Still more to learn about what leads to LON
“In large part, these findings quantify what our experience has been with LON in clinical practice,” Dr. Zonozi said. “It is indeed common, it’s often incidental, and most cases are reversible and respond well to treatment. But it can be associated with severe infections, including sepsis, and warrants close monitoring.”
Dr. Md Yuzaiful Md Yusof
In an interview, Md Yuzaiful Md Yusof, MBChB, PhD, observed that this incidence rate was notably higher than what he’d seen previously. Dr. Md Yusof presented at EULAR Congress 2015 on rituximab and LON, finding that 23 patients (2.5%) from a cohort of 912 developed rituximab-associated neutropenia.
“Most of our cases were in patients with rheumatoid arthritis,” he added, “so it may just be a difference in cohorts.”
Regardless, he applauded additional research in this area, noting that “the etiology of rituximab-associated LON is still unclear. The reasons behind this occurrence need investigating, particularly in regard to severe neutropenia cases. If we can find the predictors of those, it will be extremely helpful for the future of treatment.”
Dr. Zonozi agreed that “more investigation is needed to accurately define the mechanism of LON, which remains unknown. This will likely lead to more targeted strategies to both prevent and treat it.”
The authors acknowledged their study’s limitations, including being a single-center study that relied on retrospective data collection. They also acknowledged that, because the center is a nephrology-based practice, there was a low number of certain diseases like RA, opening up the possibility that “rates of LON are different” in those patients.
Two authors’ work on the study was funded by grants from the National Institutes of Health. The authors disclosed no potential conflicts of interest.
SOURCE: Zonozi R et al. Arthritis Rheumatol. 2020 Sep 6. doi: 10.1002/art.41501.