Measurement of Neutrophil Gelatinase-Associated Lipocalin Concentration in Canine Cerebrospinal Fluid and Serum and Its Involvement in Neuroinflammation.

Neutrophil gelatinase-associated lipocalin (NGAL) is a glycoprotein is involved in inflammation acts as an acute phase protein and chemokines as well as a regulator of iron homeostasis. NGAL has proved to be upregulated in experimental autoimmune encephalomyelitis (EAE) in mice. Increasing concentrations of NGAL in Ovine Serum the cerebrospinal fluid (CSF) and the expression in the central nervous system (CNS) have been described in human neuroinflammatory diseases such as multiple sclerosis and lupus, neuropsychiatric and bacterial meningitis. 

We aimed to investigate the involvement of NGAL in spontaneous nerve inflammation dog as an animal model of the potential immune-mediated neurological disorders. A commercially available enzyme-linked immunosorbent assay (ELISA) for the detection of NGAL dog CSF validated for use in dogs. Concentration in CSF and serum of patients suffering from steroid-responsive dog meningitis- arteriitis (SRMA), Meningoencephalitis of unknown origin (Muo), different non-inflammatory and CNS disease compared to control dogs.

The relationship between the concentration in CSF and serum NGAL and inflammatory parameters in CSF and blood (IgA concentration, the total number of nucleated cells (TNCC), protein content) as well as the association with erythrocytes in CSF, duration of disease, plasma creatinine and urine leukocytes evaluated. In dogs with SRMA and Muo, CSF concentrations of NGAL were significantly higher than in dogs with idiopathic epilepsy, press myelopathy, intracranial neoplasia and SRMA in remission (p <0.0001). 

Patients with acute SRMA had significantly higher levels of NGAL in the CSF of neurologically normal controls (p <0.0001). serum concentrations of NGAL were significantly higher in dogs with SRMA compared to patients with myelopathy and intracranial neoplasia (p <0.0001). NGAL levels in CSF were positive correlated with the concentration of IgA (rSpear = 0.60116, p <0.0001), TNCC (rSpear = 0.65746, p <0.0001) and protein levels (rSpear = 0.73353, p <0.0001) in the CSF.

 It can be measured in the CSF of healthy dogs  and Ovine Serum Albumin sick. higher concentrations in patients dogs with SRMA and positive relationship with TNCC in CSF suggests involvement in pro-inflammatory pathways and chemotaxis in SRMA. high serum NGAL levels in serum of patients SRMA in various stages of the disease may reflect systemic character of the disease.