Breakthrough CMV Lung Transplant -Multicentre

This study is looking at a phenomenon called "breakthrough CMV infection" in lung transplant recipients. Cytomegalovirus (CMV) is a very common virus that is harmless in healthy people but can cause serious illness in immunosuppressed patients. When a CMV-negative person receives a lung from a CMV-positive donor, they are at very high risk of developing CMV disease. Standard practice is to give prophylactic antiviral medication (valganciclovir) for 6 or 12 months after transplant. However, some patients develop CMV infection after this preventive treatment ends — called breakthrough infection — and this study aims to understand who is at risk and why. Participants are followed after their transplant, with regular monitoring for CMV. Researchers will look at factors like immune responses, viral characteristics, and medication adherence that predict breakthrough infection. Understanding this could lead to better-targeted prevention strategies. You may be eligible if: - You received a lung transplant from a CMV-positive donor but are CMV-negative yourself - You are 18 or older - You received the full course of valganciclovir prophylaxis as per your transplant center's protocol - You had CMV monitoring after your prophylaxis ended for at least 12 weeks - You have given signed informed consent You may NOT be eligible if: - You have a known allergy to ganciclovir or valganciclovir - You had low neutrophil count before the transplant - You had a living-donor or re-transplant lung transplant - You had a pre-existing immunodeficiency condition Talk to your doctor to see if this trial is right for you.