ABSTRACT
OBJECTIVES: The study aimed to determine the prevalence of rheumatoid factor (RF) and anti-citrullinated peptides (ACPA), to estimate the association with hepatitis B (HBV) or C (HCV) virus infections and the 15-year risk of developing RA in a large cohort from a Northern Italian region. METHODS: In 1998, 15,907 subjects between the ages of 18 and 75 were randomly selected 1:4 for HBV and HCV testing; more recently, we tested a subgroup of sera for RF (n=2196) and ACPA (n=2525). Administrative databases were searched after 15 years for incident RA diagnoses occurring between 1998 and 2013. RESULTS: RF was positive in 8.1% of cases with 10% of RF-positive subjects having HBsAg (p=0.004) and 9% anti-HCV. ACPA were detected in 4.8% of subjects with 5% of the ACPA-positive subjects having HBsAg and 5.9% anti-HCV. Older subjects had higher positivity rates for both RF and ACPA. HBsAg and anti-HCV were detected in 5.5% and 4.3% of sera, respectively. Over 15 years, 10 RA cases were recorded (9 women, median age at diagnosis 52 years) with RF previously positive in 2/10 and ACPA in 5/10 cases. RF and ACPA were associated with relative risks for developing RA of 5.7 (adjusted for HBsAg status; 95% CI 1.2-26.3) and 13.2 (95% CI 3.8-46.3), respectively. CONCLUSIONS: Our data in a large cohort from an unselected general population confirm a higher risk of RA development associated with ACPA compared to RF. HBV exposure correlates with RF but not with ACPA positivity.
Subject(s)
Arthritis, Rheumatoid , Hepatitis B , Adolescent , Adult , Aged , Anti-Citrullinated Protein Antibodies , Arthritis, Rheumatoid/diagnosis , Arthritis, Rheumatoid/epidemiology , Autoantibodies , Cohort Studies , Female , Hepatitis B/diagnosis , Hepatitis B/epidemiology , Humans , Middle Aged , Peptides, Cyclic , Rheumatoid Factor , Young AdultABSTRACT
The prevalence of ANA and anti-ENA in the general population is not well established, especially their clinical significance in healthy subjects. We herein determined the prevalence and predictive value of serum ANA and anti-ENA for connective tissue diseases (CTD), cancer, and mortality. We took advantage of a randomly selected sample of the 1998 general population (Isola I) consisting of 2828 subjects (53% women, age 43±13 years) from a well-defined Northern Italian area. Serum ANA and anti-ENA were tested on the 2690 samples available in 2012 (Isola II, 50% women, age 58±13 years). Administrative databases were searched for CTD, cancer diagnosis, and death cases occurring between enrollment and December 31, 2013. The hazard ratio (HR) was calculated for incident cases. Serum ANA is positive in 18.1% for any titer and 6.1% for titers ≥1:160, 23% in subjects over 50 years and 13.1% and 6.1% for any titer and titers ≥1:160, respectively, in women. The HR for CTD development was significantly high for all ANA titers, with the highest for ANA ≥1:160 (HR 14.19, 95% CI 3.07-65.68). ANA positivity was not associated with cancer (HR 1.03; 95% CI 0.75-1.43), or with mortality (HR adjusted for age and sex 1.40; 95% CI 0.94-2.09). Serum anti-ENA is positive in a minority of subjects with highest figures for anti-nucleosome (1.9%), -histone (1.6%) and -PM/Scl (1.5%). In conclusion, serum ANA prevalence in the general population is highest in senior subjects and in women, while the female predominance is significantly lower compared to overt CTD. Serum ANA is associated with an increased probability of CTD development over time, but does not influence survival or cancer risk.
