Polyomavirus detection in multiple sclerosis patients under natalizumab therapy: Profile and frequency of urinary shedding

Extracellular Vesicles in Multiple Sclerosis: Role in the Pathogenesis and Potential Usefulness as Biomarkers and Therapeutic Tools

Although extracellular vesicles (EVs) were initially relegated to a waste disposal role, nowadays, they have gained multiple fundamental functions working as messengers in intercellular communication as well as exerting active roles in physiological and pathological processes. Accumulating evidence proves the involvement of EVs in many diseases, including those of the central nervous system (CNS), such as multiple sclerosis (MS). Indeed, these membrane-bound particles, produced in any type of cell, carry and release a vast range of bioactive molecules (nucleic acids, proteins, and lipids), conferring genotypic and phenotypic changes to the recipient cell. This means that not only EVs per se but their content, especially, could reveal new candidate disease biomarkers and/or therapeutic agents. This review is intended to provide an overview regarding current knowledge about EVs’ involvement in MS, analyzing the potential versatility of EVs as a new therapeutic tool and source of biomarkers.

HPyV6 and HPyV7 in urine from immunocompromised patients

Background

Human polyomavirus 6 (HPyV6) and HPyV7 are two of the novel polyomaviruses that were originally detected in non-diseased skin. Serological studies have shown that these viruses are ubiquitous in the healthy adult population with seroprevalence up to 88% for HPyV6 and 72% for HPyV7. Both viruses are associated with pruritic skin eruption in immunocompromised patients, but a role with other diseases in immunoincompetent patients or malignancies has not been established.

Methods

PCR was used to determine the presence of HPyV6 and HPyV7 DNA in urine samples from systemic lupus erythematosus (n = 73), multiple sclerosis (n = 50), psoriasis vulgaris (n = 15), arthritic psoriasis (n = 15) and HIV-positive patients (n = 66). In addition, urine from pregnant women (n = 47) and healthy blood donors (n = 20) was investigated.

Results

HPyV6 DNA was detected in 21 (28.8%) of the urine specimens from SLE patients, in 6 (9.1%) of the urine samples from the HIV-positive cohort, and in 19 (40.4%) samples from pregnant women. HPyV7 DNA was only found in 6 (8.2%) of the urine specimens from SLE patients and in 4 (8.5%) samples from pregnant women. No HPyV6 and HPyV7 viruria was detected in the urine samples from the other patients.

Conclusions

HPyV6, and to a lesser extend HPyV7, viruria seems to be common in SLE and HIV-positive patients, and pregnant women. Whether these viruses are of clinical relevance in these patients is not known.