#teamclots

Anyone who had COVID-19 is at a higher risk of developing blood clots for months after recovery, a study shows.

For critically ill COVID-19 patients, a full-dose blood thinner can lower the risk of severe blood clots without increasing the risk of death.

Whilst in many patients polypharmacy is needed to tackle the co-pathology(ies) (not all of which are outlined herein), targeting coagulopathy seems essential to mitigate thrombotic risks and help mitigate other immunogenic cascades.

We contend that Long COVID patients (those with SITV) will not be ready to rehabilitate until the underlying illness and its complications have been effectively treated.

The treatment targets for SITV are microclots, hyperactive platelets, and endotheliitis. It has been proposed that treating this multifaceted inflammatory coagulopathy with a single drug will be insufficient and a combination of anticoagulant and antiplatelet drugs are required to achieve synergistic and superior outcomes [81,114,156], with early intervention recommended.

As Long COVID microclots are resistant to fibrinolysis [36,69,78], dabigatran may be superior as it increases clot susceptibility to fibrinolysis more than other anticoagulants [174,175]. Heparin inhibits spike protein ACE2 binding meaning it has antiviral and anticoagulant properties [60,176–178]. Heparin has been utilised to effectively treat pathology such as Long COVID-related perfusion defects [139], as well as microclots in the context of pulmonary emboli [179]. Further, obstetric patients (n = 291) with Long COVID who received enoxaparin antenatally to six weeks postnatally reported ongoing Long COVID symptoms less frequently than those who did not [180].

Thromboelastography can be utilised to mitigate bleeding risk.

March 2023

One of the major pathophysiological factors contributing to Long COVID is the presence of hypercoagulability; this results in insoluble amyloid microclots that are resistant to fibrinolysis. Our previous research using fluorescence microscopy has demonstrated a significant amyloid microclot load in Long COVID patients. However, this approach lacked statistical robustness, objectivity, and rapid throughput. In the current study, we have used imaging flow cytometry for the first time to show significantly increased concentration and size of these microclots. We identified notable variations in size and fluorescence between microclots in Long COVID and those of controls even using a 20x objective. By combining cell imaging and the high-event-rate nature of a conventional flow cytometer, imaging flow cytometry can eliminate erroneous results and increase accuracy in gating and analysis beyond what pure quantitative measurements from conventional flow cytometry can provide. Although imaging flow cytometry was used in our study, our results suggest that the signals indicating the presence of microclots should be easily detectable using a conventional flow cytometer.

The spike protein from the virus has a key role in causing the various pathologies; it can activate clotting factors 13, it is itself amyloidogenic 14, and it may have direct protein-protein interactions with the main plasma clotting protein, fibrinogen 2,15. These plasma protein interactions, that can also be driven by bacterial cell wall components 16,17, result in the formation of amyloid fibrin microclots (fibrinaloids) that are unusually resistant to fibrinolysis. Receptors on platelets and endothelial cells may also interact with viral inflammagens and circulating inflammatory molecules 15,18−22. These interactions may lead to widespread platelet hyperactivation and endothelial damage. Pathological platelets may also form platelet complexes with various immune cells. Hence there are potentially several ways by which platelets, endothelial cells and plasma proteins may trigger an immune-thrombotic cascade 23.

Whilst fluorescence microscopy can identify microclots and platelet hyperactivation, it lacks statistical robustness, objectivity, and high throughput. Being a research tool, it is not readily accessible to patients or clinicians. However, flow cytometric methods are widely available, and since the 1980s have been capable of detecting micron-sized objects (Davey and Kell, 1996). Flow cytometry is a powerful diagnostic tool that has broad applications in various fields including immunology, molecular biology, bacteriology, virology, cancer biology, and infectious disease monitoring (McKinnon, 2018). Here we describe an imaging flow cytometric method that we have developed to measure the level of fibrinaloid microclots in platelet-poor plasma (PPP). Whilst we used an imaging flow cytometer, the results indicate that these signals will be readily detectable on a non-imaging instrument.

Due to its quantitative and multiparametric characteristics, as well as the analytical capacity to process up to 50,000 cells per second, flow cytometry is widely recognized as the gold standard technique for counting and characterizing cells in complex samples 28. At its most fundamental level, flow cytometry entails the sequential measurement of individual cells or microscopic particles as they as they move through an optical probe volume at a high-speed rate 28.

