Patent Application
20230165890
The present invention relates to the use of heparin or its derivatives or/and other pharmaceutically acceptable polyanions in the context of a therapeutic HELP apheresis for the treatment of severe courses of viral infections, in particular covid-19 diseases.
In the era of the COVID-19 pandemic, the key question is: Which therapeutic approach should be favored to save patients who are severely ill from SARS-CoV-2 infection? What should the therapy be to avert incipient acute respiratory failure with microthrombi and inflammation of the endothelium (1,2,3) due to an exuberant immune response of the body when the first lines of immune defense have already failed? We know that SARS-CoV-2 viruses use the angiotensin-converting enzyme 2 (ACE-2) receptor and the protease TMPRSS 2 as a gateway (4) and can infect cells of the alveolar epithelium and endothelial cells of the lungs, heart, kidneys, intestine, and liver (3). Therefore, cardiac patients, hypertensives, diabetics, and patients with obesity are also particularly at risk for COVID-19, in part because receptor density is upregulated in these patients (1,2).
Pathological studies on alveolar epithelium and in endothelial cells of deceased COVID-19 patients detect the viruses in both cell types (2,3) and show a picture of a simultaneous massive inflammatory and procoagulatory activation with cell necrosis, thrombi and massive fibrinoid deposits in the microcirculation of the lung (2,3), which agglutinate the lung tissue, impede gas exchange, and thus hinder the patient's breathing. Consequently, ventilation by extracorporeal membrane oxygenation (ECMO) must also cause difficulties, just as CVVHD (continuous veno-venous hemodialysis) does not causally address this issue.
Since no drug has yet been shown to be specifically effective against the disease, there is currently no effective way to successfully treat the severely ill Covid-19 patients. Furthermore, it has now become apparent that not only the options for treating patients in an early stage of the disease, as well as those for treating patients in a highly acute, critical state are still unsatisfactory. Rather, more and more long-term impairments are becoming apparent even in patients who had only mild symptoms in the acute phase of the disease. This condition, which is now referred to as long-covoid and sometimes severely affects the lives of the affected patients, can currently only be treated relatively unspecifically and symptomatically, and patients sometimes still complain of severe symptoms months after the infection and are often unable to pursue their occupations.
The situation is similar for other severe viral infections, which also kill a tremendous number of patients worldwide each year. The inventors have therefore set themselves the task of demonstrating a different therapeutic path that takes into account the underlying mechanisms of the cellular damage observed in the patients and interrupts these mechanisms or at least slows or reduces them in such a way that the patients' demise and severe permanent health impairment can be prevented.
This task according to the invention is solved by resorting to HELP apheresis to preserve the microcirculation of the lungs and other organs, which is also already established as ultima ratio for the treatment of arteriosclerosis and in microcirculatory disorders. This method, developed by Seidel and Wieland in 1982 (5,6), was primarily aimed at patients with severe familial hypercholesterolemia (7); later, it was also successfully used in CHD (8,9), for prevention and therapy of graft vessel disease after heart transplantation (10,11,12), in peripheral arterial occlusive disease (13), acutely after strokes (14,15), and for therapy of hyperlipoproteinemia(a) (16). The procedure has anti-inflammatory and anticoagulant effects, and has proven effective in chronic as well as acute inflammatory processes of the endothelium in the micro- and macro-circulation (17).
In the method (7,17), the blood cells are first separated from the plasma in the extracorporeal circuit, a suitable amount, e.g. 400,000 units of preferably unfractionated heparin, is added to the plasma, the pH is lowered to about 4.8 to 5.25, particularly preferably 5.12, by means of a suitable buffer, particularly acetate buffer. This is close to, or in the particularly preferred form, the isoelectric point for optimal precipitation of the apolipoproteins of LDL-cholesterol, lipoprotein (a) and VLDL, which then precipitate in the precipitate filter as does fibrinogen. Downstream, the excess heparin is adsorbed and, for example, bicarbonate dialysis rebalances the pH. The treated plasma as well as the blood cells are reinfused into the patient. The duration of treatment—two hours on average—can be adapted to individual needs and extended (7,17).
