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Usuda H, Saito M, Ikeda H, Sato S, Kumagai Y, Saito Y, Kawamura S, Hanita T, Sakai H, Kure S, Yaegashi N, Newnham JP, Kemp MW, Watanabe S. Assessment of synthetic red cell therapy for extremely preterm ovine fetuses maintained on an artificial placenta life-support platform. Artif Organs 2021; 46:653-665. [PMID: 34932228 DOI: 10.1111/aor.14155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Revised: 10/29/2021] [Accepted: 12/15/2021] [Indexed: 12/01/2022]
Abstract
BACKGROUND Artificial placenta therapy (APT) is an experimental care strategy for extremely preterm infants born at 21-24 weeks' gestation. In our previous studies, blood taken from the maternal ewe was used as the basis of priming solutions for the artificial placenta circuit. However, the use of maternal blood as a priming solution is accompanied by several challenges. We explored the use of synthetic red cells (hemoglobin vesicles; HbV) as the basis of a priming solution for APT used to manage extremely early preterm ovine fetuses. METHODS Six ewes with singleton pregnancies at 95 d gestation (term = 150 d) were adapted to APT and maintained with constant monitoring of key vital parameters. The target maintenance period was 72 h in duration. A synthetic red cell solution consisting of HbV, sheep albumin and electrolytes was used as priming solutions for the APT circuit. Fetuses were evaluated on gross appearance, physiological parameters and bleeding after euthanasia. RESULTS Two out of six APT fetuses were successfully maintained for the targeted 72 h experimental period with controllable anemia (>10 g/dl) and methemoglobinemia (<10%) using an infusion of blood transfusion and nitroglycerin delivered >1 h after APT commencement, a sufficient period of time to cross-match blood products and screen for viral agents of concern. CONCLUSIONS Extremely preterm sheep fetuses were maintained for a period of up to 72 h using APT in combination with circuit priming using a synthetic red cell (HbV) preparation. Although significant further refinements are required, these findings demonstrated the potential clinical utility of synthetic blood products in the eventual clinical translation of artificial placenta technology to support extremely preterm infants.
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Affiliation(s)
- Haruo Usuda
- Division of Obstetrics and Gynecology, The University of Western Australia, Crawley, Western Australia, Australia.,Center for Perinatal and Neonatal Medicine, Tohoku University Hospital, Sendai, Japan
| | - Masatoshi Saito
- Division of Obstetrics and Gynecology, The University of Western Australia, Crawley, Western Australia, Australia.,Center for Perinatal and Neonatal Medicine, Tohoku University Hospital, Sendai, Japan
| | - Hideyuki Ikeda
- Center for Perinatal and Neonatal Medicine, Tohoku University Hospital, Sendai, Japan
| | - Shinichi Sato
- Center for Perinatal and Neonatal Medicine, Tohoku University Hospital, Sendai, Japan
| | - Yusaku Kumagai
- Center for Perinatal and Neonatal Medicine, Tohoku University Hospital, Sendai, Japan
| | - Yuya Saito
- Center for Perinatal and Neonatal Medicine, Tohoku University Hospital, Sendai, Japan
| | | | - Takushi Hanita
- Center for Perinatal and Neonatal Medicine, Tohoku University Hospital, Sendai, Japan
| | - Hiromi Sakai
- Department of Chemistry, Nara Medical University, Nara, Japan
| | - Shigeo Kure
- Center for Perinatal and Neonatal Medicine, Tohoku University Hospital, Sendai, Japan
| | - Nobuo Yaegashi
- Center for Perinatal and Neonatal Medicine, Tohoku University Hospital, Sendai, Japan
| | - John P Newnham
- Division of Obstetrics and Gynecology, The University of Western Australia, Crawley, Western Australia, Australia.,School of Veterinary and Life Sciences, Murdoch University, Perth, Western Australia, Australia.,Women and Infants Research Foundation, King Edward Memorial Hospital, Perth, Western Australia, Australia
| | - Matthew W Kemp
- Division of Obstetrics and Gynecology, The University of Western Australia, Crawley, Western Australia, Australia.,Center for Perinatal and Neonatal Medicine, Tohoku University Hospital, Sendai, Japan.,School of Veterinary and Life Sciences, Murdoch University, Perth, Western Australia, Australia.,Women and Infants Research Foundation, King Edward Memorial Hospital, Perth, Western Australia, Australia.,Department of Obstetrics and Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Shimpei Watanabe
- Center for Perinatal and Neonatal Medicine, Tohoku University Hospital, Sendai, Japan
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Musk GC, Usuda H, Kershaw H, Kemp MW, Sharp CR. Maternal-fetal Blood Major Crossmatching in Merino Sheep. Comp Med 2020; 70:355-358. [PMID: 32727639 PMCID: PMC7446640 DOI: 10.30802/aalas-cm-19-000115] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
To determine the incidence of ex vivo incompatibility between ovine maternal RBCs and fetal plasma, we performed cross-matching of blood samples from ewes and from lambs delivered by cesarean section. Twenty-one date-mated singleton pregnant Merino ewes were anesthetized for cesarean delivery of the fetus. At the time of delivery, paired maternal and fetal blood samples were collected and subsequently separated for storage as packed red blood cells and fresh frozen plasma. Gel column major cross matching was performed within 2 wk. All fetus-dam crossmatches were major crossmatches, combining fetal (recipient) plasma with dam (donor) RBCs. 172 individual dam-dam cross matches were performed. Two of these tests were incompatible (1.2%). In addition, 19 fetal blood samples collected immediately after cesarean delivery were crossmatched with 21 maternal samples to generate 174 maternal-fetal individual cross matches. No maternal-fetal incompatibility reactions were observed. The results of this study demonstrate that all maternal donors and fetal recipients were compatible. In addition, the incidence of an incompatible crossmatch between adult ewes was 1.2%. These data suggest that lambs may not be born with antibodies against other blood types, but rather may acquire such antibodies at some time during early life. In addition, these data suggest the risk of incompatibility reactions between ewes of a similar breed and from a single farm of origin is very low.
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Affiliation(s)
- Gabrielle C Musk
- Animal Care Services, University of Western Australia, Crawley, Western Australia; Division of Obstetrics and Gynaecology, University of Western Australia, Crawley, Western Australia;,
| | - Haruo Usuda
- Division of Obstetrics and Gynaecology, University of Western Australia, Crawley, Western Australia
| | - Helen Kershaw
- Animal Care Services, University of Western Australia, Crawley, Western Australia
| | - Matthew W Kemp
- Division of Obstetrics and Gynaecology, University of Western Australia, Crawley, Western Australia
| | - Claire R Sharp
- School of Veterinary Medicine, Murdoch University, Murdoch, Western Australia
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