Volume 25, Number 8—August 2019
Research Letter
No Evidence for Role of Cutavirus in Malignant Melanoma
, Steffi Silling, Martin Hufbauer, Cornelia Mauch, Paola Zigrino, Frank Oellig, Alexander Kreuter, and Baki Akgül
Table
Cutavirus DNA detection and DNA load in cutaneous malignant melanomas, melanoma metastases, and forehead swabs of healthy nonlesional skin from persons in Germany*
| Sample type | No. samples analyzed | No. cutavirus DNA–positive samples† (%; 95% CI) | Median cutavirus DNA load (IQR)‡ |
|---|---|---|---|
| Malignant melanoma tumor biopsies§¶ | 185 | 2 (1.1; 0.3–3.9) | 0.30; 2.82# |
| Malignant melanoma metastases§** | 52 | 0 (0; 0–6.9) | NA |
| Skin swabs of HIV-positive men§ | 205 | 35 (17.1; 12.5–22.8) | 0.33 (0.66–3.81) |
| Skin swabs of healthy male controls§ | 237 | 9 (3.8; 2.0–7.1) | 2.31 (0.19–11.72) |
*Bold type indicates statistical significance. IQR, interquartile range; NA, not applicable.
†All samples were analyzed with CUTA-UPL5 real-time PCR as described in the Appendix. The formalin-fixed paraffin-embedded (FFPE) biopsies (melanomas and metastases) were also analyzed with 2 different real-time PCRs targeting the cutavirus nonstructural 1 gene (Appendix). These PCRs did not detect further cutavirus DNA–positive biopsies.
‡Cutavirus DNA load was determined in all cutavirus DNA–positive samples and was defined as cutavirus DNA copies per β-globin gene copy.
§Details of the biopsies and skin swab specimens are provided in the Appendix.
¶From 21 cutavirus DNA–negative malignant melanomas, fresh frozen tissue could be analyzed in addition to the FFPE tissue samples (CUTA-UPL5-PCR). Cutavirus DNA was not detected in any of the 21 fresh frozen tissue samples. The cellular input of the fresh frozen tissue samples ranged from 1,230 to 40,600 β-globin gene copies per 2 μL extracted DNA (median 8,330, mean 10,892), indicating a high cellular input.
#Shown here are the viral DNA loads found in the 2 cutavirus DNA–positive nodular malignant melanomas, MM-A and MM-B.
**For 6 of the melanoma metastases, the primary tumor was also analyzed and was cutavirus DNA negative. The 2 patients with cutavirus DNA–positive melanoma biopsies (MM-A and MM-B) did not have metastatic disease.