Rheumatoid vasculitis in 2023: Changes and challenges since the biologics era.

BACKGROUND: Significant changes in the epidemiology and natural history of rheumatoid vasculitis (RV) have occurred with the introduction of biological therapies such as TNF inhibitors (TNFi) and rituximab. PURPOSE: This scoping review aims to address the key current challenges and propose updated criteria for RV. This will aid future descriptive observational studies and prospective therapeutic trials. METHODOLOGY: The MEDLINE database was searched for eligible articles from inception through December 2022. Articles were selected based on language and publication date after 1998, corresponding to the approval of the first TNFi in rheumatic diseases. RESULTS: Sixty articles were included in the review. The mean incidence of RV has decreased since the approval of biologic therapies in RA, from 9.1 (95% CI: 6.8-12.0) per million between 1988 and 2000 to 3.9 (95% CI: 2.3-6.2) between 2001 and 2010, probably due to significant improvement in RA severity and a decrease in smoking habits. Factors associated with an increased risk of RV include smoking at RA diagnosis, longer disease duration, severe RA, immunopositivity, and male gender (regardless of age). Homozygosity for the HLA-DRB104 shared epitope is linked to RV, while the presence of HLA-C3 is a significant predictor of vasculitis in patients without HLA-DRB104. Cutaneous (65-88%), neurologic (35-63%), and cardiac (33%) manifestations are common in RV, often associated with constitutional symptoms (70%). Histologic findings range from small vessel vasculitis to medium-sized necrotizing arteritis, but definite evidence of vasculitis is not required in the 1984 Scott and Bacon diagnostic criteria. Existing data on RV treatment are retrospective, and no formal published guidelines are currently available. CONCLUSION: The understanding of RV pathogenesis has improved since its initial diagnostic criteria, with a wider range of clinical manifestations identified. However, a validated and updated criteria that incorporates these advances is currently lacking, impeding the development of descriptive observational studies and prospective therapeutic trials. PRIMARY FUNDING SOURCE: This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Editing a γ-globin repressor binding site restores fetal hemoglobin synthesis and corrects the sickle cell disease phenotype.

Sickle cell disease (SCD) is caused by a single amino acid change in the adult hemoglobin (Hb) ß chain that causes Hb polymerization and red blood cell (RBC) sickling. The co-inheritance of mutations causing fetal γ-globin production in adult life hereditary persistence of fetal Hb (HPFH) reduces the clinical severity of SCD. HPFH mutations in the HBG γ-globin promoters disrupt binding sites for the repressors BCL11A and LRF. We used CRISPR-Cas9 to mimic HPFH mutations in the HBG promoters by generating insertions and deletions, leading to disruption of known and putative repressor binding sites. Editing of the LRF-binding site in patient-derived hematopoietic stem/progenitor cells (HSPCs) resulted in γ-globin derepression and correction of the sickling phenotype. Xenotransplantation of HSPCs treated with gRNAs targeting the LRF-binding site showed a high editing efficiency in repopulating HSPCs. This study identifies the LRF-binding site as a potent target for genome-editing treatment of SCD.