Torque Teno Virus quantification for monitoring of immunomodulation with biologic compounds in the treatment of rheumatoid arthritis
Abstract
Objectives. RA patients who fail to respond to MTX can receive biologic dMARDs (bDMARDs).
The Torque Teno Virus (TTV) is a potential novel candidate for monitoring of immunosuppression. We explore TTV in these patients and its association with clinical response to bDMARDs.
Methods. The BioBio Study is a multicentre randomized open-label trial, including RA patients with insufficient response to MTX.
Patients were randomized to either TNFi (infliximab, INF), anti-IL-6 (tocilizumab, TCZ), CTLA4-lg (abatacept, ABA) or anti-CD20 (rituximab, RTX) in addition to MTX. PCR was used to quantify TTV in the peripheral blood.
Results. TTV was measured in 95 patients (INF, n =23; TCZ, n = 22; ABA, n = 27; RTX; n = 23).
TTV increased by a median of 4.5 x 10(4) copies/ml [c/ml; interquartile range (IQR) 0-7.5 x 10(5)] after 3 months. TTV levels at month 3 were associated with the Simplified Disease Activity Index (SDAI) (P = 0 .03) and the Clinical Disease Activity Index (CDAI) response (P = 0 .026) at month 6.
A TTV cut-off level of 1.2 x 10(6) c/ml at month 3 had a positive likelihood ratio of 2.7 for prediction of an 85% reduction in SDAI at month 6. Conclusion.
Our data suggest that TTV levels increase upon TNF, CD20 and costimulation blockade and are associated with the clinical response to bDMARDs in RA patients.