Self-medication of anaphylactic reactions due to Hymenoptera stings-an EAACI Task Force Consensus Statement.

An anaphylactic reaction due to a Hymenoptera sting is a clinical emergency, and patients, their caregivers as well as all healthcare professionals should be familiar with its recognition and acute management. This consensus report has been prepared by a European expert panel of the EAACI Interest Group of Insect Venom Hypersensitivity. It is targeted at allergists, clinical immunologists, internal medicine specialists, pediatricians, general practitioners, emergency department doctors, and any other healthcare professional involved. The aim was to report the scientific evidence on self-medication of anaphylactic reactions due to Hymenoptera stings, to inform healthcare staff about appropriate patient self-management of sting reactions, to propose indications for the prescription of an adrenaline auto-injector (AAI), and to discuss other forms of medication. First-line treatment for Hymenoptera sting anaphylaxis is intramuscular adrenaline. Prescription of AAIs is mandatory in the case of venom-allergic patients who suffer from mast cell diseases or with an elevated baseline serum tryptase level and in untreated patients with a history of a systemic reaction involving at least two different organ systems. AAI prescription should also be considered in other specific situations before, during, and after stopping venom immunotherapy.

Anaphylaxis to the chlorhexidine component of Instillagel: a case series.

Anaphylaxis to chlorhexidine is rare. We report three cases of anaphylaxis attributed to the chlorhexidine component of Instillagel, presenting after urological surgery, while the patients were in the recovery room. In these cases, the cause of the collapse was not immediately obvious as the presentation was delayed. Anaesthetists should be aware that urethral lubricants may contain chlorhexidine that can trigger anaphylaxis in susceptible individuals. Anaphylaxis should be considered a possible diagnosis when a patient collapses in the recovery room. Investigation of suspected anaphylactic reactions related to anaesthesia is important to try and identify a likely trigger for a reaction and to help prevent further exposure and potential harm.

Clinical immunology review series: an approach to the use of the immunology laboratory in the diagnosis of clinical allergy.

In the last 10 years UK immunology laboratories have seen a dramatic increase in the number and range of allergy tests performed. The reasons for this have been an increase in the incidence of immunoglobulin E (IgE)-mediated allergic disease set against a background of greater public awareness and more referrals for assessment. Laboratory testing forms an integral part of a comprehensive allergy service and physicians treating patients with allergic disease need to have an up-to-date knowledge of the range of tests available, their performance parameters and interpretation as well as the accreditation status of the laboratory to which tests are being sent. The aim of this review is to describe the role of the immunology laboratory in the assessment of patients with IgE-mediated allergic disease and provide an up-to-date summary of the tests currently available, their sensitivity, specificity, interpretation and areas of future development.

A peroxidase-linked enzyme immunoassay for tumour necrosis factor alpha utilising alternative colorimetric or chemilumimetric substrates.

We present a double antibody immunoassay for tumour necrosis factor alpha (TNF alpha) with a peroxidase dependent endpoint which can be detected by absorbance or chemiluminescence depending on the choice of substrate. The chemilumimetric and colorimetric assays have a detection threshold in human serum of 3.9 pg/ml and 7.8 pg/ml respectively and are able to recognise both rTNF alpha and natural TNF alpha. Concentrations of TNF beta, interleukin-1 alpha (IL-1 alpha), IL-beta, IL-2, IL-3, IL-6 or interferon-gamma (IFN-gamma) up to 5 ng/ml failed to show any cross-reactivity. The monoclonal antibody clone 5-2, used in the assays, did not neutralise rTNF alpha in the L929 bioassay. The assay was able to detect rTNF alpha in the presence of excess concentrations of both TNF alpha receptors (p55 and p75). Removal of interference by rheumatoid factor was achieved by the absorbance of the polyclonal antiserum with mouse serum and the inclusion of 10(-2) M dithiothreitol in the buffer containing the TNF alpha polyclonal antiserum. The assay will be useful for the quantitation of endogenous human TNF alpha in serum, other body fluids and culture supernatants, and can also be used to monitor levels of rTNF alpha in clinical trials.

Investigation of IgG4 levels in atopic patients using a competitive inhibition assay employing biotinylated IgG4 myeloma and avidin peroxidase.