This method will benefit patients with severe viral infections, especially COVID-19 patients with high probability, because:
1. HELP apheresis has no allocation problem due to the extracorporeal access and allows direct access to the entire macro- and microcirculation, removes the largest clotting protein fibrinogen from the blood (−50% in 2 h) and thus directly improves the oxygen supply in the capillaries.
2. HELP apheresis usually uses 400,000 units of unfractionated heparin in the extracorporeal circuit (7,8), which allows microthrombi to be dissolved directly without risk of heparin bleeding (15), as excess heparin is eliminated before plasma reinfusion.
3. HELP apheresis not only selectively removes 50-60% or more of fibrinogen from the blood in only 2 h of application, but also partially removes 35-50% of the precursors of both the procoagulant and fibrinolytic cascades, thus de-escalating the entire hemostaseological system (18)—with the exception of antithrombin-III, which is only 25% eliminated (19,20), further minimizing the risk for bleeding complications.
4. HELP apheresis has a direct rheological effect (13,19) by sustainably increasing myocardial (11), cerebral (14) and pulmonary blood flow rates as well as coronary flow reserve (7). This facilitates oxygen exchange in the capillaries (21).
5. HELP apheresis removes cytokines such as interleukin-6, interleukin-8 and TNF alpha and also reduces CRP concentration >50% (17). The heparin adsorber completely eliminates endotoxins and ectotoxins (19), allowing the cytokine storm and excessive inflammatory response to calm down. HELP apheresis has been successfully used in pilot studies by Bengsch et al (22) in septic multiorgan failure. The HELP procedure was successful in modified form in the EHEC epidemic in haemolytic uraemic syndrome (23).
HELP apheresis is an established commercially available system (B. Braun A G, Melsungen) that has been used clinically for 35 years. In the hands of the trained person, it is easy to handle and suitable for sustainably reducing the acute and chronic complication rates of sick patients (17).
7. HELP apheresis reduces LDL cholesterol and Lp (a) concentrations by more than 50% within 2 h (16,17), thereby improving endothelial function and possibly thereby removing circulating viruses such as coronaviruses, which use cholesterol as a vector because of their lipid coat (20).
This procedure does not remove protective IgM or IgG antibodies from the circulation and does not affect leukocyte and platelet function.
9. the long clinical experience with HELP apheresis suggests that COVID-19 patients, as well as patients suffering from other severe viral infections, will almost certainly not be harmed by therapeutic use.
10. HELP therapy has been shown in the past to be well tolerated and complementary to other therapeutic approaches, such as antiviral drugs and anticoagulants.
The embodiments of the invention are further explained in the appended claims. In particular, the present invention provides an agent which also allows to treat viral infections, especially in severe courses or/and in particular SARS-CoV-2 infections, namely in the form of a therapeutic apheresis. The agent contains heparin or one of its derivatives or/and another pharmaceutically acceptable polyanion. This agent forms the basis for the treatment within the HELP apheresis system.
In preferred embodiments, the provided agent also comprises an anion adsorber or/and a pH lowering agent. The use is then carried out by treating in the extracorporeal circulation blood of a patient in such a way that
As explained above, the HELP process is already described in many ways in the literature, so that reference is made to such literature for further details in the treatment, for example DE 44 35 612 A1, but also literature references 5 to 21, which comprise detailed case studies or application examples. Information on treatment details available in these references can also be taken into account for the present application.
Some preferred embodiments of the use of HELP apheresis according to the invention or of the agent according to the invention are explained below. Thus, it is preferred that heparin or its derivatives are used in the form of unfractionated heparin or hydrolyzed heparin. To the extent that other pharmaceutically acceptable polyanions are used, it is again preferred to use sulfated glycosaminoglycan or a sulfated polysaccharide. A mixture of these substances with each other, or of one or both substances with heparin, may also be employed. Heparin, the heparin derivative or/and pharmaceutically acceptable polyanions, in particular as defined above, are used according to the invention in HELP apheresis and accordingly in the agent according to the invention in such an amount that from 0.001 to 10 mg/ml thereof, or 10 to 400 IU/ml in the case of heparin or its derivatives, are used based on the amount of plasma.
