Effects of in vivo and in vitro administration of neuro-Behcet's disease IgG

Antibody induced seizure susceptibility and impaired cognitive performance in a passive transfer rat model of autoimmune encephalitis

Objective

Autoimmune encephalitis (AE) is a distinct neuro-immunological disorder associated with the production of autoantibodies against neuronal proteins responsible for pharmacoresistant seizures, cognitive decline and behavioral problems. To establish the causal link between leucine-rich glioma inactivated 1 (LGI1) antibody and seizures, we developed an in-vivo antibody-mediated AE rat model in which serum antibodies (IgG) obtained from blood samples of leucine-rich glioma inactivated 1 (LGI1) protein antibody (IgG) positive encephalitis patients were passively transferred into non-epileptic Wistar rats. Serum IgG of N-methyl-d-aspartate receptor (NMDAR) antibody positive patients were used as positive control since the pathogenicity of this antibody has been previously shown in animal models.

Methods

Total IgG obtained from the pooled sera of NMDAR and LGI1-IgG positive patients with epileptic seizures and healthy subjects was applied chronically every other day for 11 days into the cerebral lateral ventricle. Spontaneous seizure development was followed by electroencephalography. Behavioral tests for memory and locomotor activity were applied before and after the antibody infusions. Then, pentylenetetrazol (PTZ) was administered intraperitoneally to evaluate seizure susceptibility. Immunohistochemistry processed for assessment of hippocampal astrocyte proliferation and expression intensity of target NMDAR and LGI1 antigens.

Results

No spontaneous activity was observed during the antibody infusions. PTZ-induced seizure stage was significantly higher in the NMDAR-IgG and LGI1-IgG groups compared to control. Besides, memory deficits were observed in the NMDAR and LGI1-IgG groups. We observed enhanced astrocyte proliferation in NMDAR- and LGI1-IgG groups and reduced hippocampal NMDAR expression in NMDAR-IgG group.

Significance

These findings suggest that neuronal surface auto-antibody administration induces seizure susceptibility and disturbed cognitive performance in the passive transfer rat model of LGI1 AE, which could be a potential in-vivo model for understanding immune-mediated mechanisms underlying epileptogenesis and highlight the potential targets for immune-mediated seizures in AE patients.

Effect of combined colchicine-corticosteroid treatment on neutrophil/lymphocyte ratio: a predictive marker in Behçet disease activity

BACKGROUND AND AIMS

Behçet's disease (BD) is an auto-immune vasculitis, characterized by episodic inflammation of multiple organs. The neutrophil to lymphocyte ratio (NLR) is used as a marker of inflammation in several diseases nowadays. While nitric oxide (NO) seem to be involved in BD pathogenicity. Our study aims to investigate the NLR as an inflammatory marker of BD activity as well as to evaluate the relationship between the NO production and NLR in Algerian BD patients with different clinical manifestations before and under colchicine + corticosteroid treatment.

METHODS

For this purpose, we evaluated the NLR as the ratio of neutrophil count to lymphocyte count in naïve and treated active BD patients with different clinical manifestations and in inactive ones. Furthermore, we assessed NO production by the Griess' method in the same patients. Additionally, we evaluated in vivo interferon-γ (IFN-γ) and interleukin-4 (IL-4) levels using ELISA.

RESULTS AND DISCUSSION

Our results indicate that the NLR and nitrite levels were higher in naïve active BD patients. Interestingly, this high ratio and NO production differed according to the clinical manifestations and was associated with an increased risk of mucocutaneous and vascular involvement. Importantly, in treated BD patients NLR was higher in active patients especially in those with mucocutaneous involvement while increased nitrites levels were regardless of the clinical manifestations studied. Both NLR and NO production decreased in these treated active patients. In addition, IL-4 production differed according to the clinical manifestations studied contrary to the IFN-γ production.

CONCLUSION

Collectively our results suggest that the NLR is a potential marker of BD activity in Algerian patients, predicting the disease severity. Moreover, the positive relationship between the NLR and NO production is related to an increased risk of mucocutaneous lesions and vascular involvement. Thus, the application of these two accessible tools could be benefit for the clinical prognosis and treatment of BD.

Past and Present Behçet's Disease Animal Models

Behçet's disease (BD) is presumably an autoinflammatory disease of unknown etiology for which several animal models have been described over the years. Agents and methods used for the development of these models have ranged from the herpes simplex type one virus (hsv-1) pathogen to the use of transgenic mice. Other models have also been used to investigate a possible autoimmune component. Each model possesses its own unique set of benefits and shortcomings, with no one model fully being able to recapitulate the disease phenotype. Here, we review the proposed models and provide commentary on their effectiveness and usefulness in studying the disease.