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Abstract: Background: The lymphocyte transformation test (LTT) is a standard laboratory method to identify culprit drugs in patients with a history of drug‐induced non‐immediate hypersensitivity and is mainly performed during the recovery phase. The measurement of drug‐specific interferon γ (IFN‐γ)‐releasing cells has been introduced to confirm culprit drugs, even during the acute phase of drug allergy. Objectives: This study aimed to evaluate the capability of the enzyme‐linked immunospot assay (ELISpot) to detect drug‐specific IFN‐γ‐releasing cells during the acute phase and the capability of LTT to identify culprit drugs during the recovery phase in patients presenting with severe cutaneous adverse reactions (SCARs). Methods: Peripheral blood mononuclear cells (PBMCs) from 23 SCAR patients were collected during the acute and recovery phases and assayed for drug‐specific IFN‐γ‐releasing cells and lymphocyte proliferation, respectively. Results: Drug‐specific IFN‐γ‐releasing cells were detectable in 73.9% of SCAR subjects (55.6% and 85.7% in patients who were and were not taking systemic steroids, respectively), whereas LTT results were positive in 52.2% of SCAR subjects. The frequencies of drug‐specific IFN‐γ‐releasing cells were significantly higher in patients with positive LTT than in those with negative LTT (260.1 ± 110.0 and 46.6 ± 20.7 cells/106 PBMCs, P = 0.01). A significant correlation between the results of the IFN‐γ ELISpot assay and LTT was demonstrated (r = 0.65, P value <0.01). Conclusion: The IFN‐γ ELISpot assay could be a useful tool to identify culprit drugs in SCAR patients when culprit drug identification is urgently needed during the acute phase of drug allergy. [ABSTRACT FROM AUTHOR]

Background Allopurinol is a frequent cause of severe cutaneous adverse reactions ( SCARs), such as drug reaction with eosinophilia and systemic symptoms ( DRESS), Stevens-Johnson syndrome ( SJS) and toxic epidermal necrolysis ( TEN). The reactions can potentially be fatal. As drug rechallenge in patients with a history of drug-induced SCARs is contraindicated, in vitro testing may have a diagnostic role as a confirmation test. Objectives To study the diagnostic value of interferon ( IFN)-γ enzyme-linked immunospot ( ELISpot) assay as a confirmatory test in patients with a history of allopurinol-induced SCARs. Methods Peripheral blood mononuclear cells ( PBMCs) from 24 patients with a history of allopurinol-induced SCAR (13 DRESS, 11 SJS/ TEN) and 21 control subjects were incubated with allopurinol or oxypurinol in the presence or absence of antiprogrammed death ligand 1 antibody (anti- PD-L1). The numbers of IFN-γ-releasing cells after stimulation in each group were subsequently measured with ELISpot. Results The numbers of IFN-γ-releasing cells in allopurinol-allergic subjects were significantly higher than in control subjects when stimulating PBMCs with oxypurinol 100 μg mL−1, especially when adding anti- PD-L1 supplementation. According to the receiver operating characteristic curve results, the optimal discriminatory power of IFN-γ ELISpot in confirming diagnosis of allopurinol-induced SCARs can be obtained using 16 spot-forming cells per 106 PBMCs as a cut-off value upon oxypurinol/anti- PD-L1 stimulation (79·2% sensitivity and 95·2% specificity). Conclusions The measurement of oxypurinol/anti- PD-L1-inducing IFN-γ-releasing cells yields a high diagnostic value in distinguishing between allopurinol-allergic and control subjects. This technique is beneficial in confirming diagnosis of allopurinol-induced SCARs in patients whose reaction develops while taking multiple drugs. [ABSTRACT FROM AUTHOR]

Background: Allopurinol has been causing substantial morbidity and mortality particularly in Asian population by producing cutaneous adverse drug reactions (cADRs). Nonetheless, there are no data describing whether other genetics are a valid marker for prediction of allopurinol-induced cADRs patients in addition to HLA-B*58:01 allele. The goal of this study was to identify suitable single nucleotide polymorphisms (SNPs) for allopurinol induced cADRs among Thai patients., Methods: We conducted a case-control association study after enrolling 57 Thai patients with allopurinol induced cADRs and 101 allopurinol-tolerant controls. The genetic biomarkers and associated SNPs located on chromosome 6p21 were examined by TaqMan® SNP genotyping assays in both the cases and the controls., Results: Out of fifteen SNPs in nine genes, we found four combined SNPs (rs3099844 of HCP5, rs9263726 of PSORS1C1, rs9263733 of POLR2LP, and rs9263745 of CCHCR1) were significantly associated with allopurinol-induced cADRs compared to the tolerant controls (OR 73.2; 95% CI 24.2-266.8; P = 1.9 × 10 - 24 ). The overall sensitivity, specificity, positive predictive value and negative predictive value of these combinations were 84%, 94%, 9%, and 100%, respectively. However, the variant alleles of these SNP combinations were detected in 89.5% (51/57) of the cases. Moreover, the HLA-B*58:01 allele was observed in 86.0% of patients with allopurinol-induced cADRs, but only in 4.0% of tolerant controls (OR: 137.2; 95% CI: 38.3-670.5 and p-value = 1.7 × 10 - 27 )., Conclusions: Thus, this research confirms the association between the specific HLA-B*58:01 allele and all phenotypes of allopurinol-induced cADRs in Thais. Furthermore, there was found the combined four SNPs (rs3099844, rs9263726, rs9263733, and rs9263745) could be used as alternative novel biomarkers for predicting cADRs in patients taking allopurinol., (© 2024. The Author(s).)