The pH is lowered in the HELP process to a value below 6, preferably the pH is lowered to 4.0 to 5.8, preferably 4.8 to 5.25, and particularly preferably to about 5.12 in the extracorporeal circuit. In particular, a buffer such as a citrate buffer, a lactate buffer, an acetate buffer or mixtures thereof may be present and used as the pH lowering agent in the composition according to the invention. In order to achieve a corresponding pH reduction, the pH lowering agent according to the invention is present in such an amount that in step c) of the HELP apheresis process outlined above, a dilution of the plasma with the buffer solution is carried out in a ratio of 1:5 to 5:1. In this regard, it is quite possible and may be preferred to lower the pH by adding the pH lowering agent even before adding heparin, its derivatives or/and other pharmaceutically acceptable anions. Thus, step c) of the method would be carried out before step b).
For the removal of precipitated substances, i.e. for carrying out step d) of the outlined HELP process, the precipitated substances are preferably passed over a suitable precipitate filter, in particular a filter with an average pore size of 0.01 to 1.0 μm. Alternatively, the separation can preferably be carried out by means of a flow-through centrifuge.
The anion adsorber present and used according to the invention, with the aid of which the heparin or the other acceptable polyanion with any further substances adhering thereto is separated from the blood plasma, is preferably, according to the invention, an anion exchange material which contains cations or natural, synthetic or semisynthetic polycation chains as functional groups, it being possible for polycation chains to be present in linear or branched form. Particularly preferred cations or polycations are tertiary or/and quaternary amines, in particular anion exchange materials comprising alkylaminoalkyl, dialkylaminoaryl, trialkylammoniumalkyl or trialkylammoniumaryl celluloses or/and dialkylaminoalcyl-, dialkylaminoaryl-, trialkylammoniumalkyl- or trialkylammoniumaryl-modified organic polymers or copolymers, which may optionally also be crosslinked or/and may be present in microgranular form.
The anion exchangers may preferably be based on base carrier materials of porous glass or/and silica gel coated with organic polymers or copolymers, crosslinked carbohydrates or/and organic polymers or copolymers. In particularly preferred embodiments, DEAE cellulose is used. In the use of the agent described according to the invention in the context of HELP apheresis, the original water content of the fluid is preferably restored by ultrafiltration in a further step before reinfusion of the treated plasma to the patient. Furthermore, preferably in step f) of the outlined HELP apheresis, the physiological pH is regenerated by dialysis against a suitable buffer or/and by addition of a suitable buffer, for example bicarbonate buffer.
A further object of the present invention is a method for treating viral infections, in particular severe courses of viral infections or/and SARS-COV-2 infections by means of therapeutic apheresis, which is characterized in that blood of a patient is treated in the extracorporeal circulation in such a way that
Further preferred embodiments of this process according to the invention result from the use of the agent according to the invention described in detail above and can be carried out in the same way or in a way adapted to the treatment.
The application of an agent according to the invention as described above, or a treatment method of the corresponding type, has proved very successful in the context so of applications to COVID-19 patients. The following embodiments once again explain the assumed mechanism of action and background, without wishing to commit the invention to corresponding mechanisms.
