An Increase in Tryptase on the First Day of Hymenoptera Venom Immunotherapy Might Be a Predictor of Future Systemic Reactions During Treatment.

BACKGROUND AND OBJECTIVE: Serum tryptase (ST) decreases during long-term venom immunotherapy (VIT). ST also exhibits a circadian variation, with a small decrease after sting challenge. Both findings have been related to successful VIT. Objective: To assess whether variation (increase or decrease) in ST on the first day of VIT is associated with the likelihood of future systemic adverse reactions (SARs) during treatment. METHODS: We prospectively studied patients who underwent cluster VIT, which was continued for at least 6 months. ST was measured on the first day of VIT, before the first dose (pre-IT tryptase) and after the last dose (post-IT tryptase). Differences between patient groups (with and without SAR) were analyzed. RESULTS: A total of 160 courses of VIT were administered to 150 patients. The median baseline ST value was 4.3 µg/L. A total of 25 courses (15.6%) were associated with SAR. In 64% of the 25 patients with SAR, the post-IT tryptase value was higher than the pre-IT tryptase level; the median increment was 19% in these patients. We found a significant association between the increase in ST on the first day of VIT and future SARs (risk ratio, 7.6). This elevation was independent of the scheduled VIT day, severity of the SAR, and baseline ST value. CONCLUSIONS: A slight increase in tryptase on the first day of VIT is an independent variable that is strongly related to a high risk of future SAR. This simple biomarker could improve patient safety.

Key Issues in Hymenoptera Venom Allergy: An Update.

In this review, the Hymenoptera Allergy Committee of the SEAIC analyzes the most recent scientific literature addressing problems related to the diagnosis of hymenoptera allergy and to management of venom immunotherapy. Molecular diagnosis and molecular risk profiles are the key areas addressed. The appearance of new species of hymenoptera that are potentially allergenic in Spain and the associated diagnostic and therapeutic problems are also described. Finally, we analyze the issue of mast cell activation syndrome closely related to hymenoptera allergy, which has become a new diagnostic challenge for allergists given its high prevalence in patients with venom anaphylaxis.

Insect Venom Immunotherapy: Analysis of the Safety and Tolerance of 3 Buildup Protocols Frequently Used in Spain.

INTRODUCTION: Hymenoptera venom immunotherapy (VIT) is an effective treatment but not one devoid of risk, as both local and systemic adverse reactions may occur, especially in the initial phases. We compared the tolerance to 3 VIT buildup protocols and analyzed risk factors associated with adverse reactions during this phase. MATERIALS AND METHODS: We enrolled 165 patients divided into 3 groups based on the buildup protocol used (3, 4, and 9 weeks). The severity of systemic reactions was evaluated according to the World Allergy Organization model. Results were analyzed using exploratory descriptive statistics, and variables were compared using analysis of variance. RESULTS: Adverse reactions were recorded in 53 patients (32%) (43 local and 10 systemic). Local reactions were immediate in 27 patients (63%) and delayed in 16 (37%). The severity of the local reaction was slight/moderate in 15 patients and severe in 13. Systemic reactions were grade 1-2. No significant association was found between the treatment modality and the onset of local or systemic adverse reactions or the type of local reaction. We only found a statistically significant association between severity of the local reaction and female gender. As for the risk factors associated with systemic reactions during the buildup phase, we found no significant differences in values depending on the protocol used or the insect responsible. CONCLUSIONS: The buildup protocols compared proved to be safe and did not differ significantly from one another. In the population studied, patients undergoing the 9-week schedule presented no systemic reactions. Therefore, this protocol can be considered the safest approach.

Cloning of chicken and mouse alpha 1b adrenergic receptor.

A partial cDNA encoding most of the third intracellular loop of the chicken alpha 1b adrenergic receptor subtype, obtained by reverse transcription-polymerase chain reaction (RT-PCR) techniques using degenerate primers derived from mammalian sequences, was used to isolate an alpha 1b adrenergic receptor cDNA from brain. The cDNA encodes a potential protein of 507 amino acids and Northern hybridization of poly(A)+ RNA from chicken brain of different developmental stages detected a single 3.5 kb transcript. Analysis of receptor expression indicated that the alpha 1b adrenergic receptor is widely distributed in chicken tissues, specially kidney and liver. cDNA and genomic clones encoding sequences of the mouse alpha 1b adrenergic receptor were also isolated.

