Decreased human paraoxonase-1 activity in patients with Sjögren's syndrome.
OBJECTIVE
The aim of the study was to examine human serum paraoxonase 1 (PON1) activity, phenotype distribution and lipid parameters in patients with Sjögren's syndrome. The prevalence of cardio- and cerebrovascular diseases in SS patients was also evaluated after a 5-year follow-up.


METHODS
Fifty-seven SS patients and 17 age-matched healthy controls were enrolled into the study. PON1 and arylesterase activities were measured spectrophotometrically. The phenotype distribution of PON1 was determined by the dual-substrate method.


RESULTS
Significantly lower PON1 activity was found in patients with SS compared with the control group (98.00 +/- 69.21 versus 203.3 +/- 92.78 U ml(-1); P < 0.001). There were significant differences in PON1 phenotype distribution of SS patients and controls (AA/AB/BB: 91.2/8.8/0 versus 58.8/29.4/11.8%; P < 0.01). No significant correlations were found between PON activity and disease-characteristic autoantibodies, including anti-Ro/SS-A and anti-La/SS-B concentrations. PON activity did not predict the cerebro/cardiovascular risk in SS patients during the 5-year follow-up.


CONCLUSIONS
Despite the relatively small sample size that reduces the power of the study, decreased PON activity may be a possible cardiovascular risk factor in SS. Disadvantageous PON1 phenotype distribution may contribute to the decreased PON activity in these patients.
Szántó
Antónia
A
3rd Department of Medicine, Division of Clinical Immunology, University of Debrecen Medical and Health Science Center, H-4032 Debrecen, Hungary. szantonia@freemail.hu
Harangi
Mariann
M
Seres
Ildikó
I
Paragh
György
G
Zeher
Margit
M
D043303:Aryldialkylphosphatase / Q000378:metabolism*; D001323:Autoantibodies / Q000276:immunology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D012859:Sjogren's Syndrome / Q000201:enzymology* / Q000276:immunology
D001323:Autoantibodies; D043303:Aryldialkylphosphatase; C468406:PON1 protein, human