Recent advances in the diagnosis of drug allergy:

Evaluation of Adverse Reactions to Vaccines

The development and widespread use of vaccination over the past centuries has been the single most impactful intervention in public health, by effectively preventing morbidity and mortality from infectious diseases. Vaccination is generally well tolerated in the vast majority of the population, and the benefits of vaccination largely outweigh the risk of severe adverse events in the majority of patients. Vaccine hesitancy can be a significant concern and lead to infectious disease outbreaks. All health care providers play an important role in maintaining public confidence in vaccines because their attitude and knowledge is often critical in facilitating acceptance of a vaccine. The purpose of this review is to first, provide an understanding of the basic concepts that are relevant to vaccine pharmacovigilance, and secondly, to provide an overview and discuss management of both immune and nonimmune adverse events after vaccination.

Do Battlefield Injury-acquired Indwelling Metal Fragments Induce Metal Immunogenicity?

BACKGROUND

A battlefield-related injury results in increased local and systemic innate immune inflammatory responses, resulting in wound-specific complications and an increased incidence of osteoarthritis. However, little is known about whether severe injuries affect long-term systemic homeostasis, for example, immune function. Moreover, it also remains unknown whether battlefield-acquired metal fragments retained over the long term result in residual systemic effects such as altered immune reactivity to metals.

QUESTIONS/PURPOSES

Does a retained metal fragment from a battlefield injury contribute to increased (1) adaptive metal-specific immune responses, (2) systemically elevated metal ion serum levels, and (3) serum immunoglobulin levels compared with combat injuries that did not result in a retained metal fragment?

METHODS

In this pilot study, we analyzed metal-immunogenicity in injured military personnel and noninjured control participants using lymphocyte transformation testing (LTT, lymphocyte proliferation responses to cobalt, chromium and nickel challenge at 0.001, 0.01 and 0.1-mM concentrations in triplicate for each participant), serum metal ion analysis (ICP-mass spectroscopy), and serum immunoglobulin analysis (IgE, IgG, IgA, and IgM ). Military personnel with a battlefield-sustained injury self-recruited without any exclusion for sex, age, degree of injury. Those with battlefield injury resulting in retained metal fragments (INJ-FRAG, n = 20 male, mean time since injury ± SD was 12 ± 10 years) were compared with those with a battlefield injury but without retained metal fragments (INJ-NO-FRAG, n = 12 male, mean time since injury ± SD was 13 ± 12 years). A control group comprised of male noninjured participants was used to compare measured immunogenicity metrics (n = 11, males were selected to match battlefield injury group demographics).

RESULTS

Military participants with sustained metal fragments had increased levels of metal-induced lymphocyte responses. The lymphocyte stimulation index among military participants with metal fragments was higher than in those with nonretained metal fragments (stimulation index = 4.2 ± 6.0 versus stimulation index = 2.1 ± 1.2 (mean difference 2.1 ± 1.4 [95% confidence interval 5.1 to 0.8]; p = 0.07) and an average stimulation index = 2 ± 1 in noninjured controls. Four of 20 participants injured with retained fragments had a lymphocyte proliferation index greater than 2 to cobalt compared with 0 in the group without a retained metal fragment or 0 in the control participants. However, with the numbers available, military personnel with retained metal fragments did not have higher serum metal ion levels than military participants without retained metal fragment-related injuries or control participants. Military personnel with retained metal fragments had lower serum immunoglobulin levels (IgG, IgA, and IgM) than military personnel without retained metal fragments and noninjured controls, except for IgE. Individuals who were metal-reactive positive (that is, a stimulation index > 2) with retained metal fragments had higher median IgE serum levels than participants who metal-reactive with nonmetal injuries (1198 ± 383 IU/mL versus 171 ± 67 IU/mL, mean difference 1027 ± 477 IU/mL [95% CI 2029 to 25]; p = 0.02).

CONCLUSIONS

We found that males with retained metal fragments after a battlefield-related injury had altered adaptive immune responses compared with battlefield-injured military personnel without indwelling metal fragments. Military participants with a retained metal fragment had an increased proportion of group members and increased average lymphocyte reactivity to common implant metals such as nickel and cobalt. Further studies are needed to determine a causal association between exposure to amounts of retained metal fragments, type of injury, personnel demographics and general immune function/reactivity that may affect personal health or future metal implant performance.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Implementation of a penicillin allergy skin test

The penicillin allergy skin testing is the only accurate and reliable test for penicillin hypersensitivity mediated by IgE. It is useful for identifying patients with doubtful history of allergy. Positive test for major and minor determinants presents a positive predictive value of 50% and negative predictive value of 99%. In Brazil, the Ministry of Health suggests a protocol for in house made reagents, since they are not commercially available. As the referred protocol does not mention some important details about the test procedures, we propose in the present work to implement them, critically evaluating each step in order to allow the protocol establishment at any health service, with quality and safety.

