Denis Mulleman, Katarina Vučićević, James Bluett
J Rheumatol 2026; doi: 10.3899/jrheum.2026-0538There were 2 errors in the paragraph under the subheading "Rituximab concentration thresholds associated with B-cell depletion" at the end of page 2. In this paragraph, "< 1000 ng/mL" should be "> 1000 ng/mL" and "hyperglobulinemia" should be "hypogammaglobulinemia."The correct paragraph is as follows: "A trough concentration > 1000 ng/mL was associated with hypogammaglobulinemia, whereas all patients with rituximab concentrations > 550 ng/mL maintained B-cell depletion. The authors proposed that a therapeutic window of 550-1000 ng/mL could maintain B-cell depletion while minimizing the risk of hypogammaglobulinemia.10"This correction applies to the July 1 2026 First Release and September 2026 print issue. The online issue is correct.