Flow-based basophil activation test in immediate drug hypersensitivity. An EAACI task force position paper.

Diagnosing immediate drug hypersensitivity reactions (IDHRs) can pose a significant challenge and there is an urgent need for safe and reliable tests. Evidence has emerged that the basophil activation test (BAT), an in vitro assay that mirrors the in vivo response, can be a complementary test for many drugs. In this position paper, members of Task Force (TF) "Basophil activation test in the evaluation of Drug Hypersensitivity Reactions" from the European Academy of Allergy and Clinical Immunology (EAACI) present the data from a survey about the use and utility of BAT in IDHRs in Europe. The survey results indicate that there is a great interest for using BAT especially for diagnosing IDHRs. However, there are still main needs, mainly in the standardization of the protocols. Subsequently consensus-based recommendations were formulated for: (i) Technical aspects of BAT in IDHRs including type of sample, management of drugs, flow cytometry protocols, interpretation of the results; and (ii) Drug-specific aspects that should be taken into account when performing BAT in relation to betalactams, neuromuscular blocking agents, fluoroquinolones, chlorhexidine, opioids, radio contrast media, chemotherapeutics, biological agents, nonsteroidal anti-inflammatory drugs, COVID vaccine, and excipients. Moreover, aspects in the evaluation of pediatric population have also been considered. All this indicates that BAT offers the clinician and laboratory a complementary tool for a safe diagnostic for IDHRs, although its place in the diagnostic algorithm depends on the drug class and patient population (phenotype, geography, and age). The standardization of BAT is important for generalizing this method beyond the individual laboratory.

[Diagnostics of alpha-gal syndrome : Current standards, pitfalls and perspectives]. / Diagnostik des α­Gal-Syndroms : Aktuelle Standards, Fallstricke und Perspektiven.

α-Gal syndrome results from sensitization to the carbohydrate epitope galactose-α-1,3-galactose (α­gal). The allergen occurs in mammalian meat and innards, but also in other foods and medical products of animal origin. Allergic reactions generally occur delayed after allergen intake with a latency period, depending on the individual tolerance threshold and the influence of cofactors. Details in the patient's medical history can help to establish the suspected diagnosis of α­gal syndrome. Confirmation of the diagnosis requires the expertise of specialists, experienced with the implementation and interpretation of in vitro and in vivo diagnostic tests. Whereas skin prick testing with commercial whole-meat extracts often does not provide reliable results, allergen-specific IgE (α-gal) is generally detectable in affected patients. Cell-based tests such as the basophil activation test are currently only employed in an experimental setting. To evaluate, whether a sensitization is clinically relevant, an in-patient oral food challenge should be performed, using for example cooked pork or porcine kidney in addition to suspected cofactors.

Alpha-gal is a possible target of IgE-mediated reactivity to antivenom.

BACKGROUND: Antivenoms are mammalian immunoglobulins with the ability to neutralize snake venom components and to mitigate the progression of toxic effects. Immediate hypersensitivity to antivenoms often occurs during the first administration of these heterologous antibodies. A comparable clinical situation occurred after introduction of cetuximab, a chimeric mouse-human antibody, for cancer treatment. The carbohydrate epitope galactose-alpha-1,3-galactose, located on the Fab region of cetuximab, was identified as the target responsible for IgE reactivity. OBJECTIVE: To investigate whether serum IgE antibodies directed to the α-gal epitope are associated with hypersensitivity to equine antivenoms. METHODS: Antivenoms were screened for α-gal epitopes via immunoblot and in comparison with cetuximab and pork kidney by IgE reactivity assays. Basophil activation tests were used to investigate reactivity to antivenoms in samples from 20 patients with specific IgE antibodies to α-gal and 10 controls. Additional IgE detection, IgE inhibition, ImmunoCAP inhibition, and skin prick tests were performed using samples from selected patients. RESULTS: Both antivenoms and cetuximab induced positive skin prick test results in patients with sIgE to α-gal. Alpha-gal epitopes were detected by immunoblotting on antivenoms. Measurements of IgE reactivity and ImmunoCAP inhibition indicated that the antivenoms contained lower α-gal contents than cetuximab. Deglycosylation assays and IgE inhibition tests confirmed that IgE-mediated reactivity to antivenom is associated with α-gal. Antivenoms, pork kidney, and cetuximab activated basophils from patients with IgE to α-gal. CONCLUSION: Alpha-gal is a potential target of IgE-mediated reactivity to equine antivenom and a possible cause of the high incidence of hypersensitivity reactions during the first application of equine antivenom.