Background: Diagnosing drug-induced allergy, especially nonimmediate phenotypes, is challenging. Incorrect classifications have unwanted consequences., Objective: We sought to evaluate the diagnostic utility of IFN-γ ELISpot and clinical parameters in predicting drug-induced nonimmediate hypersensitivity using machine learning., Methods: The study recruited 393 patients. A positive patch test or drug provocation test (DPT) was used to define positive drug hypersensitivity. Various clinical factors were considered in developing random forest (RF) and logistic regression (LR) models. Performances were compared against the IFN-γ ELISpot-only model., Results: Among the 102 patients who had 164 DPTs, most patients had severe cutaneous adverse reactions (35/102, 34.3%) and maculopapular exanthems (33/102, 32.4%). Common suspected drugs were antituberculosis drugs (46/164, 28.1%) and β-lactams (42/164, 25.6%). Mean (SD) age of patients with DPT was 52.7 (20.8) years. IFN-γ ELISpot, fixed drug eruption, Naranjo categories, and nonsteroidal anti-inflammatory drugs were the most important features in all developed models. The RF and LR models had higher discriminating abilities. An IFN-γ ELISpot cutoff value of 16.0 spot-forming cells/10 6 PBMCs achieved 94.8% specificity and 57.1% sensitivity. Depending on clinical needs, optimal cutoff values for RF and LR models can be chosen to achieve either high specificity (0.41 for 96.1% specificity and 0.52 for 97.4% specificity, respectively) or high sensitivity (0.26 for 78.6% sensitivity and 0.37 for 71.4% sensitivity, respectively)., Conclusions: IFN-γ ELISpot assay was valuable in identifying culprit drugs, whether used individually or incorporated in a prediction model. Performances of RF and LR models were comparable. Additional test datasets with DPT would be helpful to validate the model further., (Copyright © 2023 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Background: Elevated plasma cholesterol and/or plasma triglyceride levels in nephrotic syndrome patients are the result of impaired lipoprotein clearance and a compensatory increase in hepatic lipoprotein synthesis. Plasma proprotein convertase subtilisin/kexin type 9 levels directly correlate to the amount of proteinuria in nephrotic syndrome patients. Proprotein convertase subtilisin/kexin type 9 monoclonal antibody has been used to treat dyslipidemia in some refractory nephrotic syndrome cases. As a therapeutic protein, proprotein convertase subtilisin/kexin type 9 monoclonal antibody simply deteriorates if stored in inappropriate temperatures or conditions., Case Presentation: In this article, we present the case of a 16-year-old Thai female with severe combined dyslipidemia secondary to refractory nephrotic syndrome. She received proprotein convertase subtilisin/kexin type 9 monoclonal antibody (alirocumab) treatment. However, the drugs were mistakenly frozen in a freezer for up to 17 hours before being stored at 4 °C. After using two frozen devices, serum total cholesterol, free proprotein convertase subtilisin/kexin type 9, and lipoprotein(a) significantly decreased. Nonetheless, the patient developed a skin rash 2 weeks after the second injection and the lesion spontaneously resolved without any treatment approximately 1 month later., Conclusions: The effectiveness of proprotein convertase subtilisin/kexin type 9 monoclonal antibody seems to be stable after being stored under freeze-thaw conditions. However, improperly stored drugs should be discarded to avoid any potential undesirable side effects., (© 2023. The Author(s).)

Background: Perioperative immediate hypersensitivity reaction (POH) is an immediate hypersensitivity reaction during an anesthesiologist monitored procedure. We report data of clinically-suspected POH (csPOH) patients undergoing an allergist-performed unified diagnostic workup algorithm for POH., Objective: To describe the characteristics of patients with csPOH, POH events, and the POH outcomes of procedures after the unified diagnostic workup algorithm for POH., Methods: A prospective cohort was conducted in adult patients with csPOH at Siriraj Hospital, a tertiary hospital, in Thailand from January 2018 to August 2022. Diagnostic workup for POH by the allergist included an initial assessment, followed by comprehensive allergological evaluation. Patients were then follow-up for POH outcomes during subsequent anesthesia procedures., Results: Of 68 patients were csPOH, only 52 patients were diagnosed with POH by allergists. The incidence was 1:4,304 anesthetic procedures for POH, and 1:11,900 anesthetic procedures for at least grade III POH. Most patients had a grade III (51.2%) or II (46.4%) reaction. The leading identified causative agents were antibiotics (36.8%), antiseptics (21%), latex (13.1%), and morphine (13.1%). Cefazolin and chlorhexidine were the most common antibiotic and antiseptic, respectively. During a median follow-up time of 2.1 years, all 14 patients completing comprehensive allergological evaluation underwent subsequent anesthesia without recurrence of POH., Conclusions: The incidence of POH at our hospital was comparable to the global incidence. Antibiotics were the most common causative agent. Complete records, collaboration among the multidisciplinary team, and comprehensive evaluation of POH allow for safe subsequent procedures.

Background: Protamine administration post-cardiopulmonary bypass (CPB) can potentially cause hemodynamic instability. Histamine released from mast cells is believed to be responsible for hypotension after protamine administration. The aim of this study was to examine the effects of pretreatment with H1 and H2 antihistamines on changes in systemic arterial pressure following protamine administration., Methods: This study was a randomized, triple-blinded, placebo-controlled study, conducted at a university hospital. Forty adult patients undergoing elective coronary artery bypass grafting (CABG) or single valve surgery were included. The patients were randomly allocated (20 patients in each group) to receive a single dose of combined chlorpheniramine 10 mg and ranitidine 50 mg or normal saline intravenously immediately after separation from CPB prior to protamine administration. Trajectory changes in systolic blood pressure (SBP), mean arterial pressure (MAP), and vasoactive-inotropic score (VIS) from baseline until 35 minutes following protamine administration (24-time points) were compared between the two groups. Serial serum tryptase levels were also obtained at baseline, 30 and 60 minutes after protamine was given., Results: Forty patients were included in the analysis. Demographic and baseline blood pressure were similar between the two groups. At 30 minutes after protamine administration, there were no significant differences in both crude SBP [mean difference: -7.1 mmHg, 95% confidence interval (CI), -1.1 to 15.3 mmHg, P=0.09] and SBP after adjustment for the European System for Cardiac Operative Risk Evaluation (EuroSCORE II), CPB time, and VIS (mean difference: -3.9 mmHg, 95% CI, -11.9 to 4.0 mmHg, P=0.33). There were also no significant differences in crude MAP (mean difference: -2.1 mmHg, 95% CI, -6.9 to 2.7 mmHg, P=0.39) and adjusted MAP (mean difference: -0.7 mmHg, -5.9 to 4.4 mmHg, P=0.78) between the two groups. None of the patients in both groups had a significant increase in serum tryptase from baseline. No differences in median serum tryptase levels at baseline, 30 and 60 minutes were demonstrated between the two groups., Conclusions: Pretreatment with H1 and H2 antihistamines does not attenuate blood pressure responses to protamine administration in patients after CPB. Mechanisms other than histamine release from mast cells might be responsible for protamine-induced cardiovascular changes., Trial Registration: ClinicalTrials.gov NCT03583567.

Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) and drug reactions with eosinophilia and systemic symptoms (DRESS) are the most common severe cutaneous adverse drug reactions (SCARs). Anti-epileptic drugs are one of the most common drugs causing SCARs. Cytokine profiles of SCARs during culprit drug exposure have never been characterized. This study aimed to identify cytokine patterns between SCARs and non-SCARs in epilepsy patients and the patterns of DRESS and SJS/TEN. Epilepsy patients that showed allergic responses to anti-epileptic drugs that manifested as SJS/TEN or DRESS were recruited. Epilepsy patients with no drug allergy symptoms and healthy people were also recruited as control groups. Peripheral blood mononuclear cells (PBMCs) were isolated and co-cultured with assigned anti-epileptic drugs according to the lymphocyte transformation test (LTT). LTT and measurement of cytokine levels in supernatants were performed on day six of cell cultivation. This study identified different cytokine expression patterns between SCAR and non-SCAR in epilepsy patients. Significant levels of IL-10, IL-12, IL-17, and GM-CSF were detected in non-SCAR epilepsy. However, the levels of IL-2, IL-5, IL-13, and IFN-gamma were significantly higher in supernatants of PBMCs of DRESS cultivated with AEDs relative to those of SJS/TEN. These cytokine levels were positively correlated with the cell proliferation index. Production of IL-5 and IL-13 was a unique characteristic of DRESS PBMCs. This study was the first to demonstrate distinct differences in cytokine levels between SCAR and non-SCAR PBMCs in epilepsy, which could help explain the immune-pathomechanism of drug hypersensitivity in SCARs. Different patterns of cytokine production and cell proliferation between DRESS and SJS/TEN in AED hypersensitivity were also demonstrated. Production of IL-5 and IL-13 might be a promising marker to define drug hypersensitivity in DRESS., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Background: Association between chronic spontaneous urticaria (CSU) and autoimmunity has been well documented. Autologous serum skin testing could support the autoimmune etiology of CSU, whereas it is difficult to interpret and could not be performed on antihistamine omitted patients. It was found that immunoglobulin G (IgG) autoantibodies (autoAbs) against high-affinity IgE receptor (Fc ε R1) were suggested as a potential trigger in the pathogenesis of CSU. Although many ELISA protocols have been developed to detect these autoAbs, they lacked validation or a reliable cut-off point. We, therefore, aimed to develop a validated ELISA with a reliable cut-off point to quantitate IgG anti-Fc ε R1 α autoAbs for CSU., Methods: We developed an in-house ELISA to quantitate IgG anti-Fc ε R1 α autoAbs. Sera from 233 CSU patients and 25 healthy people were used to test with ELISA. The cut-off point was obtained from the results subjected to analyze with receiver operating characteristic (ROC) analysis. ELISA was validated with 116 CSU patients and 150 healthy donors., Results: ELISA revealed that healthy people had a basal level of IgG anti-Fc ε R1 α autoAbs, whereas their levels were significantly lower than autoAbs levels in CSU patients. ROC analysis of ELISA determined the cut-off point at 936.7 ng/ml. Our ELISA was validated and provided excellent sensitivity and specificity at 98.28% and 92.67%, respectively., Conclusion: Our ELISA could detect significant levels of IgG anti-Fc ε R1 α autoAbs in CSU, supporting that these autoAbs were associated with CSU etiology. Our validated ELISA with the reliable cut-off point provided excellent accuracy at 95.11% (98.28% sensitivity and 92.67% specificity). Our ELISA could be an alternative test benefit for the patient who is unable to omit antihistamine treatment., Competing Interests: The authors declare no conflict of interest., (Copyright © 2022 Chattip Sripatumtong et al.)

