DP041 | PARVOVIRUS B19 INFECTION IN ADULT PATIENTS AFTER AUTOLOGOUS-ALLOGENEIC STEM CELL TRANSPLANTATION OR CAR-T THERAPY: SINGLE CENTER EXPERIENCE

Parvovirus B19(B19V) is a single-stranded, envelope-free DNA virus, who can cause infectious erythema in healthy children and arthralgias in adults. The virus shows a particular tropism for bone marrow erythroid progenitors, impairing erythropoiesis. In immunocompromised patients, particularly after autologous or allogeneic hematopoietic stem cell transplantation or CAR-T cell therapy, primary infection or reactivation can lead to severe hematologic complications, such as erythroid aplasia and severe anemia. Anemia can increase morbidity, delayed engraftment, and can prolong transfusion dependence. In particular, in CAR-T patients lymphodepletion, therapy associated, further increases the risk of persistent infection. Aims: To evaluate the impact of B19 infection on patients underwent allogeneic or autologous HSCT or CarT cell therapy. Methods: We conducted a retrospective study of 63 patients undergoing at our center, CTMO (Reggio Calabria), allo or auto HSCT or CAR-T therapy between January 19, 2021 to October 10, 2024, for hematologic malignancies. Median age was 53 years (32 male, 31 female) .The median follow-up was 235,5 days. Diagnosis of B19V infection relies on PCR for viral DNA detection, as serologic tests are often unreliable due to immunosuppression. The presence of viral DNA indicates active infection or reactivation, requiring early intervention. Treatment relies primarily on intravenous immunoglobulin (IVIG) to provide passive immunity and improve erythropoiesis; erythrocyte transfusions are required in severe cases. The characteristics of our population are summarized on table 1. Results: twelve patients died from causes unrelated to B19V, while 50 were alive. Only one patient received IVIG as specific treatment. The observed viral load ranged from 408 to 941,349,600,000 copies. Respectively, at first B19 reactivation, 28.5% of patients had a copy number between 1000 and 10,000, 22.2% a copy number less than 1000 and 42.8%>10,000 copies . In our cohort, B19V reactivation had no significant impact on either overall survival or non-transplant-related mortality. Clinical symptoms such as fever, nausea, skin rash, dyspnea and diarrhea were documented independently of viral load. The most severe anemia was observed in patients undergoing allogeneic transplantation. Conclusion: Based on our results, we emphasize the importance of surveillance for B19V reactivation not only in patients undergoing alloHSCT but also in those treated with autoHSCT or CAR-T, especially in the presence of suggestive symptoms.