Application of recombinant antigen 5 allergens from seven allergy-relevant Hymenoptera species in diagnostics.

BACKGROUND: Hymenoptera stings can cause severe anaphylaxis in untreated venom-allergic patients. A correct diagnosis regarding the relevant species for immunotherapy is often hampered by clinically irrelevant cross-reactivity. In vespid venom allergy, cross-reactivity between venoms of different species can be a diagnostic challenge. To address immunological IgE cross-reactivity on molecular level, seven recombinant antigens 5 of the most important Vespoidea groups were assessed by different diagnostic setups. METHODS: The antigens 5 of yellow jackets, hornets, European and American paper wasps, fire ants, white-faced hornets, and Polybia wasps were recombinantly produced in insect cells, immunologically and structurally characterized, and their sIgE reactivity assessed by ImmunoCAP, ELISA, cross-inhibition, and basophil activation test (BAT) in patients with yellow jacket or Polistes venom allergy of two European geographical areas. RESULTS: All recombinant allergens were correctly folded and structural models and patient reactivity profiles suggested the presence of conserved and unique B-cell epitopes. All antigens 5 showed extensive cross-reactivity in sIgE analyses, inhibition assays, and BAT. This cross-reactivity was more pronounced in ImmunoCAP measurements with venom extracts than in sIgE analyses with recombinant antigens 5. Dose-response curves with the allergens in BAT allowed a differentiated individual dissection of relevant sensitization. CONCLUSIONS: Due to extensive cross-reactivity in various diagnostic settings, antigens 5 are inappropriate markers for differential sIgE diagnostics in vespid venom allergy. However, the newly available antigens 5 from further vespid species and the combination of recombinant allergen-based sIgE measurements with BAT represents a practicable way to diagnose clinically relevant sensitization in vespid venom allergy.

[Teledermoscopy by mobile phones : Reliable help in the diagnosis of skin lesions?] / Teledermatoskopie mittels Smartphone : Zuverlässige Hilfe bei der Diagnostik von Hautläsionen?

BACKGROUND: Teledermoscopy is a promising modern technique to complement or to substitute dermatologic examination. OBJECTIVE: In this pilot study, we compared the outcomes of teledermoscopic consultations with clinical examinations and histologic results. METHODS: Conventional and dermatoscopic photos of single lesions were taken in 26 patients using a mobile phone and an attached handyscope optical system. Five resident physicians performed a clinical examination including dermoscopy while the teledermatologic and teledermoscopic photos were assessed by an experienced dermatologist. Examination results were compared regarding diagnosis, differential diagnoses, recommended further management, as well as subjective and objective accuracy of diagnosis. In addition, 23% of the lesions were excised and histologically examined. RESULTS: The most frequent diagnosis was "nevus cell nevus", followed by "subungual hematoma" and "basal cell carcinoma". The concordance of diagnoses was 92.3%; the concordance of recommended further management was 76.9%. Of the 6 histologically proven diagnoses, 66.7% were given the same diagnosis by teledermatoscopy and conventional clinical assessment. Concerning accuracy of diagnosis, teledermoscopy showed no disadvantage. CONCLUSIONS: Teledermatologic photos of single lesions combined with teledermatoscopic photos can be reliably and safely assessed. Especially when access to dermatologic examination is difficult, mobile teledermoscopy is a good and reliable alternative.

Two galactose-α-1,3-galactose carrying peptidases from pork kidney mediate anaphylactogenic responses in delayed meat allergy.

