Abstract: SA-PO664
Rituximab-Associated Hypogammaglobulinemia in ANCA Vasculitis: Incidence and Time Course
Session Information
- Glomerular Diseases: ANCA, Anti-GBM, Kidney Biopsy
November 09, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1203 Glomerular Diseases: Clinical, Outcomes, and Trials
Authors
- Tariq, Anam, Johns Hopkins University, Baltimore, Maryland, United States
- Akenroye, Ayobami, Johns Hopkins University, Baltimore, Maryland, United States
- Azar, Antoine, Johns Hopkins University, Baltimore, Maryland, United States
- Seo, Philip, Johns Hopkins University, Baltimore, Maryland, United States
- Gapud, Eric J., Johns Hopkins University, Baltimore, Maryland, United States
- Geetha, Duvuru, Johns Hopkins University, Baltimore, Maryland, United States
Background
Rituximab (RTX) is approved for remission induction (I) and maintenance (M) in ANCA vasculitis (AAV). RTX depletes B cells that express CD20 but does not affect B cell precursors or antibody producing plasma cells. Persistent production of protective antibodies and replenishment of peripheral B cells by B cell precursors renders RTX a relatively safe and effective treatment option. However, several observational studies have demonstrated a decline in serum immunoglobulin (IgG) in AAV patients treated with RTX. We evaluated the risk of hypogammaglobulinemia (Hypo-IgG) among RTX-treated AAV patients.
Methods
AAV patients treated with RTX were included in this single-center observational study. Demographics, clinical and post RTX IgG levels were extracted and analyzed. Severity of Hypo-IgG was defined as mild (501-700mg/dL), moderate (301-500mg/dL), and severe (≤300mg/dL). Descriptive data are presented as mean with SD and median with IQR.
Results
Between 2013 to 2018, we investigated 105 RTX treated AAV patients, with mean (SD) age 56 (16) years, 84% Caucasians, 57% females and 64% diagnosed with Granulomatosis with Polyangiitis. Post RTX IgG were measured in 74 patients of which 50 had repeat IgG. 27 patients received RTX for remission I, 8 for remission M and the remainder received RTX for remission I and M. Hypo-IgG occurred in 43 (58%) patients and 19 (44%) had moderate to severe hypo-IgG. Overall, IgG remained stable over time (Figure). Of the 50 patients with repeat IgG, 11 (36%) had moderate to severe hypo-IgG. Infections requiring hospitalization occurred in 10 patients with hypo-IgG.
Conclusion
Hypo-IgG is common in RTX treated AAV patients. Although limited by sample size, IgG trend suggests that nadir IgG levels occur during I dosing and the IgG levels remain stable or increase over time in those receiving M.
Figure: IgG levels over time in patients receiving induction and continous Rituximab