Haemapheresis

As early as the 1960s, the first cell separators were developed as continuous or discontinuous procedures (Kiefel 2010).

Plasma exchange (PE) first occurred in the early 1970s and was used by Cardella et al. for acute humoral rejection after kidney transplantation (Chen 2022).

In 1976, plasma exchange was first reported to be useful in systemic lupus erythematosus by Jones et al (Chen 2022).

Practice guidelines for the therapeutic use of apheresis were first published by the American Society for Apheresis (ASFA) in 1986. These have been updated regularly since then (Conelly- Smith 2019).

Immunoabsorption (IAS) was first introduced as a treatment option in 1999 by Esnault et al.

Hemapheresis is the separation of blood into cellular and plasmatic components (Herold 2022) by means of flow centrifugation using apheresis devices (German Medical Association 2005).

In medicine, therapeutic apheresis (TA) and therapeutic plasma exchange are used to purify pathological substances such as immune complexes, pathological antibodies, inflammatory mediators, etc. from the patient's blood and to treat diseases (Chen 2022).

Therapeutic apheresis techniques include:

- Plasma exchange (PE)

- Immunoadsorption (IAS)

- Low-density lipoprotein apheresis (LDL- A)

- Double filtration plasmapheresis (DFPP)

(Chen 2022)

Therapeutic hemapheresis requires an adequate and stable blood flow with a flow rate of 60 - 120 ml / min. A peripheral vein, e.g., the cubital vein, is usually chosen for this purpose. For permanent apheresis, on the other hand, an AV fistula such as a cimino shunt should be created at an early stage (Kiefel 2010).

Citrate solutions are used to prevent anticoagulation of the patient's blood in the extracorporeal circuit (Kiefel 2010).

Hemapheresis serves several purposes:

- the elimination of unwanted blood components

- for therapeutic composition of blood (immunomodulation)

- delivery of substrates (Herold 2022).

Depending on the indication and the type of disease, hemapheresis can be used in a life-saving, supportive, suffering-relieving or life-prolonging manner (Herold 2022).

Blood components are separated by primary separation and secondary separation (Herold 2022).

- 1. primary separation is usually nonspecific. Various methods can be used for primary separation:

- Centrifugal process.

Centrifugal methods are usually used for primary separation of cells and plasma (Herold 2022).

- Filtration processes:

These are limited to plasma separation (Herold 2022).

- 2. secondary separation

In secondary separation, blood components can be eliminated semiselectively to selectively (as in differential filtration or heparin precision) or specifically (as in LDL immunapheresis) (Herold 2022).

Indications

Indications for hemapheresis may include:

• A. Blood donations: These can take place as
  • A. 1. thrombotic-thrombocytic apheresis: This is administered, for example, to patients with thrombocytopenias undergoing chemotherapy (Herold 2023). In thrombotic thrombocytopenic purpura (TTP), for example, daily plasmapheresis is administered until the platelet count increases again. This occurs within 2 weeks in most patients (Kasper 2015).
  • A. 2. Granulocyte apheresis: Granulocytes are administered in case of critical granulocytopenia or agranulocytosis (Herold 2023).
  • A. 3. stem cell apheresis: These are used for transplantation in patients with e.g. non- Hodgkin's lymphoma, aplastic anemia, leukemia (Herold 2023).

• B. Cytapheresis therapies: These can take the form of a
  • B.1. erythrocyte apheresis: it is used for erythrocyte exchange in e.g. sickle cell anemia I - II and as iron elimination in e.g. hemochromatosis (Herold 2023).
  • B. 2. lymphocyte apheresis: This is performed - with subsequent UV irradiation - in cases of e.g. transplant rejection or for the treatment of mycosis fungoides (also known as cutaneous T-cell lymphoma (Herold 2023).
  • B. 3. leukocyte apheresis: It is used for hyperleukocytosis, e.g. in the context of ulcerative colitis and leukemia (Herold 2023).

