Birgitta Versluijs

121 Respiratory virus infection pre-HCT and alloimmune-mediated lung syndromes mend thorough screening of all pre-HCT patients with chest HRCT and BAL in search of fungal infection but also for RVas a predictor for allo-LSs. In case of RV positivity, we would advise slower tapering of immune suppression after HCT and close monitoring for respiratory symptoms during follow-up with prompt diagnostics and treatment when an allo-LS is suspected. In conclusion, our findings show that the presence of RV DNA/RNA in BAL fluid before HCT is a strong predictor for the occurrence of allo-LSs weeks to months after HCT. Further studies are needed to unravel the mechanisms underlying alloimmune pheno- mena in different target organs after HCT and to determine a role for the respiratory microbiome. Recognizing BAL fluid RV positivity before HCT as a predictor for allo- LSs might have clinical implications for prevention (by adapting immune suppressive prophylaxis) and (pre-emptive) therapy. Early recognition might also lead to improved survival chances. Clinical implications In children positive RV results in BAL fluid before HCT predisposes to allo-LSs. Screening is important because prevention and treatment of allo-LSs is based on either prolonged or increased immune suppression. 7