[Intralymphatic immunotherapy: An effective and safe alternative route for canine atopic dermatitis]. / Intralymphatische Immuntherapie: Eine sichere und effektive Methode zur Desensibilisierung der caninen atopischen Dermatitis.

INTRODUCTION: Allergen-specific immunotherapy (ASIT) is the only etiologic treatment of atopic dermatitis in dogs. In humans it has been shown that intralymphatic immunotherapy (ILIT) enhanced efficacy and patient compliance and reduced treatment time from 3 years to 8 weeks. As only safety data have been published yet, the aim of this study was to evaluate the clinical efficacy of ILIT in dogs. 20 atopic dogs underwent ILIT with alum-precipitated allergens administered every 4 weeks for 3 to 7 times in the popliteal lymph node. Pruritus (Hill score), CADESI (canine atopic dermatitis severety index), concurrent medications and adverse reactions were recorded initially and every 4 weeks for a total period of 24 weeks. The observed clinical response was good in 12/20 (60%) patients and improvement could be seen in some dogs already after 4 weeks. The median number of injections was 5.6. All dogs tolerated the procedure well and no adverse effects were recognized during or after ILIT. Therefore ILIT should be regarded as a safe alternative to subucaneous ASIT, enabling a faster clinical improvement with the same response rate.

INTRODUCTION: L'immunothérapie spécifique de l'allergène est le seul traitement étiologique de la dermite atopique du chien. On a pu montrer que, chez l'homme, l'immunothérapie intralymphatique (ITIL) augmente la fiabilité du traitement et permet de réduire sa durée de 3 ans à 8 semaines. Comme jusqu'à ce jour seules des données relatives à la tolérance avaient été publiées, la présente étude a pour but d'examiner l'efficacité clinique de l'ITIL chez les chiens. Vingt chiens atopiques ont été désensibilisés au moyen d'allergènes précipités à l'aluminium par ITIL dans les ganglions poplités toutes les 4 semaines. Le prurit (Hill score), le CADESI (canine atopic dermatitis severity index), les médicaments appliqués et les effets secondaires observés ont été enregistrés au début du traitement puis toutes les 4 semaines durant au total 24 semaines. 12/20 (60%) des patients ont bien répondu au traitement. L'amélioration clinique a pu être partiellement constatée après 4 semaines déjà. En moyenne, 5.6 injections ont été nécessaires. Tous les chiens ont bien toléré l'ITIL et il n'a pas été observé d'effet secondaire pendant ou après le traitement. L'immunothérapie intralymphatique semble donc une alternative sure à l'immunothérapie spécifique de l'antigène sous-cutanée et permet d'obtenir un effet plus rapide avec le même taux de réponse.

A preventive immunization approach against insect bite hypersensitivity: Intralymphatic injection with recombinant allergens in Alum or Alum and monophosphoryl lipid A.

Insect bite hypersensitivity (IBH) is an IgE-mediated dermatitis of horses caused by bites of Culicoides insects, not indigenous to Iceland. Horses born in Iceland and exported to Culicoides-rich areas are frequently affected with IBH. The aims of the study were to compare immunization with recombinant allergens using the adjuvant aluminum hydroxide (Alum) alone or combined with monophosphoryl lipid A (MPLA) for development of a preventive immunization against IBH. Twelve healthy Icelandic horses were vaccinated intralymphatically three times with 10 µg each of four recombinant Culicoides nubeculosus allergens in Alum or in Alum/MPLA. Injection with allergens in both Alum and Alum/MPLA resulted in significant increase in specific IgG subclasses and IgA against all r-allergens with no significant differences between the adjuvant groups. The induced antibodies from both groups could block binding of allergen specific IgE from IBH affected horses to a similar extent. No IgE-mediated reactions were induced. Allergen-stimulated PBMC from Alum/MPLA horses but not from Alum only horses produced significantly more IFNγ and IL-10 than PBMC from non-vaccinated control horses. In conclusion, intralymphatic administration of small amounts of pure allergens in Alum/MPLA induces high IgG antibody levels and Th1/Treg immune response and is a promising approach for immunoprophylaxis and immunotherapy against IBH.

CT thoracic duct lymphography in cats by popliteal lymph node iohexol injection.

