A 26-year-old woman presents with recurrent petechiae and ecchymoses on both lower limbs, accompanied by gingival bleeding over the past 6 months. Laboratory tests show: platelets (PLT) 32×10<sup>9</sup>/L, normal white blood cell (WBC) count and hemoglobin (Hb), elevated platelet-associated immunoglobulins. A diagnosis of primary immune thrombocytopenia (ITP) is considered. Which of the following is NOT consistent with the laboratory findings of this disease?