E. von Willebrand

The Impact of Early Viral Infections and Graft-Versus-Host Disease on Immune Reconstitution Following Paediatric Stem Cell Transplantation

Viral infections and graft‐versus‐host disease (GVHD) render an impact on both the clinical and immunological recovery following allogeneic hematopoietic stem cell transplantation (HSCT). We studied the recuperation of the immune defence after transplant in the paediatric setting and assessed the impact of early (<100 days post‐HSCT) viral [cytomegalovirus (CMV), Ebstein‐Barr virus (EBV) and adenovirus] reactivations/infections and GVHD. Fifty‐one paediatric recipients of HSCT were enrolled. T cell recovery was evaluated on lymphocyte subpopulations using flow cytometry and functionally by measuring T cell excision circles (TRECs) and through the analysis of T lymphocyte responses to mitogens. B cell recovery was studied by flow cytometry and functionally by ELISPOT. Acute and mild chronic GVHD allowed for a brisk recovery of both cellular and humoral immunity while moderate to severe chronic graft‐versus‐host disease (cGVHD) associated with a significant, tampering effect on the immunological recovery after transplant. In the former group, the early viral reactivations/infections seemingly linked with a delayed recovery of T lymphocytes and low TRECs values. Moderate to severe cGVHD appears to associate with an impaired immunological recovery after HSCT. Early viral infections linked with prolonged T cell immunodeficiency and thymic dysfunction may be indicative of the presence of subclinical GVHD.

Diagnosis of acute rejection in liver transplantation

Eleven acute rejections were found in 9 patients with liver transplantation due to end-stage liver cirrhosis. The rejections were diagnosed with fine-needle aspiration biopsy (FNAB) giving the cellular picture of immunoactivation in the liver graft when compared to a simultaneous sample of peripheral blood. s-Alkaline phosphatase and s-bilirubin increased within 1 week after onset of rejection in 7 and 10 cases, respectively. s-Alanine amino-transferase and b-ammonium were of no value in the diagnosis of acute rejection. A core biopsy was obtained only in a case of severe liver damage, mainly to estimate the need for retransplantation. One year after grafting, 6 out of 7 cirrhotic patients are well, all with normal liver function. Two have died of sepsis. One patient died from pulmonary metastases of occult liver carcinoma 6 months after the transplantation. FNAB seems helpful in detecting early acute rejection and also excluding such an event in the liver graft.