Summary
Dr. David Traster interviews Dr. Peter Miller, a Johns Hopkins-trained transfusion medicine specialist who runs VIP TPE in Boca Raton. Dr. Miller provides the most technically detailed explanation of therapeutic plasma exchange, covering the ASFA (American Society for Apheresis) guidelines that categorize conditions into four evidence tiers for apheresis treatment. The conversation focuses heavily on TPE for Alzheimer's disease, where Dr. Miller discusses the landmark AMBAR trial, a double-blinded placebo-controlled study of over 500 patients. In moderate Alzheimer's patients, 70% of treated patients showed no decline compared to virtually universal decline in placebo, and many actually improved. Dr. Miller also explains the technical aspects of the procedure including one plasma volume removal per session (removing 70-78% of plasma), the importance of monitoring coagulation factors, the role of IVIG supplementation after TPE, and the typical protocol of six weekly sessions followed by monthly maintenance.
Key Points
- ASFA guidelines classify TPE indications into four categories, from mainstay treatment (Category 1) to contraindicated (Category 4)
- Alzheimer's is now a Category 3 recommendation, meaning TPE has shown to be helpful but the role remains under investigation
- The AMBAR trial showed 70% of moderate Alzheimer's patients halted disease progression with TPE versus near-universal decline in placebo
- A 2025 follow-up study with 30 patients replicated AMBAR results with even better outcomes
- One plasma volume exchange removes 70-78% of plasma; diminishing returns occur as replaced fluid mixes with remaining plasma
- Standard Alzheimer's protocol is once weekly for six weeks, then monthly maintenance
- Small doses of IVIG (2-5 grams) are often given after TPE to help calm chronic low-level inflammation
- Dr. Miller's training at Johns Hopkins included every patient type from pediatric to ICU emergency cases
Key Moments
ASFA evidence categories for apheresis treatment
Dr. Miller explains the four-tier ASFA evidence classification system for apheresis, from Category 1 (mainstay treatment) to Category 4 (contraindicated), providing a framework for understanding which conditions have the strongest evidence.
"category one means that apheresis is the mainstay of treatment. It is really the only treatment. It's the best treatment for the disease. Category two means that it's used in conjunction with something else like medication. And it's definitely a part of the treatment plan."
AMBAR trial results for Alzheimer's disease
Dr. Miller describes the landmark AMBAR trial results showing 70% of moderate Alzheimer's patients halted disease progression with TPE, compared to near-universal decline in the placebo group, with many treated patients actually improving.
"About 70% of the treated patients didn't show any decline at all."
How TPE drains Alzheimer's proteins from the brain
Dr. Miller explains how draining amyloid and tau proteins from blood via TPE also reduces their levels in the central nervous system, halting deposition into the frontal lobes.
"as we drain it from the blood, we also started draining it from the CNS. And, you know, by draining it from the CNS, then it wasn't available to deposit into the"
2025 follow-up study replicates AMBAR results
Dr. Miller discusses a 2025 study with 30 patients that replicated and even exceeded the original AMBAR trial results using different outcome measures.
"there was a second smaller study with 30 patients."
