Being younger, being male, or having an elevated C-reactive protein level are just a few of the factors that are likely to predict whether patients with ankylosing spondylitis will improve when taking tumor necrosis factor inhibitors for the first time, according to new data.
Dr. Karen M. Fagerli of the Diakonh-jemmet Hospital in Oslo, and her associates identified several independent predictors of major improvement in ASDAS (Ankylosing Spondylitis Disease Activity Score) in patients with ankylosing spondylitis (AS) after 3 months of taking a TNF inhibitor.
The independent predictors are younger age, male sex, C-reactive protein (CRP) level greater than 10 mg/L, HLA-B27 positivity, and a higher baseline patient global assessment score.
The results confirm findings from previous studies that both age and elevated CRP are predictors of success with TNF inhibitors. They could be used in selecting patients most likely to respond to treatment, especially in countries with limited access to TNF inhibitors.
Clinicians should exercise caution in applying the other predictors found in the study to a clinical setting, Dr. Fagerli stressed in an interview.
Other studies have not found gender to be a significant predictor, and few other studies have shown HLA-B27 positivity to be a predictive factor.
“The independent predictors identified in this model give information about which patients are most likely to show a good clinical response on a group level, but may have limited value for use on the individual patient level,” Dr. Fagerli said.
The researchers extracted data from the Norwegian DMARD (NOR-DMARD) register, a repository of data on adult patients with inflammatory arthropathies who are starting a new disease-modifying antirheumatic drug treatment. The patients are consecutively included from across five rheumatology departments in Norway.
The current analysis included 171 AS patients who were being treated with their first TNF inhibitor. The mean age of the patients in the sample was 42 years, more than 73% were male, and the average disease duration was 10 years. Nearly a third of the patients in the study achieved ASDAS major improvement on a TNF inhibitor at 3 months.
The researchers plan to repeat these analyses with an updated data set that includes more patients, Dr. Fagerli said.
She also noted that the results will need to be validated in other cohorts, particularly the findings related to gender, patient global assessment, and HLA-B27.
In general, more research is needed into new and more accurate predictors of response to TNF inhibitors in AS and other rheumatic diseases, Dr. Fagerli said. Pharmacogenetic studies have the potential to identify these predictors, and further research to find new soluble biomarkers as markers of response will also be important. In addition, the role of MRI in diagnosis, predicting response, and monitoring treatment will be an important field in the years to come.
Dr. Fagerli said she had no financial disclosures.
'The independent predictors identified … may have limited value for use on the individual patient level.'
Source DR. FAGERLI