title: Utility of interferon-α as a biomarker in central neuropsychiatric involvement in systemic lupus erythematosus.
abstract: OBJECTIVE
  To assess the utility of interferon-α (IFN-α) in serum and cerebrospinal fluid (CSF) as a biomarker of disease activity in central neuropsychiatric systemic lupus erythematosus (cNPSLE).
  
  
  METHODS
  Serum and CSF samples were drawn at hospitalization in 34 patients with cNPSLE, 16 surgical SLE, 4 primary neuropsychiatric conditions, and 25 with nonautoimmune conditions, except in 44 non-NPSLE patients in whom only serum was studied. Six months later, serum/CSF and serum samples were taken in 20 cNPSLE and 35 non-NPSLE patients, respectively. SLE activity was assessed at hospitalization, and 6 months later in cNPSLE and non-NPSLE patients. IFN-α was detected by Luminex technology.
  
  
  RESULTS
  The mean ± SD age of patients with cNPSLE was 31.4 ± 12.2 years, which was similar across the study groups (p = 0.46). Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) scores among cNPSLE, non-NPSLE, and SLE-surgical patients were 15.3 ± 8.2, 12.4 ± 8.2, and 3.8 ± 1.5, respectively. IFN-α levels in serum were higher in cNPSLE than in nonautoimmune patients (p = 0.02), but were similar to non-NPSLE and SLE-surgical groups. In CSF samples, IFN-α levels were higher in cNPSLE than in nonautoimmune patients (p = 0.03), and were nonsignificantly higher than in SLE-surgical and primary neuropsychiatric patients. Six months later, serum levels of IFN-α did not vary from baseline values despite a significant decrease in SLEDAI-2K score in cNPSLE and non-NPSLE patients. IFN-α levels in the CSF of patients with cNPSLE also remained stable. Among specific cNPSLE syndromes, CSF IFN-α levels were significantly higher among patients with acute confusional syndrome.
  
  
  CONCLUSIONS
  IFN-α does not seem to represent a useful biomarker of cNPSLE syndromes; its utility in specific cNPSLE manifestations merits further investigation.
authors.affiliation: Department of Immunology and Rheumatology, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico.
authors.forename: Hilda
authors.initials: H
authors.lastname: Fragoso-Loyo
authors.forename: Yemil
authors.initials: Y
authors.lastname: Atisha-Fregoso
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Núñez-Alvarez
authors.forename: Luis
authors.initials: L
authors.lastname: Llorente
authors.forename: Jorge
authors.initials: J
authors.lastname: Sánchez-Guerrero
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood / Q000134:cerebrospinal fluid; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D016898:Interferon-alpha / Q000097:blood* / Q000134:cerebrospinal fluid*; D008180:Lupus Erythematosus, Systemic / Q000097:blood / Q000134:cerebrospinal fluid / Q000175:diagnosis; D020945:Lupus Vasculitis, Central Nervous System / Q000097:blood / Q000134:cerebrospinal fluid / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012720:Severity of Illness Index
chemical_list: D015415:Biomarkers; D016898:Interferon-alpha