Autoimmune orchitis is characterized by testis inflammation and the presence of specific antisperm antibodies (ASA). It is classified in two categories. Primary autoimmune orchitis is defined by infertility and asymptomatic orchitis associated with ASA (100%) directed to the basement membrane or seminiferous tubules in infertile men, without any systemic disease and usually asymptomatic.
Secondary autoimmune orchitis is characterized by symptomatic orchitis and/or testicular vasculiti`s associated with a systemic autoimmune disease, particularly vasculitis. These patients typically demonstrate testicular pain, erythema and/or swelling. ASA in secondary autoimmune orchitis have been reported in up to 50% of patients, especially in systemic lupus erythematosus patients. (source)