Patient Experience with Congenital (Hereditary) Thrombotic Thrombocytopenic Purpura: A Conceptual Framework of Symptoms and Impacts

Background and Objective Thrombotic thrombocytopenic purpura is a rare, life-threatening disorder characterized by microangiopathic hemolytic anemia and thrombocytopenia, with variable clinical manifestations (e.g., central nervous system, renal, gastrointestinal, and cardiac effects). This study’s objective was to gain an in-depth understanding of patients’ experiences with the congenital form of thrombotic thrombocytopenic purpura, including the most salient symptoms and impacts associated with congenital thrombotic thrombocytopenic purpura and its treatment. Methods An initial conceptual model of thrombotic thrombocytopenic purpura symptoms and impacts was derived from a targeted literature review, refined by interviews with expert hematologists, and further refined by concept elicitation telephone interviews with adults with congenital thrombotic thrombocytopenic purpura in the USA. Patients reported the duration, frequency, and severity experienced for each concept, and rated level of disturbance on a minimum to maximum scale of 0–10. Results Interviews were conducted with 11 patients (mean age, 38.2 years; range 21–52 years) in three waves (n = 4, n = 4, n = 3). The most salient symptoms (reported most frequently and rated by patients as most disturbing) were fatigue, headache, bruising, joint pain, muscular pain, forgetfulness, and difficulty communicating. The most salient impacts included diminished ability to work/study, financial distress, feeling depressed, feeling anxious, and mood swings. Patients’ comments reflected the pervasive nature of congenital thrombotic thrombocytopenic purpura symptoms and impacts, and unmet treatment needs. Conclusions The final conceptual model, which includes salient symptoms and impacts of congenital thrombotic thrombocytopenic purpura and reflects the disease burden, was derived by integrating inputs from the literature review, expert opinion, and patient interviews, and will be used to develop a congenital thrombotic thrombocytopenic purpura–specific, patient-reported outcome instrument.