Utility of serum S100B protein for identification of central nervous system involvement in systemic lupus erythematosus.
OBJECTIVE
To evaluate utility of S100B protein in serum as a marker of central nervous system involvement in systemic lupus erythematosus (SLE).


METHODS
Forty patients with SLE, hospitalized because of central neuropsychiatric (cNP) manifestations (n = 36) and peripheral NP manifestations (pNP, n = 4) were studied. Patients were evaluated at hospitalization and 6 months later, including a serum and cerebrospinal fluid (CSF) sample. As controls, 4 SLE patients with septic meningitis (SLEsm), 13 surgical SLE patients (SLE surgical), 14 patients with nonautoimmune diseases, and 4 patients with primary NP syndromes were included. Serum and CSF S100B protein levels were determined by ELISA.


RESULTS
At baseline, serum levels of S100B protein did not differ across SLE groups. Using an arbitrary cutoff value, positive S100B levels in serum were observed in 7 (19%), 6 (46%), and 1 patient from the cNPSLE, SLE surgical, and SLEsm groups, respectively. S100B protein levels in cNPSLE and SLE surgical patients were similar. In CSF, S100B protein levels did not differ among SLE groups, except in patients with SLEsm. Paired serum/CSF samples were obtained in 23 patients with cNPSLE at 6 months after the acute event. Overall, levels of S100B protein in serum did not change despite the decrease observed in CSF (p = 0.004). The correlation coefficient of serum and CSF S100B protein levels among all the SLE patients at baseline was poor (r = 0.23).


CONCLUSIONS
Serum levels of S100B protein do not differentiate SLE patients with and those without central neurological manifestations.
Fragoso-Loyo
Hilda
H
Department of Immunology and Rheumatology, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Vasco de Quiroga 15, Tlalpan, 14000, México, DF, México.
Cabiedes
Javier
J
Atisha-Fregoso
Yemil
Y
Llorente
Luis
L
Sánchez-Guerrero
Jorge
J
D000328:Adult; D000704:Analysis of Variance; D015415:Biomarkers / Q000097:blood / Q000134:cerebrospinal fluid; D002490:Central Nervous System / Q000276:immunology*; D016009:Chi-Square Distribution; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000097:blood* / Q000134:cerebrospinal fluid / Q000276:immunology; D020945:Lupus Vasculitis, Central Nervous System / Q000097:blood* / Q000134:cerebrospinal fluid / Q000276:immunology; D008297:Male; D009414:Nerve Growth Factors / Q000097:blood* / Q000134:cerebrospinal fluid; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins / Q000097:blood* / Q000134:cerebrospinal fluid; D012720:Severity of Illness Index
D015415:Biomarkers; D009414:Nerve Growth Factors; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins; C579160:S100B protein, human