PB0167 - Autoimmune acquired factor XIII deficiency with underlying diseases: A Systematic Review

Background: Autoimmune acquired factor XIII deficiency (AH13), unlike acquired factor FXIII deficiency caused by depletion or underproduction, is a very rare and very serious bleeding disorder with a very high mortality rate of nearly 20%.

Aims: To analyze the clinical characteristics, treatment methods, and treatment outcomes between AH13 associated with underlying disorders and idiopathic AH13. We hope this study may provide some evidence for the precise and individualized treatment of AH13 from new insights and contribute to the reduction of mortality among patients with this disease

Methods: Web of Science, PubMed, and Google Scholar were searched up to 1 April 2023. Article screening and data extraction were independently conducted by two reviewers. This systematic review conforms with the PRISMA guidelines. The case report is following the CARE statement guidelines. And completeness of reporting was evaluated according to modified elements from the CARE report guidelines.

Results: The idiopathic AH13 group was older, predominantly male, and had lower FXIII factor levels than the AH13 group with underlying diseases. Surprisingly, there was a statistically significant difference in slightly higher inhibitor levels in the AH13 group compared to the idiopathic AH13 group. Correspondingly, the AH13 with underlying disorder group had a greater number of grade III bleeding. Importantly, the number of patients in the idiopathic AH13 group treated with prednisone in combination with rituximab or cyclophosphamide was higher than in the AH13 with underlying diseases group. Besides, there were more relapses and/or deaths among AH13 patients in the underlying disease group.

Conclusion(s): AH13 patients with underlying disease have more severe bleeding and a worse prognosis than those with idiopathic AH13, possibly stemming from difficulties in clearing factor 13 inhibitors. Regular testing of FXIII factor activity and inhibitor levels during patient bleeding is essential, particularly in AH13 patients with underlying disease.