Randomized controlled trials in therapeutic apheresis

Frequency of Alterations in Apheresis-Related Abstracts Prior to Publications as Peer-Reviewed Articles

High-quality evidence supporting clinical practice is lacking in apheresis. A potential source of evidence is provided by abstracts submitted to the Annual Meetings of the American Association of Blood Banks (AABB) and the American Society for Apheresis (ASFA). However, there is potential for study conclusions to be altered significantly following abstract presentations prior to publications in peer-reviewed journals. Therefore, we evaluated the discordance rate between apheresis-related meeting abstracts and their corresponding published articles. Abstracts accepted to either AABB or ASFA Annual Meetings from 2005 to 2012 and corresponding PubMed-indexed peer-reviewed articles' abstracts published prior to 9/2014 were reviewed for altered methods, results, and conclusions. When present, changes were evaluated for clinical significance. During the 8-year period, 198 out of 1152 abstracts were published as peer-reviewed articles. Of these, 36 (18.2%) presented discordant results, six of which (16.7%) were potentially clinically significant. An alteration in results (58.3%) was the leading reason for discordance. The discordance rate for ASFA abstracts was significantly higher (HR = 4.69, P = 0.0028) than the AABB ones. However, clinically significant alterations occurred more frequently among AABB abstracts (P = 0.025). Approximately 18% of meeting abstracts demonstrated alterations prior to publication in peer-reviewed journals. Given that approximately one in six changes represented clinically significant alterations, potentially affecting clinical practice, we recommend caution when modifying one's clinical practice based on abstract presentations at Annual Meetings. Future studies involving abstracts from both the International Society for Apheresis and the World Apheresis Association should also be performed.

Plasma exchange in thrombotic microangiopathies (TMAs) other than thrombotic thrombocytopenic purpura (TTP)

Thrombotic microangiopathies (TMAs) are a diverse group of disorders that are characterized by common clinical and laboratory features. The most commonly thought-of TMA is thrombotic thrombocytopenic purpura (TTP). Because of the marked improvement in patient mortality associated with the use of therapeutic plasma exchange (TPE) in TTP, this therapy has been applied to all of the TMAs. The issue, however, is that the pathophysiology varies and in many instances may represent a disorder of the endothelium and not the blood; in some cases, the pathophysiology is unknown. The use of TPE is further obscured by a lack of strong supporting literature on its use, with most consisting of case series and case reports; controlled or randomized controlled trials are lacking. Evidence supporting the use of TPE in the treatment of TMAs (other than TTP and TMA-complement mediated) is lacking, and therefore its role is uncertain. With the greater availability of genetic testing for mutations involving complement regulatory genes and complement pathway components, there seems to be a percentage of TMA cases, other than TMA-complement mediated, in which complement pathway mutations are involved in some patients. The ability of TPE to remove abnormal complement pathway components and replace them with normal components may support its use in some patients with TMAs other than TTP and TMA-complement mediated.

Clinical outcomes with ABO antibody titer variability in a multicenter study of ABO-incompatible kidney transplantation in the United Kingdom

BACKGROUND

ABO blood group-incompatible kidney transplantation (ABOiKTx) outcomes are good, but complications are more common than in conventional transplantation. Regimens that use extracorporeal antibody removal therapy (EART) and enhanced immunosuppression are guided by titration of ABO blood group antibodies (using hemagglutination [HA] dilution assays), and these assays vary significantly in performance between centers. This study aims to describe the differences in titer measurement and the effect on clinical practice and outcomes.

STUDY DESIGN AND METHODS

This multicentre, prospective cohort study of 100 ABOiKTx recipients assessed treatment and outcome data, including HA assay results measured retrospectively in a single central laboratory.

RESULTS

Patient and allograft survival at 1 year was 99% and 94%, respectively. There were significant differences in the number of pretransplantation EART sessions in centers undertaking plasma exchange (PEx), compared with immunoadsorption (IA) (median, 6 vs. 4 sessions; p = 0.007). The pre-EART HA titer in both groups was the same when centrally assayed. The local HA assay used to guide treatment yielded significantly higher titers in centers undertaking PEx compared with IA (median, 128 vs. 32; p < 0.005). Patients undergoing PEx rather than IA were significantly more likely to suffer postoperative hematoma (12.9% vs. 1.8%; p = 0.05) or any perioperative collection requiring drainage (19.4% vs. 3.6%; p = 0.02).

CONCLUSION

The colinearity of HA assay sensitivity with the receipt of PEx and EART limits some conclusions regarding the likely direction of causation. However, the association of differences in clinical practice with recognized perioperative complications of ABOiKTx identifies targets for further investigation and quality improvement.

Apheresis research-more abstracts should be published as full manuscripts to provide more evidence for clinical practice guidelines

High-quality evidence to support clinical practice is lacking in apheresis medicine compared to other therapeutic modalities. A potential source of evidence comes from the abstracts submitted to the Annual Meetings of the American Society for Apheresis (ASFA). Therefore, the goal of this study is to determine the proportion of abstracts from the 2005 to 2012 ASFA Annual Meetings that subsequently became PubMed-indexed publications. Furthermore, we sought to determine the factor(s) that were associated with the likelihood of abstracts to be published as full manuscripts. During the 8-year study period, 684 abstracts were available for analysis (median: 82/year, range: 64-118). Most abstracts (74%) were from US institutions, and 67% of first authors were affiliated with academic centers. There were more abstracts (64%) on therapeutic versus donor apheresis (20%) and cellular therapy (16%). Overall, 16% of the abstracts have been published in PubMed-indexed journals, with a median time of 17 months from the ASFA Annual Meeting (range: 1-96 months). Abstracts whose first authors were affiliated with academic institutions were 3.14 times more likely to have been published than abstracts with ones affiliated with an apheresis organization and/or a community hospital. However, neither the first author's location nor the type of apheresis procedure significantly affected the publication rate after adjusting for other covariates. In conclusion, the rate of publication is low and authors should be encouraged to follow their presentations at the meeting with peer-reviewed manuscripts. This change is essential to provide more published evidence for future apheresis practice guidelines. J. Clin. Apheresis 31:353-358, 2016. © 2015 Wiley Periodicals, Inc.

American Society for Apheresis guidelines on the use of apheresis in clinical practice: practical, concise, evidence-based recommendations for the apheresis practitioner

The 6th Guidelines on the use of therapeutic apheresis in clinical practice published by the American Society of Apheresis provide practical, concise, and evidence based guidance for the apheresis medicine practitioner. The overall format of the Guidelines has remained unchanged with the 6th edition, compared to the 5th edition, with enhancements in the committee process of creating the guidelines. Because of changes in the writing committee structure, a number of changes have occurred in the ASFA category and recommendation grade for the use of apheresis in the treatment for a number of previously categorized clinical indications. In addition, eight new indications for apheresis, twenty three new clinical situations for previously categorized diseases, and ten new apheresis treatments for previously categorized disorders have been added. The 6th Guidelines continue to be an invaluable resource for those involved in apheresis medicine.