Clinical Use of Apheresis (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 à 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)

 

The collection of 5% of patient’s mononuclear cells, expose them to UVA and psoralen and then re-infused 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

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

-       Clinical assessment of patient

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

-       Laboratory investigation

o   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

o   Citrate-related hypocalcaemia

o   Vasovagal syncope / pre-syncope

o   Allergic reactions

o   Albumin-bound drugs are removed by plasma exchange

-       Less Common

o   Dilutional coagulopathy

o   Type II HIT

o   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

o   (Joint Accreditation Committee – ISCT & EMBT)

-       Standard Operating Procedures

-       Local Guideline

-       Good transfusion laboratory support