Propose: The purpose of this study was to investigate panels of enzyme-linked immunospot assays (ELISpot) to detect drug-specific mediator releasing cells for confirming culprit drugs in severe cutaneous adverse reactions (SCARs)., Methods: Frequencies of drug-induced interleukin-22 (IL-22)-, interferon-gamma (IFN-γ)-, and granzyme-B (GrB)-releasing cells were measured by incubating peripheral blood mononuclear cells (PBMCs) from SCAR patients with the culprit drugs. Potential immunoadjuvants were supplemented to enhance drug-induced mediator responses., Results: Twenty-seven patients, including 9 acute generalized exanthematous pustulosis (AGEP), 10 drug reactions with eosinophilia and systemic symptoms, and 8 Stevens-Johnson syndrome and toxic epidermal necrolysis (SJS/TEN) were recruited. The average frequencies of drug-induced IL-22-, IFN-γ-, and GrB-releasing cells were 35.5±16.3, 33.0±7.1, and 164.8±43.1 cells/million PBMCs, respectively. The sensitivity of combined IFN-γ/IL-22/GrB ELISpot was higher than that of IFN-γ ELISpot alone for culprit drug detection in all SCAR subjects (77.8% vs 51.9%, P < 0.01). The measurement of drug-induced IL-22- and IFN-γ releasing cells confirmed the culprit drugs in 77.8% of AGEP. The measurement of drug-induced IFN-γ- and GrB-releasing cells confirmed the culprit drugs in 62.5% of SJS/TEN. Alpha-galactosylceramide supplementation significantly increased the frequencies of drug-induced IFN-γ releasing cells., Conclusion: The measurement of drug-induced IFN-γ-releasing cells is the key for identifying culprit drugs. The additional measurement of drug-induced IL-22-releasing cells enhances ELISpot sensitivity to identify drug-induced AGEP, while the measurement of drug-induced GrB-releasing cells could have a role in SJS/TEN. ELISpot sensitivity might be improved by supplementary alpha-galactosylceramide., Trial Registration: ClinicalTrials.gov Identifier: NCT02574988., Competing Interests: There are no financial or other issues that might lead to conflict of interest., (Copyright © 2021 The Korean Academy of Asthma, Allergy and Clinical Immunology • The Korean Academy of Pediatric Allergy and Respiratory Disease.)

Drug hypersensitivity reactions (DHRs) occur in certain people and are often not predictable. DHRs can be classified as immediate and delayed reactions regarding to onset of clinical manifestations. Both reactions are considered to be an important public health problem because they can lead to life-threatening conditions; however, this review article will focus on delayed DHRs. The most important points for diagnosis of delayed DHRs are the recognition of drug hypersensitivity characteristics and culprit drug identification. While it is usually difficult to identify a culprit drug; clinical evaluation using the causality assessment method, a non-invasive process, can identify the culprit drug without the need for intensive investigation. Delayed DHRs can cause life-threatening conditions; therefore, in vivo skin tests, as well as drug provocation tests, have to be cautiously performed by a drug allergist and have not been recommended in uncontrolled conditions. ENDA/EAACI has recommended that in vitro tests (if available) be performed prior to any in vivo tests. Therefore, in vitro diagnostic tests can be alternative methods to identify a culprit drug for delayed DHR diagnosis as there is no or very low risk for patients under investigation. There are many testing approaches to identify causative agents for delayed DHRs such as: the lymphocyte transformation test (LTT), cytokine/mediator detection assays (i.e. ELISA and flow cytometry-based bead assays), multiplex bead-based immunoassay and ELISpot. The LTT is the most standardized method whereas it has been available in medical schools affiliated with university hospitals. Other in vitro tests, like cytokine detection assays, have also been used, even though they are still being evaluated. They could supplement LTT results that would provide drug allergist's with documentary evidence and prevent risk to patients by avoiding in vivo or drug provocation testing. Hence, the in vitro tests have been promising tests contributing to the management of the delayed DHR work-up process in clinical practice., (Copyright © 2021 Elsevier B.V. All rights reserved.)

HLA-B*13:01 -positive patients in Thailand can develop frequent co-trimoxazole hypersensitivity reactions. This study aimed to characterize drug-specific T cells from three co-trimoxazole hypersensitive patients presenting with either Stevens-Johnson syndrome or drug reaction with eosinophilia and systemic symptoms. Two of the patients carried the HLA allele of interest, namely HLA-B*13:01 . Sulfamethoxazole and nitroso sulfamethoxazole specific T cell clones were generated from T cell lines of co-trimoxazole hypersensitive HLA-B*13:01 -positive patients. Clones were characterized for antigen specificity and cross-reactivity with structurally related compounds by measuring proliferation and cytokine release. Surface marker expression was characterized via flow cytometry. Mechanistic studies were conducted to assess pathways of T cell activation in response to antigen stimulation. Peripheral blood mononuclear cells from all patients were stimulated to proliferate and secrete IFN-γ with nitroso sulfamethoxazole. All sulfamethoxazole and nitroso sulfamethoxazole specific T cell clones expressed the CD4+ phenotype and strongly secreted IL-13 as well as IFN-γ, granzyme B and IL-22. No secretion of IL-17 was observed. A number of nitroso sulfamethoxazole-specific clones cross-reacted with nitroso dapsone but not sulfamethoxazole whereas sulfamethoxazole specific clones cross-reacted with nitroso sulfamethoxazole only. The nitroso sulfamethoxazole specific clones were activated in both antigen processing-dependent and -independent manner, while sulfamethoxazole activated T cell responses via direct HLA binding. Furthermore, activation of nitroso sulfamethoxazole-specific, but not sulfamethoxazole-specific, clones was blocked with glutathione. Sulfamethoxazole and nitroso sulfamethoxazole specific T cell clones from hypersensitive patients were CD4+ which suggests that HLA-B*13:01 is not directly involved in the iatrogenic disease observed in co-trimoxazole hypersensitivity patients., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Pratoomwun, Thomson, Jaruthamsophon, Tiyasirichokchai, Jinda, Rerkpattanapipat, Tassaneeyakul, Nakkam, Rerknimitr, Klaewsongkram, Srinoulprasert, Pirmohamed, Naisbitt and Sukasem.)

