International Veterinary Epilepsy Task Force Consensus Proposal: Outcome of therapeutic interventions in canine and feline epilepsy

Common criteria for the diagnosis of drug resistance and the assessment of outcome are needed urgently as a prerequisite for standardized evaluation and reporting of individual therapeutic responses in canine epilepsy. Thus, we provide a proposal for the definition of drug resistance and partial therapeutic success in canine patients with epilepsy. This consensus statement also suggests a list of factors and aspects of outcome, which should be considered in addition to the impact on seizures. Moreover, these expert recommendations discuss criteria which determine the validity and informative value of a therapeutic trial in an individual patient and also suggest the application of individual outcome criteria. Agreement on common guidelines does not only render a basis for future optimization of individual patient management, but is also a presupposition for the design and implementation of clinical studies with highly standardized inclusion and exclusion criteria. Respective standardization will improve the comparability of findings from different studies and renders an improved basis for multicenter studies. Therefore, this proposal provides an in-depth discussion of the implications of outcome criteria for clinical studies. In particular ethical aspects and the different options for study design and application of individual patient-centered outcome criteria are considered

Pharmacogenetic association study of 30 genes with phenobarbital drug response in epileptic dogs

BACKGROUND: Epilepsy, with a prevalence as high as 6%, is the most common neurological disorder in dogs. Although several antiepileptic drugs are in common use, in one-third of all epileptic dogs, adequate seizure control is not achieved with a single medication, and hence a combinatorial drug treatment must be adopted. Exploration of the genetic mechanisms involved in drug response may provide better treatment options for epileptic patients. METHODS AND RESULTS: A custom Illumina BeadChip was designed for high throughput genotyping of 384 single nucleotide polymorphisms in 30 genes involved in drug metabolism, drug targeting, and drug transport. A case-control association study of 125 epileptic dogs identified five genes with suggestive association to phenobarbital drug response: KCNQ3, P=0.0003; SNC2A2, P=0.0008; EPOX HYD, P=0.0005; ABCC4, P=0.0091; and GABRA2, P=0.0130. These associations are not significant after adjustment for multiple comparisons, but on functional grounds may tag strong candidate genes. The study was powered to detect alleles with at least 3.5-fold additive increases in responsiveness. A combined area under the curve value of 0.74 from receiver operating curve analysis also provides suggestive support for their consideration as canine pharmacogenetic markers. CONCLUSION: Further replication and assessment of breed specificity is required before these markers can be considered as predictive of responsiveness to phenobarbital in dogs

Intruders below the Radar: Molecular Pathogenesis of Bartonella spp

Summary: Bartonella spp. are facultative intracellular pathogens that employ a unique stealth infection strategy comprising immune evasion and modulation, intimate interaction with nucleated cells, and intraerythrocytic persistence. Infections with Bartonella are ubiquitous among mammals, and many species can infect humans either as their natural host or incidentally as zoonotic pathogens. Upon inoculation into a naive host, the bartonellae first colonize a primary niche that is widely accepted to involve the manipulation of nucleated host cells, e.g., in the microvasculature. Consistently, in vitro research showed that Bartonella harbors an ample arsenal of virulence factors to modulate the response of such cells, gain entrance, and establish an intracellular niche. Subsequently, the bacteria are seeded into the bloodstream where they invade erythrocytes and give rise to a typically asymptomatic intraerythrocytic bacteremia. While this course of infection is characteristic for natural hosts, zoonotic infections or the infection of immunocompromised patients may alter the path of Bartonella and result in considerable morbidity. In this review we compile current knowledge on the molecular processes underlying both the infection strategy and pathogenesis of Bartonella and discuss their connection to the clinical presentation of human patients, which ranges from minor complaints to life-threatening disease