In contrast to the pure quantitative measurements provided by conventional flow cytometry, analyzing cell images can also help eliminate erroneous results, such as distinguishing between cells and debris 28–30. This approach can lead to more accurate gating and results 28,29. Furthermore, conventional flow cytometers are incapable of providing spatially resolved information, which is frequently vital for quantifying intricate cellular phenotypes 28,30,31. Imaging flow cytometry also allows individual cells to be captured in multiple fluorescence channels, as well as brightfield (transmitted light) and darkfield (scattered light) channels 30,31.

Resia Pretorius Ph.d. has been calling attention to the dark, misshapen, gunky microclots and related problems (damaged platelets, blood vessel issues, and iron dysregulation) she’s been finding in chronic diseases for years. These clots are apparently hard for the body to break down and may be impeding blood flows to the issues.

Over the past couple of years, though, with at least six papers under their belts, she and Douglas Kell have been publishing furiously on their findings in long COVID. Last year they published the results of a small clinical trial using their multipronged approach. Eight months or so later they’re back with more results from more patients (91).

As before, their triple therapy included Dual Antiplatelet Therapy (DAPT) (Clopidogrel 75 mg/aspirin 75 mg) once a day, plus direct oral anticoagulant (DOAC) (Apixiban) 5 mg twice a day, and a proton pump inhibitor (PPI) (e.g., pantoprazole 40 mg/day for gastric protection) was used over 3-4 weeks.

The symptom assessments seemed pretty rudimentary but the results were good. Symptoms such as fatigue, sleep, and cognitive problems reportedly resolved in many patients and when asked about their “global health” approximately 50% of the participants stated that they were at the very least “better” and had received “a definite improvement that has made a real and worthwhile difference”;

The authors warned that this protocol should only be taken under the close guidance of a medical professional. Side effects were mostly minimal, however. Out of 91 participants, 75 reported bruising, 5 reported minor nosebleeds, 2 increased menstrual bleeding, and one person had a gastrointestinal bleed that required hospitalization and a 2-unit blood transfusion. The authors believed that the “relatively low bleeding risk” was due to the fact a hypercoagulable state was present that needed to be addressed.

Apparently, because it took longer to treat the longer-duration patients, the authors also warned that delaying these treatments might “prolong the duration of pharmacotherapy and also increase the likelihood of permanent hypoxic tissue damage”. (Ouch!).

They strongly urged that large, randomized, double-blind, placebo-controlled trials with objective endpoints be done as quickly as possible.

The potentially good news is that the body will slowly remove the microclots. That means that if they can stop them from forming in the first place, normal blood flows should eventually resume and healing should take place.

They also proposed that when long-COVID or ME/CFS patients rest, they build up “a cellular ‘reservoir’” that helps them feel better. When they exert themselves, that oxygen reservoir becomes depleted – leading to a “crash”.

They also proposed that the autonomic nervous system issues in these diseases are caused by damage to the blood vessels.

Their treatment approach has yet to be tested in ME/CFS, fibromyalgia, or postural orthostatic intolerance syndrome (POTS). All three diseases, however, show evidence of clotting, platelet activation, and/or blood vessel issues.

While the pathogenesis of ME/CFS and post-COVID-19 syndrome remain poorly understood, it seems that the underlying pathology involves the CNS; the autonomic nervous system; and a persistent, dysregulated immune and metabolic response to the infectious agents [10]. Previous studies have shown a high propensity of patients with ME/CFS to be misdiagnosed with a psychiatric condition.

We hypothesized that ME/CFS and post-COVID syndrome are not primary mental health conditions but share some clinical features and common pathophysiological mechanisms related to autonomic dysfunction and microcirculation disorder.

We assessed microcirculation by amplitude–frequency wavelet analysis of blood flow oscillations with laser Doppler flowmetry (LDF) [24]. Because of the proven parallelism between microcirculatory changes in the skin and inner organs, we investigated forearm blood flow in the participants with «LASMA MC-1» peripheral blood and lymph flow laser diagnostic complex.