Background: PCSK9 monoclonal antibody lowers plasma PCSK9 and LDL-cholesterol levels. The manufacturers recommend drug storage at 2-8 °C, and not above 25 °C. This study aimed to investigate drug stability at various temperatures that this drug could be exposed to during medication handling and transportation in tropical countries., Methods: Alirocumab and evolocumab were tested in 3 study conditions: room temperature (RT), cooler device with cold pack, and freeze-thaw for 9 and 18 h. Heated drugs were used as negative control. Free plasma PCSK9 levels from 9 hyperlipidemia subjects were measured with ELISA., Results: Average subject age was 49.2 ± 18.4 years. Percent PCSK9 inhibition significantly declined in heated drugs compared to baseline. Average RT during the study period was 30.4 ±2.6 °C. Change in percent PCSK9 inhibition of PCSK9 mAb at RT from baseline was - 5.8 ± 4.4% (P = 0.005) and - 11.0 ± 8.9% (P = 0.006) for alirocumab at 9 h and 18 h, and - 9.7 ± 11.8% (P = 0.04) and - 15.1 ± 14.3% (P = 0.01) for evolocumab at 9 and 18 h, respectively. In contrast, there were no significant changes in percent PCSK9 inhibition from baseline when PCSK9 mAb was stored in a cooler. In freeze-thaw condition, changes in percent PCSK9 inhibition from baseline to 9 and 18 h were - 5.2 ± 2.9% (P = 0.001) and - 2.6 ± 4.9% (P = 0.16) for alirocumab, and - 1.8 ± 4.2% (P = 0.24) and 0.4 ± 6.1% (P = 0.83) for evolocumab., Conclusion: Proper drug storage according to manufacturer's recommendation is essential. Drug storage at RT in tropical climate for longer than 9 h significantly decreased drug efficacy; however, storage in a cooler device with cold pack for up to 18 h is safe.

Drug hypersensitivity reactions (DHRs) occasionally present with severe cutaneous adverse reactions (SCARs) which result in a high risk of morbidity and mortality. Although SCARs are rare, the occurrence could lead to a significant increase in healthcare and economic burden, especially when more than one possible culprit drug is implicated. Therefore, the accurate identification of the culprit drug(s) is important for correct labeling and subsequent patient education and avoidance. To date, clinical evaluation using causality assessment has limitations because the assessment may be inaccurate due to the overlapping timelines when multiple drugs are initiated/continued. Moreover, drug provocation tests (DPTs) which is the gold standard in diagnosis, are contraindicated, and in vivo skin tests may also be associated with risks of triggering SCAR. The European Network for Drug Allergy recommended that in vitro tests, if available, should be performed before any in vivo tests. Basophil activation tests and lymphocyte transformation tests, could serve as reliable in vitro tests for both immediate and delayed-type DHR. Many academic medical centers with affiliated laboratory services offer these tests in the diagnostic evaluation of SCARs in clinical practice. This not only complements identification of the culprit drug(s), but may also be used to test for potentially non cross-reactive alternatives, hence avoiding DPTs. In this review, we summarize the roles of in vitro tests in identifying the culprit drug(s) in SCARs, issues with utilization and interpretation of test results, and our experience in clinical practice., Competing Interests: Conflict of Interest: The authors have no financial conflicts of interest., (Copyright © 2020. Asia Pacific Association of Allergy, Asthma and Clinical Immunology.)

Background: Botulinum neurotoxin A (BoNT/A) has been used for cosmetic indications for many decades. Consumption of BoNT/A usage has been markedly increased for a few years. Even new formulations of BoNT/A to decrease immunogenicity have been released, repeated treatment to maintain efficacy outcome is inevitable and could finally provoke immune response. In the past, prevalence of botulinum treatment failure (BTF) in cosmetic indication was rare leading to less medical concern. Current decade, case reports on BTF, especially antibody-induced botulinum toxin treatment failure (ABTF), have been increasingly revealed and risk factors associated with ABTF have been intensively studied., Aims: In this article, we will review antibody-induced botulinum toxin treatment failure (ABTF), risk-associated ABTF, prevalence and recent case reports of ABTF, and new approach to deal with ABTF., Methods: Literature search was conducted using PubMed. The relevant literatures published between January 2000 and May 2020 concerning BTF and ABTF including investigation for ABTF were included and analyzed., Results: Possible causes of BTF were summarized. ABTF could be a tip of iceberg of BTF, its prevalence, and currently, 10-year case reports of ABTF were published evidence. Risk factors and investigation methods for ABTF were also summarized. Based on previous studies and our experience, novel approach to management of ABTF was described., Conclusion: Effective management of BTF is to explore causes of treatment failure. Antibodies against BoNT/A complex could be one of many possibilities. Laboratory in vitro tests could be alternative tools to decrease adverse effect and rebooting immune responses in BTF patients., (© 2020 Wiley Periodicals LLC.)

Introduction: Botulinum toxin A (BoT/A) treatment failure (BTF) affects patients subjected to repeated BoT/A exposure for cosmetic indications. BoT/A's general formulation contains core BoT/A and complexing proteins. BTF may be caused by antibody-induced treatment failure. Antibodies against core BoT/A can occur; however, anti-complexing protein antibodies have never been demonstrated, and tools for anti-complexing protein antibody detection have not been developed. The aim of this study was to evaluate immune involvement in BoT/A-nonresponsive patients., Methods: Patients suspected of nonresponsiveness to BoT/A for cosmetic indications were recruited. All volunteers were categorized as BoT/A-responsive or BoT/A-tolerant according to frontalis testing with onabotulinumtoxinA (onaA). Twenty-two BoT/A-tolerant volunteers were recruited separately for frontalis testing with incobotulinumtoxinA (incoA). Anti-BoT/A and anti-complexing protein antibodies were quantified by special ELISA using sera from blood sampled before and after frontalis testing., Results: Significantly higher levels of IgG against complexing protein were detected in onaA-tolerant sera but not in onaA-responders, leading to proposals that anti-complexing protein antibodies could cause onaA unresponsiveness. Some onaA-tolerant patients according to frontalis test with incoA were responsive to incoA. Newly developed absorption ELISA confirmed that incoA-responsive sera predominantly contained IgG against complexing proteins, whereas incoA-tolerant sera contained significant levels of IgG against core BoT/A. The presence of anti-complexing protein antibodies higher than 90.75% in sera of onaA-tolerant patients could respond to incoA. The ELISA technique might be employed as a tool to predict incoA responsiveness. Our frontalis testing after incoA treatment showed that anti-incoA IgG levels were not increased by incoA., Conclusions: BoT/A-exposed patients may develop antibodies against core botulinum toxin and complexing proteins. Our study is the first to demonstrate that anti-complexing protein antibodies cause BTF. High levels of antibodies against complexing proteins can cause onaA unresponsiveness, although some patients were still incoA-responsive. Our developed ELISA to detect anti-complexing protein antibodies can determine whether onaA-tolerant patients respond to incoA without incoA frontalis testing.

