A proposal of simple calculation (ERI calculator) to predict the early response to TNF-α blockers therapy in rheumatoid arthritis

• Published in: Rheumatology international 2012-02, Vol.32 (2), p.349-356
• Main Authors: Bazzichi, Laura, Rossi, Paolo, Giacomelli, Camillo, De Feo, Francesca, Bobbio-Pallavicini, Francesca, Rossi, Alessandra, Baldini, Chiara, Consensi, Arianna, Doveri, Marica, Bonino, Claudia, Mazzantini, Maurizio, Della Rossa, Alessandra, Montecucco, Carlomaurizio, Bombardieri, Stefano
• Format: Article
• Language: English
• Subjects: Adalimumab; Adult; Aged; Antibodies, Monoclonal, Humanized - administration & dosage; Antibodies, Monoclonal, Humanized - adverse effects; Antirheumatic Agents - administration & dosage; Antirheumatic Agents - adverse effects; Arthritis, Rheumatoid - diagnosis; Arthritis, Rheumatoid - drug therapy; Female; Humans; Male; Medicine; Medicine & Public Health; Middle Aged; Models, Immunological; Original Article; Predictive Value of Tests; Rheumatology; Time Factors; Tumor Necrosis Factor-alpha - antagonists & inhibitors; Tumor Necrosis Factor-alpha - metabolism
• ISSN: 0172-8172; 1437-160X
• DOI: 10.1007/s00296-010-1619-7

Increasing evidence has been accumulated for treating rheumatoid arthritis (RA) with TNF-α blocking agents. The formulation and definition of an early indicator of patient’s reactivity during therapy may be extremely simplified by a mathematical model of clinical response. We analyzed the most significant clinical and laboratory parameters of response of 35 homogeneous patients (30 women, 5 men mean age ± SD: 52.31 ± 12.30 years) treated with adalimumab 40 mg every 2 weeks associated with methotrexate (MTX) 10–15 mg/week and with a stable dosage of steroids for 30 weeks. The over time trend of the studied parameters showed a linear response, which has allowed the realization of a simple mathematical model. The formula derived from this mathematical model was then applied and therefore validated in a group of 121 patients previously treated with several anti-TNF-alpha agents for at least 6 months. We drafted a mathematical model (early response indicator, ERI) that, by using a simple calculation, allows us to identify a high percentage of responder patients after only 2 weeks of treatment. ERI identified a high percentage (88%) of patients responding after only 2 weeks, as was confirmed at weeks 30; the use of ERI calculation after 6 weeks increases the proportion of responding patients to 92% with a percentage of false negatives of only 12%. ERI could be a useful tool to early differentiate the responder from the non-responder patients.