Saliva and blood interferon gamma levels and IFNG genotypes in acute graft-versus-host disease

Oral Diseases (2012) 18, 816–822 Objective: Graft‐versus‐host disease is a major complication after allogenic hematopoietic stem cell transplantation. Interferon gamma is an important pro‐inflammatory cytokine involved in this disease. Cytokine gene polymorphisms are associated with functional differences in cytokine expression and can alter the clinical course of graft‐versus‐host disease. This study aimed to investigate the association between IFN‐γ levels in saliva, blood, and IFNG polymorphisms, as well as the occurrence of acute graft‐versus‐host disease in allogenic HSCT. Subjects and Methods: Fifty‐eight consecutive allogenic hematopoietic stem cell transplantation recipients and their donors were prospectively studied. IFN‐g levels in saliva and blood were assessed by ELISA. Samples were collected weekly from 7 days before transplantation (day −7) to 100 days after allogenic HSCT (day +100) or until death. Saliva and/or blood samples were obtained from the recipients and donors to determine IFNG gene polymorphisms. Results: Increased saliva and blood IFN‐g levels were observed in patients that had developed aGVHD. In the saliva, the peak levels of IFN‐g could be found one week before aGVHD diagnosis, while in the blood, peak levels of IFN‐g could be only observed upon diagnosis. A significant association could be identified between the recipients’IFNG genotypes and the IFN‐g levels in their blood, at +14 days after HSCT. No association could be observed between IFNG gene polymorphisms and the aGVHD. Conclusion: The present study shows that the genetic background of recipients can influence the production of IFN‐g. Moreover, as IFN‐g levels in the saliva and blood were found to be associated with aGVHD development, this cytokine may be a useful predictor of acute graft‐versus‐host disease.