Modification of a 'sandwich' ELISA assay developed for the determination of serum IgE levels proved to be unsatisfactory for the measurement of IgG4. This was attributed to the limited capacity of the microtitre plate solid phase which required high serum dilutions in order to measure IgG4 levels. To overcome this problem a competitive inhibition assay was developed with monoclonal anti-IgG4 attached to the plate. In this system biotinylated IgG4 myeloma and sample IgG4 compete for the limited antibody binding sites present on the solid phase. The attached biotinylated myeloma is detected by addition of avidin conjugated with peroxidase and following development with substrate, IgG4 levels are calculated by reference to a calibrated inhibition curve. The inhibition ELISA assay has been used clinically to measure IgG4 levels in atopic and normal individuals and the values obtained correlated closely (r = 0.99) with the IgG4 levels determined by radial immunodiffusion. For 43 atopic dermatitis patients investigated the median IgG4 level was 1.1 g/l which was significantly elevated when compared to a median of 0.385 g/l for 60 blood donors (P less than 0.0001, Mann-Whitney U). Among the 47 hay fever patients investigated the median was 0.6 g/l which, although lower than in atopic dermatitis, was again significantly increased (P less than 0.025). Within this latter group, 25 patients were investigated for the effects of desensitization with commercial grass pollen injections. The total IgG4 showed a variable but significant rise between the start and finish of treatment (P less than 0.01 Wilcoxon signed ranks test).

Postmortem findings after fatal anaphylactic reactions.

AIMS: To determine the frequency at which classic manifestations of anaphylaxis are present at necropsy after fatal anaphylactic reactions. METHODS: A register has been established of fatal anaphylactic reactions in the UK since 1992, traced from the certified cause of death and other sources. Details of the previous medical history and the reaction suggest anaphylaxis as the cause of death for 130 cases; a postmortem report was available for 56. RESULTS: The 56 deaths studied included 19 reactions to bee or wasp venom, 16 to foods, and 21 to drugs or contrast media. Death occurred within one hour of anaphylaxis in 39 cases. Macroscopic findings included signs of asthma (mucous plugging and/or hyper-inflated lungs) (15 of 56), petechial haemorrhages (10 of 56), pharyngeal/laryngeal oedema (23 of 56), but for 23 of 56 there was nothing indicative of an allergic death. Mast cell tryptase was raised in 14 of 16 cases tested; three of three tested had detectable IgE specific for the suspected allergen. CONCLUSIONS: In many cases of fatal anaphylaxis no specific macroscopic findings are present at postmortem examination. This reflects the rapidity and mode of death, which is often the result of shock rather than asphyxia. Investigations that might help determine whether anaphylaxis was the cause of death had rarely been performed. In the presence of a typical clinical history, absence of postmortem findings does not exclude the diagnosis of anaphylaxis.

Pure red cell aplasia associated with malignant thymoma, myasthenia gravis, polyclonal large granular lymphocytosis and clonal thymic T cell expansion.

A case with the triad of pure red cell aplasia (PRCA), myasthenia gravis, and malignant thymoma is reported. There was a clonal proliferation of T cells within the thymoma, as demonstrated by a T cell antigen receptor (TCR) delta chain gene rearrangement. However, despite a large granular lymphocytosis, clonality could not be shown in the peripheral blood either before or after thymectomy. There was no evidence of human T cell lymphotrophic virus type 7 (HTLV1) infection. It is postulated that the clonal thymic T cell population secreted cytokine(s), which stimulated the polyclonal proliferation of large granular lymphocytes, which in turn suppressed erythropoiesis. Thymectomy removed the stimulus to the large granular lymphocytes and hence there was a resurgence of erythropoiesis.

An unusual association of Felty syndrome and TCR gamma delta lymphocytosis.

Felty syndrome, comprised of neutropenia, rheumatoid arthritis and splenomegaly, occurs in approximately 1% of patients with rheumatoid arthritis. Up to one third of these patients have an increased number of large granular lymphocytes. The usual immunophenotype of these cells is CD3+, CD8+, CD57+, T cell receptor (TCR) alpha beta. A patient with Felty syndrome and large granular lymphocytosis, who had an unusual immunophenotype CD3+, CD4-, CD8-, TCR gamma delta, is described. Her neutropenia responded to treatment with granulocyte colony stimulating factor (G-CSF), which was given in order to raise her neutrophil count prior to bilateral knee replacement surgery. Thus, Felty syndrome with large granular lymphocytosis is a heterogeneous condition, one in which TCR gamma delta large granular lymphocytosis may be found, and also shows a response to treatment with G-CSF.

