Retrospective evaluation of hyperproteinorrachia without pleocytosis (albuminocytologic dissociation) and survival in dogs

Abstract

Background: Hyperproteinorrachia (raised cerebrospinal fluid total protein [CSF-TP]) without pleocytosis (HP) (also known as albuminocytologic dissociation) is identified in dogs with different neurologic diseases. However, the association between survival and increased CSF-TP is unknown.

Objectives: (a) Identify conditions commonly associated with HP in dogs and (b) investigate whether higher CSF-TP concentrations or other relevant factors are associated with 1-year survival.

Methods: This is a retrospective study that identified dogs with HP (Cisternal CSF-TP >0.30 g/L, Lumbar CSF-TP >0.45 g/L with total nucleated cell concentrations [TNCCs] and RBC counts within RIs) from 2008 to 2019: recording signalment, weight, vital parameters, inflammation, neuroanatomic localization, CSF-TP, sampling site, final diagnosis, etiologic classification, and 1-year survival. Corrected CSF-TP was calculated as CSF-TP minus 0.3 (cisternal) or 0.45 (lumbar or unknown). Descriptive statistics were produced, CSF-TP differences between groups (eg, neuroanatomic localizations) were evaluated using the Mann-Whitney U test or Kruskal-Wallis test (post-hoc testing). The Cox proportional hazards model was used for survival data. Statistical significance was set at a P < 0.05.

Results: In all, 39 dogs had HP, associated with 17 conditions, including neoplasia (n = 6), meningoencephalitis of unknown origin (n = 4) (MUO), and intervertebral disc disease (n = 4) (IVDD) as the most common conditions. There was no significant difference between the CSF-TP/corrected CSF-TP between 1-year survivors and non-survivors, nor was there a difference between different neuroanatomic localizations or etiologic classifications (P > 0.05). Neoplasia, after adjustment for age, was the only variable associated with a worse survival (P = 0.01 HR: 2.08 (95% CI: 1.65-39.2). CSF-TP was not associated with age (P > 0.05).

Conclusions: HP in dogs is associated with a wide range of conditions; the most common conditions are neoplasia, MUO, and IVDD. Higher CSF-TP levels do not correlate with a worse 1-year survival; however, they do correlate with neoplastic lesions.