Lymphocyte transformation test and cytokine detection assays: Determination of read out parameters for delayed-type drug hypersensitivity reactions

Lymphocyte transformation tests predict delayed-type allergy to piperacillin/tazobactam in patients with cystic fibrosis

BACKGROUND

Antibiotic treatment is crucial for patients with chronic bacterial infections. Suspected drug allergies often lead to inconsistent therapies and challenging clinical management for patients and caregivers. The objective of this study was to evaluate the value of lymphocyte transformation tests in comparison to skin tests for the prediction of delayed-type allergic reactions.

METHODS

This prospective, observational study tested the diagnostic value of skin prick tests, intradermal tests (reading: 15 min and 72 h) and lymphocyte transformations tests for the prediction of allergic reactions in CF patients with physician reported allergy to piperacillin/tazobactam, meropenem and ceftazidime. The tests were performed directly before a 14d intravenous drug challenge.

RESULTS

We performed 33 drug challenges in 29 subjects. 21 drug challenges were negative (63 %); 12 lead to a reaction (37 %), of those 2 were immediate and 10 were delayed-type. 100 % of the skin prick tests were negative. 97 % (33/34) of the intradermal tests with early reading and 100 % of the intradermal tests with late reading yielded negative results. 5/11 patients who experienced a delayed-type reaction during the drug challenge had a positive lymphocyte transformations test. All 17 patients who did not react had a negative lymphocyte transformations test. For piperacillin/tazobactam, 4/5 patients who experienced a delayed-type reaction during the drug challenge had positive lymphocyte transformations tests. Hence, for piperacillin/tazobactam, the sensitivity of the lymphocyte transformation test for prediction of reactions was 80.0 % and the specificity 100 %.

CONCLUSION

We demonstrate that the lymphocyte transformation test predicts delayed-type allergy to piperacillin/tazobactam in contrast to skin tests.

Diagnosis and selection of alternative antibiotics in beta-lactams hypersensitivity reactions: Current recommendations and challenges

Beta-lactam (BLM) antibiotics, including amino-penicillin and cephalosporins, are typically the first-choice treatment for bacterial infections. However, adverse reactions to these antibiotics are frequently reported, causing non-allergist physicians to select alternative broad-spectrum antibiotics that can have harmful consequences. Patients with unclear histories of hypersensitivity reactions to BLMs should undergo an allergy workup to establish a firm diagnosis, particularly when different drugs are prescribed simultaneously. However, finding the safest, most precise, and cost-effective methods for confirming BLMs hypersensitivity and selecting the most appropriate alternative BLM is uncertain, particularly in severe delayed reactions. This review aims to provide data and recommendations on the availability and validity of skin tests (STs), drug provocation test (DPT) protocols, based on the latest published literature and guideline. To make the process more practical, we focused on cross-reactivity between BLMs and diagnostic tests. There are two main novel aspects of this document: 1) For T-cell-mediated reactions, patient stratification into high, moderate, and low-risk groups based on the mortality and morbidity of adverse drug reactions. 2) For IgE-mediated reactions, stratification of individuals with isolated limited urticarial without anaphylaxis in a low-risk group and removal of the extensive limitation.

Tools for Etiologic Diagnosis of Drug-Induced Allergic Conditions

Drug hypersensitivity reactions are a serious concern in clinical practice because they can be severe and result in lifelong sequelae. An accurate diagnosis and identification of the culprit drug is essential to prevent future reactions as well as for the identification of safe treatment alternatives. Nonetheless, the diagnosis can be challenging. In vivo and in vitro tests can be helpful, although none are conclusive; therefore, the tests are not usually performed in isolation but as part of a diagnostic algorithm. In addition, some in vitro tests are only available in research laboratories, and standardization has not been fully accomplished. Collaborating research is needed to improve drug hypersensitivity reaction diagnosis. In this review, we update the current available in vivo and in vitro tools with their pros and cons and propose an algorithm to integrate them into clinical practice.

IFN-γ secretion of PBMC from non-drug-allergic control persons: Considerations for the validity of a positive lymphocyte transformation test

BACKGROUND

The lymphocyte transformation test (LTT) is used for the in vitro detection of a drug sensitization in assumed drug allergic patients. It is based on the detection of antigen (drug)-specific activation of T cells indicated by e.g. proliferation or cytokine secretion. However, occasional stimulatory effects of the drug unrelated to specific drug-allergic mechanisms can only be detected if a larger number of non-drug allergic control persons are tested with this specific drug. In this respect, the overall specificity of the LTT with ELISA read-out is summarized in several review articles, but the impact of a specific drug on the specificity has not yet been analyzed in a larger set of control persons.

OBJECTIVE

Do amoxicillin, cefuroxime and clindamycin induce an interferon (IFN)-y or interleukin (IL)-5 secretion of PBMC from control persons using the LTT with ELISA read-out?

