title: Influence of Allergy on Immunoglobulins and Amyloid-β in the Cerebrospinal Fluid of Patients with Alzheimer's Disease.
abstract: BACKGROUND
  Peripheral inflammation has been suggested to influence the development of Alzheimer's disease (AD). Elevated levels of pro-inflammatory markers in the plasma of patients with AD indicate that a systemic pro-inflammatory status occurs concomitantly with inflammatory changes in the brain.
  
  
  OBJECTIVE
  To investigate whether allergy influences the levels of immunoglobulins (Ig) and of pro- and anti-inflammatory cytokines in the serum and cerebrospinal fluid (CSF) from patients with AD, mild cognitive impairment (MCI), and subjective cognitive impairment (SCI).
  
  
  METHODS
  IgA, IgG, and its subclasses, IgM, and cytokines were analyzed in CSF and serum from patients with SCI, MCI, and AD, with or without allergy. The relation between allergy and Mini-Mental State Examination (MMSE) scores, and between allergy and CSF biomarkers for AD (phosphorylated (p)-tau, total (t)-tau, amyloid-β 42 (Aβ₄₂), were analyzed.
  
  
  RESULTS
  In MCI, the CSF levels of IgG2 were lower in allergic patients, and in AD, the levels of IgA and the IgG1/total IgG ratio were lower in allergic patients, compared to patients without allergy. MCI subjects with allergy had higher serum IgM levels compared to those without allergy. CSF levels of Aβ₄₂ were lower and MMSE scores were higher in AD patients with allergy than in those without allergy.
  
  
  CONCLUSIONS
  The presence of allergy was associated with seemingly beneficial effects on AD as suggested by higher Aβ₄₂ levels in CSF, and higher MMSE scores. Higher IgM levels and lower other Ig classes suggest that allergy may influence senescence of the immune response.
authors.affiliation: Karolinska Institutet, Department of Neurobiology, Care Sciences and Society, Center for Alzheimer research, Section for Neurodegeneration, Novum, Huddinge, Sweden.
authors.forename: Heela
authors.initials: H
authors.lastname: Sarlus
authors.affiliation: Karolinska Institutet, Department of Neurobiology, Care Sciences and Society, Center for Alzheimer research, Section for Clinical Geriatrics, Novum, Huddinge, Sweden.|Department of Geriatric Medicine, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Helga
authors.initials: H
authors.lastname: Eyjolfsdottir
authors.affiliation: Karolinska Institutet, Department of Neurobiology, Care Sciences and Society, Center for Alzheimer research, Section for Clinical Geriatrics, Novum, Huddinge, Sweden.|Department of Geriatric Medicine, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Maria
authors.initials: M
authors.lastname: Eriksdotter
authors.affiliation: Karolinska Institutet, Department of Neurobiology, Care Sciences and Society, Center for Alzheimer research, Section for Neurodegeneration, Novum, Huddinge, Sweden.|Department of Neurology, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Mircea
authors.initials: M
authors.lastname: Oprica
authors.affiliation: Karolinska Institutet, Department of Neurobiology, Care Sciences and Society, Center for Alzheimer research, Section for Neurodegeneration, Novum, Huddinge, Sweden.
authors.forename: Marianne
authors.initials: M
authors.lastname: Schultzberg
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000097:blood / Q000134:cerebrospinal fluid / Q000150:complications / Q000276:immunology*; D016229:Amyloid beta-Peptides / Q000097:blood / Q000134:cerebrospinal fluid*; D015415:Biomarkers / Q000097:blood / Q000134:cerebrospinal fluid; D003072:Cognition Disorders / Q000097:blood / Q000134:cerebrospinal fluid / Q000150:complications / Q000276:immunology*; D016207:Cytokines / Q000097:blood / Q000134:cerebrospinal fluid; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000097:blood / Q000134:cerebrospinal fluid* / Q000150:complications; D007136:Immunoglobulins / Q000097:blood / Q000134:cerebrospinal fluid*; D008297:Male; D008609:Mental Status Schedule; D008875:Middle Aged; D010446:Peptide Fragments / Q000097:blood / Q000134:cerebrospinal fluid*; D016875:tau Proteins / Q000097:blood / Q000134:cerebrospinal fluid
chemical_list: D016229:Amyloid beta-Peptides; D015415:Biomarkers; D016207:Cytokines; D007136:Immunoglobulins; C054369:MAPT protein, human; D010446:Peptide Fragments; C075222:amyloid beta-protein (1-42); D016875:tau Proteins
keywords: Cerebrospinal fluid; Mini-Mental State Examination; cytokines; mild cognitive impairment; serum; subjective cognitive impairment; systemic inflammation; tau