidences of pediatric hypersensitivity reactions and the recommended interventions for future diagnosis and treatment of hypersensitivity reactions in the pediatric population

The Three R\u27s of Delayed Hypersensitivity

Delayed hypersensitivity is one of several immune responses initiated by thymus-derived (T) lymphocytes. The mononuclear infiltrate of delayed hypersensitivity is a collaborative phenomenon between T lymphocytes and monocytes. This collaboration can be separated into components which I have chosen to call the three R\u27s of delayed hypersensitivity. In this discussion I will define these three R\u27s and examine the usefulness of this concept in clinical medicine

Revised scored sensory perception quotient reveals sensory hypersensitivity in women with autism

Previous research using the Sensory Perception Quotient (SPQ) has reported greater sensory hypersensitivity in people with autism spectrum condition (ASC) compared to controls, consistent with other research. However, current scoring of the SPQ does not differentiate between hyper and hyposensitivity, making it uncertain whether individuals with ASC might also show differences in hyposensitivity. Furthermore, no research to date has focused on sensory differences in females, and whether differences in sensory sensitivity extend to the broader autism phenotype (BAP). The present study aimed to fill these gaps. The present study developed and validated a Revised Scoring of the Sensory Perception Quotient (SPQ-RS) in order to investigate self-reported hypersensitivity and hyposensitivity in three groups of adults: a female ASC group (n = 152), mothers of children with ASC (BAP mothers group; n = 103), and a control mothers group (n = 74). All participants completed the SPQ as a self-report measure of sensory processing and the Autism-Spectrum Quotient (AQ) as a measure of the degree of autism traits. The female ASC group reported significantly more hypersensitivity, but not more hyposensitivity, compared to the control female and BAP mothers groups. The BAP mothers group did not differ from the control mothers group in either reported hypersensitivity (p = .365) or hyposensitivity (p = .075), suggesting atypical sensory sensitivity is not a BAP trait within females. SPQ-RS hypersensitivity scores positively correlated with autistic traits in the female ASC (r = .266) and BAP mothers groups (r = .350). The present findings revealed greater sensory hypersensitivity, but not hyposensitivity, in females with ASC compared to BAP and control female groups, and that a greater degree of autism traits relates to higher hypersensitivity in ASC females. The results offer support for the enhanced perceptual functioning model using large samples of females, who are an understudied population, and demonstrate the validity of the SPQ-RS as a valuable new research tool for exploring self-reported hypersensitivity and hyposensitivity

Acute coronary syndrome in diclofenac sodium-induced type I hypersensitivity reaction : Kounis syndrome

Drug-induced type I hypersensitivity reactions are frequent. Sometimes, acute coronary syndrome (ACS) can be registered in such patients, which may have a serious impact on the course and management of the allergic reaction. Because of potentially atypical ACS clinical presentations, the ECG is an obligatory diagnostic tool in any allergic reaction. Coronary artery spasm is the pathophysiological basis of ACS, triggered by the action of potent vasoactive mediators (histamine, neutral proteases, arachidonic acid products) released from the cells involved in type I hypersensitivity. Allergic angina and allergic myocardial infarction are referred to as Kounis Syndrome. We describe herein a case of ACS in a patient with registered systemic immediate hypersensitivity reaction which developed following the muscular administration of diclofenac sodium.peer-reviewe

Prospective genetic screening decreases the incidence of Abacavir hypersensitivity reactions in the Western Australian HIV cohort study

Abacavir therapy is associated with significant drug hypersensitivity in ∼8% of recipients, with retrospective studies indicating a strong genetic association with the HLA-B*5701 allelle. In this prospective study, involving 260 abacavir-naive individuals (7.7% of whom were positive for HLA-B*5701), we confirm the usefulness of genetic risk stratification, with no cases of abacavir hypersensitivity among 148 HLA-B*5701–negative recipients

Delayed-Type hypersensitivity to latex: Computational prediction of MHC class II epitopes on latex allergens