BACKGROUND: Serum IgE antibodies directed at galactose-α-1,3-galactose (α-Gal) are associated with a novel form of delayed anaphylaxis occurring upon consumption of red meat or innards. Pork kidney is known as the most potent trigger of this syndrome, but the culprit allergens have not yet been identified. The aim of this study was the identification and characterization of pork kidney proteins mediating delayed anaphylactic reactions through specific IgE to α-Gal. METHODS: A cohort of 59 patients with specific IgE to α-Gal was screened by immunoblot for IgE-reactive proteins in pork kidney. Proteins were identified by peptide mass fingerprinting. Isolated proteins were assayed in ELISA and ELISA inhibition, basophil activation and skin prick test. RESULTS: Several IgE-binding proteins of high molecular weight (100- >200 kDa) were detected in pork kidney extracts by immunoblot using patient sera and an anti-α-Gal antibody. Two major IgE-binding proteins were identified as porcine angiotensin-I-converting enzyme (ACE I) and aminopeptidase N (AP-N). Reactivity of patient sera and anti-α-Gal antibody to both proteins was abolished by carbohydrate oxidation. The α-Gal IgE epitopes were resistant to heat denaturation. Pork kidney extract, isolated ACE I, and AP-N were able to activate patient basophils and elicit positive responses in skin prick tests. CONCLUSION: Two cell-membrane proteins carrying α-Gal epitopes were identified in pork kidney. For the first time, isolated meat proteins were shown to induce basophil activation in patients with delayed anaphylaxis to red meat providing further confirmation for the clinical relevance of these α-Gal-carrying proteins.

To remember: Radiotherapy - a successful treatment for early Dupuytren's disease.

Dupuytren's disease (DD) is a common fibroproliferative condition of the hand which tends to cause progressive digital flexion contracture. Therapeutic strategies to treat the disease include radiotherapy, injections of collagenase clostridium histolyticum, needle fasciotomy and extended surgical intervention dependent on involvement and duration of the disease. We have reviewed the literature with the aim to assess the conditions and effects of radiotherapy in DD. In early stages of the disease, radiotherapy resulted in regression of symptoms/a lack of progression found on average in 40% (range 10-85%)/81% (range 50-100%) of the patients with recurrence rates of only 12-31% after long-term follow-up (>4 years). These results proved to be significantly better than in the untreated patients with natural course of the disease (about 50% progression after a follow-up of 5-6 years). Long-term side-effects (skin dryness) are observed on average in one quarter of the patients, but are well tolerated. Local occurrence of malignancies has not been reported yet. Due to severe functional impairment leading to individual suffering and the high economic burden, treatment of DD in early stages is necessary and radiation therapy represents an effective, safe and economic treatment option.

Newly acquired kiwi fruit allergy after bone marrow transplantation from a kiwi-allergic donor.

BACKGROUND: The phenomenon of allergy transfer from an allergic donor to a non-allergic recipient via hematopoietic cell transplantation has been described by several reports. However, it could not yet been conclusively shown that allergic reaction of the recipient is elicited by the donor's cells. OBJECTIVES: In the case of a 46-year-old male patient who - for the first time in his life - had two episodes of oral allergic syndrome upon kiwi consumption after having received myeloablative hematopoietic stem cell transplantation (HCT) from his kiwi-allergic sister, we aimed to clarify the origin of allergen reactive cells in the donor. We not only intended to demonstrate if allergy was transferred by HCT but also to present an experimental workup for the analysis of allergy transfer by HCT. METHODS: Allergic sensitization to kiwi in recipient and donor was proven by ImmunoCAP. Furthermore, origin of peripheral blood mononuclear cells (PBMCs) was analyzed by chromosomal fluorescence in situ hybridization (FISH). To confirm allergic reaction and activation of hematopoietic cells by customized kiwi extract, we performed basophil activation test from whole blood as well as T cell proliferation assays from purified PBMCs of both recipient and donor. RESULTS: Basophil activation upon kiwi extract was demonstrated in both recipient and donor. Besides, we showed proliferation of CD4(+) T cells after incubation with kiwi extract. FISH analysis proved that hematopoietic cells of the male recipient completely originated from the female donor. CONCLUSION: Exemplified in this patient, we show for the first time that allergy transfer is mediated by the donor's cells. Moreover, our experimental approach using customized kiwi extract to prove contribution of kiwi-specific T and B cells in both kiwi-allergic recipient and donor could serve as a model approach for future studies.

