Bootcongres

Primary varicella zoster virus (VZV) infection causes varicella (chickenpox) and subsequently lifelong latent infection in ganglia from which it may reactivate, because of immunosuppression related to transplantation or ageing, leading to herpes zoster (HZ: shingles). Recently, we reported that VZV-reactive memory T-cells are significantly lower in transplant recipients compared to healthy controls. In addition, the VZV-specific IgG titres after transplantation were significantly lower than before transplantation. Data on the incidence and timing of VZV reactivation after lung transplantation is limited. Therefore, we investigated the incidence of HZ after lung transplantation. Additionally, we questioned whether the VZV-specific T-cell and B-cell memory responses are recovered after VZV reactivation. The records of 101 patients (n=50 female, n=51 male) who underwent lung transplantation between April 2002 and April 2013 were analysed for VZV-PCR DNA till October 2013. Median age at transplantation was 54 years (range: 19-66). VZV infection was clinically diagnosed and confirmed by PCR in 15 patients. One patient who was VZV IgG negative before transplantation, developed primary VZV infection 1.2 years after transplantation. Fifteen patients developed HZ: one patient had systemic dissemination, one patient developed disseminated vesicular rash in C2-C5 and died 6 days later, and 13 patients had uncomplicated cutaneous HZ involving 1-3 dermatomes. The median time to HZ was 1.4 years (range: 0.1-3.1) after transplantation. The overall incidence rate of HZ after transplantation (38 cases/1000 person-years) was significantly higher than the age-matched healthy population (50-70 years: 7-8 cases/1000 person-years).

PBMC from 5 patients were available before and after HZ. Their VZV-specific B and T-cell memory responses were compared with 5 patients without HZ. In 4 out of 5 patients the number of VZV-specific IgG producing B-cells increased after HZ to higher frequencies than those without HZ (p=0.06). The percentage of VZV-reactive CD4 and CD8 central and effector memory T-cells increased in all patients after HZ to significantly higher frequencies compared to those without HZ (p=0.03). In conclusion, HZ is a frequent complication after lung transplantation and increases VZV-specific T- and B-cell memory responses. Boosting the VZV adaptive immune response by prophylactic VZV vaccination before transplantation may limit the incidence of HZ after transplantation.