Mortality Ratio of Rheumatoid Arthritis Under Biological Treatment: HUR-BIO real life results.

Background/Purpose: Rheumatoid arthritis (RA) is a chronic inflammatory disease, which, in many patients, leads to a substantial disability and has a major effect on the quality of life. Patients with RA also have an increased mortality compared with the general population. Main causes of mortality in RA are cardivascular events and serious infections. The objective of this study was to evaluate mortaility ratio in patients with RA during biological treatment.

Methods : HUR-BIO (Hacettepe University Rheumatology Biologic Registry)  is a single center biological registry since 2005 that include 815 RA patients under biological treatments. Data collected includes demographic data, co–morbidities, smoking, switch ratio, baseline and follow–up disease activity parameters (such as DAS28, CRP, ESR, global VAS, swollen joint count ad tender joint count). For all individuals in the study population, follow up time began at the first known use of etanercept, infliximab, or adalimumab. The outcome of interest was death from any cause, which was identified through linkage of the study population to the Turkish Cause of Death Register through May 31, 2014. Overall and anti-TNF biologic stratified incidence rates per 1000 person–years were calculated.

Results : HUR-BIO includes 815 RA patients (77,9% female). Mean age was 51±13 years and mean disease duration was 11±8 years. TNFi drug duration was 2,7±2,6 years and 176 (21,5%) patients were used TNFÝ drugs more than 5 years. Positive ACPA and RF were 297/465 (63,9%) and 454/740 (61,3%), respectively. First biological drugs were etanercept 321 (39,4%), adalimumab 223 (27,4%) and infliximab 115 (14,1%), rituksimab 92 (11,3%), abatecept 43 (5,3%), golimumab 20 (2,5) and tocilizumab 1 (0,1%). TNFi switch was found in 262 (32,1%) patients. Among the 815 patients in our entire study population and during a total of 2,235 person–years of follow–up (mean 2,7 years; median 1,8 years), 21 patients died. The all–cause mortality rate was 9,4 per 1000 person–years. Five of 21 patients died in our hospital (3 patients were lung infection, 1 tuberculosis and 1 acute coronary syndrome). Mortality ratio was sligthly, not significantly, higher in male patients (%38,1 vs %21,4 p=0.071). There were certain difference in age (60,1±10,9 vs 51,1±13,1, p=0.004), biological drug duration (2,7±2,7 vs 0,6±0,9 years, p<0.001), baseline erytrocyte sedimentation rate (53±18 vs 40±25 mm/hour, p=0.018), positive RF (%89,5 vs %60,6, p=0.039) and level of RF (median 103 (0-2500) vs 44 (0-2710), p=0.032).

Conclusion : Crude mortality ratio in our biological database was comparable with literature, that between 5.3 to 16.8 (1-2). Crude mortality ratio of our patients is slightly higher than general population [9,3/1000 person–year vs 4,9/1000 person–year (3)].  Biological treatments seem like relatively safe drug in our database, however, we need biological naive RA cohort for certain conclusion.   

References:

1.  Semin Arthritis Rheum. 2012;42:223-33.

2. Arthritis Rheum. 2010;62:3145-53.

3. www.tuik.gov.tr