For Pulmonologists

Although the concept of the interaction of the «humours» of the body may seem archaic, the ancient methods of treatment (bloodletting, the use of diuretics and laxatives) have proven their effectiveness over the course of centuries. In recent years the methods of detoxification therapy have been developing rapidly, among which a leading place is occupied by extracorporeal blood purification: plasmapheresis, plasma filtration, hemo- and plasmosorption.

The most widespread and accessible method of influencing the internal environment of the body is membrane plasmapheresis. For the treatment of bronchial asthma (BA) plasmapheresis was first applied by G. Gartman in 1978. More often the effect of the therapy is explained by the mechanical removal from the blood of circulating pathological components (antibodies, immune complexes, mediators of inflammation). However, modern studies show that the clinical effect often exceeds the result of mechanical «purification» alone. Extracorporeal elimination of pathological substances remains a reliable guideline for determining the volume of therapy, but important mechanisms are also the restoration of the functional activity of cell membranes, the increase of receptor sensitivity and the optimization of the immune response.

Techniques of membrane plasmapheresis

There are two main methods: gravitational (centrifugation) and filtration (membrane). The latter is considered the most physiological.

The success of the procedure is connected with the use of new-generation plasma filters PFM-01-TT «Rosa» (manufactured by «TRACKPORE TECHNOLOGY», distributor in Ukraine — LLC «Solar-Ukraine»). The filter is based on a track-etched Lavsan membrane (thickness 10 µm, pore diameter 0,4 µm), which freely passes the liquid components of the blood but retains the formed elements, high-molecular-weight compounds, immunoglobulins and circulating immune complexes (CIC).

The most advanced device for this method is the AMPld-TT «Hemophenix». Its chamber pump provides cyclic withdrawal of blood and its return into the very same vein, which is maximally comfortable for the patient.

Techniques of membrane plasmapheresis

There are two main methods: gravitational (centrifugation) and filtration (membrane). The latter is considered the most physiological.

The success of the procedure is connected with the use of new-generation plasma filters PFM-01-TT «Rosa» (manufactured by «TRACKPORE TECHNOLOGY», distributor in Ukraine — LLC «Solar-Ukraine»). The filter is based on a track-etched Lavsan membrane (thickness 10 µm, pore diameter 0,4 µm), which freely passes the liquid components of the blood but retains the formed elements, high-molecular-weight compounds, immunoglobulins and circulating immune complexes (CIC).

The most advanced device for this method is the AMPld-TT «Hemophenix». Its chamber pump provides cyclic withdrawal of blood and its return into the very same vein, which is maximally comfortable for the patient.

3. Plasmapheresis in bronchial asthma

Pathogenetic rationale

In BA mast cells, eosinophils, lymphocytes and a whole cascade of mediators (histamine, leukotrienes, cytokines) are involved in the pathological process. Long-term therapy with inhaled corticosteroids (ICS) and $beta_2$- agonists often leads to a decrease of the sensitivity of the receptors of the bronchial tree.

Plasmapheresis promotes:

• The removal of «blockers» of receptors (CS metabolites, excess of catecholamines, products of lipid peroxidation).
• The restoration of the activity of the adenylate cyclase system.
• The deblocking of cell membranes, which increases sensitivity to sympathomimetics and corticosteroids.

Procedure technique and dosage

For patients with BA the course usually consists of 4–5 procedures with an interval of 2–3 days.

• Volume of removal: 1/3–1/2 of the CPV is removed per procedure (on average 600–900 ml or 1% of body weight).
• Replacement: is carried out with saline, which promotes hemodilution and the improvement of microcirculation.
• Anticoagulation: heparinization (150 IU/kg) and the use of sodium citrate (Glugicir) are performed.

Indications and contraindications

Indications:

• Increasing resistance to basic ICS therapy.
• The necessity of reducing the daily dose of systemic corticosteroids.
• A high level of CIC and IgE.
• Intolerance or contraindications to long-term CS therapy.

Contraindications: an active inflammatory process, status asthmaticus, severe cardiovascular insufficiency (stage III), thrombophlebitis, a tendency to bleeding.

Plasmapheresis in fibrosing alveolitis

The method increases the effectiveness of standard therapy and makes it possible to reduce the volume of the medication load.

• Indications: exogenous allergic alveolitis (with respiratory insufficiency), idiopathic fibrosing alveolitis (with marked infiltration on CT).
• Technique: a course of 3 procedures (800–1000 ml of filtrate) with intervals of 5–7 days. In systemic diseases of the connective tissue it is combined with cytostatics and GCS.

Efficacy criteria (for both nosologies)

• Reduction of the severity of clinical symptoms.
• Improvement of the indicators of external respiration function and of the gas composition of the blood.
• Reduction of interstitial changes on radiographs and CT.
• The possibility of a successful reduction of the dose of the basic drugs.

Table: Dynamics of the indicators of respiratory function in BA (example)