. 2009 Jan 8;2:1–19. doi: 10.4137/ijtr.s2097

Table 2.

Studies investigating kynurenine metabolites in CSF.

Ref.	Pathology	Compound	Patients	Controls	Comments
Young et al. 1983¹⁸³	Epilepsy	TRP (μM)	1.58 ± 0.61	1.66 ± 0.64	CSF data shown here were from the lumbar region. Cisternal CSF showed no differences between patients and controls and there were no CSF gradient differences either.
		KYN (nM)	28.4 ± 15.3^*	43.9 ± 24.5
		5-HIAA (nM)	96.7 ± 37.7	117.2 ± 62.7
Larsson et al. 1989¹⁶⁶	HIV	TRP (nM)	1518	2179	No significant change in 5-HIAA.
Baig et al. 1991¹²⁵	MS and Cerebro-vascular disease (CVD)	TRP (nM)	1.25 ± 0.14⁺ (MS)	2.02 ± 0.34	Metabolites of the noradrenergic and dopaminergic systems [3-methoxy-4-hydroxyphenylglyco (MHPG), 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA)] were also found to be significantly different in MS and CVD patients compared to controls.
		TRP (nM)	3.34 ± 0.54⁺ (CVD)	2.02 ± 0.34
		5-HT (pM)	5 ± 1^* (MS)	7 ± 2
		5-HT (pM)	7 ± 2 (CVD)	7 ± 2
		5-HIAA (pM)	116 ± 15^** (MS)	173 ± 20
		5-HIAA (pM)	299 ± 50^** (CVD)	173 ± 20
Gisslen et al. 1994¹⁸⁴	HIV	TRP (nM)	1097 (pre)		3–14 months treatment with zidovudin. Decrease in neopterin correlated with increase in TRP. 5-hydroxyindoleacetic acid (5-HIAA).
Gisslen et al. 1994¹⁸⁴	HIV	TRP (nM)	1535.8 (post)
Heyes et al. 1994¹⁶⁷	Epilepsy (intractable complex partial)	TRP (μM)	No difference	1.32 ± 0.13	I.I.: inter-ictal; P.I.: post-ictal Data are shown only when differences were significant. Patients’ data are approximates as results were presented only with a bar graph. QUIN:KYNA in patients vs. controls: 61.1 ± 11.1^ (I.I.), 58.3 ± 5.55^(P.I.) vs.* 86.1 ± 19.4
		KYN (nM)	68.1 ± 2.78⁺ (I.I.)	42.2 ± 3.8
		KYN (nM)	65.3 ± 2.78⁺ (P.I.)	42.2 ± 3.8
		KYNA (nM)	No difference	2.32 ± 0.35
		QUIN (nM)	72.2.1 ± 2.78⁺ (I.I.)	21.9 ± 2.8
		QUIN (nM)	68.1 ± 2.78⁺ (P.I.)	21.9 ± 2.8
Demitrack et al. 1995¹¹⁷	Eating disorders (anorexia nervosa)	TRP (nM)	1.9 ± 0.5	2.1 ± 0.3	In anorectics, weight normalized restored all compounds tested to within the control range. The relative amount of QUIN (QUIN: KYNA) was significantly higher during the underweight phase for anorectics. Kynurenines were within control range for normal weight bulimics.
		KYN (nM)	25.6 ± 9.9	34.4 ± 12.3
		KYNA (nM)	1.5 ± 0.5^*	2.8 ± 1.2
		QUIN (nM)	13.4 ± 5.4	13.8 ± 4.3
		5-HIAA (nM)	107.2 ± 31.4^*	146.3 ± 30.2
Heyes et al. 1995¹⁸⁵	CNS pathology	QUIN (nM)	31 ± 5 (Hy)	20 ± 2	Hy: hydrocephalus; H: haemorrhage; T: tumour; C: CSF infection. Subjects were all children. Both TNF-a and IL-6 were increased, with a significant correlation between IL-6 and QUIN.
			200 ± 113^** (H)
			282 ± 82^** (T)
