Scientists use breast milk to treat Covid-19 in a woman with immunodeficiency

Researchers at the State University of Campinas (Unicamp) have resorted to an unconventional method to treat Covid-19 in a patient with a rare genetic disease that makes the immune system unable to fight viruses and other disease-causing agents.

For a week, she was instructed to ingest 30 milliliters of breast milk – from a donor vaccinated against the disease – every three hours. After this period, the result of the molecular diagnostic test (RT-PCR), which indicates the genetic material of the virus, came negative for the first time more than 120 days ago.

The case was reported in an article published in the scientific journal Virusesfrom projects supported by the Fundação de Amparo à Pesquisa do Estado de São Paulo (Fapesp).

“I have been following this patient since she was a child and when she told me she had Covid-19 I was very apprehensive. The innate error of immunity that she presents leaves her defense system all unregulated. Its inflammatory response is deficient, there are few cells mobilizing to the site of inflammation and low production of antibodies”, says pediatrician Maria Marluce dos Santos Vilela, professor at the Faculty of Medical Sciences at Unicamp and lead author of the article.

In these patients, the impact of infectious agents such as viruses can lead to chronic infection with the risk of death.

The researcher explains that the human and other mammalian immune systems normally produce five types of antibodies: immunoglobulins IgM, IgG, IgA, IgE and IgD. People with this condition – known as immunodysregulation syndrome – often have little IgE and, in some cases, a complete absence of IgA, the main neutralizing antibody to viruses and other disease agents, which is often present in breast milk, respiratory secretions and gastrointestinal.

In addition, these patients may have a very low production of IgG, normally the most abundant antibody in the blood and responsible for recognizing and neutralizing foreign microorganisms (antigens) with which the body has had previous contact.

There are only 157 cases of the type described in the world, characterized in study published in the Journal of Allergy and Clinical Immunology, of which the specialist is a co-author.

“Our strategy was to keep the patient isolated at home, under the care of her mother – who monitored her oxygenation, body temperature and nutrition. In the hospital she could contract a bacterial infection, which would make the situation even more serious. And, since the diagnosis, in March 2021, we have periodically monitored her by video”, says the doctor.

In the first 15 days of infection, the patient presented fever, loss of appetite and weight, cough and indisposition. To the surprise of the medical team, the lung and other systems remained unchanged.

Two months later, the condition remained the same and the group then decided to test, in partnership with Unicamp’s Hemocentro, the treatment with convalescent plasma, that is, the transfusion of antibodies produced by people who had been cured of Covid-19, mainly those of the IgG type.

The procedure was performed and promoted improvement of symptoms and reduction of inflammatory markers in the blood. But, after 15 days, the molecular diagnostic test remained positive and the patient continued to present mild symptoms and signs of what doctors call adynamia, which is a great muscle weakness associated with prolonged infectious processes.

Antibody replacement

“We were concerned that the infection would continue for a long time, which would weaken it further and increase the risk of infecting other people. At the same time, the results of a study came out showing that lactating women immunized with the Pfizer vaccine produced milk with a reasonable amount of IgA. So we decided to do the care experience of replacing IgA via breast milk”, says Marluce.

The researcher says that it was only possible to carry out the test because there is strict legislation in the country that guarantees the safety of milk banks. Only healthy women with negative tests for infectious diseases such as AIDS, syphilis and hepatitis, among others, can donate. The system also lets you know if the donor has been immunized.

“We recommend that she consume milk orally, as IgA works like a ‘broom’, that is, it sticks to pathogens throughout the gastrointestinal tract and everything that is inappropriate is eliminated in the feces. The three-hour interval between doses – except at night – was designed to not give the virus a chance to continue replicating itself”, says the pediatrician.

The test came back negative after a week and two other tests, carried out at intervals of ten days each, also did not detect the presence of SARS-CoV-2, the virus that causes Covid-19. “And we are still doing RT-PCR tests for SARS-CoV-2. Our concern is that, with the new variants, she will acquire an asymptomatic infection”, says the doctor.

persistence of infection

According to data in the article, the patient remained at least 124 days with the virus active in her body. To make sure it was the same pathogen and not successive infections, the Unicamp researchers sequenced the SARS-CoV-2 genome isolated from three samples collected at different times.

In two samples it was also possible to quantify the number of viral particles. This part of the investigation was led by Professor José Luiz Proença Módena, coordinator of the Laboratory for the Study of Emerging Viruses (Leve).

“The sequencing results showed that the patient was infected with the Gamma variant (P.1) of SARS-CoV-2, the one that emerged in Manaus in late 2020 and caused a collapse in the health system there in early 2021″ , says Modena.

According to the researcher, the data showed that the patient was chronically infected by the same virus and not successively infected by different viruses. “No mutation in the viral genome was found in the three sequencing reactions carried out with samples from the patient collected at different times”, explains the researcher.

In Marluce’s assessment, the trial was only possible thanks to the resources offered by the Unified Health System (SUS).

“It was the SUS network that allowed the rescue of samples for genomic analyses. And, in addition, it ensured the safety of both convalescent plasma and breast milk used in the treatment. And as the quality control of the network is the same throughout the country, I was able to instruct a colleague from Acre to care for a patient with a similar immunodeficiency”, he says.