Abstract Number: PB1146
Meeting: ISTH 2022 Congress
Theme: Hemophilia and Rare Bleeding Disorders » Hemophilia - Clinical
Background: Immune tolerance induction (ITI) is the only therapy to eradicate anti-factor VIII (FVIII) antibodies (inhibitors) in persons with hemophilia A (PwHA). However, this burdensome treatment fails in 10-40% of patients. In order to predict the ITI outcome is it important to identify predictors of ITI success.
Aims: To summarize the current evidence on factors associated with ITI outcome in PwHA.
Methods: On February 15 2021, a comprehensive literature search was conducted, which was updated on December 29 2021. Randomized controlled trials (RCT), cohort -, or case-control studies reporting on predictors for ITI outcome in PwHA were eligible for inclusion. ITI success was defined according to the methods of the investigators of the original studies. Data were extracted on study characteristics, outcome definitions, and predictors of ITI outcome, using a data collection form. Methodological quality was assessed by using an adapted Joanna Briggs Institute checklist for cohort studies. Studies were rated as high quality if ≥11/13 criteria were met.
Results: The literature searches yielded 1,079 unique papers of which 27 studies were included. We included 1 (4%) RCT and 26 (96%) cohort studies, involving a total of 1,734 PwHA. Six studies were rated as high quality (22%). ITI success was predominantly defined as negative inhibitor titer ( < 0.6 BU/mL), FVIII recovery ≥66% of expected, and FVIII half-life ≥6 hours (16/27; (59.3%)). Historical peak titer < 100 BU/mL, pre-ITI titer < 10 BU/mL, and peak titer during ITI < 100 BU/mL were associated with ITI success with pooled odds ratios of 1.50 (95% CI, 1.19-1.89), 1.68 (95% CI, 1.33-2.13), and 2.43 (95% CI, 1.58-3.74), respectively.
Conclusion(s): This systematic review and meta-analysis summarized and analyzed all available evidence of single variables that influence ITI outcome. However, the effects of multiple variables on ITI outcome were not investigated in this review.
To cite this abstract in AMA style:
Oomen I, Camelo R, Rezende S, Voorberg J, Mancuso M, Oldenburg J, Carcao M, Matino D, Lillicrap D, Fischer K, Fijnvandraat K, Gouw S. Determinants of successful immune tolerance induction in persons with hemophilia A – systematic review and meta-analysis [abstract]. https://abstracts.isth.org/abstract/determinants-of-successful-immune-tolerance-induction-in-persons-with-hemophilia-a-systematic-review-and-meta-analysis/. Accessed August 16, 2022.« Back to ISTH 2022 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/determinants-of-successful-immune-tolerance-induction-in-persons-with-hemophilia-a-systematic-review-and-meta-analysis/