P353. Screening for latent tuberculosis is effective but does not fully protect against tuberculosis reactivation during anti-TNF treatment in areas with high background incidence of tuberculosis
Z. Zelinkova1, M. Zakuciova2, L. Gombosova2, E. Veseliny2, M. Horakova3, P. Lietava3, K. Palencikova3, B. Kadleckova4, M. Gregus5, K. Gregusova5, I. Pav6, T. Hlavaty1, T. Koller1, J. Toth1, M. Hlista7, I. Bunganic8, J. Zan9, I. Mincik9, M. Huorka1, 1University Hospital Bratislava, Gastroenterology Unit, 5th Department of Internal Medicine, Bratislava, Slovakia, 2University Hospital of Louis Pasteur, Gastroenterology Unit, 1st Department of Internal Medicine, Kosice, Slovakia, 3University Hospital, Department of Gastroenterology, Martin, Slovakia, 4Thalion, Gastroenterology & Hepatology Centrum, Bratislava, Slovakia, 5Gastroenterology and Hepatology Unit Nitra, GHU Nitra, Nitra, Slovakia, 6University Hospital, Gastroenterology Department, Bratislava, Slovakia, 7Medical Faculty Hospital, Gastroenterology Unit, Department of Internal Medicine, Trencin, Slovakia, 8Gastro I, Gastroenterology Center, Presov, Slovakia, 9Central Military Hospital, Gastroenterology Unit, Ruzomberok, Slovakia
Screening for latent tuberculosis (LTB) prior anti-tumor necrosis factor (antiTNF) treatment is recommended but its true effectiveness in prevention of TB reactivation is unknown.
The aim of this study was to assess the results and effectiveness of screening for LTB prior antiTNF therapy. We performed a retrospective survey of results of screening for LTB in all IBD patients referred for antiTNF therapy to 9 out of 12 referral centres for biological therapy in Slovakia since 2003. Medical records of all patients were reviewed and results of respective LTB screening procedures, i.e. X-ray, tuberculine skin test (TST) and interferon gamma releasing assay (IGRA), were noted.
In total 945 patients were screened prior antiTNF therapy (54% males; Crohn's disease/ulcerative colitis/unclassified 601/342/2, 63.6%/36.2%/0.2%). In the screening procedure, X-ray was performed in 98%, TST in 82% and an IGRA test in 95% of patients.
Based on the screening, LTB was found in 53 (5.6%) patients. LTB diagnosis was based on a positive IGRA test alone in 35 pts (66%), in 9 pts (17%) on a positive TST, 2 pts (4%) had findings on X-ray without positivity of other tests. Positive findings at more than one of screenings procedure were present only in 7 pts (13%; 3 pts positive X-ray and TST or IGRA; 4 pts with positive TST and an IGRA). All patients with positive screening for LTB received prophylactic treatment, initiated the treatment with antiTNF after 2 to 6 months of prophylactic treatment and had no TB reactivation during antiTNF treatment.
In total, 8 (0.8%) cases of TB were diagnosed after initiation of antiTNF therapy; 5 cases within the first year of treatment (two after 3 months, one after 5 months and two after 9 months of antiTNF treatment), the other three after 3, 3 and 4 years of treatment, respectively. All but one patient were screened for LTB prior therapy and tested negative in the screening procedure. All patients considered to have TB reactivation rather than de novo infection (i.e. TB complicating antiTNF treatment during the first year of the treatment after testing negative in the screening) were from regions with high background incidence of TB.
Screening for latent tuberculosis based on a combination of chest X-ray, Mantoux and an IGRA test with subsequent prophylactic treatment in patients tested positive seems to be effective in preventing TB reactivation during antiTNF treatment. This, however, does not apply for IBD patients from regions with high background incidence of tuberculosis.