Secondary treatment failure (STF) of botulinum toxin A (BoNT/A) therapy in cosmetic indication has been postulated as production of antibody against active sites of BoNT/A in unresponsive patients. To prove of concept, detection of anti-BoNT/A antibody is required, however, current enzyme-linked immunosorbent assay (ELISA) detects human IgGs against whole BoNT/A molecule. We developed an inhibition ELISA to quantify antibodies bound to the active sites of BoNT/A using three mouse monoclonal antibodies targeting translocation domain, receptor binding site and catalytic domain of BoNT/A prior to processing ELISA to detect human IgG (hIgG) against BoNT/A. Adults naïve to BoNT/A, or treated and responsive (toxin-response), or treated but unresponsive (toxin-tolerance) were recruited. Detection of hIgG revealed that naïve volunteers had basal level of hIgG against whole BoNT/A, whereas its level was significantly lower than those hIgG in BoNT/A-exposed cohorts. Higher anti-BoNT/A levels in sera from volunteers ever-exposed to BoNT/A indicates that BoNT/A may provoke immune responses in BoNT/A-treated cohorts. Inhibition ELISA demonstrated that levels of BoNT/A-specific hIgG in tolerance patients had a dramatic decrease in mouse monoclonal antibody blockage, suggesting presence of hIgG specific to BoNT/A's three active sites in STF patients. Therefore, our ELISA detected hIgG against whole BoNT/A protein and BoNT/A active sites suggesting that human antibodies may cause STF. To compare with frontalis test, our inhibition ELISA provided good accuracy at 83.1% (50% sensitivity and 89.9% specificity). Our test may help clinicians to diagnose possibility of STF and also to monitor immune status against BoNT/A., (Copyright © 2019. Published by Elsevier B.V.)

Objective: To adapted the Drug Hypersensitivity Quality of Life (DrHy-Q) Questionnaire from Italian into Thai and assessed its validity and reliability., Design: Prospectively recruited during January 2012-May 2017., Setting: Multicenter; six Thai tertiary university hospitals., Study Participants: Total of 306 patients with physician-diagnosed drug hypersensitivity., Interventions: Internal consistency and test-retest reliability were evaluated among 68 participants using Cronbach's ɑ and intra-class correlation coefficient (ICC). The validity of Thai DrHy-Q was assessed among 306 participants who completed World Health Organization Quality of Life-BREF (WHOQOL-BREF-THAI). Construct and divergent validities were assessed for Thai DrHy-Q. Known-groups validity assessing discriminating ability was conducted in Thai DrHy-Q and WHOQOL-BREF-THAI., Main Outcome Measures: Validity; reliability; single vs. multiple drug allergy; non-severe cutaneous adverse reactions (SCAR) vs. SCAR., Results: Thai DrHy-Q showed good reliability (Cronbach's ɑ = 0.94 and ICC = 0.8). Unidimensional factor structure was established by confirmatory factor analysis (CFI&TLI = 0.999, RMSEA = 0.02). Divergent validity was confirmed by weak correlation between Thai DrHy-Q and WHOQOL-BREF-THAI domains (Pearson's r = -0.41 to -0.19). Known-groups validity of Thai DrHy-Q was confirmed with significant difference between patients with and without life-threatening SCAR (P = 0.02) and patients with multiple implicated drug classes vs. those with one class (P < 0.01); while WHOQOL-BREF-THAI could differentiate presence of life-threatening SCAR (P < 0.01) but not multiple-drug allergy., Conclusions: Thai DrHy-Q was reliable and valid in evaluating quality of life among patients with drug hypersensitivity. Thai DrHy-Q was able to discriminate serious drug allergy phenotypes from non-serious manifestations in clinical practice and capture more specific drug-hypersensitivity aspects than WHOQOL-BREF-THAI., (© The Author(s) 2018. Published by Oxford University Press in association with the International Society for Quality in Health Care. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Pythium insidiosum has been mainly reported to cause morbidity and mortality in thalassemia patients. P. insidiosum zoospores can germinate to be hyphae within a few hours; therefore, it is difficult to study the initial immune response that P. insidiosum zoospores induce. The present study aims to compare immune responses against P. insidiosum zoospore infection by comparing monocytes/macrophages from thalassemia patients with those from non-thalassemia controls., Methods: In order to keepP. insidiosum in the zoospore stage in vitro for inoculation, the P. insidiosum zoospores were preserved without germination by treatment with inorganic hypochlorite solution. CD14+ cells were isolated from peripheral blood mononuclear cells of thalassemia and non-thalassemia donors and then left to transition to macrophages. Monocytes/macrophage culture was infected with P. insidiosum zoospores and culture supernatants were subjected to Th1/Th2 multiplex cytokine detection., Results: Our study of cytokine production revealed that the basal level of GM-CSF produced by thalassemia monocytes/macrophages was lower than that observed in monocytes/macrophages of non-thalassemia individuals. Higher GM-CSF and IFN-γ response was also found when cells from non-thalassemia people were stimulated with P. insidiosum zoospores compared to thalassemia cells. It was also found that TNF-α, GM-CSF and IFN-γ productions from monocytes/macrophages of thalassemia patients who received iron chelator treatment were significantly higher than those produced from thalassemia patients without iron chelator treatment., Conclusion: For the first time, the present study demonstrates defective immune responses in monocytes/macrophages derived from thalassemia patients in response toP. insidiosum zoospore infection. The results also show an inverse correlation between iron overload and cytokine production in monocytes/macrophages of thalassemia patients. This finding could explain why thalassemia patients are susceptible to P. insidiosum infection., (Copyright © 2019 Elsevier GmbH. All rights reserved.)

