Intrauterine administration of allogeneic platelet lysate in mares

Clinical tolerability and reproductive outcomes following intrauterine administration of allogeneic platelet lysate in mares resistant to post-breeding induced endometritis
Anim Reprod Sci. 2026 Nov:294:108358. doi: 10.1016/j.anireprosci.2026.108358. Epub 2026 Oct 24.
Authors
Thiago Magalhães Resende 1 , Lorenzo G T M Segabinazzi 2 , Renata de Pino Albuquerque Maranhão 1 , Ana Luisa Soares de Miranda 1 , Fabiola de Oliveira Paes Leme 1 , Priscila Fantini 3
Affiliations

1 Federal University of Minas Gerais, School of Veterinary Medicine, Av Presidente Antônio Carlos, 6627, Belo Horizonte, Minas Gerais, ZIP Code:31270-901, Brazil.
2 Ross University School of Veterinary Medicine, Basseterre, PO Box 334, Saint Kitts and Nevis. Electronic address: LSegabinazzi@rossvet.edu.kn.
3 Federal University of Minas Gerais, School of Veterinary Medicine, Av Presidente Antônio Carlos, 6627, Belo Horizonte, Minas Gerais, ZIP Code:31270-901, Brazil. Electronic address: fantinivet@ufmg.br.

PMID: 42933167
DOI: 10.1016/j.anireprosci.2026.108358

Abstract

Platelet-based therapies have gained interest in broodmare practice due to their immunomodulatory and antimicrobial effects. Platelet lysate (PL) is produced by freeze-thawing platelet-rich plasma (PRP), releasing growth factors and cytokines. As an acellular product, PL reduces immunogenic risk, allows long-term storage, and enables allogeneic use, supporting its application in human and veterinary medicine. Therefore, this study evaluated the safety and post-breeding reproductive outcomes in mares treated with allogeneic PL. Platelet lysate (PL) was prepared from 11 healthy mares using a double-centrifugation PRP protocol. PRP was divided and subjected to three freeze-thaw cycles (-196 °C to 37 °C), then filtered (0.22 µm). Post-filtration PL was aliquoted: samples were stored at -196 °C or -20 °C for PDGF-BB analysis, and the remaining volume was reserved for intrauterine therapy. Each mare provided autologous PL (A-PL), and pooled PL (P-PL) was also generated. Nine mares resistant to endometritis underwent three cycles, randomly assigned to receive A-PL, P-PL, or placebo (LRS) 6 h post-breeding. Mares were inseminated with fresh semen; cytology and ultrasonography were performed before, and 24 and 48 h post-breeding. Embryo flushing was conducted 8 days post-ovulation. PDGF-BB concentrations were similar between A-PL and P-PL (P = 0.97) and between PL samples stored at -20 °C and -196 °C (P = 0.57). Additionally, no differences were detected among groups in uterine ultrasonographic findings, endometrial inflammation, or embryo recovery rates (A-PL, 87.5%; P-PL, 87.5%; LRS, 71.4%; P = 0.65). These results support the absence of observed adverse reactions following intrauterine allogeneic PL and suggest that its use does not adversely affect post-breeding uterine response or embryo recovery in resistant mares.

Keywords: Endometritis; Equine; PRP; Plasma.

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