Evidences indicate that oxidative stress and inflammation are important processes in the development of destructive synovial tissue in rheumatoid arthritis (RA). The two major bioscavenger enzymes that are associated with inflammation and oxidative stress are human-butyrylcholinesterase (BuChE) and paraoxonase-1 (PON-1). Thus, the objective of this study was to determine the relation of BuChE phenotypes and PON-1 Q192R polymorphism with inflammatory markers such as anti-cytroline circulated peptide (CCP)-antibodies, CRP, neopterin, DAS28-CRP in RA patients.
In this study, we examined association of BuChE-phenotypes and activity, PON192rs662 (Q192R) polymorphism and its arylesterase activity (ARE) with systemic-inflammatory-markers and oxidative stress. The present case-control study consisted of 419-RA patients and 398 gender-age-matched unrelated healthy controls from west population of Iran. PON192rs662 polymorphism was detected by real-time-PCR. BuChE phenotype, TAC level, serum BuChE and ARE activities were determined spectrophotometrically. Anti-CCP-antibody and CRP were measured by ELISA and neopterin level was detected by HPLC. We used the EULAR activity criteria to measure DAS28-CRP.
We found that PON-1-Q192R was associated with severity of RA [remission-to-low and moderate-to-high in dominant Q/Q+Q/R vs. R/R: OR=2.27, p<0.001; codominant Q/Q vs. R/R: OR=1.65, p<0.001 and Q/R vs. R/R: OR=2.12, p=0.003; recessive Q/Q vs. R/R+Q/R: OR=1.79, p=0.032; and allele Q vs. R: OR=1.68, p<0.001] and presence of anti-CCP-antibody (codominant model Q/Q vs. R/R: OR=1.28, p=0.042). The carriers of Q/Q genotype PON-1-Q192R and BuChE non-UU-phenotype had higher ARE activity, serum levels of neopterin, anti-CCP antibody titer and number of tender-joint and lower activity of BuChE and serum level of TAC than that of R/R genotype and BuChE-UU-phenotype.
The current findings demonstrate for the first time that there is a link between systemic inflammatory markers, oxidative stress, the PON192rs662-Q allele and BuChE-non-UU-phenotype and their corresponding enzymatic activity which may be considered as a risk factor for the severity of RA for a population in Iran.