Abstract 15: Invasive Aspergillus Niger Infection Cured after V Hematopoietic Stem Cell Transplantation in a Pediatric Patient with Severe Congenital Neutropenia

Abstract Introduction Severe congenital neutropenia (SCN) is a non-malignant haematological disorder characterized by a quantitative deficit of neutrophils (N<500/mmc), recurrent severe infections and need for prolonged granulocyte growth factor (G- CSF) therapy. Objectives This clinical case describes a life-saving unrelated cord blood transplant in a patient with previous multiple graft failures while ha had a severe active maxillary aspergillosis. Methods R.A. is a child suffering from SCN type I (mutation of the ELANE gene) who required the administration of granulocyte growth factor (G-CSF) from birth, at progressively increasing doses. The patient was a haploidentical allogeneic HSCT given the lack of HLA matched/minor mismatched donors from the international registries. The patients received sequentially 4 haplo HSCTs (2 from father with αβ+/CD19+ depletion of the graft, 2 from mother without in vitro graft manipulation and using post-transplant cyclophosphamide) without obtaining myeloid engraftment. and remaining aplastic. DSAs (patient-specific antibodies against the donor's HLA antigens) were found after the third transplant but the desensitization procedures did not prevent the rejection of the 4th transplant. Being aplastic for 4 months, he developed a progressively worsening Aspergillus niger infection of the oral cavity, maxillary bone and right maxillary sinus, with intermediate sensitivity to amphotericin B (Image 1). After identification of a DSA-negative unrelated cord blood unit (HLA match 6/8) a 5th HSCT was performed. Results The 5th transplant successfully engrafted for neutrophils and platelets and the aspergillosis infection gradually solved. Currently, three years after the transplant, the patient is in good conditions with a complete donor chimerism and without significant immunological consequences post-HSCT Discussion in this patient, the use of an unrelated cord blood allowed to bypass the lack of donors in the international registries and the graft failure/rejection of the haploidentical donors due to DSAs. Moreover, Aspergillosis refractory to antifungal medical therapy is not a contraindication to HSCT because myeloid recovery and immune reconstitution after HSCT are able to achieve a control of the infection together with antifungal therapy.