Spectra Optia for automatic red blood cell exchange in people with sickle cell disease

The Spectra Optia Apheresis System (Terumo BCT) is an apheresis and cell collection platform which can be used in the treatment of sickle cell disease. The purpose of this evaluation is to assess the use of Spectra Optia for automated red blood cell exchange or depletion-exchange in adults or children with sickle cell disease who are on a transfusion regime. In this procedure, sickle red blood cells are replaced by healthy red blood cells according to a user defined software protocol. The system comprises 3 components: the apheresis machine, embedded software and a single-use blood tubing set. Venous access for Spectra Optia may be through peripheral or central veins. Cannulation of deep peripheral veins or central veins in the neck region or groin may require ultrasound guidance. A permanent indwelling line may sometimes be left in a central vein to avoid the need for repeated cannulations. In a typical exchange procedure, Spectra Optia separates and removes selected components of the blood from the patient using continuous flow and centrifugation. A patented optical detection technology (known as automated interface management) monitors the composition of the blood throughout the procedure. A red blood cell exchange software algorithm is used to calculate the targets for the procedure, and controls the pumps and valves to remove red blood cells. The rest of the blood components (plasma and other cells) are returned to the patient. The device protocol, software and automated interface management system also control the replacement of the removed red blood cells with donor red blood cells. The device has a depletion function, which can reduce the number of circulating red blood cells by replacing a portion of the removed cells with fluid. The procedure typically takes 2 hours to 3 hours.

Spectra Optia has a CE mark as a class 2b medical device. The Cobe Spectra predecessor system first received a CE mark in 1994 and was also used for this indication. Spectra Optia first received a CE mark in 2007. It is also indicated for bone marrow processing, mononuclear and granulocyte collection, and therapeutic plasma exchange which are not within the scope of this evaluation.

The list prices (excluding VAT) for the components of the Spectra Optia system are as follows:

• Capital costs:

  • Spectra Optia device: £45,350

  • Exchange software: £6,700

• Consumables:

  • Spectra Optia exchange set: £1,007 per 6

  • Astotube with injection port: £218 per 50

  • ACD-A anticoagulant (750 ml): £57 per 12

  • Service charge: £4,572 per year.
    
    Bulk order discounts are available on the consumable sets.

The company's claimed benefits of Spectra Optia compared with manual red blood cell exchange are:

• Less frequent treatment (that is, exchange with Spectra Optia needs to be done less often).

• Shorter treatment duration.

• Less iron overloading in patients having treatment (so may allow patients to reduce or cease iron chelation treatment).

• Increased patient compliance and efficiency of the procedure.

• Reduced hospital stay and staff time.

• Reduced complications from sickle cell disease leading to reduced hospitalisation and associated treatment.

• The depletion–exchange protocol of the machine makes better use of donor blood because only the necessary component is used, allowing the remaining blood components to be used in other patients.

Existing NICE guidance on managing sickle cell disease addresses patients with an acute painful episode, which is outside the scope of this evaluation.

The chemotherapy drug hydroxycarbamide is used in people with chronic symptoms of sickle cell disease, but up to 25% of people cannot have or choose not to have it. For example, pregnant and breast‑feeding mothers and people planning to conceive should not take hydroxycarbamide.

Regular elective transfusion programmes are also used to treat sickle cell disease and are the first-line treatment in the primary and secondary prevention of stroke in high-risk individuals. Occasionally, emergency transfusion for acute complications may also be needed. Transfusions may be administered as top-up transfusion or as manual or automated red blood cell exchange. The initial choice of transfusion strategy is likely to depend on a variety of factors including clinical status and the local availability of facilities and services. In general, top-up transfusions are recommended if the main purpose of treatment is to manage anaemia, and if the introduction of transfusions does not pose an unacceptable increase in the risk of vaso-occlusive events, such as stroke. However, top-up transfusions are 'iron positive' and are therefore associated with an accumulation of iron, which will need to be counteracted with chelation therapy (typically after 20 transfusions). Top-up transfusions are commonly used in children who are unlikely to be iron overloaded.

An alternative to top-up transfusion is red blood cell exchange transfusion. This is considered to be 'iron neutral' because packed red blood cells replace those removed from the patient's blood in an isovolaemic manner. This can be done manually or by using automated systems such as Spectra Optia. Exchange transfusions require larger lines and higher flow rates compared with top-up transfusions, but this is usually achievable via peripheral venous access.

Iron overload may lead to serious long‑term complications. This can be avoided through iron-neutral exchange transfusion or the use of chelation therapy. However, chelation therapies are poorly tolerated by patients; they may cause severe gastrointestinal adverse effects, renal dysfunction, liver dysfunction, arthropathy and decreased white blood cell count. When desferrioxamine is used, this needs to be administered by an overnight infusion pump which is less convenient for patients.

Regular exchange transfusions are considered to be the best option for patients at high risk of vaso-occlusive events because, unlike top-up transfusion, they do not increase blood viscosity. High-risk patients include those who have had recurrent hospitalisations because of disease complications such as secondary stroke, painful crises, acute chest syndrome and priapism. Patients at high risk of stroke may also be identified through the use of screening tests such as transcranial Doppler.

Services for people with sickle cell disease vary by region and tend to be concentrated in major cities. Patients outside these areas may have alternative, possibly suboptimal, treatment or need to travel large distances for red blood cell exchange. Almost all patients with sickle cell disease are black or from minority ethnic groups, and all treatment options should be available to people with sickle cell disease to ensure that complications are avoided and a good quality of life is maintained. The NHS England specialised commissioning clinical reference group that advises on this service, F05 Haemoglobinopathies, is currently reviewing service provision across the UK.