Introduction: The incidence of immunological graft loss after the first months oy years following kidney transplantation ranges from 30 to 50%. In the majority of cases, non-adherence with the immunosuppressive therapy is considered to be the main reason of rejection. Single daily tacrolimus (Tac) immunosuppression was initiated with the aim of alleviating non-adherence. However, mycophenolate acid (MPA) is almost given in association to Tac but twice a day.

Methods: After a previous pharmacokinetic profile study comparing MPA twice a day versus once a day in 9 kidney transplant patients, we decided in 2017 to prospectively give the total dose of MPA in a single morning oral dose intake to patients already receiving Tac once a day. This was a mono-centre observational study. Patients who accepted to participate gave their consent  and were switched during a regular out-put clinical visit. We included kidney or pancreas/kidney transplant recipients transplanted at least more than 6 months after surgery. Inclusion  lasted 12 months.

Results: Mean follow-up was 16.3 months (6 to 48). 65 patients (53 kidney, 12 pancreas/kidney) were included. 78% (n=51) of recipients received organs from a cadaver donor. 63% (n=41) were not sensitized. Recipient’s mean age was 49.8 years. 40% (n=26) of patients were on steroid maintenance. Mean conversion time to once daily MPA was 33 months after transplantation. Daily dose ranged from 360 to 1440 mg; 57 patients (88%) received 720 mg. At MPA conversion, no DSA was detected among 55 patients (84%) whereas 10 (16%) were DSA positive. During the first 6 months after conversion, 3 (4.6%) patients developed cellular rejection (all reversible), one BKV nephropathy, one pneumonia, and one PTLD.  MPA was only stopped in 2 patients because of gastro-intestinal disorders. No case of severe leukopenia was noted. No other adverse events were observed thereafter. No de novo DSA was noted even among the 3 patient with acute rejection.

Conclusion: Once daily Tac in association to one daily MPA could represent a good strategy to decrease non-adherence and improve quality of life of transplant recipients.