Effects of interleukin-6 on depression risk in dialysis patients.
OBJECTIVE
Depression represents the most frequent psychiatric disorder in nephrology. Cytokines, and especially IL-6, were found to be elevated in depressed patients with normal renal function. The objective of this pilot study was to examine the relationship between depression and cytokines (IL-6, TNF-alpha, and IL-10) in patients with end-stage kidney disease (ESKD).


METHODS
We studied 44 stable patients with ESKD for 71 +/- 66 months (32 males; 64 +/- 13 years; 27 on hemodialysis and 17 on peritoneal dialysis). The control group included 20 healthy age- and gender-matched individuals (12 males; 60 +/- 12 years). Depression was assessed by the Zung Self-Rating Depression Scale (ZS). Nephelometry for high-sensitivity CRP and ELISA kits for IL-6, IL-10 and TNF-alpha were used.


RESULTS
Compared to controls, patients with ESKD had higher ZS scores (56.8 +/- 16.8 vs. 44 +/- 12.7, p < 0.01), WBC (7,987 +/- 2,347 vs. 6,413 +/- 870/mm(3), p < 0.01), ESR (36.3 +/- 15.8 vs. 9.4 +/- 3.3 mm, p < 0.001), TNF-alpha (52 +/- 18.4 vs. 10.7 +/- 2.8 pg/ml, p < 0.001) and IL-6 (6.3 +/- 4 vs. 1.8 +/- 0.4 pg/ml, p < 0.001). No differences in high-sensitivity CRP and IL-10 were noted between the ESKD and control groups. Serum IL-6 levels were the only parameter positively correlated with the values of the ZS score in ESKD patients (r = 0.34, p < 0.02).


CONCLUSIONS
IL-6 may play a role in the pathogenesis of depression in patients with ESKD.
Sonikian
Makrouhi
M
Department of Nephrology, A. Fleming General Hospital, Athens, Greece.
Metaxaki
Polyxeni
P
Papavasileiou
Dimitrios
D
Boufidou
Fotini
F
Nikolaou
Chrysoula
C
Vlassopoulos
Dimosthenis
D
Vlahakos
Demetrios V
DV
D003863:Depression / Q000097:blood / Q000209:etiology*; D005260:Female; D006801:Humans; D016753:Interleukin-10 / Q000097:blood / Q000502:physiology; D015850:Interleukin-6 / Q000097:blood / Q000502:physiology*; D007676:Kidney Failure, Chronic / Q000097:blood / Q000150:complications* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D006435:Renal Dialysis; D012307:Risk Factors; D014409:Tumor Necrosis Factor-alpha / Q000097:blood / Q000502:physiology
D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10