Antibodies against N-methyl-D-aspartate receptors in patients with systemic lupus erythematosus without major neuropsychiatric syndromes.
OBJECTIVE
Approximately 14-54% of patients with systemic lupus erythematosus without a history of major neuropsychiatric syndromes (nonNPSLE) have cognitive deficits. Elevated N-methyl-D-aspartate (NMDA) receptor antibodies (anti-NR2) have been reported in 35% of patients with SLE, but few studies have utilized controls or a composite memory index. We hypothesized that serum anti-NR2 would be elevated in nonNPSLE compared to healthy controls, and that elevated anti-NR2 would be associated with memory dysfunction and depression.


METHODS
Subjects included 43 nonNPSLE patients with a mean age of 36.5 (SD=9.0) and mean education level of 14.7 years (SD=2.5). Twenty-seven healthy control subjects with similar demographic characteristics were also enrolled in this study. A global Cognitive Impairment Index (CII) and a Memory Impairment Index (MII) were calculated using impaired test scores from the ACR-SLE neuropsychological battery. Serum samples were analyzed using a standard ELISA for anti-NR2.


RESULTS
Elevations of serum anti-NR2 were found in 14.0% of the nonNPSLE and 7.4% of the controls (p=0.47). There was no relationship between elevated anti-NR2 status and higher CII or performance on the MII. No relationship between levels of depressive symptoms and anti-NR2 was found.


CONCLUSIONS
The frequency of elevated anti-NR2 was low (14.0%) in this sample of SLE patients and not significantly different from controls. A relationship was not found between the presence of anti-NR2 in serum and global cognitive or memory indices, or with depression. Results suggest that serum anti-NR2 is not likely related to mild cognitive dysfunction in SLE patients without a prior history of NPSLE.
Kozora
Elizabeth
E
National Jewish Health, Denver, CO 80206, USA. Kozorae@njhealth.org
West
Sterling G
SG
Maier
Steven F
SF
Filley
Christopher M
CM
Arciniegas
David B
DB
Brown
Mark
M
Miller
David
D
Grimm
Alex
A
Zhang
Lening
L
D000109:Acetylcholine / Q000378:metabolism; D000293:Adolescent; D000328:Adult; D000906:Antibodies / Q000097:blood*; D003072:Cognition Disorders / Q000209:etiology; D005260:Female; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000097:blood* / Q000150:complications / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011446:Prospective Studies; D016194:Receptors, N-Methyl-D-Aspartate / Q000276:immunology*; D055815:Young Adult
D000906:Antibodies; C120997:NR2A NMDA receptor; D016194:Receptors, N-Methyl-D-Aspartate; D000109:Acetylcholine