Differential expression of the alpha 1c adrenergic receptor subtype in rat tissues.

Three alpha 1 adrenergic receptor subtypes have been identified by molecular cloning techniques. However, the detection of the mRNA for the alpha 1c subtype has not yet been reported in rodent tissues. We have isolated from rat lung, by polymerase chain reaction techniques, a cDNA fragment corresponding to the third intracellular domain of the alpha 1c adrenergic receptor subtype. The nucleotide and deduced amino acid sequences of the cloned fragment presented an 87% and 96% identity, respectively, with those from the bovine receptor. Analysis of the distribution of the receptor mRNA in brain shows highest expression levels in cerebellum and striatum, whereas in non-neural tissues the receptor is mainly expressed in lung and heart. It was also found that the gene sequence which codes for this domain is not interrupted by introns.

Immunodetection of serotonin transporter from mouse brain.

A DNA fragment encoding amino acid sequences from the amino terminal region of the mouse serotonin transporter was isolated and sequenced. This transporter is widely distributed throughout the mouse brain, as deduced by heminested reverse transcription-polymerase chain reaction (RT-PCR) assays. To identify the serotonin transporter protein, we have developed specific antibodies against a fusion protein containing its amino terminal region, a domain which shows a low degree of homology between the different neurotransmitter transporters. Western blot analysis of mouse brain membranes detected the serotonin transporter as a 71 kDa polypeptide.

Measurement of serum levels of eosinophil cationic protein in the diagnosis of acute gastrointestinal anisakiasis.

Thirty-two patients with abdominal pain and/or intestinal pseudo-obstruction who had consumed raw or undercooked fish in the previous 72 h, were included in a study of anisakiasis, a parasitation of the human gastrointestinal tract by third stage Anisakis simplex larvae. Skin prick test (SPT) against A. simplex were positive in all the patients. High median eosinophil cationic protein (ECP) serum concentrations (> 15 mg/L) at day 0 with normal serum levels at day 30 and a rise of median total and specific IgE against A. simplex at day 30, were observed. We conclude that a raised serum level of ECP in the first 72 h from the onset of symptoms coinciding with a positive SPT against A. simplex and high total and specific immunoglobulin (IgE) in the first month after the parasitation, could be a useful tool in the diagnosis of gastrointestinal anisakiasis, even if the parasite cannot be isolated.

Identification of a long huntingtin mRNA transcript in mouse brain.

Two mRNA species of the Huntington disease (HD) gene that share identical protein coding sequences but differ in their 3' untranslated region have been identified in human. Although a similar situation has been suggested to occur in mouse, only one cDNA has been isolated to date. We report the isolation of a novel partial cDNA of the mouse HD gene that is identical in its protein coding sequence to the previously reported cDNA, although it differs in the distal portion of the 3' untranslated region. Northern blotting assays indicate that this mRNA transcript is preferentially expressed in brain, with highest levels in cerebellum, cerebral cortex and striatum.

Identification of a cyclic adenosine 3',5'-monophosphate-dependent protein kinase phosphorylation site in the carboxy terminal tail of human D1 dopamine receptor.

Each of the dopamine receptor subtypes contains several consensus sites for phosphorylation in their intracellular domains. We have used fusion proteins of the carboxy terminal tail of D1 and D5 dopamine receptors to study the phosphorylation of these proteins by cyclic adenosine 3',5' monophosphate (cAMP)-dependent protein kinase (PKA) and protein kinase C (PKC). The fusion protein of D1 dopamine receptor was efficiently phosphorylated by PKA, but not by PKC. Site-directed mutagenesis of serine 380 to an alanine residue precluded the phosphorylation by the kinase. No phosphorylation of the D5 dopamine receptor fusion protein was observed with either PKA or PKC, which indicates that these receptor subtypes might differ in their mechanisms of regulation.

Phosphorylation of the third intracellular loop of the mouse alpha1b-adrenergic receptor by cAMP-dependent protein kinase.

