American Society of Hirudotherapy

Draft genome of the European medicinal leech Hirudo medicinalis (Annelida, Clitellata, Hirudiniformes) with emphasis on anticoagulants

Research article published in Scientific reports (2020)

Last Updated: June 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Evidence: Preclinical (animal)Genomics & ProteomicsDrug DevelopmentKvist S et al. · Scientific reports, 2020

Abstract

The European medicinal leech has been used for medicinal purposes for millennia, and continues to be used today in modern hospital settings. Its utility is granted by the extremely potent anticoagulation factors that the leech secretes into the incision wound during feeding and, although a handful of studies have targeted certain anticoagulants, the full range of anticoagulation factors expressed by this species remains unknown. Here, we present the first draft genome of the European medicinal leech, Hirudo medicinalis, and estimate that we have sequenced between 79-94% of the full genome. Leveraging these data, we searched for anticoagulation factors across the genome of H. medicinalis. Following orthology determination through a series of BLAST searches, as well as phylogenetic analyses, we estimate that fully 15 different known anticoagulation factors are utilized by the species, and that 17 other proteins that have been linked to antihemostasis are also present in the genome. We underscore the utility of the draft genome for comparative studies of leeches and discuss our results in an evolutionary context.

Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.

Publication typeJournal ArticleResearch Support, Non-U.S. Gov't
Indexed MeSH termsAnimalsAnticoagulantsDNADNA Copy Number VariationsGenomeHemostasisHirudinsHirudo medicinalisOrganic ChemicalsPhylogenyTandem Repeat Sequences

Summary

The European medicinal leech has been used for medicinal purposes for millennia, and continues to be used today in modern hospital settings. Its utility is granted by the extremely potent anticoagulation factors that the leech secretes into the incision wound during feeding and, although a handful of studies have targeted certain anticoagulants,...

Why This Matters for Hirudotherapy

This study presents the first draft genome of the European medicinal leech Hirudo medicinalis, covering an estimated 79–94% of the full genome, and uses BLAST-based orthology searches and phylogenetic analyses to identify anticoagulation factors encoded within it. The authors report 15 known anticoagulation factors and 17 additional proteins linked to antihemostasis, offering the most comprehensive genomic inventory to date of the molecular agents underlying this species' therapeutic utility. For hirudotherapy and the study of the leech salivary secretome, this resource is foundational, enabling comparative genomic studies across leech species and informing mechanistic understanding of how H. medicinalis achieves its potent anticoagulant effects during feeding. However, the identified candidates are based on sequence homology and bioinformatic prediction rather than functional validation or demonstrated secretion, and the genome remains incomplete (up to ~21% unsequenced). The study does not assess protein expression, activity, or clinical efficacy, so the relevance is primarily as a reference genome and a roadmap for future functional work.

Citation

Draft genome of the European medicinal leech Hirudo medicinalis (Annelida, Clitellata, Hirudiniformes) with emphasis on anticoagulants.

Kvist S et al. · Scientific reports, 2020

Added to ASH library: March 18, 2026 · Site last updated: June 18, 2026

This website provides educational information and does not constitute medical advice, diagnosis, or treatment recommendations. Medicinal leech therapy carries clinically meaningful risks and should be performed only by qualified clinicians under institutionally approved protocols. FDA 510(k) clearance for medicinal leeches is limited to specific indications; investigational and off-label discussions are labeled accordingly. For patient-specific guidance, consult a qualified healthcare provider.