Fig. 1

Identification of important blood proteins in Long-COVID outpatients. A Subjects plotted in two dimensions, following t-SNE dimensionality reduction of all 119 important proteins determined by Boruta feature reduction, shows cluster separation of Long-COVID outpatients from acutely ill COVID-19 ward/ICU inpatients and healthy control subjects. B Subjects plotted in two dimensions, following t-SNE dimensionality reduction of top 9 important proteins determined by Recursive Feature Selection with 50% threshold, shows separation cluster of Long-COVID outpatients from acutely ill COVID-19 ward/ICU inpatients and healthy control subjects C Subjects plotted in two-dimensions, following t-SNE dimensionality reduction of top 5 important proteins determined by Recursive Feature Selection with 80% threshold, shows separation cluster of Long-COVID outpatients from acutely ill COVID-19 ward/ICU inpatients and healthy control subjects with some mixing D A heatmap demonstrated the pairwise cosine similarity between cohort’s protein profiles for top 9 proteins. Greater cosine similarity measure between subjects indicates similar protein profiles while smaller measure indicates large differences between profiles (distance was pseudocolored on the bar scale). The protein profile of Long-COVID outpatients is distinctively different from all other cohorts. E A heatmap demonstrated the pairwise cosine similarity between cohort’s protein profiles with respect to top 5 proteins. Greater cosine similarity measure between subjects indicates similar protein profiles while smaller measure indicates large differences between profiles (distance was pseudocolored on the bar scale). The protein profile of Long-COVID outpatients is distinctively different from all other cohorts