(Unreliable?) In Long COVID, Blood Markers Are Linked to Neuropsychiatric Symptoms

Reliability of this study is probably low. The controls were from pre-pandemic people, a time when nobody had S or N protein. Nonetheless, the abstract states:

Abnormal NDEV and ADEV levels of SARS-CoV-2 N and S1 protein and MPs [mitochondrial proteins] correlate with NP [neuropsychiatric manifestations] and may be biomarkers for long-COVID prognostics and therapeutic trials.

So they discovered that people exposed to SARS-CoV-2 have N and S protein in their body. These people were infected by SARS-CoV-2, so it’s not surprising that they have these proteins in their body.

To some degree, their data may actually show that N and S1 protein in the body don’t matter. People can have those proteins without developing PASC / long COVID. There also doesn’t seem to be a correlation between the blood levels and severity of neuropsychiatric symptoms.

Also, it’s not clear to me why the authors assume that their ELISA test is measuring S1 protein versus the possibility that it may be measuring other things. In is unlikely that the controls had any S1 because SARS-CoV-2 did not exist back then. Presumably the ELISA test is cross-reacting with something.

Easy to read article:

Scientific paper version: