Serum albumin level is associated with the severity of neurological dysfunction of NMOSD patients

Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory autoimmune disease of the central nervous system. Serum albumin (SA) has antioxidant, immunomodulatory and anti-inflammatory effects. However, the roles of SA in NMOSD have not been studied. The current study aimed to clarify the association of SA with disease severity and prognosis in NMOSD patients.

Serum levels of albumin were measured by Bromcresol Green method. Serum level measurements of interleukins were performed using enzyme-linked immunoassay (ELISA) method.

Of all the 130 NMOSD patients, 96 patients were in the acute phase while 34 patients were in the remission phase of disease at the time of sampling. SA concentration was significantly correlated with EDSS score in patients in the acute phase but not in remission phase (r = - 0.388, p < 0.001 and r = - 0.467, p = 0.809, respectively). Logistic analysis revealed that SA was the only significant factor to predict severe NMOSD (EDSS 8.0-9.5) OR = 0.698, 95%CI 0.563-0.865, p = 0.001) after adjustment of other confounding factors. Furthermore, SA was negatively correlated with the serum level of IL-33 (r = -0.438, p = 0.016) in the acute phase of NMOSD patients.

The current study found that low level of SA was an independent indicator of more severe neurological deficit in patients in acute phase of NMOSD. SA concentration was negatively correlated with the serum level of IL-33 in the acute phase of the disease, which implies that SA might participate in the immunopathology of NMOSD partly through its interaction with IL-33.