The third intracellular loop of adrenergic receptors has been implicated in their interaction with guanine nucleotide-binding proteins (G proteins). One of the mechanisms involved in the modulation of receptor function is the phosphorylation of specific residues by intracellular kinases. alpha1b-Adrenergic receptor is phosphorylated in vitro by cAMP-dependent protein kinase (PKA), although its physiological effect remains to be determined. We have produced fusion proteins formed by glutathione S-transferase and sequences of the third intracellular loop of mouse alpha1a-, alpha1b-, and alpha1d-adrenergic receptor subtypes, and used them as substrates for PKA. Only the fusion protein containing the alpha1b sequence was phosphorylated in vitro by this kinase. Site-directed mutagenesis of a serine (homologue to serine 278 of the rat sequence, RSS) to an alanine residue precluded phosphorylation by PKA.

Fluorocytometric analysis of induced sputum cells in an asthmatic population.

BACKGROUND: Bronchial mucosal inflammation is the major pathogenic process in asthma. In the latest years, induced sputum (IS) examination has become an important non-invasive method of assessing airway inflammation. Flow cytometry has been recently applied to the study of IS though it is not exempt of methodological difficulties. The aim of the present study was to further study if the fluorocytometric analysis of IS could represent a reliable tool to assess the presence of bronchial activated lymphocytes in stable mild asthmatic patients. METHODS: Induced sputa from controls and asthmatic patients were processed in isotonic 3mM dithiothreitol (DTT), a mucolytic agent required for cell dispersion. The individualized cells were then stained with monoclonal antibodies for three-colour flow-cytometric analysis. Total IgE and ECP were measured in serum and in the sputum fluid phase. RESULTS: The cellularity of asthmatic sputa is enriched in eosinophils (mean, 26.63%) with respect to controls, but not in lymphocytes. However, lymphocytes from asthmatics show increased surface expression of activation markers (CD25 in T cells, CD23 in B cells). Surprisingly, no differences were observed in the detected levels of CD54 on IS lymphocytes and eosinophils between asthmatics and non-asthmatics. Furthermore, there was a significantly higher concentration of ECP and total IgE in the sputum from the asthmatic group. CONCLUSION: Fluorocytometric analysis of induced sputum is a reliable non-invasive method for the study of bronchial immune cells. It could provide complementary information on activated cells in the bronchial mucosa even in non-smokers, mild and stable asthmatics and it is reasonable to speculate that it will be useful in monitoring the effect of the treatment in these patients.

Adverse reaction to tetrazepam.

Adverse reactions caused by benzodiazepines rarely occur. We present a case of a 70-year-old man who developed a maculopapular exanthema after the ingestion of tetrazepam. For his diagnosis, skin tests were performed, including prick and patch tests, not only with the benzodiazepine implicated in the reaction, but also with benzodiazepines of other groups. Single-blind oral challenge tests were also performed in the patient, in order to assess his tolerance to other benzodiazepines.

Anisakis simplex: a cause of intestinal pseudo-obstruction.

OBJECTIVE: the ingestion of Anisakis simplex larvae may lead to the appearance of gastrointestinal symptoms. However, the number of reported cases of parasitization by Anisakis in Spain is lower than would be expected in a country with the second-highest fish consumption per inhabitant in the world, particularly since fish is often eaten raw or only slightly cooked. We suggest that the incidence of anisakiasis in Spain would be higher if complementary studies were used in all patients suspected of having anisakiasis. METHODS: we studied 6 patients with a diagnosis of intestinal obstruction who frequently ate fish. Skin prick tests with seafood, inhalant allergen and Anisakis extracts were done. Total and specific IgE against Anisakis larvae were tested with a CAP system radioimmunoassay and immunoblot assays. Oral challenge tests with frozen larvae were also used. RESULTS: a positive skin prick result and high levels of total and specific IgE were found in all patients. The results of immunoblot assays for IgE did not show a consistent pattern, but a group of several low (14-18 kDa) and intermediate molecular weight antigens (30-50 kDa) were found in all patients. All patients tolerated the oral challenge test well. CONCLUSIONS: in our patients with intestinal pseudo-obstruction and a history of frequent fish eating, the clinical and laboratory findings were suggestive of parasitization by Anisakis simplex larvae as the cause of the obstruction. Such complementary studies should be used whenever there is a suspicion of anisakiasis. The results of the oral provocation test show that the intake of dead larvae does not induce clinical parasitization.

[Hypersensitivity to allopurinol. Efficacy of a desensitizing protocol in 3 cases]. / Hipersensibilidad al alopurinol. Eficacia de un protocolo de desensibilización en tres casos.