[Diagnostic methods for confirming drug-allergy--the lymphocyte transformation test in dermatology]

Recognizing the adverse drug reactions and confirming the role of the drug causing the symptoms is a great challenge for a medical team. The aim of this article is to review the diagnostic methods for confirming drug-allergy and to evaluate the lymphocyte transformation test according to dermatological aspect. Lymphocyte transformation test relies on the observation that specific T-cells divide and expand after encountering the antigen. T-cell sensitization is measured by 3H-thymidine uptake in dividing cells. The main advantage of this test is its applicability with many different drugs in different immune reactions, as drug-specific T-cells are almost always involved in drug hypersensitivity reactions. Its disadvantage is that the test is cumbersome and technically demanding. The method is not unequivocally accepted, it is necessary to carry out a systematic evaluation of its sensitivity and specificity to make the test more widely appreciated. Despite of its deficits, the lymphocyte transformation test plays an important role in diagnosing drug-hypersensitivities.

Th1 type lymphocyte reactivity to metals in patients with total hip arthroplasty

BACKGROUND

All prostheses with metallic components release metal debris that can potentially activate the immune system. However, implant-related metal hyper-reactivity has not been well characterized. In this study, we hypothesized that adaptive immunity reaction(s), particularly T-helper type 1 (Th1) responses, will be dominant in any metal-reactivity responses of patients with total joint replacements (TJAs). We tested this hypothesis by evaluating lymphocyte reactivity to metal "ions" in subjects with and without total hip replacements, using proliferation assays and cytokine analysis.

METHODS

Lymphocytes from young healthy individuals without an implant or a history of metal allergy (Group 1: n = 8) were used to assess lymphocyte responses to metal challenge agents. In addition, individuals (Group 2: n = 15) with well functioning total hip arthroplasties (average Harris Hip Score = 91, average time in-situ 158 months) were studied. Age matched controls with no implants were also used for comparison (Group 3, n = 8, 4 male, 4 female average age 70, range 49-80). Group 1 subjects' lymphocyte proliferation response to Aluminum+3, Cobalt+2, Chromium+3, Copper+2, Iron+3, Molybdenum+5, Manganeese+2, Nickel+2, Vanadium+3 and Sodium+2 chloride solutions at a variety of concentrations (0.0, 0.05, 0.1, 0.5, 1.0 and 10.0 mM) was studied to establish toxicity thresholds. Mononuclear cells from Group 2 and 3 subjects were challenged with 0.1 mM CrCl3, 0.1 mM NiCl2, 0.1 mM CoCl2 and approx. 0.001 mM titanium and the reactions measured with proliferation assays and cytokine analysis to determine T-cell subtype prominence.

RESULTS

Primary lymphocytes from patients with well functioning total hip replacements demonstrated a higher incidence and greater magnitude of reactivity to chromium than young healthy controls (p < 0.03). Of the 15 metal ion-challenged subjects with well functioning total hip arthroplasties, 7 demonstrated a proliferative response to Chromium, Nickel, Cobalt and/or Titanium (as defined by a statistically significant >2 fold stimulation index response, p < 0.05) and were designated as metal-reactive. Metals such as Cobalt, Copper, Manganese, and Vanadium were toxic at concentrations as low as 0.5 mM while other metals, such as Aluminum, Chromium, Iron, Molybdenum, and Nickel, became toxic at much higher concentrations (>10 mM). The differential secretion of signature T-cell subsets' cytokines (Th1 and Th2 lymphocytes releasing IFN-gamma and IL-4, respectively) between those total hip arthroplasty subjects which demonstrated metal-reactivity and those that did not, indicated a Th1 type (IFN-gamma) pro-inflammatory response.

CONCLUSION

Elevated proliferation and production of IFN-gamma to metals in hip arthroplasty subjects' lymphocytes indicates that a Th1 (vs. Th2) type response is likely associated with any metal induced reactivity. The involvement of an elevated and specific lymphocyte response suggests an adaptive (macrophage recruiting) immunity response to metallic implant debris rather than an innate (nonspecific) immune response.

