Lupus nephritis with antineutrophil cytoplasmic antibody seropositivity is a medical term used to describe a kidney disease that occurs in people with systemic lupus erythematosus. It is a condition where the immune system attacks healthy cells in the kidneys, leading to inflammation and damage. The condition can cause symptoms such as blood in urine, swelling of the legs, and high blood pressure. While this term accurately represents the disease, it can be quite a mouthful to say. Therefore, some synonyms for this condition include anti-GBM disease, ANCA-associated vasculitis, or mixed connective tissue disease. These alternative terms are often used by doctors and medical professionals to communicate the condition more easily.