In COVID-19 patients with a severe, critical course as a result of infection with SARS-CoV-2, milky glass-like, interstitial clogging can be seen in the X-ray image (1), which—it is assumed—can lead to acute lung failure similar to ARDS/SIRS as a result of an excessive, no longer controllable immune response (2). Such an advanced stage of the disease only occurs when the initial antiviral lines of defence of the human body have failed: i.e. when the protective effect of interferons and secretory IgA on alveolar epithelium has not been sufficient to limit inflammation and eliminate the virus. It is currently unclear whether SARS-CoV-2 infection causes relevant viremia. This would be a prerequisite for the formation of humoral antibodies of the IgM or IgG type, which could lyse virus-infected cells in the presence of complement factors. The nature and extent of the cellular immune response to viral antigens is almost entirely T-lymphocyte dependent. Similarly, cell-mediated antibody-dependent cytotoxicity is T-cell dependent and the subject of intensive virological and cell biological research.
Ideally, it is advisable to intervene as early as possible in the inflammatory process, i.e. before—as assumed in the case of SARS-CoV-2 infection—a cytokine tsunami is triggered, which—simultaneously and inseparably—triggers an uncontrollable coagulation and inflammatory activity with the consequences already described for the microcirculation of the lung. The cytokine storm phenomenon was first described in 1973 in graft versus host disease (GVHD) after organ transplantation, later in acute respiratory distress syndrome (ARDS), sepsis, Ebola, avian influenza H5N1, smallpox, systemic inflammatory response syndrome (SIRS) and can also lead to the triggering or intensification of the disease in COVID-19.
Cytokines are peptides that act as pilots to coordinate and amplify the cellular immune response: they guide leukocytes, especially T lymphocytes and monocytes, to the site of inflammation by the viral antigen and activate them, whereupon these cells also secrete cytokines and positively feed back the immune response.https://de.wikipedia.org/wiki/Zytokinsturm-cite_note-janeway-2 In a cytokine storm, leukocytes are activated to such an extent that the immune response does not settle down. Here, high concentrations of cytokines, especially IL-1β, interleukin-6 and interleukin-8, are overexpressed. Furthermore, interleukin-1β, interleukin-6 together with TNF-alpha—the latter mainly expressed by macrophages—direct the inflammatory response and systemic effects, such as the increase of body temperature and cause capillary leakage of the microcirculation due to the increased blood flow and permeability of the capillaries. Interleukin-6 (IL-6 for short), by the nature of its complex regulation and functions in the orchestra of other cytokines and cells, plays a key role in the transition from mechanisms of innate immunity to mechanisms of acquired immunity within the inflammatory process, among others. CRP triggers II-6, IL-6 is at the same time the link to procoagulatory activation, as it is the most important trigger of fibrinogen production in the liver.
The anti-inflammatory effects of the HELP procedure had already been intensively investigated by Bengsch et al. (22) in the 1990s and used in pilot studies to successfully treat patients requiring intensive care with sepsis and impending multiple organ failure. In 2012, the inventors were able to free a patient with an EHEC-induced hemolytic uremic syndrome from her comatose state of consciousness within hours and from renal failure within two days (23).
In the case of Covid-19, HELP apheresis will be of immediate benefit because this extracorporeal system can simultaneously drastically reduce the trigger and the effector of the immune response: circulating cytokines, CRP and, above all, the fibrinogen concentration in the blood are reduced by 50% within two hours, and thus the rheology of the pulmonary microcirculation is immediately relieved—without reducing the erythrocyte concentration. Fibrinogen is the effector of plasmatic coagulation and is the key determinant of plasma viscosity and erythrocyte aggregability in the microcirculation ( ). In the extracorporeal system, 400,000 units of unfractionated heparin are preferably used, thus microthrombi can be dissolved directly in the extracorporeal system.
Previous studies on cardiac perfusion by positron emission tomography in heart transplanted patients have shown that the median coronary blood flow rate remains significantly elevated 24 h after a single HELP apheresis (of 2 h duration): it is still 17.5% higher at rest than before apheresis and increases by 27% under simulated stress by adenosine administration. Mainly, the lowering of fibrinogen concentration causes the rheologically significant effects in the microcirculation that facilitate oxygen exchange: plasma viscosity is reduced by an average of 19% and erythrocyte aggregability is significantly lowered by 60% (19). VEGF release and NO release are also favorably affected (17). Analogously, this improvement could also be demonstrated for the cerebral perfusion of patients with heart disease by means of Doppler examination, which can be read off from a 63% increase in CO2 reserve capacity (19).