The clinical utility of basophil activation testing in diagnosis and monitoring of allergic disease.

The basophil activation test (BAT) has become a pervasive test for allergic response through the development of flow cytometry, discovery of activation markers such as CD63 and unique markers identifying basophil granulocytes. Basophil activation test measures basophil response to allergen cross-linking IgE on between 150 and 2000 basophil granulocytes in <0.1 ml fresh blood. Dichotomous activation is assessed as the fraction of reacting basophils. In addition to clinical history, skin prick test, and specific IgE determination, BAT can be a part of the diagnostic evaluation of patients with food-, insect venom-, and drug allergy and chronic urticaria. It may be helpful in determining the clinically relevant allergen. Basophil sensitivity may be used to monitor patients on allergen immunotherapy, anti-IgE treatment or in the natural resolution of allergy. Basophil activation test may use fewer resources and be more reproducible than challenge testing. As it is less stressful for the patient and avoids severe allergic reactions, BAT ought to precede challenge testing. An important next step is to standardize BAT and make it available in diagnostic laboratories. The nature of basophil activation as an ex vivo challenge makes it a multifaceted and promising tool for the allergist. In this EAACI task force position paper, we provide an overview of the practical and technical details as well as the clinical utility of BAT in diagnosis and management of allergic diseases.

Radiotherapy with soft X-rays in Dupuytren's disease - successful, well-tolerated and satisfying.

BACKGROUND: Up to present no curative treatment is known for Dupuytren's disease (DD). Surgery remains the most common treatment but lack of long-term efficacy and complications limit this therapeutic option. OBJECTIVE: In a retrospective analysis, the results of radiotherapy with soft X-rays in the treatment of DD were evaluated. METHODS: A total of 206 patients (297 affected hands) with DD were included. Radiation therapy was carried out with soft X-rays. A structured questionnaire considering patient and disease characteristics and effects of radiotherapy was evaluated after a median follow-up time of 40 months. RESULTS: Ninety-three (45%) of the 206 treated patients were reported on a regression of symptoms after radiation. No further disease progression (including patients with regression) was present in 165 patients (80%). Satisfaction with the therapy was expressed with an average score of 7.9 points (visual analogue scale, 0 = not satisfied, 10 = extremely satisfied). Subjective therapeutic effects for 426 nodules and/or cords showed a reduction of 92 nodules and/or cords. CONCLUSION: In 206 DD patients further disease progression was stopped in most patients. Radiotherapy proved to be well-tolerated, successful and satisfying for the patients.

Efficacy of bath psoralen plus ultraviolet A (PUVA) vs. system PUVA in psoriasis: a prospective, open, randomized, multicentre study.

BACKGROUND: Plaque psoriasis is an inflammatory disease affecting approximately 2% of the population. The clinical hallmarks of psoriasis are sharply demarcated, erythematous plaques with thick scales. Photochemotherapy (psoralen plus ultraviolet A, PUVA) is one of the most effective therapies of psoriasis. The photosensitizer 8-methoxypsoralen (8-MOP) can be applied either orally (system PUVA) or topically in a warm water bath (bath PUVA). OBJECTIVES: To compare bath PUVA and system PUVA in the treatment of plaque psoriasis. METHODS: This was a randomized, open, prospective, multicentre trial. We included 74 patients with moderate-to-severe plaque psoriasis during a 6-week treatment and a 4-week follow-up period. Of the patients enrolled in the study, 38 received bath PUVA and 36 system PUVA. RESULTS: Both treatment modalities significantly reduced the median Psoriasis Area and Severity Index (PASI) score in the intention-to-treat population. Within 6 weeks bath PUVA reduced the median PASI by 74% (16·4 to 4·2) while system PUVA did so by 62% (15·3 to 5·8). The difference between the two modalities was not significant with regard to treatment efficacy (P = 0·389). CONCLUSION: There is no difference between bath PUVA and system PUVA in the treatment of psoriasis.

