Diadenosine polyphosphates in tears of Sjogren syndrome patients.
OBJECTIVE
To analyze the levels of diadenosine tetraphosphate (Ap(4)A) and diadenosine pentaphosphate (Ap(5)A) in tears of subjects with Sjögren syndrome and to compare them with those in a control group.


METHODS
Twelve subjects with a diagnosis of Sjögren syndrome and 20 healthy control subjects were invited to participate in the present study. Schirmer strips were used to measure tear secretion (Schirmer I test) and to collect tears. Ap(4)A and Ap(5)A were measured by high-pressure liquid chromatography (HPLC), and a dry eye questionnaire (DEQ) was used to evaluate dry eye symptomatology.


RESULTS
The mean concentrations of Ap(4)A and Ap(5)A in the Sjögren syndrome group were 2.54 ± 1.02 and 26.13 ± 6.95 μM, respectively. This group of patients was divided in two subgroups: four patients with normal tear production and eight patients with low tear production. Concentrations of Ap(4)A, and Ap(5)A in patients with normal tear production (Schirmer test result, 12.3 ± 1.2 mm) were 0.47 ± 0.20 and 8.03 ± 3.27 μM, respectively. In the patients with low tear production (Schirmer test result, 1.0 ± 0.3 mm), the concentrations were 4.09 ± 1.36 and 39.51 ± 8.46 μM, respectively and in the control group, 0.13 ± 0.03 and 0.04 ± 0.02 μM, respectively.


CONCLUSIONS
Patients with Sjögren syndrome have abnormally elevated concentrations of diadenosine polyphosphates, indicating that these compounds could be used in the diagnosis of this disease.
Carracedo
Gonzalo
G
Departamento de Óptica II, Optometría y Visión, Escuela Universitaria de Óptica, Universidad Complutense de Madrid, Madrid, Spain. jgcarrac@opt.ucm.es
Peral
Assumpta
A
Pintor
Jesús
J
D000328:Adult; D000368:Aged; D002851:Chromatography, High Pressure Liquid; D015226:Dinucleoside Phosphates / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012859:Sjogren's Syndrome / Q000175:diagnosis / Q000378:metabolism*; D011795:Surveys and Questionnaires; D013666:Tears / Q000378:metabolism*
D015226:Dinucleoside Phosphates; C012275:P(1),P(5)-di(adenosine-5'-)pentaphosphate; C020733:diadenosine tetraphosphate