Thymoglobulin (Thymo) induction is given to prevent early rejection while initiating maintenance immunosuppression. Modification of dosing is common for multiple reasons. Our center recently underwent an induction protocol change with less restricting dose modifications for the adult kidney transplant alone (KTA) population with a goal of increasing adherence and simplifying the induction course. This was initiated after 2013 data showed the group receiving less Thymo than goal had a higher incidence of acute cellular rejection (AR) and the group receiving more than goal had a higher infection rate [ATC 2014].

Methods: In 2013, protocol was 5 doses of Thymo at 1.25 mg/kg, goal 6.25 mg/kg. Doses were decreased by 50% for absolute lymphocyte count (ALC) < 0.2, held for ALC = 0 and adjusted for WBC and PLT per package insert, resulting in missed and partial doses. In 2015, protocol was changed to 3 doses of 2 mg/kg, goal 6 mg/kg. ALC is no longer used to determine dose and partial or held doses due to WBC or PLT count are given at a later date.

A retrospective chart review of adult KTA recipients given induction immunosuppression per protocol from 1-12/2013 and 1-7/2015 was conducted. Outcomes included the number of dose adjustments, achievement of goal Thymo dose, biopsy proven AR and infection.

Results: 2013 data included 121 patients: 17.3% re-transplant, 83% Caucasian and 64% male. 2015 data included 90 patients: 23.3% re-transplant, 62% Caucasian and 56% male. No graft loss occurred secondary to rejection in either year.

When evaluating protocol adherence, 47% of patients in 2013 met the Thymo goal of 5.5-7 mg/kg as opposed to 96% in 2015(p<0.0001). 68% of 2013 patients had doses adjusted compared to 24% in 2015(p<0.0001).

The AR rate 30 days post transplant was 7.4% in 2013 and 3.3% in 2015. At 90 days post transplant the AR rate was 10.7% in 2013 and 6.7% in 2015.

The fungal and viral infection rate 90 days post transplant was 3.3% in 2013 and 1.1% in 2015.

Conclusions: Routine adherence to a protocol without unnecessary dosing adjustment is important to achieving goal Thymo induction. Compared to the 2013 population, AR and infection rates have decreased, although not significantly, despite having an ethnically diverse population, high re-transplant rate and an increased immunologic risk due to the change in kidney allocation. The new protocol is also beneficial as it does not require daily ALC labs or additional post discharge Thymo infusions.

CITATION INFORMATION: Sarumi H, Beck L, Borscheid C, Fast B, Hogan S, James M, Vassar K, Vock D, Pruett T. Quality Assessment and Process Improvement of Thymoglobulin Dosing. Am J Transplant. 2016;16 (suppl 3).

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