Structural Similarities, in Relation with the Cross-Reactivity, of Hymenoptera Allergenic Dipeptidyl Peptidases IV-An Overall Comparison Including a New Dipeptidyl Peptidase IV Sequence from Vespa velutina.

(1) Background: Dipeptidyl Peptidases IV (DPPIVs), present in many organisms, are minor components in the venoms of Hymenoptera, where they have been identified as cross-reactive allergenic molecules. Considering that the structure of homologous DPPIVs is well characterized, we aimed to explain which regions have higher similarity among these proteins and present a comparison among them, including a new Vespa velutina DPPIV sequence. Moreover, two cases of sensitization to DPPIVs in wasp- and honeybee-sensitized patients are presented. (2) Methods: Proteomic analyses have been performed on the venom of the Asian hornet Vespa velutina to demonstrate the sequence of its DPPIV (allergen named Vesp v 3, with sequence accession number P0DRB8, and with the proteomic data available via ProteomeXchange with the identifier PXD046030). A comparison performed through their alignments and analysis of the three-dimensional structure showed a region with higher similarity among Hymenoptera DPPIVs. Additionally, ImmunoCAP™ determinations (including specific inhibition experiments), as well as IgE immunoblotting, are performed to demonstrate the allergenicity of Api m 5 and Ves v 3. (3) Results and Conclusions: The data presented demonstrate that the similarities among Hymenoptera DPPIVs are most likely localized at the C-terminal region of these enzymes. In addition, a higher similarity of the Vespa/Vespula DPPIVs is shown. The clinical cases analyzed demonstrated the allergenicity of Api m 5 and Ves v 3 in the sera of the allergic patients, as well as the presence of this minor component in the preparations used in venom immunotherapy.

[Severe and rare adverse reaction to hydrochlorothiazide]. / Reacción grave e infrecuente con hidroclorotiazida.

BACKGROUND: The immune mechanism involved in the reaction to hydrochlorothiazide, which is widely used to control hypertension, is unknown. The short latency period between the take of the drug and the onset of symptoms suggests immediate hypersensitivity. CASE REPORT: 63-year-old woman with arterial hypertension who, on three occasions, experienced nausea, vomiting, general malaise, shivering, arthralgias, dysthermic sensation, back pain of mechanical characteristics and mild non-productive cough, as well as fever and chest tightness with increased dyspnea and desaturation of up to 88 %, after taking hydrochlorothiazide. CONCLUSIONS: Clinical presentation in the patient was similar to a septic shock, which is a rare allergic reaction. The diagnosis has to be clinical. This type of reaction might be due to type III hypersensitivity owing to the formation of immune complexes. Avoiding of the culprit drug is key to a good evolution.

Antecedentes: Se desconoce el mecanismo inmunológico implicado en la reacción a la hidroclorotiazida, de amplio uso para el control de la hipertensión arterial. El corto periodo de latencia entre la toma del fármaco y la aparición de síntomas sugiere hipersensibilidad inmediata. Reporte de caso: Mujer de 63 años con hipertensión arterial quien en tres ocasiones presentó náuseas, vómitos, malestar general, tiritona, artralgias, sensación distérmica, dolor lumbar de características mecánicas y tos escasa no productiva, así como fiebre y opresión torácica con incremento de la disnea y desaturación hasta de 88 %, tras la toma de hidroclorotiazida. Conclusiones: La presentación clínica en la paciente fue similar a choque séptico, reacción alérgica rara cuyo diagnóstico es clínico Este tipo de reacción podría deberse a hipersensibilidad tipo III debido a la formación de inmunocomplejos. Evitar el fármaco implicado es clave para la buena evolución.