HELP apheresis is not limited in its application to two hours duration. The system can be recirculated for many hours—until the precipitate filter is saturated, and the filter can also be replaced on the fly—so that the fibrinogen concentration can theoretically be reduced by up to 99%, depending on requirements. Detailed preliminary studies on the influence of HELP apheresis on the kinetics of the procoagulant and fibrinolytic cascades have shown that not only fibrinogen but also the precursors of both cascades are reduced by 35-50%—with the exception of antithrombin III, which is only reduced by 25% (19,20). In sum, HELP apheresis thus causes a de-escalation of the coagulation situation of both cascades without causing bleeding because the heparin used in excess is completely adsorbed in the extracorporeal circuit of HELP apheresis (17).
The heparin adsorber, which is integrated into the apheresis, has the ability to completely eliminate endo- and ectotoxins, LP-S and LTA—of viral or bacterial origin from the patient's blood (22). Although it is currently unknown whether and to what extent toxins are also significant in the pathogenesis of SARS-CoV-2 infection, it is undisputed that the course of pulmonary infection is aggravated when toxins are present in the bloodstream. Data from the American Thoracic Society (24) also show that pneumonia is much more severe when the patient's lung microbiome is pre-colonized with, for example, Gram-negative toxin-producing bacteria.
Therefore, the use of HELP apheresis should be urgently considered at least in an advanced disease phase of a COVID-19 infection to prevent unnecessary suffering, to spare the limited intensive care capacities worldwide and to reduce costs.
In the context of the invention, HELP apheresis comprises reagents and apparatus as used in the aforementioned literatures or as described, for example, in DE 44 35 612A1. The corresponding disclosure of these literatures is therefore equally applicable to the present invention. In a particularly preferred embodiment, the HELP apheresis system of the company B.Braun Melsungen or components thereof are used and the treatment is carried out in accordance with the description of the system. Deviations within the scope of reagents, the apparatus design and treatment times can be useful and provided depending on the requirements of the individual treatment, in particular individual elements of HELP apheresis devices and methods of the prior art can be combined and interchanged with each other.
Explanations in the context of the Covid-19 disease, which is currently the focus of attention, also apply to other viral diseases in which similar mechanisms take place and which lead to similar damage. Examples of viruses causing similar mechanisms and damage are Ebola virus, RS viruses, SARS and MERS viruses, but also Coxsackie virus. Therefore, the present invention is not limited to the treatment of Covid-19, but is equally applicable to the treatment of many other severe viral infections. Thus, the present invention opens up a new treatment principle for diseases that have had little to counteract.
The following case descriptions and therapeutic examples further explain the effects of the invention:
1) non-invasive ventilation (NIV) has long been an established therapeutic option for the treatment of COPD and emphysema, which is used when there is acute or chronic exhaustion of the respiratory muscles. (Quote from Wikipedia)
2) Nasal High-flow (NHF) therapy is the application of a warmed and moistened air/oxygen mixture by means of a specialized nasal cannula. This flow of up to 60 l/min results in a reduction of the functional dead space, a washout of the airways and a small increase in respiratory pressure. This leads to an increase in respiratory efficiency with a decrease in work of breathing. Particularly in the case of pneumonia-related hypoxaemic respiratory insufficiency, an advantage over other oxygen application systems is becoming apparent. This is achieved in particular by the stable oxygenation especially at higher respiratory rates. However, the NHF is already being used successfully in other indications as well. First data show a reduction of hypercapnia. Quote from Springermedizin (J. Bräunlich and Prof. Dr. Wirtz)
b) Beate R. Jaeger, Carlos A. Labarrere, Raimund Erbel: Fibrinogen Review Herz 2006
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2020 205 557.2 | Apr 2020 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2021/061427 | 4/30/2021 | WO |
