Cutaneous Vasculitis in Cogan's Syndrome: A Report of Two Cases Associated with Chlamydia Infection

Atypical Cogan's Syndrome Mimicking Giant Cell Arteritis Successfully Treated with Early Administration of Tocilizumab

A 49-year-old Japanese man with a 2-month history of a fever, headache, and bilateral conjunctival hyperemia was admitted. His condition fulfilled the giant cell arteritis classification criteria (new headache, temporal artery tenderness, elevated ESR) and atypical Cogan's syndrome (CS) with scleritis and sensorineural hearing loss (SNHL). The interleukin (IL)-6 serum level was extremely high. Two weeks after his insufficient response of SNHL and scleritis to oral prednisolone, we administered tocilizumab (TCZ); rapid improvements in scleritis and SNHL occurred. Early IL-6 target therapy can help prevent irreversible CS-induced sensory organ damage.

Pathogenesis of liver injury in Takayasu arteritis: advanced understanding leads to new horizons

Liver injury in Takayasu arteritis (TA) is a rare phenomenon. Most symptoms are nonspecific, and the exact pathogenesis remains to be elucidated. Early diagnosis and new treatment methods are important for an improved prognosis. A summary of the clinical information and mechanistic analyses may contribute to making an early diagnosis and development of new treatment methods. A PubMed search was conducted using the specific key words “Takayasu arteritis” and “liver” or “hepatitis” or “hepatic”. Symptoms and treatment of TA with an accompanying liver injury were reviewed retrospectively. Many factors are presumed to be involved in the mechanism of TA with liver injury, including the immune response, genes, infections, and gut microbiota. There are several lines of evidence indicating that immune dysfunction is the main pathogenic factor that triggers granuloma formation in TA patients. However, the role of genetics and infections has not been fully confirmed. Recently, the gut microbiota has emerged as an essential component in the process. We reviewed in detail the current concepts that support the complex pathogenesis of TA accompanied by liver injury, and we presented recent theories from the literature. Finally, we discussed future research directions of liver injury in TA.

Familial HLA-B*52 Vasculitis: Maternal, Atypical Cogan's Syndrome with Takayasu Arteritis-mimicking Aortitis and Filial Takayasu Arteritis

Cogan's syndrome (CS), a rare vasculitis characterized by non-syphilitic, interstitial keratitis and Ménière-like attacks, is classified into "typical" and "atypical" forms, while Takayasu arteritis (TAK) is a rare large-vessel vasculitis associated with human leukocyte antigen (HLA)-B*52. Very few cases meet both the CS and TAK classification criteria. We herein report a 53-year-old woman diagnosed with atypical CS and aortitis similar to TAK. Her 25-year-old daughter manifested TAK without symptoms of CS, and both are HLA-B*52 positive. Our case highlights the difficulties of distinguishing aortitis with atypical CS from aortitis with TAK.

New Insights on the Pathogenesis of Takayasu Arteritis: Revisiting the Microbial Theory

Takayasu arteritis (TAK) is a chronic vasculitis that mainly affects the aorta, its major branches, and the pulmonary arteries. Since the description of the first case by Mikito Takayasu in 1908, several aspects of this rare disease, including the epidemiology, diagnosis, and the appropriate clinical assessment, have been substantially defined. Nevertheless, while it is well-known that TAK is associated with a profound inflammatory process, possibly rooted to an autoimmune disorder, its precise etiology has remained largely unknown. Efforts to identify the antigen(s) that trigger autoimmunity in this disease have been unsuccessful, however, it is likely that viruses or bacteria, by a molecular mimicry mechanism, initiate or propagate the auto-immune process in this disease. In this article, we summarize recent advances in the understanding of TAK, with emphasis on new insights related to the pathogenesis of this entity that may contribute to the design of novel therapeutic approaches.