Introduction: Kidney transplant recipients (KTRs) are at increased risk of invasive pneumococcal disease, which may worsen allograft and patient survival. However, the effect of immunosuppression (IS) on pneumococcal specific immunity in KTRs is unknown. We investigated how IS affects pneumococcal specific immunoglobulin G (PnIgG) levels after kidney transplantation.

Methods: KTRs transplanted between June 2011 and 2014 at the UCL Centre for Nephrology were included. Serum PnIgG was measured using an ELISA (www.bindingsite.com) at the time of transplantation, and at 12 weeks thereafter. PnIgG levels at these time points were determined in patients who had standard IS (Basiliximab induction, pulsed methylprednisolone and rapid prednisolone taper to zero; maintenance tacrolimus and MMF) without augmentation, and in patients who had standard IS augmented for the management of early rejection.

Results: 30 KTRs were included (age 47 ± 13 years; 60% male). 8 (27%) patients had rejection within the first 12 weeks of transplantation, and IS augmented. All patients had detectable PnIgG at the time of transplantation (mean PnIgG 153 ± 83mg/l). In patients without augmented immunosuppression there was no significant difference in PnIgG levels at 12 weeks after transplantation compared to baseline (baseline 151 ± 77mg/l; 12 weeks 144 ± 81mg/l; p. = 0.19). However, in patients who had augmented immunosuppression for early rejection, there was a significant reduction in PnIgG levels at this time point (baseline 160 ± 102 mg/l; 12 weeks 123 ± 97mg/l; p = 0.03; Figure 1)

Discussion: PnIgG levels were significantly lower at 3 months after transplantation compared to baseline in KTRs who had IS augmented due to early rejection. PnIgG maybe a useful biomarker for impaired immunity in this group and a guide to revaccination.

[P103] The effect of immunosuppression on pneumococcal specific immunoglobulin G levels in kidney transplant recipients