Editorial – ANCA associated vasculi s treatment: outcomes and complica ons

Matija Crnogorac^1*Lea Salamon¹Maria Letizia Urban²Giacomo Emmi^2,3

• ¹Clinical Hospital Dubrava, Zagreb, Croatia
• ²Clinical Medicine and Rheumatology Unit, Cattinara University Hospital, Trieste, Italy
• ³Department of Medical, Surgical and Health Sciences, University of Trieste, Trieste, Italy

ANCA-associated vasculi s (AAV) is a group of rare systemic autoimmune diseases characterized by the inflamma on of small blood vessels and usually presence of circula ng ANCA an bodies. (1). Due to advancements in treatment op ons, the prognosis of these diseases has been significantly improved and the risk of relapse reduced. (2). There is also an increased need to iden fy clinical subtypes within the classical AAV classifica on that would, based on individual disease traits and par cular biomarkers, benefit from specific therapeu cal approaches (3). The explored biomarkers might poten ally allow for more personalized plans for pa ents' retreatment by predic ng disease ac vity or flares before clinical relapse. (4).The aim of this special issue is to describe the state of the art in AAVs prognos c tools, treatment goals and poten al biomarker use. This collec on contains 5 ar cles including two original research publica ons and three reviews nicely balancing biomarker research with subtype clustering and specific treatment modali es suppor ng the importance of this topic.Moving beyond earlier classifica on systems of rare diseases is necessary even within specific clinical phenotypes in order to have a be er prognos c informa on which could guide treatment decisions. Okazaki A et al. in their mul center cohort study iden fied four unique subgroups of microscopic polyangii s (MPA) pa ents with different outcomes. The two subgroups, one with renal involvement and diffuse alveolar hemorrhage (DAH) and the other including elderly onset pa ents with systemic inflamma on, had the worst overall survival and the first one highest chance for ESKD. This suggests the importance of pooling data and cluster analysis such as was already shown in the works of FAIRVASC consor um (5). Individualized treatment approach for each subgroup may be required in order to improve survival and reduce the chance for ESKD. (Okazaki A et al.)In a nice review, Alberici F et al. explored the challenges in defining treatment goals for AAV pa ents. Treatment advances in recent decades have made it easy to treat AAVs which meant not just be er overall survival and reduced end-organ damage but have also made AAVs chronic diseases. With that in mind, the authors pointed that the preserva on of quality of pa ents' lives became as important as controlling disease ac vity. This requires the clinicians to balance both clinical and pa ent needs. One of the most important aspects is reducing treatment side effects by developing more targeted therapies. The future of successful management of AAV will have to be based on both reducing AAV organ damage and achieving pa ent sa sfac on. (Federici A et al.)The treatment goals o en depend on assessing the disease ac vity tools, for which are s ll limited. Therefore, there is a growing need for adequate and validated candidate biomarkers. On that note, Marvisi C et al. in their detailed review explored variety of serological, cellular, and urinary biomarkers with the focus on their use for assessing disease ac vity, disease related damage and prognosis. It is more plausible that the future of personalized treatment and disease ac vity assessment will be based on biomarker panels rather than individual biomarkers. Though, at the moment, according to the authors there are two promising commercially available biomarkers: urinary sCD163 and MCP-1 (6,7). Both seem to dis nguish well between ac ve renal AAV and remission. Shiomi M et al. in their REVEAL study, showed in their cohort of pa ents with EGPA that mepolizumab contributes to both disease ac vity control and glucocor coid (GC) dose reduc on, which may increase pa ent survival and reduce GC side effects. This was further reaffirmed in detailed review presented by Lazzeroni M et al. The authors reviewed treatments consis ng of benralizumab, mepolizumab and reslizumab protocols. All these an -IL-5/IL-5 drugs proved efficacy in remission control and cor costeroid tapering. The analysed data strongly suggests the benefits of integra ng an IL-5/IL-5 receptor therapies into EGPA treatment strategies, to both improve pa ents' outcomes and reduce the side effects of prolonged GC therapy. The challenge, it seems, is when to ini ate an -IL5/IL-5R therapy since this has not been uniformly done across the included studies.In conclusion, this special issue collects papers highligh ng current state of the art in the field of AAVs as well as original manuscripts iden fying both treatment op ons and new ways of clustering AVVs as a way of advancing prognos c tools that may contribute to further progress in this field. We believe that the reader will gain an understanding of this topic. (Shiomi M et al.) (Lazzeroni M et al.)