• C. Plasma therapies: These are used in the following cases
  • C. 1. plasma adsorption treatment: These include the
    • Ig- apheresis: These are used in antibody-mediated autoimmunopathies such as Guillain- Barre- syndrome, AB=- differentiated organ transplantation (II), Evans- syndrome (III), myasthenia gravis, antibody-mediated graft rejection (II), Goodpasture- syndrome (Herold 2023).
    • Lp (a) apheresis: It is used in cases of premature arteriosclerosis symptoms (I - II) for the therapy of hereditary Lp (a) metabolic disorders (Herold 2022).
    • LDL apheresis: This is used for the therapy of severe atherosclerosis in hereditary hypercholesterolemia, if the drug treatment alternatives do not show the desired success (Herold 2022). LDL apheresis is used, for example, in patients with CHD and a plasma LDL-C level of > 200 mg/dl or in patients without CHD and a plasma LDL-C level of > 300 mg/dl. LDL apheresis is usually performed in a specialized lipid center every 14 days (Kasper 2015).
  • C. 2. plasma exchange: This is used in e.g. macroglobulinemias (II), immune complex mediated autoimmunopathies (III), thrombotic microangiopathy (HUS, TTP), acute pancreatitis with extreme hypertriglyceridemia (Herold 2023).
  • C. 3. plasma differential filtration: This form of filtration is used especially for elimination of LDL- and Lp- (a). They find application in microcirculatory diseases such as diabetic perfusion disorders of the macula and dry macular degeneration (Herold 2023).

• D. Renal diseases

Therapeutic apheresis is used for primary renal diseases such as Goodpasture's syndrome, focal segmental glomerulosclerosis [FSGS]) as well as secondary renal diseases such as hemolytic uremic syndrome [HUS], thrombotic microangiopathy (TTP) with renal involvement, and systemic lupus erythematosus (Chgen 2022).

• E. Covid- 19

Apheresis has also been used to reduce mortality in Covid- 19- disease. However, to date, there are only single case reports, and randomized trials are currently lacking (Griveas 2022).

1. Bundesärztekammer (2005) Richtlinien zur Gewinnung von Blut und Blutbestandteilen und zur Anwendung von Blutprodukten (Hämotherapie). Drawn up in accordance with the Transfusion Act by the German Medical Association in agreement with the Paul Ehrlich Institute. Deutscher Ärzteverlag Cologne 79
2. Cardella C J, Sutton D, Uldall P R, deVeber G A (1997) Intensive plasma exchange and renal-transplant rejection. Lancet. 1 (8005) 264
3. Chen Y Y, Sun X, Huang W, He F F, Zhang C (2022) Therapeutic apheresis in kidney diseases: an updated review. Ren Fail. 44 (1) 842 - 857
4. Conelly- Smith, L, Dunbar N M (2019) The 2019 guidelines from the American Society for Apheresis: what's new? Curr Opin Hematol. 26 (6) 461 - 465
5. Esnault V L, Besnier D, Testa A, Coville P, Simon P, Subra J F, Audrain M A (1999) Effect of protein A immunoadsorption in nephrotic syndrome of various etiologies. J Am Soc Nephrol. 10 (9) 2014 - 2017.
6. Griveas I (2022) Apheresis and Covid-19. transfus Apher Sci. 61 (6) 103601 DOI: 10.1016/j.transci.2022.103601.
7. Herold G et al (2022) Internal Medicine. Herold Publishers 963
8. Jones J V, Cumming R H, Bucknall R C (1976) Plasmapheresis in the management of acute systemic lupus erythematosus? Lancet. 1 (7962) 709 - 711
9. Kasper D L, Fauci A S, Hauser S L, Longo D L, Jameson J L, Loscalzo J et al (2015) Harrison's Principles of Internal Medicine. Mc Graw Hill Education 138- e 2, 1839, 1848, 2449.
10. Kiefel V (2010) Transfusion medicine and immunohematology: principles - therapy - methodology. Springer Verlag Berlin / Heidelberg 458