Increased soluble interleukin‐2 receptor concentrations in suicide attempters

Abstract

Several biochemical parameters such as monoamines and corticosteroids are considered to play a role in the underlying pathogenetic mechanisms in mood disorders. It has also been proposed that disturbances of the immune system may be responsible for mental disorders. Increased concentrations of plasma soluble interleukin-2 receptor (S-IL-2R) reflect an activation of T-lymphocytes. In plasma samples from medication-free suicide attempters with various psychiatric diagnoses (mainly mood disorders), we found a median S-IL-2R concentration far above the range of healthy controls. No sex differences and no differences between diagnostic and suicidal subgroups were noted. In follow-up samples, the S-IL-2R remained at high levels. In cerebrospinal fluid samples from patients, S-IL-2R levels were all below 200 U/ml. No samples from controls were available. We were unable to find pronounced associations between plasma S-IL-2R and various monoaminergic measures in plasma, 24-h urine and cerebrospinal fluid. There was, however, a tendency of an association between S-IL-2R and the ratio of norepinephrine-epinephrine in 24-h urine, as well as plasma and cerebrospinal fluid 4-hydroxy-3-methoxymethylglycol. There was no significant association between post-dexamethasone plasma cortisol, 24-h urinary cortisol and plasma S-IL-2R. Both when studied as medication-free inpatients and during follow-up as outpatients, there were no apparent associations between ratings of psychopathology and plasma S-IL-2R. This study clearly shows that an imbalance of the immune system was present in psychiatric patients studied after a suicide attempt.(ABSTRACT TRUNCATED AT 250 WORDS)

The immune-mediated alteration of serotonin and glutamate: towards an integrated view of depression

“…115 An epidemiological study also hypothezized that high IL-2 levels are associated with suicidality. 116 One study showed increased levels of serum sIL-2R in medication-free suicide attempters irrespective of the psychiatric diagnosis, 117 and treatment with high-dose IL-2 has been associated with suicide in a case report. 118 Different types of MD were observed to exhibit different immune profiles, the subgroup of melancholic depressed patients showed a decreased type 1 activation accompanied with a marked activation of the HPA axis, whereas the non-melancholic depressed patients showed signs of inflammation such as increased monocyte count and increased levels of IL-1b and a2-macroglobulin.…”

Soluble receptors in human disease

“…Soluble IL-2 receptor levels have also been reported to be elevated in those who attempted suicide and in patients after surgery [150,151]. In these situations, the reason for having increased circulating soluble IL-2 receptor is uncertain and may represent a nonspecific response to inflammation or stress.…”

Cytokine levels in the blood may distinguish suicide attempters from depressed patients

“…An initial study reported elevated concentrations of soluble IL-2 receptor (sIL-2R) in the blood of suicide attempters (Nassberger and Traskman-Bendz, 1993).…”