Clinical Use of Apheresis (BSH 2015)

 

Plasma Exchange

 

SD-FFP for TMA’s, otherwise 4.5% HAS

  • SD-FFP due to anticipated large total volumes of FFP so want to reduce TTI risk.

  • SD-FFP also contains some fibrinogen, making hypofibrinogenaemia less likely.

 

Indications

  • Disease caused by pathogenic antibodies or other macromolecules found in the plasma

  • TTP / aHUS

  • Cryoglobulinaemia

  • Waldenstroms with symptomatic hyperviscosity

  • Non-haem  - Myasthenia Gravis, Guillain-Barre, Anti-GBM disease, ANCA-vasculitis, ABO-incompatible living donor renal transplant, HLA donor specific antibody rejection in renal transplant, CIDP

 

Technical Aspects

  • Aim 1-1.5 plasma volumes exchanged per session

  • TTP regimen – daily 1.5 plasma vol exchange until platelet count normal for 3 days, then wean down.

  • Typically centrifugation or filtration system (addenbrookes use centrifugation)

  • Newer column-based extracorporeal immunoadsorption techniques more rapid effect

  • SE: Hypofibrinogenaemia

 

Red Cell Apheresis

 

Indications

  • Primarily sickle cell disease – ACS, stroke (acute, 1o or 2o prevention), pre-op

  • Also used in severe malaria and erroneous Rh D+ blood transfusion to Rh D- woman.

  • Also considered in polycythaemia – isovolaemic haemoreduction by erythrocytopheresis

 

Advantages over top-up transfusion

  • Faster reduction in HbS in acute setting

  • Reduced frequency of treatments for patient on chronic programs

  • Reduced iron loading

  • Top up should not be used where patients Hb is within the normal range

 

Technical Aspects

  • Red cell units should be ABO compatible, Rh and Kell compatible, HbS-

  • Ideally RBC less <8 days old —> longer lasting reduction in HbS, less risk of hyperkalaemia

  • Typically 8-10 RBC units required to maintain HbS <30% in chronic Ex program

 

Extracorporeal Photopheresis (ECP)

 

Collect 5% of patient’s mononuclear cells, expose them to UVA and psoralen and then re-infuse into patient.

 

Indications

  • Cutaneous T-cell Lymphoma, Mycosis fungoides / Sezary Syn

  • Chronic GVHD – 2nd line treatment for skin, mucosal and liver chronic GVHD

  • Acute GVHD – 2nd line

 

Technical Aspects

  • Can use an open or closed system – open gives higher cell dose but risk of infection

 

Cytoreductive Apheresis (Leukopheresis / Thrombocytapheresis)

 

Indications

  • Cytoreduction in leukaemia / MPN with WBC >100 and clinical hyperviscosity

  • Must be used in combination early initiation of chemotherapy

  • NOT to be used in APML as worsen coagulopathy

Thrombocytapheresis exists, and has been used occasionally in MPN.

 

Cellular Therapy Product Collection by Apheresis

 

Indications

  • Stem cell collection in Auto and Allograft

  • T-cell collection for DLI

 

Technical Aspects

  • Donors for allograft should be mobilized by GCSF alone

  • Autograft patients may use GCSF + Chemotherapy. Plerixafor is a 2nd line option

  • CD34+ count should be assessed by flow cytometry prior to starting apheresis to ensure adequate mobilization. Most centres use cut-off of CD34+ cells >10ul-1.

  • 2-3 blood volumes are processed for stem cell collection

 

Patient Management

 

Pre-Apheresis Care

Written informed consent

  • Rationale, alternative options, explanation of procedure, serious and frequent complications, use of blood products

Clinical assessment of patient

  • Psychological issues, General health, Haemodynamic stability, Adequate vascular access, Lifestyle of stem cell donors (for TTI risks)

Laboratory investigation

  • FBC, biochemistry, fibrinogen, microbiology screening if stem cell donor

Prepare an apheresis treatment plan specific for patient

 

During the procedure

Omit 1 prior dose of ACEI to avoid vasovagal

With exception of IV calcium to correct hypocalcaemia, no meds should be administered during procedure

Continuous monitoring by trained healthcare professional throughout procedure

 

Post-treatment care

Contact card for patient

Written information about any blood products they received

 

Complications

More Common

  • Citrate-related hypocalcaemia

  • Vasovagal syncope / pre-syncope

  • Allergic reactions

  • Albumin-bound drugs are removed by plasma exchange

Less Common

  • Dilutional coagulopathy

  • Type II HIT

  • Line-related thrombosis

 

Apheresis Service Management

 

Apheresis service requires

  • An apheresis lead

  • Trained staff with regular competency assessment

  • Adherence to JACIE standards if transplant centre

    • (Joint Accreditation Committee – ISCT & EMBT)

  • Standard Operating Procedures

  • Local Guideline

  • Good transfusion laboratory support