Background Infliximab has been successfully used for the treatment of IBD for many years. However, treatment failures are common. Primary non-response was reported to occur in 13%–14% of patients in clinical trials. Therefore the early identification of non-response and timely switch to another agent, dose adjustment is of paramount importance.
Aim In literature, there is very little known about primary non-response to infliximab. Most of the studies done in the past are based on loss of response or emergence of anti-infliximab antibodies. No such single study exists in the literature.
Method Total 218 patients records were searched. Out of 218, only 20 were included as cases. The inclusion criteria was either Crohns or Ulcerative colitis patient who were primary non-responders. Primary non-response was defined as all those patients who fail to respond to the standard induction doses of infliximab. Another 20 subjects were selected from the same pool as controls and were matched with cases in terms of age, sex and disease type.
This study was analysed using EPI-INFO STATCALC software from the CDC.gov.
Results Odds ratios were calculated using the 2by2 tables for matched-pair case control study.1. Smoking was associated with primary non-response and the OR was 2.33 with 95% CI. Similarly, in this study, there was a trend of primary non-response with low levels of CRP at the time of start of therapy with the odds ratio of 0.25 (95% CI) and p-value 0.054. The odds for albumin, weight and Haemoglobin were 0.8,0.42 and 0.33 respectively and their p-values did not reach significance due to small sample size.
Conclusions From this study, there is a trend towards primary non-response to infliximab if a patient is a smoker with low levels of CRP at the time of initiation of therapy. Further studies with large sample size are needed to study the clinical significant association between haemoglobin, Albumin, and weight of the patients at the time of initiation of therapy.