IgM ganglioside GM1 antibodies in patients with autoimmune disease or neuropathy, and controls.

AIMS: To compare the titre of anti-ganglioside antibodies (AGA) to GM1 ganglioside in patients with central and peripheral neurological disease and pure motor and sensorimotor neuropathy, in patients with classic autoimmune diseases, and controls. METHODS: AGA to GM1 were measured using an enzyme linked immunosorbent assay (ELISA) technique, highly purified bovine GM1 ganglioside, and sequential dilution of control and test sera. Antibody titre was calculated using the optical density readings of three consecutive serum dilutions multiplied by the dilution factor. RESULTS: A considerable overlap was evident in the titre of AGA to GM1 in control and test sera. High antibody titres were most frequent in patients with multifocal motor neuropathy with conduction block (MMNCB). Low AGA titre were observed in several patient groups. Compared with the controls, the median titre of AGA to GM1 was significantly higher in patients with multiple sclerosis, rheumatoid arthritis, primary Sjögren's syndrome and systemic lupus erythematosus. In contrast, the median titre in patients with diabetic peripheral neuropathy, motor neurone disease, sensorimotor neuropathy and chronic inflammatory demyelinating polyneuropathy was no different from that in normal control subjects. CONCLUSIONS: Estimation of AGA to GM1 may be helpful in the diagnosis of MMNCB in patients with a pure motor neuropathy but in few other conditions. Low titre AGA to GM1 are evident in several autoimmune conditions. The pathogenetic importance of AGA to GM1 in patients with neuropathy is not clear.

Peritoneal endometriosis in women requesting reversal of sterilization.

Seventy-six women requesting reversal of sterilization underwent at least 1 operative procedure during a 27-month period, and 14 (18.4%) were found to have pelvic endometriosis. The endometriosis patients were noted to have had significantly fewer pregnancies (1.8 versus 2.9, P less than 0.01) before sterilization than those without endometriosis, but the two groups did not differ significantly in mean age (30.8 versus 30.3 years), type of sterilization or in mean number of years since sterilization (5.0 versus 5.5 years). In only two individuals were proximal tubal segment fistulas found at the time of reversal, and neither had endometriosis. We conclude that pelvic endometriosis is more common in patients with bilateral tubal occlusion than previously suspected and that its presence indicates that endometriosis implants can persist for prolonged periods of time, can give rise to new implants, or do not require the tubal reflux of menstrual debris to form.

Increased levels of sCD23 in rheumatoid arthritis are related to disease status.

The low affinity receptor for IgE (Fc epsilon RII, CD23) is involved in many aspects of T and B cell regulation. In the current study, serum levels of sCD23 were measured in monozygotic (MZ) twins discordant for rheumatoid arthritis (RA) to examine whether an increased level of sCD23 in RA is, at least in part, genetically determined. Paired analysis showed significantly elevated sCD23 levels in affected twins when compared with their unaffected co-twins (p < 0.01). There was no significant difference in sCD23 in the unaffected twins compared with normal controls. Higher levels of sCD23 were found in males compared to females in both affected and unaffected twins. Soluble CD23 showed a significant increase with age in RA affected twins (p = 0.013), but no association with disease duration (p = 0.87). There was no significant variation in sCD23 level with HLA-DR phenotype. We conclude that elevations in serum sCD23 in patients with RA are primarily disease related.

Allergic reactions in the community: a questionnaire survey of members of the anaphylaxis campaign.

BACKGROUND: Allergic reactions to food are well recognized in both children and adults, but because of their relative infrequency their typical features may not be readily recognized by patients and their medical care givers who are not allergists. OBJECTIVE: We sought to investigate the circumstances and clinical characteristics of food allergies in adults and children in the community. METHODS: Self-completed questionnaire responses over a 6-month period from 109 members of the Anaphylaxis Campaign, the major British patient resource group for people who have suffered severe allergic reactions. RESULTS: One hundred and nine respondents reported 126 reactions during the study period. Seventy-five were children (under 16 years, median age 6 years at the time of reaction). Predictably more boys than girls were reported to have had reactions but more women reported reactions than men (P<0.05). Although the groups were equally aware of their food allergies the children had undergone diagnostic tests more often (P<0.001). Foods were implicated in 112 (89%) of reports. Restaurants were implicated less often (14%) than in other series, probably reflecting British eating habits. Children with asthma reported more severe reactions than those without asthma (P=0.008), although frequency or severity of recent asthma symptoms was not associated with severity of allergic reaction reported. When available, self-injectable adrenaline was used in 35% of severe reactions and 13% of non-severe reactions (P=0.01). A quarter of adults who received one dose of adrenaline also received a second dose. CONCLUSION: The allergens implicated in this report reflect previous data from similar patient groups in North America. Asthmatic children suffer more severe reactions than non-asthmatic children. It appears that British adults need better access to expert care of their allergies. Even when it is prescribed and available self-injectable adrenaline appears under-used in severe reactions. The incidence of severe but non-fatal allergic reactions in the UK may have been underestimated in the past.