Three different doses (1.0, 1.5, and 2.0 ml) of iohexol (300 mgl/ml) were injected percutaneously into the popliteal lymph node of eight adult cats under ultrasound guidance. Serial transverse CT images of five regions of interest (L3, T13, T8, T4, and T1 level) were performed at 2-min intervals, and the attenuation in Hounsfield Units (HU) of the lymphatic vessels was measured for determination of the optimal dose of iohexol and CT scan parameters. The optimal dose was 1.5 ml and helical CT acquisition is recommended to be performed as soon as possible after iohexol injection. In helical scans, the thoracic duct was characterized by variable branch numbers that formed a single trunk and entered the venous system at variable levels. CT lymphography using this protocol was performed in a cat with chylothorax. The thoracic duct was tortuous and focally dilated, and leakage of contrast medium was observed. Percutaneous CT lymphography using ultrasound-guided administration of iohexol into the popliteal lymph node appears reliable for delineation of the thoracic duct in cats.

Ultrasound-guided mesenteric lymph node iohexol injection for thoracic duct computed tomographic lymphography in cats.

Computed tomographic (CT) lymphography was performed in cats using percutaneous ultrasound-guided injection of contrast medium into a mesenteric lymph node. The thoracic duct and its branches were clearly delineated in CT images of seven cats studied. The thoracic duct was characterized by anatomic variation and appeared as single or multiple branches. The thoracic duct and the cisterna chyli were identified along the ventral or left ventral aspect of the vertebrae from the level of the cranial lumbar to the caudal cervical vertebrae. The thoracic duct was identified in the central caudal mediastinum, deviated to the left in the cranial mediastinum, and finally moved toward the venous system. Small volumes of extranodal contrast medium leakage were identified in all cats. After injection, the mesenteric lymph nodes were cytologically normal. Ultrasound-guided CT lymphography via percutaneous mesenteric lymph node injection appears safe and effective in cats.

Immunization with Staphylococcus aureus lysate incorporated into microspheres.

Antibiotics are of limited value against Staphylococcus aureus due to development of resistant strains, scar tissue formation, and blockage of ducts due to inflammation. Though macrophages are the predominant cell type in the mammary gland, they are primarily scavenger cells and are not effective against bacteria entering the gland. Neutrophil phagocytosis is the bovine's primary defense against S. aureus mastitis. Attempts to develop vaccines that enhance neutrophil phagocytosis by stimulating production of opsonizing antibodies to S. aureus have met with limited success because of the low immunogenicity of the exopolysaccharide capsule surrounding S. aureus. Staphylococcus aureus can also adhere to and penetrate epithelial tissue. This study was conducted to determine whether lysates of S. aureus encapsulated in biodegradable microspheres would increase the production of opsonizing antibodies to capsule and block adherence. Four groups of four cows each were injected with 1 ml of the respective treatment in the area of the supramammary lymph node and 1 ml in the hip muscle. The treatments were: lysate in NaCl, lysate in Freund's incomplete adjuvant (FICA), lysate in microspheres in NaCl, and lysate in microspheres in FICA. Antigen in microspheres produced a similar antibody response to antigen emulsified in FICA, but to a lesser magnitude. Antigen in microspheres produced antibodies that were more opsonic for neutrophils at 20 and 52 wk postimmunization and inhibited S. aureus adherence to mammary epithelium. Ability to control antigen release and presentation, and the benefit of a single injection for long-term immunity using microspheres warrants additional studies.

Effect of whole Staphylococcus aureus and mode of immunization on bovine opsonizing antibodies to capsule.

Exopolysaccharide capsule is a major virulence factor of Staphylococcus aureus because it inhibits neutrophil recognition of antibodies to highly antigenic S. aureus cell wall. To circumvent this inhibition, two modes of immunization were tested for ability to induce anticapsular opsonins. Cows were immunized at drying off and boosted on d 14 and 28 by injection of Smith diffuse S. aureus plus dextran sulfate in the area of the supramammary lymph node or intramammarily. In cows immunized in the area of the supramammary lymph node, IgG1 and IgG2 sera antibody titers to capsule increased and remained elevated to the end of the study, 120 d postcalving. The IgM titers increased during the dry period but declined to preimmunization levels at calving. Response of serum IgG1 and IgM to intramammary immunization was similar to that with supramammary lymph node immunization, but more delayed and lower in magnitude. Antibodies of all four isotypes, IgG1, IgG2, IgA, and IgM, increased in dry secretions following immunization via lymph node. In cows immunized in the lymph node, IgG1 antibodies remained elevated throughout the study, but IgG2 antibodies dropped to baseline 15 d postcalving. In cows immunized intramammarily, only IgA antibodies increased significantly in lacteal secretions and remained elevated throughout the study. Immunization of cows in the lymph node during the dry period enhanced the ability of dry secretions and colostrum to support phagocytosis.