Predominant Merkel Cell Polyomavirus DNA Detection in Essential Thrombocythemia within Myeloproliferative Neoplasms

Area of Science:

• Oncology
• Virology
• Hematology

Background:

• Merkel cell polyomavirus (MCPyV) is an oncogenic human polyomavirus linked to Merkel cell carcinoma.
• Mouse polyomavirus Middle T gene expression induces acute thrombocythemic myeloproliferative disease in mice.
• Myeloproliferative neoplasms (MPNs) are a group of diseases characterized by the overproduction of myeloid cells.

Purpose of the Study:

• To investigate the presence of MCPyV DNA in bone marrow (BM) aspirates from patients with MPNs.
• To explore the potential association between MCPyV and MPNs, particularly essential thrombocythemia (ET).

Main Methods:

• MCPyV-specific DNA polymerase chain reaction (PCR) was used to detect MCPyV DNA in 78 MPN patient BM samples and 66 control BM samples.
• MCPyV mRNA detection was performed in MCPyV-DNA-positive samples to assess viral transcription.
• Statistical analyses, including Fisher's exact test, were employed to compare MCPyV prevalence between MPN patients and controls and to identify correlations.

Main Results:

• MCPyV DNA prevalence was significantly higher in MPN patients (17.9%) compared to controls (3%) (p = 0.0063, OR = 7.95).
• Positivity for MCPyV DNA was predominantly observed in patients with essential thrombocythemia (ET) (11 out of 14 positive cases).
• MCPyV mRNA was detected, indicating low-level viral transcription in positive samples. Positivity correlated with female sex and myeloproliferative leukemia virus oncogene (MPL) mutations.

Conclusions:

• The findings suggest a potential association between MCPyV and the development of MPNs, especially ET.
• Further research is warranted to elucidate the role of human polyomaviruses in megakaryocytic lineage biology and MPN pathogenesis.
• MCPyV may represent a novel etiological factor or cofactor in a subset of MPN patients.