Predictive risk factors before the onset of familial rheumatoid arthritis: the Tatarstan cohort study

BACKGROUND: A familial history of rheumatoid arthritis (RA) predisposes an individual to develop RA. This study aimed at investigating factors associated with this conversion from the Tatarstan cohort. METHODS: A total of 144 individuals, referred to as pre-RA and at risk for familial RA, were selected 2 years (range: 2–21 years) before conversion to RA and compared to non-converted 328 first-degree relatives (FDR) from RA as assessed after ≥2 years follow-up, and 355 healthy controls were also selected (HC). Preclinical parameters and socio-demographic/individual/HLA genetic factors were analyzed when data were available at the time of enrollment. RESULTS: As compared to FDR and HC groups, pre-RA individuals were characterized before conversion to RA by the presence of arthralgia, severe morning symptoms, a lower educational level, and rural location. An association with the HLA-DRB1 SE risk factor was also retrieved with symmetrical arthralgia and passive smoking. On the contrary, alcohol consumption and childlessness in women were protective and associated with the HLA-DRB1(*)07:01 locus. CONCLUSION: Before RA onset, a combination of individual and genetic factors characterized those who are at risk of progressing to RA among those with familial RA relatives.