Diagnostic reliability of cerebral spinal fluid tests for acute confusional state (delirium) in patients with systemic lupus erythematosus: interleukin 6 (IL-6), IL-8, interferon-alpha, IgG index, and Q-albumin.
OBJECTIVE
Acute confusional state (ACS) is an uncommon but severe central nervous system (CNS) syndrome in systemic lupus erythematosus (SLE) defined by clinical manifestations. To develop useful and reliable diagnostic tools for ACS, we evaluated the association of cerebral spinal fluid (CSF) tests with ACS and their predictive values for the diagnosis of ACS in SLE.


METHODS
We performed a prospective study using a cohort of 59 patients with SLE and compared those with and without ACS. Associations between ACS and each CSF test [interleukin 6 (IL-6), IL-8, interferon-alpha, IgG index, and Q-albumin] were statistically evaluated. Each patient underwent all CSF evaluations.


RESULTS
ACS was diagnosed in 10 patients (ACS group), SLE-related CNS syndromes except ACS in 13, and no CNS syndromes in 36 (non-CNS group). CSF IL-6 levels in the ACS group were significantly higher than those in the non-CNS group (p < 0.05). A positive IgG index (p = 0.028) was significantly associated with ACS. No other test showed a significant association with ACS. The positive and negative predictive values for the diagnosis of ACS in SLE were 80% and 85% for elevated CSF IL-6 levels (> or = 31.8 pg/ml), and 75% and 83% for the IgG index, respectively.


CONCLUSIONS
No single CSF test had sufficient predictive value to diagnose ACS in SLE, although CSF IL-6 levels and the IgG index showed statistical associations with ACS. Use of CSF tests combined with careful history and clinical examinations is recommended for proper diagnosis of ACS in SLE.
Katsumata
Yasuhiro
Y
Institute of Rheumatology ,Tokyo Women's Medical University, Tokyo, Japan. katsumata@ior.twmu.ac.jp
Harigai
Masayoshi
M
Kawaguchi
Yasushi
Y
Fukasawa
Chikako
C
Soejima
Makoto
M
Takagi
Kae
K
Tanaka
Michi
M
Ichida
Hisae
H
Tochimoto
Akiko
A
Kanno
Tokiko
T
Nishimura
Katsuji
K
Kamatani
Naoyuki
N
Hara
Masako
M
D000293:Adolescent; D000328:Adult; D015331:Cohort Studies; D003693:Delirium / Q000134:cerebrospinal fluid / Q000175:diagnosis / Q000209:etiology; D005260:Female; D006801:Humans; D016898:Interferon-alpha / Q000134:cerebrospinal fluid; D015850:Interleukin-6 / Q000134:cerebrospinal fluid; D016209:Interleukin-8 / Q000134:cerebrospinal fluid; D008180:Lupus Erythematosus, Systemic / Q000134:cerebrospinal fluid / Q000150:complications; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests
D016898:Interferon-alpha; D015850:Interleukin-6; D016209:Interleukin-8