P46 – Clostridium difficile associated colitis post transplant is not associated with elevation of Tacrolimus levels

Author(s):
Hugo Bonatti, Karim Sadik, Costi Sifri, Robert Sawyer, Easton Memorial Hospital

Background: Diarrhea is a common condition after solid organ transplant (SOT); Clostridium difficile associated colitis (CDAC) is one of the most common infection following SOT. We previously documented that some types of enteritis are associated with an elevation of tacrolimus (TAC) trough levels by interfering with the drugs complex metabolism.

Hypothesis: To investigate if TAC trough levels rise during CDAC post transplant.

Methods: TAC levels of 25 SOT recipients including 12 renal and 13 liver recipients before, during and after CDAC were retrospectively analyzed.

Results: Median age of the 25 patients was 54 years (range 36-71), there were 15 men and 10 women. CDAC developed at a median of 55 days (range 2-4551) post-SOT. Median TAC levels prior to the outbreak of CDAC were 6.9 (range <1.5-17.2) ng/ml, 5.6 (range <1.5-13.2) ng/ml during diarrhea and 7.4 (range <1.5-24.3) ng/ml after resolution of diarrhea (p>0.05, n.s.). Treatment of CDAC consisted of metronidazole for 14 days in all cases. All patients recovered from CDAC but seven patients had CDAC relapse.

Conclusions: In contrast to other types of infectious diarrhea such as Rota virus enteritis and cryptosporidiosis, CDAC is not associated with a rise in TAC levels. This is due to the fact that C. difficile causes primarily colitis as opposed to other organisms, which are associated with enteritis.