Temporal trends in the misdiagnosis rates between Crohn's disease and intestinal tuberculosis

AIM To investigate the temporal trends in the misdiagnosis rate between Crohn's disease(CD) and intestinal tuberculosis(ITB) in South Korea. METHODS We retrospectively reviewed the medical records of patients managed for CD or ITB at Asan Medical Center, a tertiary referral hospital, Seoul, Korea between 1996 and 2014. The temporal trends in the misdiagnosis rates between the two diseases were analyzed. The demographic and clinical characteristics were compared between CD patients who were initially misdiagnosed as ITB(final CD group) and vice versa(final ITB group). Final diagnostic criteria for ITB and medication for CD before definite diagnosis of TB were also analyzed in final ITB group.RESULTS In total, 2760 patients were managed for CD and 772 patients for ITB between 1996 and 2014. As well, 494 of the 2760 CD patients(17.9%) were initially misdiagnosed as ITB and 83 of the 772 ITB patients(10.8%) as CD. The temporal trend in misdiagnosing CD as ITB showed a decrease(OR = 0.89, 95%CI: 0.87-0.91, P < 0.001), whereas the temporal trend in misdiagnosing ITB as CD showed an increase(OR = 1.06, 95%CI: 1.01-1.11, P = 0.013). Age at diagnosis, presenting symptoms, and proportion of patients with active/past perianal fistula and active/inactive pulmonary tuberculosis(TB) were significantly different between final CD group and final ITB group. Forty patients(48.2%) in final ITB group were diagnosed by favorable response to empirical anti-TB treatment. Seventeen patients(20.5%) in final ITB group had inappropriately received corticosteroids and/or thiopurines due to misdiagnosis as CD. However, there were no mortalities in both groups. CONCLUSION Cases of CD misdiagnosed as ITB have been decreasing, whereas cases of ITB misdiagnosed as CD have been increasing over the past two decades.

Clinical correlations of infliximab trough levels and antibodies to infliximab in South Korean patients with Crohn's disease

AIM To investigate the clinical implications of infliximab trough levels(IFX-TLs) and antibodies to infliximab(ATI) levels in Crohn's disease(CD) patients in Asian countries. METHODS IFX-TL and ATI level were measured using prospectively collected samples obtained with informed consent from CD patients being treated at Asan Medical Center, South Korea. We analyzed the correlations between IFX-TLs/ATI levels and the clinical activity of CD(quiescent vs active disease) based on the CD activity index, C-reactive protein level, and physician's judgment of patients' clinical status at enrollment. The impact of concomitant immunomodulators was also investigated. RESULTS This study enrolled 138 patients with CD(84 with quiescent and 54 with active disease). In patients with quiescent and active diseases, the median IFX-TLs were 1.423 μg/mL and 0.163 μg/mL, respectively(P < 0.001) and the median ATI levels were 8.064 AU/m L and 11.209 AU/m L, respectively(P < 0.001). In the ATI-negative and-positive groups, the median IFXTLs were 1.415 μg/mL and 0.141 μg/mL, respectively(P < 0.001). In patients with and without concomitant immunomodulator use, there were no differences in IFX-TLs(0.632 μg/mL and 1.150 μg/mL, respectively; P = 0.274) or ATI levels(8.655 AU/mL and 9.017 AU/mL, respectively; P = 0.083).CONCLUSION IFX-TL/ATI levels were well correlated with the clinical activity in South Korean CD patients. Our findings support the usefulness of IFX-TLs/ATI levels in treating CD patients receiving IFX in clinical practice.