Delayed type hypersensitivity to natural rubber latex is rare compared to IgE mediated immediate reactions. Binding of allergens to MHC Class II is a crucial step in the presentation of antigens to CD4+ T Cells responsible for delayed reactions. Computational prediction of MHC class II epitopes on thirteen known latex allergens using SMM-align method revealed strong binding with several alleles. This shows that latex allergens are capable of initiating delayed type hypersensitivity in susceptible individuals.
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Association of immune response with efficacy and safety outcomes in adults with phenylketonuria administered pegvaliase in phase 3 clinical trials

Background: This study assessed the immunogenicity of pegvaliase (recombinant Anabaena variabilis phenylalanine [Phe] ammonia lyase [PAL] conjugated with polyethylene glycol [PEG]) treatment in adults with phenylketonuria (PKU) and its impact on safety and efficacy. Methods: Immunogenicity was assessed during induction, upward titration, and maintenance dosing regimens in adults with PKU (n = 261). Total antidrug antibodies (ADA), neutralizing antibodies, immunoglobulin (Ig) M and IgG antibodies against PAL and PEG, IgG and IgM circulating immune complex (CIC) levels, complement components 3 and 4 (C3/C4), plasma Phe, and safety were assessed at baseline and throughout the study. Pegvaliase-specific IgE levels were measured in patients after hypersensitivity adverse events (HAE). Findings: All patients developed ADA against PAL, peaking by 6 months and then stabilizing. Most developed transient antibody responses against PEG, peaking by 3 months, then returning to baseline by 9 months. Binding of ADA to pegvaliase led to CIC formation and complement activation, which were highest during early treatment. Blood Phe decreased over time as CIC levels and complement activation declined and pegvaliase dosage increased. HAEs were most frequent during early treatment and declined over time. No patient with acute systemic hypersensitivity events tested positive for pegvaliase-specific IgE near the time of the event. Laboratory evidence was consistent with immune complex-mediated type III hypersensitivity. No evidence of pegvaliase-associated IC-mediated end organ damage was noted. Interpretation: Despite a universal ADA response post-pegvaliase administration, adult patients with PKU achieved substantial and sustained blood Phe reductions with a manageable safety profile. Fund: BioMarin Pharmaceutical Inc. Keywords: Enzyme replacement therapy, Antidrug antibody, Circulating immune complex, Hypersensitivity, Phenylalanin

Calcium channel α2δ1 proteins mediate trigeminal neuropathic pain states associated with aberrant excitatory synaptogenesis.

To investigate a potential mechanism underlying trigeminal nerve injury-induced orofacial hypersensitivity, we used a rat model of chronic constriction injury to the infraorbital nerve (CCI-ION) to study whether CCI-ION caused calcium channel α2δ1 (Cavα2δ1) protein dysregulation in trigeminal ganglia and associated spinal subnucleus caudalis and C1/C2 cervical dorsal spinal cord (Vc/C2). Furthermore, we studied whether this neuroplasticity contributed to spinal neuron sensitization and neuropathic pain states. CCI-ION caused orofacial hypersensitivity that correlated with Cavα2δ1 up-regulation in trigeminal ganglion neurons and Vc/C2. Blocking Cavα2δ1 with gabapentin, a ligand for the Cavα2δ1 proteins, or Cavα2δ1 antisense oligodeoxynucleotides led to a reversal of orofacial hypersensitivity, supporting an important role of Cavα2δ1 in orofacial pain processing. Importantly, increased Cavα2δ1 in Vc/C2 superficial dorsal horn was associated with increased excitatory synaptogenesis and increased frequency, but not the amplitude, of miniature excitatory postsynaptic currents in dorsal horn neurons that could be blocked by gabapentin. Thus, CCI-ION-induced Cavα2δ1 up-regulation may contribute to orofacial neuropathic pain states through abnormal excitatory synapse formation and enhanced presynaptic excitatory neurotransmitter release in Vc/C2