GSTM1, GSTT1 and GSTP1 gene polymorphism in polymorphous light eruption.

BACKGROUND: Polymorphous light eruption (PLE) is the most common chronic and idiopathic photodermatosis. PLE is assumed to represent an immunological hypersensitivity reaction to a radiation-induced cutaneous antigen involving reactive oxygen species (ROS) on the basis of a genetic predisposition. Among others, cellular protection against ROS is provided by glutathione S-transferases (GSTs). Different variants of the GST enzymes may influence the activity and efficiency of detoxification and biotransformation of unknown UV-induced skin-antigens and other factors that may play an important role in the pathogenesis of PLE. METHODS: In this study the relationship between isoenzymes of the GST genes GSTM1, GSTT1 and GSTP1 and possible protective or predisposing effects on PLE was examined in 29 patients and 144 controls. Diagnosis of PLE was based on the presence of characteristic clinical features. RESULTS: No association between the functional polymorphisms of the GST gene family and PLE was found. Prevalence of certain GST isoenzymes or polymorphisms in patients with PLE did not differ from healthy controls. CONCLUSION: Our data do not support prevalence of GST isoenzymes or polymorphisms as a protective effect against PLE. Especially a higher carrier frequency of GSTP1 Val(105) as a protective factor against PLE which has been published before could not be proved. The GST genotypes GSTM1, GSTT1 and GSTP1 (including SNPs) seem to have no relevant association with PLE.

Ultraviolet A1 phototherapy: a British Photodermatology Group workshop report.

Whole-body ultraviolet (UV)A1 (340-400 nm) phototherapy was first introduced 30 years ago, but is currently available in the UK in only three dermatology departments. A workshop to discuss UVA1 was held by the British Photodermatology Group in May 2009, the aim of which was to provide an overview of UVA1 phototherapy and its role in practice, and to identify areas in which further studies are required. The conclusions were that UVA1 phototherapy is an effective treatment in several inflammatory skin diseases, including localized scleroderma and atopic eczema (AE); however, deficiencies and limitations exist in the published evidence base. For most diseases, such as AE, other treatments also exist, which are generally more effective than UVA1. However, for some diseases, particularly morphoea, the evidence of efficacy is stronger for UVA1 than for other treatments. Acute adverse effects of UVA1 are minimal. The risk of long-term adverse effects, particularly skin cancer, is unknown. Medium to high doses of UVA1 are needed for efficacy in most situations, but the equipment to deliver such doses is large, expensive and difficult to install. UVA1 is currently underprovided, and the recommendation of the workshop is that more tertiary centres should have access to UVA1 phototherapy in the UK.

A new basophil activation test using CD63 and CCR3 in allergy to antibiotics.

BACKGROUND: Flow cytometric basophil activation tests (BAT) have been developed as cellular tests for in vitro diagnosis of IgE-mediated reactions. Different markers and techniques have been used after stimulation with various allergens. OBJECTIVE: It was the aim of the present study to compare an established BAT (Flow-CAST) with a newly developed basophil activation protocol using CD63 and CCR3 (Flow2 CAST) in patients with type-I allergy to antibiotics. MATERIALS AND METHODS: Twenty-four patients with a history of type-I allergy to antibiotics were examined. A careful allergy history was taken, and skin tests and determination of specific IgE antibodies were performed. Two different BAT using CD63 expression but different protocols were carried out after stimulation with different concentrations of antibiotics. Fifteen healthy subjects without a history of antibiotic allergy were studied as controls. RESULTS: The Flow2 CAST showed a higher sensitivity than the Flow-CAST (55% vs. 53%) with regard to patients' history. Specificity was 80% both for the Flow2 CAST and for the Flow-CAST with regard to controls with negative history and negative RAST. CONCLUSION: These results show the value of two different BAT as cellular tests in the in vitro diagnosis of patients with antibiotic allergy with equal specificity and a slightly higher sensitivity for the Flow2 CAST.