Quinolinic acid in patients with systemic lupus erythematosus and neuropsychiatric manifestations.
OBJECTIVE
To evaluate the relationship between quinolinic acid, a neuroactive metabolite of L-tryptophan, and neuropsychiatric manifestations of systemic lupus erythematosus (SLE).


METHODS
Forty specimens of cerebrospinal fluid (CSF) were obtained from 39 patients with SLE who were evaluated for 40 episodes of neuropsychiatric dysfunction. The diagnosis of the neuropsychiatric dysfunction was determined clinically. CSF and serum specimens were analyzed for levels of quinolinic acid without knowledge of the clinical diagnosis.


RESULTS
Neuropsychiatric dysfunction attributed to SLE (NPSLE) was confirmed in 30 patient-episodes (Group 1), whereas in the other 10 (Group 2) other etiologies were felt to explain their CNS dysfunction. The median levels of CSF quinolinic acid for Group 1 (232.5 nmol/l) were significantly higher than those for Group 2 (median 38.2 nmol/l) (p < 0.014). CSF and serum quinolinic acid levels correlated significantly (p < 0.003) but there was not correlation between CSF quinolinic acid and CSF protein concentrations or white blood cell counts.


CONCLUSIONS
We conclude that elevated quinolinic acid levels in the CSF and serum may be associated with NPSLE and could possibly play a role in its pathogenesis.
Vogelgesang
S A
SA
Rheumatology Services, Walter Reed Army Medical Center, Washington, DC. USA.
Heyes
M P
MP
West
S G
SG
Salazar
A M
AM
Sfikakis
P P
PP
Lipnick
R N
RN
Klipple
G L
GL
Tsokos
G C
GC
D000328:Adult; D001927:Brain Diseases / Q000175:diagnosis / Q000209:etiology* / Q000378:metabolism; D003710:Demography; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000097:blood / Q000134:cerebrospinal fluid / Q000150:complications*; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D017378:Quinolinic Acid / Q000032:analysis*; D014057:Tomography, X-Ray Computed; D014364:Tryptophan / Q000378:metabolism
D014364:Tryptophan; D017378:Quinolinic Acid