CO-88 | TRANSIENT IDIOPHATIC ACQUIRED VON WILLEBRAND DISEASE: A RARE, CHALLENGING CONDITION WITH A POSSIBLE RAPID AND FAVORABLE EVOLUTION

G. Murante^1|2|3, S. Bergonzi^1|2|3, M. Capetta^1|2|3, F. Valeri^1|2, C. Dainese^1|2, A. Valpreda⁴, R. Pastorino^1|3, F. Bocchi^1|3, B. Bruno^2|3, A. Borchiellini^1|2 | ¹Regional Centre for Hemorrhagic and Thrombotic Diseases, AOU Città della Salute e della Scienza of Turin, Italy; ²Division of Hematology, AOU Città della Salute e della Scienza, University of Turin, Italy; ³Dep. of Molecular Biotechnology and Health Sciences, University of Turin, Italy; ⁴Central Lab. Baldi and Riberi, AOU Città della Salute e della Scienza of Turin, Italy

Background and Aims. The AvWD is a rare but probably underestimated bleeding disorder characterized by laboratory findings and clinical presentations similar to those of inherited vWD. However, unlike the inherited disease, AvWS occurs in adults with no personal or family history of bleeding diathesis. Although AvWS is particularly frequent in lymphoproliferative or myeloproliferative disorders, it can also be associated with solid tumors, immunologic and cardiovascular disorders, and other miscellaneous conditions. The aim of this abstract is to demonstrate the significance of follow-up in cases of AvWS without a recognized underlying cause, given the possibility of spontaneous clinical and laboratory resolution of the hemorrhagic condition.
Case Report. We present a case of a 56-year-old woman that was referred to our center in 2024 due to multiple episodes of epistaxis and easy bruising. She exhibited negative bleeding histories even in trigger conditions (surgery, childbirth) and had no family history of bleeding diathesis. No comorbidities were present at diagnosis, and both autoimmune evaluation and cancer screening were negative. One year after diagnosis, a complete clinical and laboratory resolution was observed. As a rare disease, the diagnostic process is complex and involves multiple steps, requiring an experienced and specialized laboratory. Despite pathological laboratory results, confirming the acquired nature of this disorder remains a significant diagnostic challenge. The first step routine coagulation tests and vWF screening were performed: factor VIII (FVIII:C) dosage, VWF antigen (vWF:Ag), VWF activity (VWF:Ac), VWF ristocetin cofactor activity (VWF:RCo), and collagen binding assay (CBA). Afterwards, dilution and subsequent in vivo recovery tests with plasma-derived von Willebrand factor concentrate were performed. A genetic test was performed. Dilution and in vivo recovery tests strongly suggested an acquired form. Genetic analysis was inconclusive. One year after diagnosis, no more antibodies were found.
Conclusions. The AvWS is a rare bleeding disorder with a diagnostic work-up and optimal treatment highly individualized. The management remains challenging, particularly when discrepancies arise between laboratory findings and the patient’s medical history. For this reason, especially in cases without an underlying cause, it is important to perform close follow-up for the possibility of rapid favorable resolution of the condition.