Dialysis of saliva improves accuracy of saliva lithium determinations.
BACKGROUND
Saliva lithium (Li) determinations have been explored as a potential alternative to plasma levels. Unfortunately, this method has been shown to be unreliable. Saliva has two major components: the aqueous and the mucopolysaccharide portions.


METHODS
Since Li is likely to distribute only in the aqueous fraction, we dialyzed the saliva through a 3000 Da filter to isolate the aqueous component and determine the Li level in it.


RESULTS
Lithium levels in the dialyzed saliva agreed more closely with plasma levels (Spearman's rho = 0.901, p < 0.001) than did whole saliva (Spearman's rho = 0.775, p = 0.012).


CONCLUSIONS
Dialysis of saliva may contribute to more accurate saliva Li levels.
El-Mallakh
Rif S
RS
Mood Disorders Research Program, Department of Psychiatry, School of Public Health and Information Sciences, University of Louisville, Louisville, KY 40292, USA. rselma01@athena.louisville.edu
Linder
Mark
M
Valdes
Roland
R
Looney
Stephen
S
D000328:Adult; D001714:Bipolar Disorder / Q000097:blood / Q000188:drug therapy* / Q000378:metabolism; D003956:Dialysis; D005260:Female; D006801:Humans; D008094:Lithium / Q000032:analysis*; D008297:Male; D012463:Saliva / Q000737:chemistry / Q000378:metabolism*
D008094:Lithium