Patterson says that about 70 per cent of people who take the test are judged to have this “pure” form of long Covid, of which 85 per cent respond well to the typical treatment regimen (six to twelve weeks) recommended by IncellDx. Eventually the spike protein “goes away”.
Some experts are sceptical, though. Jonathan Edwards, a professor at UCL and expert in autoimmune diseases, says: “The immediate problem with these profiles is that they are generated by machine learning, which maximises the chances of throwing up something unreproducible and irrelevant. It is also worth noting that in mainstream medicine, dealing with long-term inflammatory and autoimmune disease tests on cytokines like this have been essentially useless.”
Brett Lidbury, an associate professor at the National Centre for Epidemiology and Public Health in Australia, who has also previously researched biomarkers for ME/CFS, believes that the fundamental research is fine, but, he says, “I don’t think it is ready to be released commercially. If they can report successful results from thousands of patients, including volunteers from several countries, then this is an exciting development.”
Ten thousand patients have been tested, according to IncellDx, but only 933 of them in trials. The company says a large-scale clinical trial is forthcoming, dependent on funding.
Questions about the treatment persist too. The drugs, including steroids and statins (prednisolone and atorvastatin, typically) and maraviroc (a drug traditionally used to treat HIV), are being used “off-label”, ie not for the purposes for which they have been approved for use by the National Institute for Health and Care Excellence. As a result, GPs might not prescribe them, although IncellDx works with several private doctors who will.
“I am pretty certain there is no reliable evidence for efficacy [for these drugs in this context],” Edwards says. “We used to try things out ad hoc 40 years ago but we know enough now to know that we shouldn’t. Drugs are toxic. Unless you’ve tested in a controlled, double-blind setting, you don’t begin to treat people.”