Résumé
Lupus anticoagulant hypoprothrombinemia syndrome (LAHPS) is a rare but potentially serious condition. Approximately one hundred pediatric cases with a heterogeneous clinical presentation have been reported in the literature with a post-infectious (PI) or autoimmune (AI) origin, but we have no clear data on the difference between these two forms. Method: we performed a retrospective multicenter study of cases in France and a review of cases in the literature, and then compared post-infectious and autoimmune forms of LAHPS. Result: we included 84 patients: 17 from our French cohort, 67 from a systematic review of the literature. 95% of patients presented with hemorrhagic symptoms, almost half of which were severe (47%). An infectious or autoimmune context (mainly lupus) was present in 33% and 53% of cases, respectively. The majority of patients were treated with corticosteroids (54%), and nearly one-third received adjuvant immunomodulatory therapy (30%). The AI group consisted of older children and had significantly more severe bleeding (p<0.001%). The incidence of thrombosis was not significantly associated with this subgroup. FII levels were comparable between the two groups, but FXI deficiency was significantly associated with the AI group. Treatment was more frequent and intensive, and the relapse rate was higher in the AI group (p<0.001%). Conclusion: acquired hypoprothrombinemia in children is a rare and heterogeneous entity. PI hypoprothrombinemia tends to occur in young children with mild hemorrhagic symptoms, and therapeutic abstinence may be considered. In the setting of AI disease, bleeding is often severe. Treatment, sometimes intensive, is required. Relapses are common.