Viral Orchitis - Fact or Fiction?

• Applicant: Professor Dr. Adrian Pilatz
• Subject Area: Reproductive Medicine, Urology ; Virology
• Term: from 2019 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 425976748

Acute orchitis is a sudden, isolated infection or post-infectious inflammation of one or both testicles without concomitant epididymitis with an incidence of 14 to 100,000 men and year. Clinical characteristics of orchitis are a painful enlargement of the testicles and hyperperfusion of the affected testicles in ultrasound. Aetiologically, a testicular involvement in the context of systemic viral infections is assumed. Orchitis occurs in approximately 30% of cases in mumps and in about 3% of cases in epidemic pleurodynia (Cocksackie viruses). Conversely, there are no systematic studies in patients with isolated orchitis in terms of viral aetiology. Furthermore, the relevance of viruses in semen is currently widely unclear with regard to sexual transmission, local inflammation and impact on male fertility. In our relevant preliminary work, we could show in a prospective study, which has been ongoing since 2007, that enteroviruses were etiologically relevant and detectable in the semen in patients with acute epididymitis. Therefore, the aim of this proposal is to examine the viral aetiology in patients with isolated orchitis with modern molecular diagnostics. This will imply an already established hierarchical analysis method considering 21 different viruses (screening, confirmation, sequencing, follow-up). For this purpose, cryopreserved samples from the patients with isolated orchitis recruited since 2007 (n = 22) are available at initial presentation and follow-up (2 weeks, 3 months). In addition to the aetiology, the effects of acute isolated orchitis on seminal inflammation and testicular function is largely unknown. Thus, local inflammation will be evaluated on a cellular and cytokine level and the testicular function will be investigated on the basis of the sex hormones (endocrine function) as well as the sperm parameters (exocrine function). The planned investigations are intended to be a milestone in terms of meaningful viral diagnostics and the impact of orchitis on testicular function in patients with isolated orchitis.

• DFG Programme: Research Grants