Table 3.
Summary of nongenetic biomarkers of response to MTX and other DMARDs.
| Factors | Predictors of response?k | Comments |
|---|---|---|
| RF | No | Some results confounded by its poor prognostic role; however, most evidence is clear in that it does not influence treatment response |
| ACPA | Not likely | More data needed but does not seem to predict response; associated with worse outcomes in some studies but may reflect more severe disease; interesting reports in UA, pending confirmation |
| Anti-MCV | Unknown | Suggested to relate to more severe disease; not yet addressed in terms of response to treatment |
| Creatinine clearance | No | Few studies analyzed this factor, no association with MTX response in a meta-analysis |
| Hb levels | Uncertain | Anecdotal reports of association with better response; needs confirmation and its role should be clarified in future studies |
| Cytokines | Uncertain | Small/pilot studies suggesting association with response; potential promising role of baseline TNF levels, TNFID50 and IL-1ra/IL-1β ratio |
| Others | Uncertain | Other interesting factors analyzed in small studies and not further confirmed include MMP-3, urinary 7-OH-MTX and IgG hypogalactosylation |
Conclusions and comments are based on the findings reported and discussed in the text. ACPA, anti-citrullinated protein antibodies; anti-MCV, anti-modified citrullinated vimentin antibodies; DMARDs, disease modifying anti-rheumatic drugs; Hb, hemoglobin; IgG, immunoglobulin G; IL-1ra, interleukin-1 receptor antagonist; IL-1β, interleukin-1β; MMP-3, matrix metalloproteinase-3; MTX, methotrexate; RF, rheumatoid factor; TNF, tumor necrosis factor; TNFID50, dose required to suppress by 50% the production of tumor necrosis factor; UA, undifferentiated arthritis; 7-OH-MTX, 7-hydroxy-methotrexate.