…the belonging of four symptoms to the domain of “sleep disturbance” and one symptom to the domain of “pain syndromes” confirms the validity of the treatment approach to ME/CFS, described in the recent guidelines from the European Network on Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (EUROMENE). According to this approach, to reduce the severity of fatigue, patients are provided first of all with symptomatic help to normalize sleep and combat pain.

…the belonging of four symptoms to the domains associated with disorders of the nervous system (autonomic, sensory, and motor functions) confirms the classification of ME/CFS in ICD-10, where it belongs to the chapter G—“Diseases of the nervous system”.

Our data, therefore, not only agree with the concept of ME/CFS as a disease with neuroimmune pathogenesis but also allow us to make assumptions about approaches to diagnosis and treatment of this disease, as well as the most effective organization the patient care in ME/CFS, which optimally should be provided by neurologists.

In the past, ME/CFS has often been misdiagnosed as a psychiatric disorder of the affective spectrum, leading to mismanagement and deterioration of the patient’s health [31]. Today, it is believed that anxiety and depressive symptoms, which are common in ME/CFS [32,33], should not always be considered as a sign of an alternative diagnosis.

it should be remembered that recent research data on this topic suggests that depression and anxiety in ME/CFS are associated with the neuroinflammation process, pain syndromes, psychological distress due to the inability to return to work, and reduced physical functioning, social isolation, as well as insufficient knowledge of medical specialists about the disease. Consequently, they are deontologically vulnerable and have skeptical attitudes toward the patient’s problems.

POTS itself often develops following infectious diseases and, at least in some cases, may be associated with the production of autoantibodies against adrenergic and cholinergic receptors.

…in ME/CFS that developed after COVID-19, there is a more pronounced increase in heart rate starting from the 6th minute of the test compared to the control group. This allowed us to assume that POTS is one of the key characteristics of ME/CFS of post-COVID genesis. It is important to note that in 4/13 people who met POTS criteria in our study, the required increase in heart rate was achieved only at the 8–10th minute of the active orthostatic test. This confirms the practice of carrying out the test in its complete (within 10 min) and not abridged (5 min) version.

The rhythmic characteristics of oscillatory processes in the microcirculation system are useful for the diagnosis of many diseases related to the changes in the microcirculation [36]. The LDF method allows a non-invasive assessment of human blood microcirculation system disturbances. In this work, LDF was applied to assess the dynamic characteristics of microcirculation in ME/CFS, including post-COVID genesis (in the latter subgroup—it was done for the first time, to the best of our knowledge). A change in the microcirculation index (increase or decrease) characterizes, respectively, an increase or decrease in perfusion. Its increase can be associated with a lower tonus of the arterioles, which leads to an arterial hyperemia, or with the congestion of blood in the venules and venous hyperemia. Regarding the regulation of microcirculation, there are “active” and “passive” mechanisms. The “passive” mechanisms include external factors that act outside the microcirculatory bed: a pulse wave and the suction action of the “respiratory pump” from the veins. “Active” factors directly affect the vessels of the microvasculature by periodically changing the resistance of blood vessels to blood flow through vasomotions and creating transverse fluctuations in blood flow. These active factors are sympathetic nerve fibers, smooth muscle cells of the vascular wall, and endothelium-derived regulatory molecules. When carrying out spectral analysis, the active factors correspond to low-frequency oscillations [37]. There are several forms of microcirculation disorders: arterial hyperemia, venous hyperemia, combined hyperemia, ischemia, and stasis [38]. The changes identified in this study in ME/CFS, including ME/CFS of post-COVID-19 nature, correspond to the hyperemic form of microcirculation disorders, which is characterized by increased blood flow into the microcirculatory bed. It is distinguished by a significant increase in the number of functioning capillaries, an increase in tortuosity, vasodilation, and an increase in the permeability of the vascular wall. This form of microcirculation disorder is usually observed in acute inflammatory response or other conditions of decreased systemic vasoconstriction.

Bond et al. showed that chronic oxidative stress could contribute significantly to the development of ME/CFS symptoms due to the development of endothelial dysfunction [39]. The relationship between chronic inflammatory processes and increased arterial stiffness is well-known [40]. An increase in vascular resistance in cohort 1 compared to cohort 2 may reflect the contribution of the chronic inflammatory process of a long course to microcirculation disorders and suggests the existence of long-term consequences of ME/CFS, in particular, an increased risk of cardiovascular diseases.