Drug allergy claims in children: from self-reporting to confirmed diagnosis

BACKGROUND

Poorly documented self-reported drug allergy (DAll) is a frequent problem in daily clinical practice and has a considerable impact on prescription choices. The diagnostic work-up of drug hypersensitivity (DHs) allows a better classification of the reactions and provides patients with more reliable information and recommendations for future treatments.

OBJECTIVE

To assess the prevalence of self-reported adverse drug reactions (ADRs) and DAll in a paediatric population and to investigate children reporting suspected DAll in order to achieve a firm diagnosis.

DESIGN

The first phase was based on a cross-sectional survey assessing the life occurrence of ADRs and self-reported DAll carried out at the outpatient clinic of a paediatric hospital. The second phase was based on the diagnostic work-up in children with parent-reported DAll, including detailed anamnesis and in vitro and in vivo investigations (skin and provocation tests). Participants One thousand four hundred and twenty-six parents responded to the initial survey. Sixty of the 67 patients with reported DAll were evaluated at the allergy clinic.

RESULTS

The prevalences of self-reported ADRs and DAll were 10.2% and 6.0%, respectively. Most of the suspected allergic reactions were non-immediate cutaneous events attributable to beta-lactam antibiotics and occurred in very young children. Thirty-nine of the 60 patients consulting for evaluation had a plausible clinical history and were recommended further investigation. DHs was diagnosed in three children only, based on positive responses in skin (n=1) and oral provocation (n=2) tests.

CONCLUSION

ADRs are frequently reported in children, and many children are classified as having a DAll. After complete evaluation, only a few of these reactions can be attributed to DHs and DAll. Most of the patients (94% in this study) could actually tolerate the initially suspected drug.

Detection of autoimmunity by pharmaceuticals

Despite the important health and economic impact of autoimmunogenicity or allergenicity by pharmaceuticals models to detect such adverse effects are not available yet. The most important reason for this is the related complex interplay of multiple factors, for which reason these adverse effects are also referred to as idiosyncratic in nature. Moreover, clinical effects are quite diverse, and involve both organ-specific and systemic effects, including a diversity of skin diseases. Because of its complexity on the one hand and the fundamental knowledge on certain particular mechanistic effects it may be more relevant to design a rationalistic toolbox of test models from which a predictive strategy can be composed. Since one mechanistic aspect centers around T cell sensitization a straightforward lymph node assay such as the reporter antigen-popliteal lymph node assay (RA-PLNA) would fit in such a toolbox. This RA-PLNA holds a strong promise to distinguish sensitizing and/or neoantigen-forming capacity of low molecular weight pharmaceuticals. In addition, from the pharmacokinetic point of view a rationalistic toolbox should also contain oral exposure models with immunological read out parameters in normal or in genetically predisposed animal strains. This review focuses on these two categories of candidate test methods, PLNA and oral exposure models, and proposes to use these in tandem in order to predict the hazard of induction of allergy or autoimmune phenomena by new pharmaceutical candidates.

Comparison of pharmacovigilance algorithms in drug hypersensitivity reactions

BACKGROUND

A firm diagnosis of drug hypersensitivity, because it may re-induce the reaction, is seldom confirmed. Causality assessment algorithms are therefore of interest.

AIMS

The objective of this work was to compare three algorithms in the diagnosis of drug hypersensitivity.

METHODS

Evaluation of 120 clinical histories of drug hypersensitivity was carried out: 60 involving beta-lactams (50%) and 60 involving non-steroidal anti-inflammatory drugs (50%). Each of these groups of patients underwent a standardised allergy diagnosis, which included a detailed anamnesis, skin tests and, often, provocation tests under strict hospital surveillance. Unaware of the final allergy diagnosis, scores were established for all of the cases and compared using algorithms suggested by Begaud and coworkers [2, 20], Jones [13] and Naranjo et al. [21].

RESULTS

Although the methods of Jones [13] and Naranjo et al. [21] were perfectly concordant (k=1), no concordance was noted using the Begaud and coworkers [2, 20] method.

CONCLUSIONS

All three algorithms are dissimilar regarding the diagnosis of drug hypersensitivity.

Update on beta-lactam allergy diagnosis

Allergic reactions to penicillin and cephalosporin antibiotics are common. The mechanisms involved are heterogeneous and not yet completely understood. However, clinical and immunologic studies suggest that type I (IgE-mediated) and type IV (cell-mediated) pathogenic mechanisms are involved in most immediate and non-immediate reactions, respectively. The diagnostic procedure has recently been standardized under the aegis of the European Network for Drug Allergy and the European Academy of Allergy and Clinical Immunology interest group on drug hypersensitivity. In this review, we describe the general guidelines for evaluating subjects in whom there is suspicion of allergic reactions to beta-lactams.

