Development of Spondyloarthritis After COVID-19 in HLA-B27-Positive Monozygotic Twins: Case Reports With Single Cell Transcriptome Profiling.

A subset of spondyloarthritis (SpA) called 'reactive arthritis' is triggered by causal pathogens, usually bacteria related to venereal disease or gastrointestinal infection. During the outbreak of coronavirus disease 2019 (COVID-19), there have been case reports about SpA after COVID-19, but the causality is still elusive. We described cases of 23-year-old monozygotic twins both diagnosed with SpA after COVID-19.

Salivary ultrasonography and histopathologic evaluation of secondary Sjögren's syndrome in rheumatoid arthritis patients.

Novel modalities, such as salivary ultrasonography (SGUS) and shear wave elastography (SWE), have previously been introduced to evaluate Sjögren's syndrome (SS). However, in secondary SS (sSS), the diagnostic performance of SGUS and its relationship with clinicopathological characteristics have not yet been clearly defined. In this study, we aimed to investigate sSS in RA patients using SGUS and SWE and sought to determine its pathological correlations.