			1084 ± 549^** (C)
		KYN (nM)	185 ± 40 (Hy)	54 ± 7
			254 ± 128^** (H)
			1698 ± 589^** (T)
			2610 ± l 067^** (C)
Fujigaki et al. 1998¹⁶⁹	None	KYN (nM)		29.1 ± 3.2	Species (human, macaques, rabbit, guinea pig, rat, gerbil and mouse) differences detected in levels of KYN and AA.
Fujigaki et al. 1998¹⁶⁹	None	AA (nM)		16.3 ± 4.2
Heyes et al. 1998¹⁷⁰	HIV	QUIN (nM)	3789 ± 888^**	22.1 ± 2.1
Erhardt et al. 2001a⁵¹	Schizophrenia	KYN (nM)	1.67 ± 0.027^*	0.97 ± 0.07	A correlation between age and KYN was found in schizophrenics.
Medana et al. 2002¹⁸⁶	Malaria (severe)	KYNA (μM)	0.06	0.07	None of the kynurenines were associated with convulsions or coma.
		QUIN (μM)	0.80⁺⁺	0.07
		PIC (μM)	0.19⁺	0.08
Rejdak et al. 2002¹⁸⁷	MS	KYNA (nM)	0.41^** (MS)		MS: were patients with relapsing MS during remission or not progressing for at least 2 months; ID: infectious inflammatory disease; OND: non-inflammatory neurological disorders. MS had significantly lower KYNA than either ID or OND.
			0.67 (OND)
			1.7 (ID)
Ilzecka et al. 2003¹⁷³	ALS	KYNA (nM)	2.41 ± 1.7 (grp)	1.59 ± 0.9	Bul: bulbar onset; s.c.s: severe clinical status No significant difference between KYNA levels and gender and no correlation between KYNA and age.
			3.61 ± 2.0^** (bul)
			3.26 ± 2.1^*(s.c.s.)
Medana et al. 2003¹⁰⁹	Cerebral Malaria (Malawian children)	QUIN (μM)	0.09		For QUIN, KYNA and PIC, 72% (2%), 77% (43%) and 74% (38%) of Malawian children had higher levels than median (reference range) UK control levels respectively. Elevated levels of QUIN and PIC were associated with a fatal outcome. Other diseases tested include convulsions, sepsis and acute hepatitis.
		KYNA (μM)	0.21
		PIC (μM)	0.18
Nilsson et al. 2005¹⁸⁸	Schizophrenia	KYNA (nM)	1.45 ± 0.10^* (grp)	1.06 ± 0.06	Grp: All patients; 1st: Drug naive, first episode patients; T: patients undergoing treatment with anti-psychotic drugs; no D: patients who had been treated but are now drug free. In patients, a positive correlation was found between KYNA levels and age.
			1.53 ± 0.19^* (1st)
			1.53 ± 0.17^*(T)
			1.16 ± 0.06 (noD)
Atlas et al. 2007¹⁸⁹	HIV	KYNA (nM) median levels	4.54 (psy.) 3.02 (no psy.)	1.23	psy: psychotic symptoms In controls, KYNA levels were significantly higher in females (2.29 nM) than males (1.10 nM) (P < 0.05). However, this gender difference was absent in the patient population.
Chen et al. unpublished¹⁸²	ALS	TRP (μM)	5.02 ± 0.19	2.58 ± 0.16
		KYN (μM)	0.23 ± 0.0016	0.027 ± 0.001
		QUIN (μM)	0.053 ± 0.0054^*	0.038 ± 0.006
		PIC (μM)	0.36 ± 0.034	0.51 ± 0.11
		K/T(×10³)	43.7 ± 2	11.1 ± 0.8

P < 0.05;

^**

P < 0.01;

^***

P < 0.005;

⁺

P < 0.001;

⁺⁺

P < 0.0001.