{"id":490007,"date":"2024-01-19T12:55:23","date_gmt":"2024-01-19T17:55:23","guid":{"rendered":"https:\/\/platohealth.ai\/scientists-are-finding-signals-of-long-covid-in-blood-they-could-lead-to-new-treatments\/"},"modified":"2024-01-19T15:25:51","modified_gmt":"2024-01-19T20:25:51","slug":"scientists-are-finding-signals-of-long-covid-in-blood-they-could-lead-to-new-treatments","status":"publish","type":"post","link":"https:\/\/platohealth.ai\/scientists-are-finding-signals-of-long-covid-in-blood-they-could-lead-to-new-treatments\/","title":{"rendered":"Scientists are finding signals of long covid in blood. They could lead to new treatments.","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"
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For many people, covid is an illness that blusters in and out of our lives as cases spike and recede. But for tens of millions of others, a case of covid is the beginning of a chronic and sometimes debilitating illness that persists for months or even years.  What makes individuals with long covid different from those who get infected and recover? According to a new paper<\/a>, an often overlooked part of the immune system is unusually active in these people.<\/p>\n

A team of researchers from Switzerland compared protein levels in blood samples taken from patients who had never had covid, those who had recovered from covid, and those who had developed long covid. \u201cWe wanted to understand what drives long covid, what keeps long covid active,\u201d says Onur Boyman, an immunologist at the University of Zurich and an author of the study.<\/p>\n<\/p><\/div>\n<\/div>\n

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The scientists found that people with long covid exhibit changes in a suite of proteins involved in the complement system, which helps the immune system destroy microbes and clear away cellular debris. The results echo what at least one other group <\/a>has found. <\/p>\n

None of the existing research proves that these changes drive the disease. But they offer up a new avenue for treatment exploration by helping doctors pick the best people to trial certain drugs \u201cThere aren\u2019t really any effective therapies,\u201d says Aran Singanayagam, a respiratory medicine specialist who studies lung infections at Imperial College London. \u201cSo we are quite desperate, and it\u2019s a big problem.\u201d <\/p>\n

The researchers began by looking at levels of more than 6,500 proteins in the blood of 113 people who tested positive for SARS-CoV-2 and 39 people who had never been infected. Six months later, they took new blood samples. By that time, 73 people who had been infected had recovered, and 40 had gone on to develop long covid. Many of the proteins elevated in people with long covid were also elevated in people who had recovered from severe covid. But the markers that were unique to the long covid groups pointed to abnormal activation of the complement system.<\/p>\n

What is the complement system? Good question. \u201cWe never hear of it as non-immunologists,\u201d Boyman says. But it plays a vital role in defending the body against microorganisms. The complement system is composed of more than 30 proteins produced by the liver that travel the bloodstream and act as an immune surveillance system. Activation of the complement system kicks off a cascade of reactions that recruits immune cells to the site of an infection, flags pathogens for destruction, or even destroys microbes by poking holes in them. The system, as its name suggests, complements<\/em> the activity of antibodies. But when it goes awry, it can cause widespread inflammation and damage cells and blood vessels<\/p>\n

When the results pointed to abnormal activation of the complement system as a distinguishing feature of long covid, \u201cwe all of a sudden said \u2018Oh, this makes so much sense,\u2019\u201d Boyman says. \u201cThe complement system is so central, not only communicating with the immune system but also communicating with the blood clotting system\u2014with the endothelial cells, with platelets, with red blood cells, and going into all the organs.\u201d That might explain why some researchers have found tiny clots in people with the disease.<\/a><\/p>\n

Why the complement system might go awry after a covid infection isn\u2019t clear. \u201cTo me, when you see complement activation like this, it suggests that you have ongoing infection,\u201d says Timothy Henrich, an immunologist at the University of California, San Francisco. That residual virus could keep the complement system active. Or it\u2019s possible that lingering tissue damage keeps the system engaged. Or maybe it\u2019s something else entirely. \u201cThe fundamental issue that we have with long covid research right now is that we have a lot of associations, but we don\u2019t have a lot of causations that have been proven,\u201d Henrich says. <\/p>\n<\/p><\/div>\n<\/div>\n