Baseline Risk Score Predicts Serious Infection Risk in TNF-Treated RA Patients Save

Curtis and colleagues have analyzed the certolizumab (CZP) RAPID1 and RAPID2 trials to assess the risk of serious infectious events (SIEs), and shown that steroids combined with an age-adjusted comorbidity index (AACI) yields a 2-3 fold predictable risk for SIE.

Their goal was to develop an infection risk score that may help clinicians to anticipate a patients potential SIE.  Data from other studies have shown that disease activity, drugs, steroids, and comorbidities significantly augments this risk.

The AACI was developed by assigning specific weights to patient age and comorbidities on the basis of relative SIE risk. SIE rates were predicted using AACI score and baseline glucocorticoid use, and they were compared with observed rates.

Among the 1224 CZP patients in the randomized controlled trials (RCT) there were 40 reported with an SIE (incidence rate [IR] 5.09/100 patient-years [PY]).  When considering all 1506 CZP exposed (including the open-label extensions) patients there were 201 with ≥ 1 SIE (IR 3.66/100 PY).

Age ≥ 70 years, diabetes mellitus, and chronic obstructive pulmonary disease/asthma made the greatest contributions to AACI score. Each was given a baseline risk score of 1-3 (age 50-69=1; age>70=3; 2 points each for COPD, DM, Hyperlipidemia and osteoporosis).

AACI scores ≥ 2 with glucocorticoid use was associated with nearly a 3 fold higher SIE risk (RCT CZP HR 2.86 [1.23–6.62]; All CZP HR 2.59 [1.79–3.76]) compared to those with AACI of 0.

SIE rates predicted using AACI and glucocorticoid use at baseline showed good agreement with observed SIE rates across low-risk and high-risk groups.

At 1 year, more high-risk All CZP patients than low-risk All CZP patients reported SIEs (IR 8.4/100 PY vs. IR 3.4/100 PY).

AACI and glucocorticoid use were strong baseline predictors of SIE risk in CZP-treated patients with RA.