SARS-CoV-2 antibody titration may help protect cancer patients

Patients with cancer and undetectable antibodies after COVID-19 vaccination had a three-fold increased risk of intercurrent SARS-CoV-2 infection and a more than six-fold increased risk of hospitalization related to an infection than those who have mounted a COVID-19 response. , reveals a new study.

The results support the use of antibody titration against the SARS-CoV-2 spike protein to identify patients with lower levels of antibody protection and immunity against the virus, the researchers concluded.

“Antibody titration can prepare these individuals to take other preventative measures to reduce the risk of infection,” wrote first author Dr. Lennard YW Lee, Ph.D., Affiliate. University of Oxford in the United Kingdom, and its collaborators.

The study was published online December 22 in the newspaper JAMA Oncology.

Immunocompromised people, including cancer patients, are much more likely to have intercurrent infection after Covid vaccination. However, identifying people who are less protected and therefore more susceptible to intercurrent infections is not yet so simple.

In the on-screen study, Dr. Lennard and his collaborators aimed to understand whether the risks of SARS-CoV-2 infection or virus-related hospitalization in cancer patients were related to antibody titers. after vaccination.

By using the National COVID Cancer Antibody Survey from the UK, researchers assessed 4,249 antibody titer results against the SARS-CoV-2 spike protein from 3,555 cancer patients and 294,230 antibody titer results from 225,272 non-cancer patients from the population general. Antibody titration was performed after the second or third dose of the vaccine.

In the cancer and control groups, people who received the third dose had significantly higher antibody titers than those who received only two doses (11,146.5 against 8,765 U/mL in the cancer cohort and 23,667 vs.. 12,126.0 U/mL in the control cohort).

Doctor. Lennard and colleagues found that patients with cancer were significantly more likely to have undetectable antibody responses against the viral spike than patients without cancer (4.68% vs.. 0.13%; P < 0.001).

Patients with leukemia or lymphoma had the lowest antibody titers: 19.3% had no detectable antibody response to vaccines, compared to 4.2% of patients with solid tumors and 0.1% of patients witnesses. Patients on systemic antineoplastic therapy and those with stage IV cancer were also more likely to produce fewer antibodies.

After multivariate adjustments, cancer patients who had an undetectable antibody response had a three-fold increased risk of intercurrent SARS-CoV-2 infection (odds ratio 3.05; P < 0.001) and a 6.5-fold increased risk of SARS-CoV-2-related hospitalization (odds ratio 6.48; P < 0.001) than those that mounted an antibody response.

In total, in the cancer cohort, 259 patients had an intercurrent infection and 55 patients had a SARS-CoV-2-related hospitalization after antibody titration. Hospitalized subjects had significantly lower median antibody titers than other patients (147.0 U/mL vs.. 10,961.0 U/mL).

The results suggest that titration of antibodies against the viral spike protein “can identify cancer patients with a lower level of protection and immunity conferred by antibodies against SARS-CoV-2 and, therefore, against covid -19,” the authors concluded. . The authors noted that to their knowledge, this is the first study to demonstrate this association.

The researchers acknowledged that they had not comprehensively assessed the time between vaccination and antibody titer or the effect of viral variants. The study was carried out at the end of the period of delta variant dominance and the beginning of the dissemination of the omicron variant of the SARS-CoV-2 virus.

However, Dr. Lennard and colleagues concluded that “expanding access to antibody titration for cancer patients should be evaluated.” This “could help inform national guidelines [dos EUA] for physicians who guide patients and could help create a risk monitoring strategy that can be used to structure vaccine booster programs.”

The results can also help people make more informed choices about their personal risk and take precautions to reduce the risk of infection and transmission.

The authors noted, however, that antibody titration is only “one part of a larger strategy that includes collective efforts such as [uso de] two-way ventilation, filtration and masks, which will make life safer for vulnerable and immunocompromised patients. »

The authors of editorial accompanying the study proposed additional strategies to meet the needs of the most vulnerable patients, such as efforts to expand education and access to vaccines, improve access to antibody titers, and provide information on a range of topics ranging from how the virus spreads to how to reduce the spread at home.

Finally, the editorial writers concluded that the study provides “compelling” evidence that cancer patients are more vulnerable to covid-19 and suggested that “vaccines and antibody titration are essential elements of a comprehensive protection strategy of the most vulnerable cancer patients during the ongoing COVID-19″. pandemic”.

The study was funded by the institutions University of Oxford, University of Birmingham, University of Southampton, UK Health Security Agency and Blood cancer UK. The full list of author conflicts of interest can be found in the original article. The columnists revealed no relevant financial relationship.

This content was originally posted on Medscape .

follow him medical landscape in Portuguese in Facebookto Twitter and not Youtube

Add Comment