Convalescent plasma transfusion for pregnant patients with COVID-19

We read with great interest the Correspondence by Roman Rodionov and colleagues¹ on the benefit of convalescent plasma transfusions for patients with impaired immune function due to B-cell depletion. Similarly to people who are immunocompromised, pregnant women are at a higher risk of infection with SARS-CoV-2² because pregnancy is a state of partial immune suppression that, along with the normal physiological changes in pulmonary function, makes pregnant women more susceptible to viral infections and to the clinical severity of pneumonia. Pregnant women, even with no additional risk factors, have approximately 40% fewer B and NK cells in peripheral blood than non-pregnant women,³ and a trend of lower lymphocyte counts has been observed in pregnant women infected with SARS-CoV-2.⁴ We herein report our experience with convalescent plasma administered to two pregnant patients (a 31-year-old Somalian woman at 24 weeks of gestation, and a 26-year-old Italian woman at 34 weeks of gestation) in the early-intermediate stage of COVID-19, with evidence of multifocal, bilateral, ground-glass areas, mainly in the lower lobes on pulmonary CT scan. Neither had detectable IgG against SARS-CoV-2 at the time of transfusion. At admission, both patients were hypoxic and received two units of convalescent plasma collected from an ABO-compatible donor who had recovered from COVID-19. The donor plasma had an anti-SARS-CoV-2 IgG titre of more than 1:1000 (endpoint dilution titre assayed by ELISA) and a neutralisation titre of more than 40:1000 (endpoint dilution titre). The first convalescent plasma unit was administered on the day of admission and the second unit on the following day, in addition to standard-of-care treatment. Both patients underwent daily blood tests and assessments of the safety and efficacy of convalescent plasma therapy, and developed detectable anti-SARS-CoV-2 IgG (assayed by SARS-CoV-2 ELITe MGB Kit in combination with ELITe InGenius, ELITech Group, Torino, Italy) 24 h after the first transfusion. The patients showed clinical recovery, defined as an improvement of 1 point or more on the WHO Clinical Progression Scale, and both later underwent vaginal delivery at term with no complications. After a review of the published literature in PubMed, we found only one case of a critically ill obstetric patient with COVID-19 and 11 reports of non-critically ill obstetric patients with COVID-19 treated with convalescent plasma.⁵ Some publications report encouraging results from the use of convalescent plasma in pregnant women, but others show conflicting results. We agree with the conclusions of Rodionov and colleagues, and we hypothesise that, similarly to patients with a deficient B-cellular immune response, pregnant women with no detectable anti-SARS-CoV-2 IgG are potential candidates for treatment with convalescent plasma with high antibody titres in an early stage of the disease, accompanied by a close follow-up of the antibody titre as a predictive prognostic marker.

We declare no competing interests.