Lymphocyte responses in patients with total hip arthroplasty

How lymphocyte-mediated metal sensitivity affects orthopaedic implant performance remains poorly understood. Do patients with implants exhibit elevated lymphocyte reactivity to metals and is this reactivity more generalized or more implant-alloy specific? We investigated these questions by measuring lymphocyte responses to implant metals (Cr(+3), Co(+2), Ni(+2) at 0.1mM, and Ti(+4) at 0.001 mM) in six subject groups: Group 1a=young controls, Group 1b=age matched controls, Group 2a=subjects with osteoarthritis (OA) and no history of metal sensitivity, Group 2b=OA subjects with history of metal sensitivity, Group 3a=total hip arthroplasty (THA) subjects with no to mild radiographic osteolysis, and Group 3b=THA subjects with moderate osteolysis. Lymphocyte proliferation, using Lymphocyte Transformation Testing (LTT), and cytokine release provided quantitative reactivity measurement, where a stimulation index of >2 indicated metal sensitivity. OA subjects with a history of metal sensitivity (Group 2b) were more metal reactive to Ni than any other group, as expected (66% incidence and Stimulation Index >20). However, THA subjects (Groups 3a and b) were >3 fold more reactive to Cr (p<0.04), than were controls (Groups 1a & b) or OA subjects (Groups 2a & b). THA subjects with moderate vs mild osteolysis (Group 3b vs 3a) were more reactive to Co (43% vs 0% incidence). Only osteolytic THA subjects demonstrated increased cytokine responses with >two-fold (p<0.05) increases in soluble interferon-gamma (IFN-gamma) and interleukin-2 (IL-2) levels in response to Cr challenge. This elevated incidence and averaged level of lymphocyte reactivity supports a metal-specific adaptive immune response and suggests involvement in the pathogenesis of poor implant performance, e.g. aseptic osteolysis.

Drug-induced eosinophilic lung disease

For most patients who have suspected drug-induced eosinophilic lung disease, the history provides a presumptive diagnosis that can be confirmed by pulmonary findings and eosinophilia after cessation of the drug. As new drugs are developed and released for clinical use, many will result in eosinophilic lung disease in susceptible patients. Therefore, development of pulmonary abnormalities in conjunction with blood or lung eosinophilia after prescription ofa newly released medication should raise the possibility of drug-induced lung disease, even if that medication has not yet been reported to cause eosinophilic lung disease. In all patients, the diagnosis requires exclusion of other causes of eosinophilic lung disease by history, and, if necessary, laboratory testing or lung biopsy.

Antibiotic desensitization for the allergic patient: 5 years of experience and practice

BACKGROUND

Antibiotic desensitization is an option for patients with suspected IgE-mediated antibiotic allergy when no other alternative exists for treating life-threatening bacterial infections. However, there are limited data describing the outcomes of this procedure with newer, commonly used antibiotics.

OBJECTIVE

To evaluate the safety and utility of antibiotic desensitization.

METHODS

We retrospectively reviewed the medical records of all patients undergoing antibiotic desensitization in our institution between November 1996 and November 2001.

RESULTS

There were a total of 57 desensitizations performed in 21 patients. The mean age of the patients was 22.8 years (range, 1.9-44.5 years) and 15 (71%) were female. Nineteen (90%) of the 21 patients had been diagnosed as having cystic fibrosis. In 33 (100%) of 33 desensitizations to unique antibiotics that occurred during the study period, the indication for desensitization was a history suggestive of an IgE-mediated reaction to the antibiotic and/or a positive skin test result to the antibiotic or a known cross-reactive antibiotic. Desensitizations were performed to 12 different antibiotics. Successful outcomes were achieved in 43 desensitizations (75%). Of the 11 cases (19%) that were terminated due to an allergic reaction, there were no fatalities, intubations, or other aggressive interventions besides the use of epinephrine, antihistamines, and corticosteroids. In 7 of 11 unsuccessful desensitizations, a non-IgE mechanism appeared to be responsible for the allergic reaction.

CONCLUSIONS

Antibiotic desensitization is a useful option when treating patients with life-threatening infections who must receive antibiotics to which they have an IgE-mediated allergy. These data indicate that in most cases, patients with presumed IgE-mediated antibiotic allergy may safely receive antibiotics after desensitization.