World apheresis registry report

The establishment of national apheresis registries has been helpful to learn about therapeutic profiles and adverse event incidences. During 2003, the World Apheresis Registry was established and centers from all countries were invited to participate to register their apheresis activities (at www.iml.umu.se/medicin).

In this paper, we will report and analyze the first data retrieved from three centers, in 2 European countries, that registered a total of 388 therapeutic apheresis treatments in 122 patients, 95% due to acute indications. Statistical analyses were performed using an independent Student t-test and Fisher's test. A p-value of less than 0.05 was considered significant.

Fifty percent of the treated patients were women. The mean age of the patients was 51 years (+/-17, range 16-84) and there was no difference between genders (w 50.4, m 51.6 years). Diagnoses for treatment were mainly neurological and vasculitis. In 63% peripheral access was used with a central double lumen catheter, 22% in the jugular vein, 8% in the subclavian vein and 6% the femoral vein. Significant inter-center differences were seen in regard to the access used. The main technique used was centrifugation for conventional plasma exchange (86%), while other modes were leukapheresis, erythrapheresis, platelet apheresis, LDL-apheresis and adsorption of antibodies. Citrate was the only anticoagulant in 92%. During plasma exchange procedures using centrifugation, replacement was by albumin only (58%) or plasma, the latter often in combination with albumin (42%). Adverse events (AEs) were noted in 11% of the procedures. Patients with hypocalcaemia side effects with tingling sensations were included in those data as mild AE and as moderate AEs if they received calcium (Ca) medication. No patient died due to adverse effects. A mild AE was present in 1.8% and moderate in 8.5%. During two procedures (0.5%), the AE was considered severe and therefore the procedure was interrupted. If those with AEs due to lower calcium were removed from analyses, 6.4% had AEs. Significantly more AEs were found when plasma was used as a replacement fluid (p=0.017, RR 2.05, CI 1.17-3.60). There were no differences in the incidence of AEs between genders. The number of procedures was too small to allow sub analyses of AEs in relation to the diagnoses. Adverse events were not related to the procedure used (p=0.095). Those who received additional Ca infusion during the procedure had no AEs (40 sessions) while the others who received no prophylactic Ca had an AE on 45 occasions (p=0.0141, RR 1.116, CI 1.08-1.15).

Data from the registry shows that centers have various approaches to apheresis. One can learn from each other's experience to reduce side effects and improve efficacy. From these data we noted that prophylactic Ca infusion reduced side effects.