METHODS

We performed LTTs with amoxicillin, cefuroxime and clindamycin and determined drug-specific IFN-γ and IL-5 secretion measured by ELISA read-out. We included PBMC from 60 non-drug allergic control persons, who were unexposed to the tested drug at the time of blood donation.

RESULTS

PBMC from 12 out of 23 control persons tested with amoxicillin gave a positive stimulation index (SI > 3.0) for IFN-γ resulting in a specificity of 47.8%. The corresponding specificity was 75% for cefuroxime (5/20 if SI > 3.0) and 58.8% for clindamycin (7/17, if SI > 2.0), respectively. In a next step, we calculated the Δ IFN-γ concentration by subtracting the background IFN-γ concentration in the unstimulated sample from the stimulated sample. After stimulation with amoxicillin, a mean concentration of 21.0 pg/mL IFN-γ was secreted. The less outlier prone median concentration was 7.4 pg/mL and much higher than for cefuroxime (1.7 pg/mL) and clindamycin (1.0 pg/mL). Remarkably, IL-5 concentrations were below the detection limit (< 1 pg/mL) for all drugs in all control persons who responded to TT.

CONCLUSION

Consideration of these observations may be helpful since a positive LTT result in a control patient may challenge the validity of a positive LTT result in the same experiment for a patient with assumed drug allergy.

Value of the Lymphocyte Transformation Test for the Diagnosis of Drug-Induced Hypersensitivity Reactions in Hospitalized Patients with Severe COVID-19

In the first wave of COVID-19, up to 20% of patients had skin lesions with variable characteristics. There is no clear evidence of the involvement of the SARS-CoV-2 virus in all cases; some of these lesions may be secondary to drug hypersensitivity. To analyze the possible cause of the skin lesions, we performed a complete allergology study on 11 patients. One year after recovery from COVID-19, we performed a lymphocyte transformation test (LTT) and Th1/Th2 cytokine secretion assays for PBMCs. We included five nonallergic patients treated with the same drugs without lesions. Except for one patient who had an immediate reaction to azithromycin, all patients had a positive LTT result for at least one of the drugs tested (azithromycin, clavulanic acid, hydroxychloroquine, lopinavir, and ritonavir). None of the nonallergic patients had a positive LTT result. We found mixed Th1/Th2 cytokine secretion (IL-4, IL-5, IL-13, and IFN-γ) in patients with skin lesions corresponding to mixed drug hypersensitivity type IVa and IVb. In all cases, we identified a candidate drug as the culprit for skin lesions during SARS-CoV-2 infection, although only three patients had a positive drug challenge. Therefore, it would be reasonable to recommend avoiding the drug in question in all cases.

A quarter of a century fundamental and translational research in perioperative hypersensitivity and anaphylaxis at the Antwerp university hospital, a Belgian Centre of Excellence of the World Allergy Organization

Perioperative hypersensitivity constitutes an important health issue, with potential dramatic consequences of diagnostic mistakes. However, safe and correct diagnosis is not always straightforward, mainly because of the application of incorrect nomenclature, absence of easy accessible in-vitro/ex-vivo tests and uncertainties associated with the non-irritating skin test concentrations. In this editorial we summarize the time line, seminal findings, and major realizations of 25 years of research on the mechanisms, diagnosis, and management of perioperative hypersensitivity.

Estimating Culprit Drugs for Adverse Drug Reactions Based on Bayesian Inference

The utility of big data in spontaneous adverse drug reactions (ADRs) reporting systems has improved the pharmacovigilance process. However, identifying culprit drugs in ADRs remains challenging, although it is one of the foremost steps to managing ADRs. Aiming to estimate the likelihood of prescribed drugs being culprit drugs for given ADRs, we devised a Bayesian estimation model based on the Japanese Adverse Drug Events Reports database. After developing the model, a validation study was conducted with 67 ADR reports with a gross of 1,387 drugs (67 culprit drugs and 1,320 concomitant drugs) prescribed and recorded at Yamaguchi University Hospital. As a result, the model estimated a culprit drug of ADRs with acceptable accuracy (area under the receiver operating characteristic curve 0.93 (95% confidence interval 0.88-0.97)). The estimation results provided by the model to healthcare practitioners can be used as one clue to determine the culprit drugs for various ADRs, which will improve the management of ADRs by shortening the treatment turnaround time and increasing the precision of diagnosis, leading to minimizing the adverse effects on patients.