Allopurinol is often prescribed for the treatment of hyperuricemia. It inhibits the uric acid production binding tightly to xanthine oxidase. Although it is generally well tolerated, an almost 10% prevalence of adverse reactions has been reported, particularly gastrointestinal and neurological effects. Some hypersensitivity syndromes have also been described (rash, vasculitis or exfoliative dermatitis). In these cases, if a substitute treatment is not available, a desensitization procedure to the drug must be considered. We present three patients with cutaneous hypersensitivity to allopurinol, two who developed urticaria and other one who had a fixed drug eruption. Skin test were all negatives with positive oral challenge test. An out- patient desensitization procedure to allopurinol was initiated, repeating the last tolerated doses for 4 or 5 days, and reaching maintenance therapeutic drug doses without any significant adverse effect (only one case of cutaneous pruritus). These experiences and the previously reported in the literature, show that the desensitization to allopurinol is a good therapeutic alternative in hypersensitivity reactions to the drug.

An increase in tryptase on the first day of hymenoptera venom immunotherapy might be a predictor of future systemic reactions during treatment

Background: Serum tryptase (ST) decreases during long-term venom immunotherapy (VIT). ST also exhibits a circadian variation, with a small decrease after sting challenge. Both findings have been related to successful VIT. Objective: To assess whether variation (increase or decrease) in ST on the first day of VIT is associated with the likelihood of future systemic adverse reactions (SARs) during treatment. Methods: We prospectively studied patients who underwent cluster VIT, which was continued for at least 6 months. ST was measured on the first day of VIT, before the first dose (pre-IT tryptase) and after the last dose (post-IT tryptase). Differences between patient groups (with and without SAR) were analyzed. Results: A total of 160 courses of VIT were administered to 150 patients. The median baseline ST value was 4.3 μg/L. A total of 25 courses (15.6%) were associated with SAR. In 64% of the 25 patients with SAR, the post-IT tryptase value was higher than the pre-IT tryptase level; the median increment was 19% in these patients. We found a significant association between the increase in ST on the first day of VIT and future SARs (risk ratio, 7.6). This elevation was independent of the scheduled VIT day, severity of the SAR, and baseline ST value. Conclusions: A slight increase in tryptase on the first day of VIT is an independent variable that is strongly related to a high risk of future SAR. This simple biomarker could improve patient safety

Antecedentes: Se ha observado una disminución progresiva del nivel de triptasa sérica (TS) basal durante la inmunoterapia con veneno de himenópteros (ITVH), así como la conservación de la variación circadiana de triptasa en pacientes que han tolerado una repicadura controlada. Ambos hallazgos se han relacionado con la eficacia del tratamiento. Objetivo: Estudiar si la variación (aumento o disminución) de la TS durante el primer día de ITVH se relaciona con un mayor riesgo de presentar reacciones adversas sistémicas (RAS) con futuras dosis de ITVH. Método: Estudio prospectivo de pacientes sometidos a ITVH en pauta de inicio agrupada y que continuaron con el tratamiento durante al menos 6 meses. Se determinó la TS el primer día de ITVH, antes de la primera dosis (triptasa pre-IT) y tras la última dosis (triptasa post-IT). Se analizaron las diferencias entre los dos grupos de pacientes (con o sin RAS). Resultados: Se administraron 160 ITVH a 150 pacientes. El valor medio de TS basal fue 4,3 μg/L, siendo > 11,4 μg/L en 4 casos. Un total de 25 ITVH (15,6%) presentaron RAS. En 64% de los 25 pacientes con RAS, el valor de triptasa post-IT fue más alto que el valor de triptasa pre-IT; el incremento medio fue del 19% en estos pacientes. Encontramos una relación significativa entre este aumento de triptasa el primer día de ITVH y la aparición de RAS con futuras dosis de ITVH (risk ratio 7,6). Esta elevación fue independiente del día de aparición de la reacción, de la gravedad de la misma, así como del valor basal de triptasa. Conclusiones: Un ligero aumento de triptasa el primer día de ITVH es una variable independiente, fuertemente relacionada con un alto riesgo de presentar una futura RAS. Este sencillo biomarcador podría ser útil para mejorar la seguridad de estos pacientes