Disease Activity and Tendency to Relapse in ANCA-Associated Vasculitis Are Reflected in Neutrophil and Intermediate Monocyte Frequencies.

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a group of autoimmune diseases with inflammation affecting small blood vessels and includes granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA). In this study, we investigated granulocyte and monocyte subsets in a large cohort of AAV patients with emphasis on disease activity and tendency to relapse. A cohort of 105 patients with GPA or MPA and 126 healthy controls (HCs) were included. Clinical and laboratory data were collected for all patients, including disease activity, tendency to relapse, and pharmacological treatment. Using flow cytometry, circulating eosinophils, basophils, neutrophils, and monocytes were assessed. The monocytes were subdivided into classical (CD14++CD16-), intermediate (CD14++CD16+), and nonclassical (CD14-CD16+) monocytes. Mature (CD16high) or newly released (CD16dim) neutrophils were defined, as well as the frequency of CD177+ neutrophils. AAV patients displayed increased frequencies of intermediate monocytes, mature and newly released neutrophils, and an expanded population of CD177+ neutrophils compared to HC. MPA patients differed from GPA patients in terms of lower frequency of classical monocytes. No differences in cell frequencies regarding ANCA phenotype were observed. Paired data from 23 patients demonstrated that active disease was associated with an increased frequency of mature neutrophils and a decreased frequency of monocytes, in particular intermediate monocytes. Moreover, GPA patients with a tendency to relapse displayed an increased frequency of mature neutrophils with increased expression of CD177+. Relapsing MPA patients, on the other hand, showed decreased frequency of intermediate monocytes. Finally, rituximab treatment was associated with increased frequencies of classical and intermediate monocytes. In conclusion, AAV patients exhibit a skewing of different neutrophil and monocyte subpopulations that are associated with disease subtypes, disease activity, rituximab treatment, and propensity to relapse. These changes may contribute to the inflammatory process and could potentially be used as biomarkers for relapse prediction.

Rituximab como terapia de mantenimiento en las vasculitis asociadas a ANCA: ¿cómo, cuándo y por qué? / Rituximab as maintenance therapy for ANCA associated vasculitis: how, when and why?

Las vasculitis asociadas a ANCA son enfermedades autoinmunes crónicas que se caracterizan por inflamación y destrucción de vasos de pequeño tamaño. El rituximab es un tratamiento efectivo para la fase de inducción de estas patologías. Durante los últimos años, varios estudios no controlados han reportado que también es eficaz durante la fase de mantenimiento terapéutico. En estas series, el fármaco se administró solo durante las recaídas, a intervalos fijos o sobre la base en cambios en algunos biomarcadores. Los resultados del estudio MAINRITSAN mostraron que el rituximab es superior a la azatioprina como terapia de mantenimiento en estas enfermedades. Este trabajo de revisión resume la información más reciente sobre el uso de rituximab como opción para la fase de mantenimiento de las vasculitis asociadas a ANCA, detallando su efectividad, los diversos protocolos de administración, el perfil de seguridad y el uso potencial de biomarcadores para guiar el tratamiento (AU)

ANCA-associated vasculitides (AAV) are chronic autoimmune diseases characterized by inflammation and destruction of small vessels. Rituximab is now licensed for use as a remission-induction agent in the treatment of these disorders. During recent years, several non-controlled studies have suggested that rituximab may be of value in maintaining disease remission in AAV. In these series, 3 techniques have been tried: 'watch-and-wait', repeated cycles in fixed intervals, or administration based on proposed biomarkers. More importantly, the results of the MAINRITSAN trial showed that this anti-CD20 agent is superior to azathioprine for preventing major relapses in AAV. This review summarizes current information regarding the effectiveness, timing, dosing, duration and safety of rituximab as a valid option for remission maintenance (AU)