Computer models of the human immunoglobulins shape and segmental flexibility.

At present there is interest in the design and deployment of engineered biosensor molecules. Antibodies are the most versatile of the naturally occurring biosensors and it is important to understand their mechanical properties and the ways in which they can interact with their natural ligands. Two dimensional representations are clearly inadequate, and three dimensional representations are too complicated to manipulate except as numerical abstractions in computers. Recent improvements in computer graphics allow these coordinate matrices to be seen and more easily comprehended, and interactive programs permit the modification and reassembly of molecular fragments. The models which result have distinct advantages both over those of lower resolution, and those showing every atom, which are limited to the few fragments(2-5) or mutant molecules for which the X-ray crystallographic coordinates are known. In this review Richard Pumphrey describes the shape and flexibility of immunoglobulin molecules in relation to the three dimensional structure.

Lessons for management of anaphylaxis from a study of fatal reactions.

BACKGROUND: The unpredictability of anaphylactic reactions and the need for immediate, often improvised treatment will make controlled trials impracticable; other means must therefore be used to determine optimal management. OBJECTIVES: This study aimed to investigate the circumstances leading to fatal anaphylaxis. METHODS: A register was established including all fatal anaphylactic reactions in the UK since 1992 that could be traced from the certified cause of death. Data obtained from other sources suggested that deaths certified as due to anaphylaxis underestimate the true incidence. Details of the previous medical history, the reaction and necropsy were sought for all cases. RESULTS: Approximately half the 20 fatal reactions recorded each year in the UK were iatrogenic, and a quarter each due to food or insect venom. All fatal reactions thought to have been due to food caused difficulty breathing that in 86% led to respiratory arrest; shock was more common in iatrogenic and venom reactions. The median time to respiratory or cardiac arrest was 30 min for foods, 15 min for venom and 5 min for iatrogenic reactions. Twenty-eight per cent of fatal cases were resuscitated but died 3 h-30 days later, mostly from hypoxic brain damage. Adrenaline (epinephrine) was used in treatment of 62% of fatal reactions but before arrest in only 14%. CONCLUSIONS: Immediate recognition of anaphylaxis, early use of adrenaline, inhaled beta agonists and other measures are crucial for successful treatment. Nevertheless, a few reactions will be fatal whatever treatment is given; optimal management of anaphylaxis is therefore avoidance of the cause whenever this is possible. Predictable cross-reactivity between the cause of the fatal reaction and that of previous reactions had been overlooked. Adrenaline overdose caused at least three deaths and must be avoided. Kit for self-treatment had proved unhelpful for a variety of reasons; its success depends on selection of appropriate medication, ease of use and good training.

Computer models of the human immunoglobulins Binding sites and molecular interactions.

In last month's issue(1) Richard Pumphrey showed how low resolution computer models could be used to investigate the shape and segmental flexibility of human immunoglobulin molecules. In this article, he extends the use of these models to the study of interactions between immunoglobulins and other molecules, such as their receptors, J chain, secretory component and complement fragments. Although precise studies of molecular interaction require computation in atomic detail, there is still much to be learnt from low resolution modelling, in which atomic details are glossed over but general principles become more obvious.

The anti-trust suit against the AMA, 1939-1943: background for today's health planning.

Today, prepaid group medical schemes form a significant component of many legislative health care proposals. Although the concept is over 60 years old, its legality was not established until 1943 by a United States Supreme Court decision that convicted the American Medical Association and the District of Columbia Medical Society for restraint of trade. The history of that suit highlights the antagonisms that exist between prepaid group medical care and the more traditional fee-for-service system.