Persistent capillary rarefication in long COVID syndrome.

"Declarations Competing interestsIO, AS, GE, KH, PK, MM and AR declare that they have no competing interests. HV is Chief Science Officer of GlycoCheck™ BV, The Netherlands. GlycoCheck™ and MVHS™ are trademarks registered by Microvascular Health Solutions LLC (Alpine, UT, United States). Ethical approvalThe study was performed in accordance with the Declaration of Helsinki and approved by the Ethics Committee of the General Medical Council Westfalen-Lippe and the WWU Münster, Germany (file number: Ref. 2020-585-f-S & amendments of Ref. 2016-073-f-S). Informed consentWritten informed consent has been obtained from all individuals. Competing interests IO, AS, GE, KH, PK, MM and AR declare that they have no competing interests. HV is Chief Science Officer of GlycoCheck™ BV, The Netherlands. GlycoCheck™ and MVHS™ are trademarks registered by Microvascular Health Solutions LLC (Alpine, UT, United States)."

"Funding Open Access funding enabled and organized by Projekt DEAL. This work was supported by the German Research Foundation (rotational position of KFO 342—ZA428/18-1 to AR; KU 2873/3-1 to PK) and the fund Innovative Medical Research of the University of Münster Medical School (I-RO221907 to AR). The funding sources had no role in study design, data collection and analysis, the decision to publish, or preparation of the manuscript."