Similar immune profile in bipolar disorder and schizophrenia: selective increase in soluble tumor necrosis factor receptor I and von Willebrand factor.
BACKGROUND
Alterations in the inflammatory system have been associated with schizophrenia and major depression, while bipolar disorder has been less studied. Most previous studies examined small samples, and the literature is inconsistent with regard to specific underlying immune mechanisms. In the present study, we examined markers representing different inflammatory pathways, and the aim was to investigate whether the levels of inflammatory parameters in a representative sample of bipolar disorder and schizophrenia are elevated compared to healthy controls, and to investigate whether the inflammatory profile is different between the groups.


METHODS
Plasma levels of soluble tumor necrosis factor receptor 1 (sTNF-R1), interleukin-1 receptor antagonist (IL-1Ra), interleukin-6 (IL-6), high-sensitivity CRP (hs-CRP), soluble CD40L ligand (sCD40L), and von Willebrand factor (vWf) were measured with ELISA techniques in a catchment area based sample of consecutively referred patients with severe mental disorders [N = 311, comprising bipolar disorder (n = 125) and schizophrenia (n = 186)] and in healthy volunteers (n = 244).


RESULTS
Plasma levels of sTNF-R1 and vWf were statistically significantly increased in both bipolar disorder and schizophrenia compared to controls (p < 0.00001), and were also increased in unmedicated patients, but there were no major differences between the two diagnostic groups. Controlling for age, gender, ethnicity, cardiovascular disorders, kidney and liver function, and other confounders did not affect the results. There were no differences in other inflammation factors between the groups.


CONCLUSIONS
The present results indicate specific alterations of endothelium-related inflammation processes in both bipolar disorder and schizophrenia.
Department of Psychiatry, Østfold Hospital, Eidsberg, Norway. sigrun.hope@medisin.uio.no
Sigrun
S
Hope
Ingrid
I
Melle
Pål
P
Aukrust
Nils Eiel
NE
Steen
Astrid B
AB
Birkenaes
Steinar
S
Lorentzen
Ingrid
I
Agartz
Thor
T
Ueland
Ole A
OA
Andreassen
D000293:Adolescent; D000328:Adult; D000368:Aged; D001714:Bipolar Disorder / Q000097:blood* / Q000276:immunology; D002097:C-Reactive Protein / Q000378:metabolism; D023201:CD40 Ligand / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D006801:Humans; D053590:Interleukin 1 Receptor Antagonist Protein / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D008297:Male; D008875:Middle Aged; D012559:Schizophrenia / Q000097:blood* / Q000276:immunology; D018709:Statistics, Nonparametric; D014409:Tumor Necrosis Factor-alpha / Q000097:blood*; D055815:Young Adult; D014841:von Willebrand Factor / Q000378:metabolism*
D053590:Interleukin 1 Receptor Antagonist Protein; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D014841:von Willebrand Factor; D023201:CD40 Ligand; D002097:C-Reactive Protein