Alzheimer's disease (AD) is the most common type of dementia. Plasmapheresis is a procedure consisting of removing the plasma, or specific elements which are considered to be involved in pathological processes. Plasmapheresis could reduce the A beta peptides load in the brain. The objective is to study the safety and efficacy of plasmapheresis for AD.
Systematic review, with all studies published before April 2016 reviewed. Selected studies included patients with AD treated with plasmapheresis. GRADE was used to assess quality. Efficacy outcomes include: (i) Cognitive, functional and behavior status, through Mini Mental State Examination, and Alzheimer Disease Assessment Scale-Cognitive test; (ii) Plasma and cerebrospinal fluid A beta levels; (iii) Brain-imaging and functional neuroimaging studies. Safety outcomes included side effects related to the treatment.
Two papers reporting results from three studies were selected: (i) pilot study (n = 10), (ii) its extended study (12 months more of follow-up) (n = 7), and (iii) clinical trial (n = 39). The quality of evidence was very low. About efficacy, the studies didn't report quantitative results and were inconclusive. The pilot study and its extended study reported (1): a tendency towards stabilization in cognitive status; the plasma levels of A beta peptides didn't show a clear pattern; and the brain-imaging assessment suggested a progressive volume increase in the hippocampus. The clinical trial reported in the experimental group vs control (2): a better score for the cognitive status; an increase of plasma A beta peptides; and did not find significant differences between groups for cerebrospinal fluid A beta peptides. The brain-imaging assessment showed a progressive loss of hippocampus volume in both groups. Regarding safety, the studies didn't report quantitative data. We didn't find economic evaluation studies.
The included studies had very high risk of bias and very low quality. We found no evidence on efficacy and safety of plasmapheresis treating AD. Plasmapheresis isn't a priority line in research of AD treatment.