A nationwide population-based study on therapeutic plasma exchange for 10 years in Korea using Health Insurance Review and Assessment database

INTRODUCTION

Indications for therapeutic plasma exchange (TPE) have expanded over the years, and the number of procedures is expected to have been increased. Apheresis registries can be difficult to sustain due to workload and privacy issues. This study aimed to analyze national claims data to characterize the use of TPE.

MATERIALS AND METHODS

Patients who underwent TPE were retrospectively identified between January 2008 and December 2017 from the Korean Health Insurance Review and Assessment Service database. Data of patients' characteristics, primary diagnosis, hospitalization, treatment, and procedures were analyzed.

RESULTS

A total of 9944 patients underwent 62 606 TPE procedures. The median number of TPE procedures performed per patient was 5 (interquartile range, 3-7). Fresh frozen plasma (71.4%) was most commonly used as the replacement fluid. The most common indication was renal diseases (36.8%), followed by hepato-biliary (17.6%) and hematological (15.2%) diseases. Increased frequency of renal diseases was the most remarkable change, which increased from 529 (21.2%) procedures in 2008 to 4107 (44.5%) procedures in 2017, reflecting the widespread implementation of ABO-incompatible kidney transplantation. The top five hospitals conducted 59.6% of the procedures, which showed a centralized distribution.

CONCLUSIONS

The most common indication was renal diseases. The number of TPE procedures performed annually increased by approximately 3.7 times from 2008 to 2017. This study shows that other than a registry, claims data can be successfully used to analyze various aspects of TPE procedures on a nationwide scale. This approach could be used by other countries, especially those that have national health insurance.

Re-examination of 30-day survival and relapse rates in patients with thrombotic thrombocytopenic purpura-hemolytic uremic syndrome

BACKGROUND AND OBJECTIVES

Thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome (HUS) are characterized by microangiopathic hemolytic anemia and thrombocytopenia. Interestingly, markedly different survival rates have been reported despite increases in survivability. We studied TTP-HUS 30-day mortality and relapse rates of patients who received TPE at our institution and compared them to published data.

PATIENTS AND METHODS

Retrospective study analyzed 30-day mortality and relapse rates attributed to TTP-HUS from 01/01/2008 to 12/31/2012 and compared them to comparable literature reporting mortality and survival. Studies describing other etiologies for TPE and different mortality time interval were excluded.

RESULTS

Fifty-nine patients were analyzed and all were initially treated with TPE and corticosteroids. Eleven patients were classified as not having TTP-HUS due to testing or clinical reassessment which ruled in other etiologies, and 18/59 patients had ADAMTS13 activity <10%. Of remaining patients, 36/48 (75%) were diagnosed as idiopathic and 12/48 (25%) as secondary TTP-HUS. Patients received a mean of 12 TPEs (range 1-42); 42/48 (87.5%) patients had ADAMTS13 activity measured; complete response obtained in 39/48 (81.2%) patients (platelet count >100 x 10(9)/L); partial response in 4/48 (8%); and 5/48 (10.4%) did not have increases in platelet counts (2/5 of these patients died within the study period). Forty percent of patients obtained platelet counts >150 x 10(9)/L. Overall 30-day mortality for our patient cohort was 6.7% (4/59). Comparison of our mortality rate to combined data of five published studies of 16% (92/571) showed a significant difference, p = 0.04. Our relapse rate was 18.6% (11/59) similar to previous reports.

CONCLUSIONS

Wide differences in mortality may be due to grouping of two distinct pathologic entities under TTP-HUS; and presence of confounding factors in the patient populations under study such as co-morbidities, promptness of TPE initiation, delay in diagnosis and therapeutic practice.