Thrombotic thrombocytopenic purpura: Description and analysis of 23 cases treated in Chile between 2017 and 2022.

Introduction: Since the first description of Thrombotic Thrombocytopenic Purpura, caused by a severe deficiency of ADAMTS13, plasma exchange and immunosuppression have become standard treatments, allowing to decrease its high mortality rate. Prospective records of Thrombotic Thrombocytopenic Purpura have provided valuable information on its pathophysiology, clinical presentation, and outcomes. The objective of this study is to update the local Chilean experience in the diagnosis and management of this disease, through a case series of patients treated between 2017 and 2022.

Methods: Case series study that included patients over 18 years old diagnosed with Thrombotic Thrombocytopenic Purpura, treated between June 2017 and August 2022 at Hospital Clínico UC Christus. Information was collected from clinical records, which were used for cohort description and statistical analysis. Accepted definitions from the literature were used to describe the outcomes. The study was approved by the local ethics committee (ID 220524001).

Results: Our series had higher age and prevalence of comorbidities compared to those reported in the literature. The most important clinical manifestations included constitutional, gastrointestinal, hemorrhagic, and neurological symptoms, with different presentation frequencies than those described internationally. We found a lower capacity of the PLASMIC Score for the detection of Thrombotic Thrombocytopenic Purpura in our series. The predominant therapeutic strategy was a combination of glucocorticoids and plasma exchange (61% of the patients). There was a high mortality rate (56.5%) and adverse events related to plasma exchange, especially of infections related to its use.

Conclusions: This study highlights the diagnostic and therapeutic challenges of Thrombotic Thrombocytopenic Purpura in the local context and the need to improve our management strategies through standardizing care and better application of clinical guidelines to reduce the high mortality rate in these patients.