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Current patterns of use in therapeutic apheresis: a metropolitan center experience

New York Blood Center (NYBC) performs apheresis for approximately 95 hospitals in the greater metropolitan area. The hospital mix is mostly urban, mostly public, and approximately equally teaching and nonteaching, with sizes ranging from small to large. Therefore NYBC’s case mix is probably representative of the distribution of apheresis procedures occurring for various diagnoses within the Northeast region. Of interest are the most frequent diagnoses for which apheresis is performed and whether an estimate of the number of procedures per patient seems reasonable for the diagnosis. A retrospective review of all 9374 apheresis procedures performed by the NYBC in 2011 and 2012 was performed. A NYBC physician review and approval was required before initiating new patients. Diagnoses were categorized whenever possible using the 2013 American Society for Apheresis (ASFA) guidelines. A total of 7193 (76.8%) apheresis procedures in 1289 patients were for therapeutic indications. The remaining procedures were hematopoietic progenitor cell or other mononuclear cell collections, predominantly for sipuleucel-T (autologous dendritic cell derived) prostate cancer treatment. Of the patients receiving therapeutic apheresis, 52% were male and 48% were female. Patient age ranged from 3 to 95 years old, with 11% being pediatric (<18 years old), 41% between 18 and 45 years, 30% between 45 and 65 years, and 18% more than 65 years. Of the total procedures, 81.9% were plasma exchanges, 15.1% were red blood cell exchanges (RCEs), 2.4% were leukapheresis procedures, and 0.1% were plateletpheresis procedures. A breakdown of individual diagnoses is listed in Table 1. A total of 88% of patients and 95% of procedures were done for either ASFA Grade I or II indications. A total of 11.9% of patients and 4.8% of procedures were done for ASFA Grade III indications; only one patient had an ASFA Grade IV indication (refractory idiopathic thrombocytopenic purpura). The most common indications for plasma exchange were thrombotic thrombocytopenic purpura (TTP), hemolytic uremic syndrome (HUS), thrombotic microangiopathy, myasthenia gravis, and renal transplant desensitization or rejection. The precise fraction of patients with TTP versus HUS versus thrombotic microangiopathy is not available; however, more than 90% are recollected to be TTP cases. RCE was predominantly for sickle cell disease (SCD). Indications for RCE treatment in SCD were available for 88.5% of patients and 94% of procedures, with acute conditions being the indication for approximately 70% of SCD patients and 36% of RCE procedures. The remaining procedures were performed either preoperatively or for chronic prophylaxis (predominantly stroke and rarely pain crisis prophylaxis). Other diagnoses treated, which could not be ASFA categorized, possibly due to lack of information, include nonspecific polyneuropathy, nonspecific transverse myelitis, nonspecific vasculitis, and thrombocytopeniaassociated multiple organ failure. Additional information and/or outcome data would be required to clarify the appropriateness of therapeutic apheresis in these instances. Compared to the 2010 guidelines, the 2013 guidelines additionally included heparin-induced thrombocytopenia and Stevens-Johnson syndrome and/or toxic epidermal necrolysis (Category III indications) and the revision of polycythemia vera from a Category III to Category I indication, as reflected in Table 1. Monitoring of changes in practice helps us remain informed of new potential indications and to advise partnering institutions. Evidence-based guidelines for therapeutic apheresis are intended to advise and educate clinicians on the quality of evidence as well as the strength of recommendation based on published practice and outcomes. Based on our experience, the vast majority of procedures performed (>90%) fall into either Grade I or Grade II.