Portal Vein Thrombosis as a Cause of Undetermined Thrombocytopenia with Liver Dysfunction in a Patient with Eosinophilic Granulomatosis with Polyangiitis.

We herein report a 20-year-old woman who developed eosinophilic granulomatosis with polyangiitis (EGPA) and portal vein thrombosis (PVT). EGPA was diagnosed based on the patient's history of asthma, hypereosinophilia, and mononeuritis complex. Thrombocytopenia and liver dysfunction were observed, necessitating contrast-enhanced computed tomography (CECT), which revealed PVT. Her symptoms soon improved with glucocorticoids and anticoagulation therapy. As patients with EGPA often suffer from asthma, they can be hesitant to undergo CECT. However, if patients with EGPA show uncertain thrombocytopenia with liver dysfunction, a further evaluation using CECT is warranted to detect PVT.

Appearance of anti-MDA5 antibody-positive dermatomyositis after COVID-19 vaccination.

The direct causes of dermatomyositis, a common autoimmune disease, have not yet been accurately identified, but several studies have linked this condition to various patient-associated and environmental factors, such as viral infections and area of residence. In the present report, we describe our experience with a patient presenting with anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive dermatomyositis, which developed after vaccination against coronavirus disease 2019 (COVID-19). This patient was simultaneously diagnosed with anti-glutamic acid decarboxylase antibody-positive slowly progressive insulin-dependent diabetes (SPIDDM); her human leucocyte antigen test revealed that she expressed the DRB1*04:05 allele. This is important as this genotype is known to increase susceptibility to both anti-MDA5 antibody-positive dermatomyositis and type I diabetes. To the best of our knowledge, this is the first case of dermatomyositis complicated by SPIDDM identified after COVID-19 vaccination against COVID-19 and presenting with an underlying susceptible genotype. The patient's genetic predisposition may also be important for the development of autoimmune disease after COVID-19 vaccination.

Cryoglobulinemic Vasculitis Associated with Monoclonal Gammopathy of Undetermined Significance Developed after Sustained Virologic Response of Hepatitis C.

A 72-year-old woman had a history of chronic hepatitis C virus (HCV) infection previously treated with interferon to achieve a sustained virologic response. Thereafter, she developed polyarthritis and purpura of the lower extremities as well as progressive renal dysfunction with hypertension and proteinuria that had occurred in the last three months. Laboratory investigations revealed seropositivity for cryoglobulin but negative findings for HCV RNA. She was ultimately diagnosed with cryoglobulinemic glomerulonephritis complicated by monoclonal gammopathy of undetermined significance (MGUS) based on the pathological findings of the kidney and bone marrow, indicating that MGUS-induced cryoglobulinemic vasculitis may occur even after HCV elimination.