Baseline predictors of remission, pain and fatigue in rheumatoid arthritis: the TITRATE trial.

BACKGROUND: Clinical trials show intensive treatment to induce remission is effective in patients with highly active rheumatoid arthritis (RA). The TITRATE trial showed that the benefits of intensive treatment also extend to moderately active RA. However, many patients failed to achieve remission or show improvements in pain and fatigue. We investigated whether baseline predictors could identify treatment non-responders. METHODS: The impact of obesity, depression, anxiety and illness perception on RA outcomes, including disease activity, remission, pain and fatigue were determined using a pre-planned secondary analysis of the TITRATE trial data. RESULTS: Body mass index was associated with disease activity levels and remission: obese patients had a higher overall disease activity and fewer obese patients achieved remission. Intensive management was not associated with increased remission in these patients. Obesity was also associated with increased overall pain and fatigue. Anxiety, depression and health perceptions had no discernible impact on disease activity but were associated with high levels of pain and fatigue. There was a strong association between anxiety and high pain scores; and between depression and high fatigue scores; and health perception was strongly related to both. None of the predictors had an important impact on pain and fatigue reduction in cross-sectional analysis. CONCLUSIONS: Disease activity is higher in obese patients and they have fewer remissions over 12 months. Anxiety, depression and health perceptions were associated with higher pain and fatigue scores. Intensive management strategies need to account for these baseline features as they impact significantly on clinical and psychological outcomes. TRIAL REGISTRATION: ISRCTN 70160382 ; date registered 16 January 2014.

When not to trust therapeutic drug monitoring.

Therapeutic drug monitoring (TDM) is the measurement of serum or plasma drug concentration to allow the individualization of dosing. We describe the case of a patient who was prescribed inappropriately large doses of vancomycin due to inaccurate TDM. Specifically, our laboratory reported progressively lower vancomycin concentrations despite dose increases. Eventually, when duplicate samples were sent to a different laboratory vancomycin concentrations were found to be in the toxic range. We hypothesize this was due to the patient generating immunoglobulin antibodies against her infection that interfered with the original TDM immunoassay. Immunogenic TDM interference has been known to rarely occur in patients with immune related comorbidities; however, if we are correct, this is a unique case as this patient did not have such a background. This case illustrates the importance of using clinical judgement when interpreting TDM as, in this case, substantial harm to the patient was likely only narrowly avoided.