Elevated cerebrospinal fluid levels of total protein in patients with secondary central nervous system vasculitis and giant cell arteritis.

Objectives: Secondary central nervous system vasculitis (SCNSV) is an extremely rare, refractory, and fatal disease in patients with giant cell arteritis (GCA). We compared the characteristics of GCA patients with and without SCNSV. Methods: This retrospective, single-center, observational cohort study included 35 patients with GCA admitted to Juntendo University Hospital from April 2009 to March 2019. The primary outcome was all-cause mortality. Results: We diagnosed four patients with GCA and SCNSV (SCNSV group) and 31 patients with GCA but no SCNSV (non-SCNSV group). The mortality rate of the SCNSV and non-SCNSV groups were 100% and 10%, respectively (p = 0.001). The SCNSV group had lower serum levels of C-reactive protein at the time of GCA diagnosis and higher cerebrospinal fluid (CSF) levels of total protein (102 mg/dL vs. 38 mg/dL, p = 0.008) and albumin (66 mg/dL vs. 21 mg/dL, p = 0.008) at the time of SCNSV diagnosis. Conclusions: At the time of SCNSV diagnosis, GCA patients had elevated CSF total protein and albumin levels. CSF examination in GCA patients suspected of having SCNSV may be useful for early diagnosis of SCNSV.