Temporary hold of mycophenolate augments humoral response to SARS-CoV-2 vaccination in patients with rheumatic and musculoskeletal diseases: a case series.

Mycophenolate is the mainstay of treatment for many organ and life-threatening manifestations of rheumatic and musculoskeletal diseases (RMD). In contrast to most patients with RMD, those taking mycophenolate have an attenuated humoral response to SARS-CoV-2 mRNA vaccination.1 2 The American College of Rheumatology recently recommended withholding mycophenolate for 1 week after vaccination to enhance immunogenicity in this vulnerable population.3 Thus, we sought to analyse the impact of withholding perivaccination mycophenolate in 24 patients with RMD. We leveraged our observational prospective cohort of patients with RMD without prior COVID-19 who underwent SARS-CoV-2 vaccination between 17 December 2020 and 13 May 2021.2 Information on demographics, diagnoses, immunosuppressive regimens and management of perivaccination immunosuppression was collected via electronic questionnaire. One month following vaccination, venipuncture samples were obtained and tested on the semiquantitative Roche Elecsys anti-SARS-CoV-2 S enzyme immunoassay which tests for antibodies against the receptor binding domain (RBD) of the SARS-CoV-2 spike protein; a consistent correlate of neutralising antibody.4 We compared the percentage of participants with detectable anti-RBD antibody in the group that withheld mycophenolate (n=24) to the group that continued mycophenolate (n=171) using Fisher’s exact test (online supplemental table 1). Crude and adjusted logistic regression analyses were performed to assess associations between antibody response and the primary variable of withholding mycophenolate, as well as after adjusting for clinical characteristics (age, sex, race, vaccine type (mRNA vs adenovirus vector), use of rituximab and glucocorticoids). Wilcoxon rank-sum test was used to compare anti-RBD titers of the …