Patients With SLE Have Lower COVID-19 Vaccine Antibody Responses

Compared with health care workers, patients with systemic lupus erythematous (SLE) had lower spike immunoglobulin (Ig)G antibody levels after COVID-19 vaccination, regardless of background immunosuppressive therapy, according to study findings published in Arthritis Care & Research.

Using data from the Hopkins Lupus Cohort, researchers conducted a prospective cohort study to evaluate the association between immunosuppressive medications in SLE and immune responses to COVID-19 vaccination.

Immune response to 2 mRNA COVID-19 vaccines were evaluated among patients with SLE and a control group of health care workers enrolled at 5 hospitals affiliated with the Johns Hopkins Health System. Serum samples were collected every 3 to 4 months.

The patient and control cohorts included 92% and 80% women; 51% and 90% were White; and 59% and 81% had received the Pfizer vaccine, respectively.

Immunosuppressant medications were held in some patients with SLE around the time of vaccination. However, withholding treatment did not appear to have a significant effect on Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) or Physician’s Global Assessment (PGA) outcomes, and the number of Systemic Lupus Erythematosus National Assessment (SELENA) or PGA flares.

Overall, the SLE vs control group had lower levels of SARS-CoV-2 spike protein IgG antibody levels (P =.003). Antibody levels were 7.4 and 8.9 g/L at 15 to 59 days; 6.5 and 8.1 g/L at 60 to 119 days; 5.1 and 6.3 g/L at 120 to 179 days; and 4.8 and 5.0 g/l at least 180 days after vaccination.

In the SLE cohort, the average IgG antibody level was significantly lower among those who received vs did not receive treatment with mycophenolate mofetil, tacrolimus, prednisone, belimumab, calcium channel blockers, angiotensin-converting enzymes and angiotensin II receptor blockers, other antihypertensives, and immunosuppressant medications.

With regard to the effect of SLE disease activity characteristics on COVID-19 vaccine response, the researchers observed that patients with PGA scores of greater than vs lower than 1 at the time of antibody testing (P =.020) or at vaccination (P =.023) had lower mean IgG antibody levels. A PGA score of greater than 1 at the time of antibody testing was also associated with a decreased rate of IgG antibody positivity (P =.039).

In the multivariate regression model, a mycophenolate mofetil dose of greater than 1000 mg/day associated with a decrease in an average IgG antibody level of -2.38 g/L (P <.0001), tacrolimus use by -1.49 g/L (P =.0092), and belimumab use by -2.29 g/L (P =.015).

Certain study limitations warrant mention. Because this was an outpatient study, the visits were not timed to the vaccine date, and data on breakthrough infections were unavailable.

The study authors concluded, “[P]atients [with SLE], regardless of background immunosuppressive therapy, had lower vaccine IgG levels than healthcare workers. Mycophenolate, tacrolimus, and belimumab significantly reduced IgG response to vaccination. Holding mycophenolate for one week improved vaccine efficacy, providing clinical benefit on vaccine response without leading to clinical flares.”