Background: Natural rubber latex and chlorhexidine have previously been identified as causative substances in perioperative anaphylaxis. A pelvic examinations is generally considered noninvasive, however, this procedure is rarely associated with severe allergic reactions. We reported a rare case of dual latex and chlorhexidine allergies which caused anaphylaxis after pelvic examination in a woman with a history of latex-related fruits allergy., Case Presentation: A 54-year-old woman had severe anaphylaxis after a pelvic examination due to dual latex and chlorhexidine (CHX) allergies. The gynecologist used CHX for the vaginal preparation and wore latex-containing gloves with lubricating gel during the examination. In vivo and in vitro tests revealed CHX sensitization by a positive skin prick test to chlorhexidine at a very low concentration (0.002 mg/mL), and a positive basophil activation test to CHX. Latex allergy was confirmed by a positive specific IgE to latex and a positive glove-use test at 20 min. An analysis of specific IgE to latex component revealed positive results for Hev b 1, 5, 6.02, and 11. As she also had a past history of fruit allergy, prick-to-prick testing with latex-related fruits was performed. The results were positive for avocado, banana, jackfruit, kiwi, and longan., Conclusions: Concomitant mucosal exposure of both natural rubber latex and CHX in highly sensitized patients during pelvic examinations can lead to severe anaphylaxis. Pre-procedural screening for an allergy to latex or CHX, or to any other allergen, should be performed in patients where there is suspicion of a specific allergy due to a previous allergic reaction. Increased awareness of these two allergens in all healthcare settings may improve patient safety., Competing Interests: The authors declare that they have no competing interests.

Background: The prevention and confirmation of drug-induced severe cutaneous adverse reactions (SCARs) are difficult., Objective: To determine the benefit of HLA-B allele prescreening and the measurement of drug-specific IFN-γ-releasing cells in the prevention and identification of the culprit drug in patients with SCARs., Methods: A total of 160 patients with SCARs were recruited from 6 university hospitals in Thailand over a 3-year period. HLA-B alleles were genotypically analyzed. The frequencies of drug-specific IFN-γ-releasing cells in patients with SCARs were also measured., Results: The drugs commonly responsible for SCARs were anticonvulsants, allopurinol, beta-lactams, antituberculosis agents, and sulfonamides. If culprit drugs had been withheld in patients carrying known HLA-B alleles at risk, it would have prevented 21.2% of SCAR cases, mainly allopurinol- and carbamazepine-related SCARs. Culprit drug-specific IFN-γ-releasing cells could be identified in 45.7% (53 of 116) of patients with SCARs caused by 5 major drug groups, particularly in patients diagnosed with drug reactions with eosinophilia and systemic symptoms (DRESS) (50.0%), followed by Stevens-Johnson syndrome/toxic epidermal necrolysis (46.0%), and acute generalized exanthematous pustulosis (31.3%). According to our study, high frequencies of drug-specific IFN-γ-releasing cells were significantly demonstrated in patients who suffered from DRESS phenotype, having anticonvulsants or the drugs belonging to the "probable" category based on the Naranjo algorithm scale, as the culprit drugs., Conclusions: HLA-B prescreening would succeed in preventing only a minority of SCAR victims. Drug-specific IFN-γ-releasing cells are detectable in almost half of patients. Better strategies are required for better SCAR prevention and culprit drug confirmation., (Copyright © 2019 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Phenytoin (PHE) and carbamazepine (CBZ) are first rank causative drugs that can induce drug rash with eosinophilia and systemic symptoms (DRESS) and Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN). Identification of anti-epileptic drugs as a culprit drug has been problematic; hence, in vitro tests could be promising methods to define causative drugs without clinical risk. The aim of this study is to evaluate the efficacy of lymphocyte transformation tests (LTT) and cytokine detection assays in identifying PHE and CBZ as culprit drugs. Peripheral blood mononuclear cells were collected from normal, PHE/CBZ tolerance and PHE/CBZ hypersensitivity cohorts and utilized for cell-culture assays. LTT was performed and culture supernatants were subjected to multiple cytokine detection assays. Our study showed that LTT correlated with outcomes of Naranjo's assessment with statistical significance (r = 0.614). Various sensitivities of LTT and cytokine detection assays were demonstrated. Although both assays provided excellent specificity, LTT yielded higher sensitivity as compared to those of cytokine detection assays in both DRESS and SJS/TEN. Regardless whether specificity is, this is the first report to demonstrate that IL-4 detection assay could enhance sensitivity to identify culprit drug when it was combined with LTT for SJS/TEN patients or it was combined with IL-2/IFN-γ detection assays for DRESS ones., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Multiple drug hypersensitivity (MDH) is a syndrome that develops as a consequence of massive T-cell stimulations and is characterized by long-lasting drug hypersensitivity reactions (DHR) to different drugs. The initial symptoms are mostly severe exanthems or drug rash with eosinophilia and systemic symptoms (DRESS). Subsequent symptoms due to another drug often appear in the following weeks, overlapping with the first DHR, or months to years later after resolution of the initial presentation. The second DHR includes exanthema, erythroderma, DRESS, Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN), hepatitis, and agranulocytosis. The eliciting drugs can be identified by positive skin or in vitro tests. The drugs involved in starting the MDH are the same as for DRESS, and they are usually given in rather high doses. Fixed drug combination therapies like sulfamethoxazole/trimethoprim or piperacillin/tazobactam are frequently involved in MDH, and 30-40% of patients with severe DHR to combination therapy show T-cell reactions to both components. The drug-induced T-cell stimulation appears to be due to the p-i mechanism. Importantly, a permanent T-cell activation characterized by PD-1+/CD38+ expression on CD4+/CD25low T cells can be found in the circulation of patients with MDH for many years. In conclusion, MDH is a drug-elicited syndrome characterized by a long-lasting hyperresponsiveness to multiple, structurally unrelated drugs with clinically diverse symptoms., (© 2017 The Author(s) Published by S. Karger AG, Basel.)

