28 Apr When Recovery Stalls: What Long COVID Is Actually Doing to the Immune System and What Apheresis May Be Able to Do About It
Most people with COVID-19 got sick, recovered, and moved on. A subset did not. Months in — sometimes over a year — they are still exhausted after climbing a flight of stairs, still losing words mid-sentence, still waking up as tired as when they went to bed. This is Long COVID, and by some estimates it now affects somewhere between 10 and 30% of those who contracted the virus. The numbers are staggering. The biology behind it is stranger than most people expect.
Here is what makes Long COVID different from typical post-viral fatigue: the immune response does not resolve. It just keeps going.
The Immune System That Wouldn’t Stand Down
Under normal circumstances, once a virus is cleared the immune system dampens its activity, withdraws the inflammatory signals it sent out during the acute phase, and returns to baseline. In a significant proportion of Long COVID patients, that dampening step does not happen properly. Levels of IL-6, TNF-α, and IL-17 remain elevated for months — in some documented cases, well beyond 180 days post-infection. T-cells, instead of returning to a resting state, show persistent activation and progressive exhaustion — still firing but losing their ability to do anything useful.
One strong candidate for what triggers this is viral persistence. SARS-CoV-2 RNA and spike protein fragments have been detected in gut tissue, lymph nodes, liver, cardiac tissue, and blood vessel walls — in some biopsies up to 230 days after the initial infection cleared. The immune system is still reacting to something. The problem is that it is reacting indefinitely, and the chronic inflammation that results starts doing its own damage to tissues the virus itself never directly harmed.
Microclots, Damaged Endothelium, and Why Fatigue Is Physical
One of the more concrete findings to come out of Long COVID research in recent years is the discovery of amyloid fibrin microclots in patient blood samples — abnormal fibrin structures that resist normal fibrinolysis and can impair blood flow through small vessels. These are not detectable on standard clotting tests. They require specialist assays. But when you look for them, they show up consistently in Long COVID patients and do not appear in healthy controls.
Alongside this, endothelial dysfunction is well-documented. Von Willebrand factor, a protein released from activated endothelial cells, is markedly elevated in Long COVID patients, while ADAMTS13 — the enzyme that normally keeps vWF under control — is reduced. The net result is a pro-coagulant environment that impairs microcirculation. Muscles and organs that need oxygen are not getting adequate perfusion. That explains a great deal about post-exertional malaise: the exhaustion after minor activity that does not simply resolve with rest.
Mitochondrial dysfunction layers onto this further. Data from both Long COVID cohorts and ME/CFS research shows disruption to oxidative phosphorylation pathways — cells are quite literally struggling to produce ATP. What is clear clinically is that these are patients with measurably impaired cellular energy production, not patients with unexplained subjective fatigue.
What the Apheresis Center Has Observed Clinically
The Apheresis Center in Larnaca, Cyprus — founded in part by Markus Klotz, himself a former Long COVID patient — began developing combination apheresis protocols for Long COVID in 2021. Medical Director Dr. Inbar Tofan, a Consultant Rheumatologist with extensive post-graduate training in immune-mediated conditions, has overseen an evolving treatment framework drawn from both peer-reviewed evidence and clinical patterns observed within their own patient cohort.
Their patients have typically already been through multiple treatment attempts — antivirals, immunomodulators, rehabilitation programmes — without sustained improvement. What the clinic’s team consistently observes is the combination of persistent inflammatory burden in bloodwork, evidence of microclotting on dark-field microscopy, and mitochondrial and autonomic dysfunction that does not resolve without physically clearing circulating pathogenic mediators. One patient — eleven years into post-viral ME/CFS, having exhausted conventional options — regained normal daily function within months of treatment. A POTS patient with over thirty concurrent symptoms reported near-complete resolution within weeks.
These outcomes are documented, not anecdotal. The center’s protocols have been reviewed in collaboration with Dr. Beate Jaeger, a pioneer in apheresis for post-COVID conditions, and presented at the International Society for Apheresis World Conference in 2023.
H.E.L.P. Apheresis: The Mechanism That Makes It Relevant
H.E.L.P. apheresis — Heparin-mediated Extracorporeal LDL Precipitation — has been in clinical use since the late 1980s, originally for severe cardiovascular patients who did not respond to pharmacological lipid management. The technique works by separating plasma from blood cells, then precipitating lipoproteins, fibrinogen, and inflammatory proteins by adding heparin in an acetate buffer at low pH. What is relevant to Long COVID is that heparin also binds spike protein fragments, pulling them out of circulation along with the fibrinogen, LDL, and CRP.
A single H.E.L.P. session produces a roughly 70% reduction in fibrinogen and approximately 50% reduction in von Willebrand factor, with measurable improvements in blood viscosity and erythrocyte aggregation documented in dark-field microscopy post-treatment. A 2023 study following 17 severe Long COVID patients through H.E.L.P. apheresis cycles found that 16 of 17 experienced significant clinical benefit, with improvements maintained at six to ten month follow-up.
For long COVID treatment, the Apheresis Center uses H.E.L.P. within a broader “Cyprus Protocol” that may also include INUSpheresis (which selectively removes IgG, IgM, and endotoxins), intravenous high-dose vitamin C and NAD+, whole-body hyperthermia in selected patients, clinical nutrition, and pacing coaching. The combination matters — apheresis removes circulating burden, infusions support mitochondrial and redox recovery, and health coaching prevents patients from triggering the post-exertional crashes that undo progress.
An Evolving Picture, Honestly Presented
It would be misleading to suggest that all of this is settled science. The Apheresis Center itself notes in its published materials that therapeutic apheresis for Long COVID is still an evolving field, that larger controlled trials are needed, and that results vary between individuals. What exists is a biologically coherent rationale, a well-established safety record from four decades of cardiovascular apheresis, an emerging body of evidence specific to Long COVID, and documented clinical outcomes from specialist programs that have treated these patients systematically since 2021.
Long COVID is not a mystery in the way it once was. The mechanisms — viral persistence, sustained immune activation, endothelial damage, microclotting, mitochondrial compromise — are increasingly well-characterized. The challenge now is building treatment approaches that match their complexity, and the literature strongly suggests those approaches need to work at the level of the biology, not just the symptoms.
Sources
- Gavin Publishers (H.E.L.P. Apheresis Long COVID study) — gavinpublishers.com
- WHO Chronic Disease Frameworks — who.int
- RECOVER Initiative (NIH) — recovercovid.org
- International Society for Apheresis (ISFA) — theisfa.org
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Last Updated on April 29, 2026 by Marie Benz MD FAAD