title: Serum IL-7 and G-CSF in major depressive disorder.
abstract: Major depressive disorder (MDD) has been associated with dysregulated immune systems and impaired T cell function, but data on depression-related alterations in the levels of immunomodulatory growth factors are scarce. In order to further clarify the mechanisms underlying immune system dysregulation in depressed subjects, we examined the associations between MDD and serum levels of two immunomodulatory growth factors, interleukin (IL)-7 and granulocyte-colony stimulating factor (G-CSF), in 122 subjects (MDD with long-term symptomatology, n=61; controls, n=61). The MDD subjects had lowered levels of IL-7. In a model adjusted for age, gender and body mass index, subjects in the lowest tertile of IL-7 had a 3.4-fold increased likelihood for MDD (p=0.010). Further adjustments for sleep disturbances, alcohol use, smoking, and metabolic syndrome did not alter these findings. Moreover, the exclusion of subjects with rheumatoid arthritis, coronary heart disease, or the use of non-steroidal anti-inflammatory medications or oral corticosteroids only slightly attenuated the findings. The G-CSF levels did not differ between the two groups. The lowering of the serum levels of IL-7, a regulator of T cell homeostasis, in MDD subjects may underlie the depression-related impaired T cell function.
authors.affiliation: Department of Psychiatry, Kuopio University Hospital and University of Eastern Finland, 70210 Kuopio, Finland. Soili.Lehto@kuh.fi
authors.forename: Soili M
authors.initials: SM
authors.lastname: Lehto
authors.forename: Anne
authors.initials: A
authors.lastname: Huotari
authors.forename: Leo
authors.initials: L
authors.lastname: Niskanen
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Herzig
authors.forename: Tommi
authors.initials: T
authors.lastname: Tolmunen
authors.forename: Heimo
authors.initials: H
authors.lastname: Viinamäki
authors.forename: Heli
authors.initials: H
authors.lastname: Koivumaa-Honkanen
authors.forename: Kirsi
authors.initials: K
authors.lastname: Honkalampi
authors.forename: Sanna
authors.initials: S
authors.lastname: Sinikallio
authors.forename: Heli
authors.initials: H
authors.lastname: Ruotsalainen
authors.forename: Jukka
authors.initials: J
authors.lastname: Hintikka
mesh_terms: D000328:Adult; D003865:Major Depressive Disorder / Q000097:blood*; D005260:Female; D016179:Granulocyte Colony-Stimulating Factor / Q000097:blood*; D006801:Humans; D015851:Interleukin-7 / Q000097:blood*; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011569:Psychiatric Status Rating Scales; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric
chemical_list: D015851:Interleukin-7; D016179:Granulocyte Colony-Stimulating Factor