Hypersensitivity reactions to small molecule drugs

Drug hypersensitivity reactions induced by small molecule drugs encompass a broad spectrum of adverse drug reactions with heterogeneous clinical presentations and mechanisms. These reactions are classified into allergic drug hypersensitivity reactions and non-allergic drug hypersensitivity reactions. At present, the hapten theory, pharmacological interaction with immune receptors (p-i) concept, altered peptide repertoire model, and altered T-cell receptor (TCR) repertoire model have been proposed to explain how small molecule drugs or their metabolites induce allergic drug hypersensitivity reactions. Meanwhile, direct activation of mast cells, provoking the complement system, stimulating or inhibiting inflammatory reaction-related enzymes, accumulating bradykinin, and/or triggering vascular hyperpermeability are considered as the main factors causing non-allergic drug hypersensitivity reactions. To date, many investigations have been performed to explore the underlying mechanisms involved in drug hypersensitivity reactions and to search for predictive and preventive methods in both clinical and non-clinical trials. However, validated methods for predicting and diagnosing hypersensitivity reactions to small molecule drugs and deeper insight into the relevant underlying mechanisms are still limited.

Tools to improve the diagnosis and management of T-cell mediated adverse drug reactions

Delayed drug T-cell immune-mediated hypersensitivity reactions have a large clinical heterogeneity varying from mild maculopapular exanthema (MPE) to severe cutaneous adverse reactions (SCARs) such as acute generalized exanthematous pustulosis (AGEP), drug reaction with eosinophilia and systemic symptoms (DRESS) and severe skin necrosis and blistering as seen in Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). Given the knowledge gaps related to the immunopathogenesis of these conditions, the absence of validated diagnostic tools and the significant associated morbidity and mortality, patients with SCARs often have limited drug choices. We performed a comprehensive review aiming to evaluate in vivo diagnostic tools such as delayed intradermal skin and patch testing and ex vivo/in vitro research assays such as the lymphocyte transformation test (LTT) and the enzyme-linked ImmunoSpot (ELISpot) assay. We searched through PubMed using the terms “drug allergy,” “in vivo” and “ex vivo” for original papers in the last 10 years. A detailed meticulous approach adapted to the various clinical phenotypes is recommended for the diagnostic and management of delayed drug hypersensitivity reactions. This review highlights the current diagnostic tools for the delayed drug hypersensitivity phenotypes.

Lymphocyte Transformation Test for drug allergy detection: when does it work?

BACKGROUND

The lymphocyte transformation test (LTT) is an in vitro test system for the detection of a sensitization in the context of allergies to drugs. Its reported sensitivity varies largely and seems to be affected by different parameters. In review articles, the average LTT performance was often calculated by combining overall mean sensitivities of various published studies, but without considering different patient characteristics or varying patient numbers per publication.

OBJECTIVE

This meta-analysis aims to investigate the impact of different patient-specific and methodical parameters on the sensitivity of the LTT based on data on the level of the individual patient extracted from single studies.

METHODS

We performed an advanced literature search in Pubmed and screened the identified publications according to previously defined inclusion criteria. In total, individual patient data from 721 patients were extracted from 30 studies. Random-effects meta-regression analyses were performed.

RESULTS

The analysis indicate that the ELISA-based read-out is more sensitive compared to the classical radioactivity method (ELISA: 80% vs. radioactivity: 66%;p=0.084). Interestingly, DRESS/DHISS is associated with a higher probability of a positive LTT test result compared to other investigated clinical phenotypes ("DRESS/DHISS" vs. "bullous reaction"; OR: 2.52;p-value=0.003). Our analysis also revealed an impact of the time to testing period after the occurrence of the allergic event ("<2 weeks" vs. "2 weeks-2 months"; OR: 2.12;p-value=0.034).

CONCLUSION

The read-out method and relevant clinical parameters affect the sensitivity of the LTT. These findings are based on a meta-analysis providing a higher level of evidence than a single study or previous reviews not considering individual patient data.

Diagnostic potential and future directions of matrix metalloproteinases as biomarkers in gingival crevicular fluid of oral and systemic diseases

Gingival crevicular fluid (GCF) is a physiological fluid and an inflammatory serum exudate derived from the gingival plexus of blood vessels and mixed with host tissues and subgingival plaque flows. In addition to proteins, GCF contains a diverse population of cells, including desquamated epithelial cells, cytokines, electrolytes, and bacteria from adjacent plaques. Recently, matrix metalloproteinases(MMPs), which are endopeptidases that are active against extracellular macromolecules, in GCF have been revealed as potential utility biomarkers for the diagnosis and follow-up of oral and systemic diseases, thereby facilitating the early evaluation of malignancy risk and the monitoring of disease progression and treatment response. Tissue inhibitors of metalloproteinases (TIMPs) are specific inhibitors of matrixins that participate in the regulation of local activities of MMPs in tissues. This review provides an overview of the latest findings on the diagnostic and prognostic values of MMPs and TIMPs in GCF of oral and systemic diseases, including periodontal disease, pulpitis, peri-implantitis and cardiovascular disease as well as the extraction, detection and analytical methods for GCF.