Infectious Complications in Tocilizumab-treated Kidney Transplant Recipients

Tocilizumab is an interleukin-6 receptor antagonist recently described as a promising treatment for antibody-mediated rejection. We compared infectious complications among tocilizumab-treated kidney transplant patients with those receiving intravenous immunoglobulin (IVIG)/rituximab.

Infections occurring among 148 kidney recipients treated with tocilizumab 8 mg/kg IV monthly (n = 83) or IVIG/rituximab (n = 65) for donor-specific antibodies and antibody-mediated rejection through 1 year after treatment cessation were reviewed. Incidence rates of infections were compared using Poisson regression.

There were 106 infections observed over 190.1 person-years, yielding an incidence rate of 558 infections/1000 patient-years. A lower incidence rate of infections was observed among tocilizumab-treated compared with IVIG/rituximab-treated patients (463 infections/1000 patient-years versus 730 infections/1000 patient-years; P = 0.02). Twenty-five of 49 infections (51%) in the IVIG/rituximab group required hospitalization compared with 31 of 57 (54%; P = 0.85) in the tocilizumab group. There were no infection-related deaths in either group. Urinary tract infections and pneumonia were the most common types of infections, whereas gastrointestinal, blood, skin/soft tissue, viral, and fungal infections were less common. On multivariable Poisson regression, there was a lower incidence rate of infections associated with tocilizumab compared with IVIG/rituximab (incidence rate ratio, 0.63; 95% confidence interval, 0.43-0.93).

Among kidney transplant patients treated with tocilizumab, there was no excess risk of infections compared with standard therapy with IVIG/rituximab.