Anti-tumor necrosis factor (TNF)s form a major part of therapy in Crohn's disease and have a primary nonresponse rate of 10%-30% and a secondary loss of response rate of 5% per year.
Myopenia is prevalent in Crohn's disease and is measured using body composition analysis tools.
Dr Ding and colleagues from the United Kingdom tested the hypothesis that body composition can predict outcomes of anti-TNF primary nonresponse and secondary loss of response.
|Immunomodulator therapy was associated with decreased secondary loss of response|
|Alimentary Pharmacology & Therapeutics|
The team found that between 2007 and 2012, 106 anti-TNF naïve patients underwent anti-TNF therapy for Crohn's disease with body composition parameters analyzed using CT scans to estimate body fat-free mass.
The outcome measures were primary nonresponse and secondary loss of response.
COX-regression analysis was used with 3 year follow-up data.
The researchers noted that a total of 106 patients were included for analysis with 25% of primary nonresponders, and 27% with secondary loss of response to anti-TNF therapy.
The team ascertained sex-specific cut-offs for muscle and fat by stratification analysis.
The research team's primary nonresponse was associated with low albumin, and presence of myopenia when taking into account patient's medical therapy, severity of disease and body composition.
On further analysis, the team noted that the presence of myopenia was associated with primary nonresponse.
The team found that immunomodulator therapy was associated with decreased secondary loss of response.
BMI was poorly correlated with lean body mass.
Dr Ding's team comments, "In this cohort study, body composition profiles did not correlate well with BMI."
"Myopenia was associated with primary nonresponse with potential implications for dosing and serves as an explanation for pharmacokinetic failure."