Background: The lymphocyte transformation test (LTT) is used for in vitro diagnosis of drug hypersensitivity reactions. While its specificity is over 90%, sensitivity is limited and depends on the type of reaction, drug and possibly time interval between the event and analysis. Removal of regulatory T cells (Treg/CD25(hi)) from in vitro stimulated cell cultures was previously reported to be a promising method to increase the sensitivity of proliferation tests., Objective: The aim of this investigation is to evaluate the effect of removal of regulatory T cells on the sensitivity of the LTT., Methods: Patients with well-documented drug hypersensitivity were recruited. Peripheral blood mononuclear cells, isolated CD3(+) and CD3(+) T cells depleted of the CD25(hi) fraction were used as effector cells in the LTT. Irrelevant drugs were also included to determine specificity. (3)H-thymidine incorporation was utilized as the detection system and results were expressed as a stimulation index (SI)., Results: SIs of 7/11 LTTs were reduced after a mean time interval of 10.5 months (LTT 1 vs. LTT 2). Removal of the CD25(hi) fraction, which was FOXP3(+) and had a suppressive effect on drug-induced proliferation, resulted in an increased response to the relevant drugs. Sensitivity was increased from 25 to 82.35% with dramatically enhanced SI (2.05 to 6.02). Specificity was not affected., Conclusion: Removal of Treg/CD25(hi) cells can increase the frequency and strengths of drug-specific proliferation without affecting specificity. This approach might be useful in certain drug hypersensitivity reactions with borderline responses or long time interval since the hypersensitivity reaction., (© 2014 S. Karger AG, Basel.)

P. marneffei is a thermal dimorphic fungus which causes penicilliosis, an opportunistic infection in immunocompromised patients in South and Southeast Asia. Little is known about the innate immune response to P. marneffei infection. Therefore, the initial response of macrophages to P. marneffei conidia was evaluated by us. Adhesion between monocytes from healthy humans and fungal conidia was examined and found to be specifically inhibited by MAbs against PRR, such as MR, (TLR)1, TLR2, TLR4, TLR6, CD14, CD11a, CD11b, and CD18. To study the consequences of these interactions, cytokines were also examined by ELISA. Binding of P. marneffei conidia to monocytes was significantly inhibited, in a dose-dependent manner, by MAbs against MR, TLR1, TLR2, TLR4, TLR6, CD14, CD11b and CD18. When monocytes were co-cultured with the conidia, there was an increase in the amount of surface CD40 and CD86 expression, together with TNF-alpha and IL-1beta production, compared to unstimulated controls. In assays containing anti-TLR4 or anti-CD14 antibody, reduction in the amount of TNF-alpha released by monocytes stimulated with P. marneffei conidia was detected. In addition, it was found that production of TNF-alpha and IL-1beta from adherent peripheral blood monocytes was partially impaired when heat-inactivated autologous serum, in place of untreated autologous serum, was added to the assay. These results demonstrate that various PRR on human monocytes participate in the initial recognition of P. marneffei conidia, and the engagement of PRR could partly initiate proinflammatory cytokine production.

Penicilliosis is a disseminated infection in immunocompromised individuals caused by the dimorphic fungus, Penicillium marneffei. Very little is known about its route of infection, however, it is thought that initial infection occurs through inhalation of conidia. We investigated the role played by various extracellular matrix glycosaminoglycans (GAGs) in the initial adherence of P. marneffei conidia using a direct adhesion assay. GAGs were further used to block the binding of fungal spores to human lung epithelial cells and highly sulfated GAGs were tested for their inhibitory effects owing to their degree of sulfation. Our results demonstrated high levels of conidial adhesion to chondroitin sulfate B, heparin and highly sulfated chitosan (CP-3). No direct adherence was observed to immobilized chondroitin sulfate (CS) A, CSC, CSD and hyaluronic acid, as well as chitosans with low sulfate content. The results suggested that P. marneffei conidia bind to iduronic acid (IdoA) of the polysaccharide chains. Involvement of negatively charged sulfate groups in adhesion was also indicated. Furthermore, significant inhibition of conidial adherence to A549 cells was observed in the presence of CSB, heparan sulfate (HS), heparin and CP-3. It was further demonstrated that GAGs can affect the adhesion of conidia to fibronectin and laminin, glycoproteins that have previously been implicated as adhesive receptors for fungal conidia. CSB and HS could partially inhibit the adhesion of fungal conidia to laminin and fibronectin implying that conidia can weakly interact with the IdoA GAG-binding domain(s) of these molecules. The data indicated that, in addition to fibronectin and laminin, IdoA-containing GAGs may play an important role in fungal adherence to the surface of human lung epithelium.

Although chemokines have been thought of primarily as leukocyte attractants, a growing body of evidence indicates that they also contribute to a number of tumor-related processes, such as tumor cell growth, angiogenesis/angiostasis, local invasion, and metastasis. The current knowledge of the possible involvement of chemokines and their receptors in these cellular events are reviewed here. The operating mechanism of chemokines in relation to metastatic processes in vivo are also discussed.

Two recently produced monoclonal antibodies were used to develop an antigen capture enzyme-linked immunosorbent assay (ELISA) for rapid diagnosis of Penicillium marneffei. The method was evaluated with 53 patients with culture-confirmed penicilliosis and 240 controls. The diagnostic sensitivity, specificity, and accuracy of the ELISA were 92.45, 97.5, and 96.59%, respectively.