Background Cervical cancer is the second most common cancer in women worldwide. Nearly all cases of cervical cancer can be attributable to HPV infection. SLE patients have a higher risk of presenting HPV infection and a higher incidence of cervical dysplasia. Recently, immunosuppressive therapy of SLE patients has been related with diminished NK cell levels and an enhanced risk for HPV infection. However, the association between different immune parameters and cervical HPV infection has not been explored in SLE patients.
Objectives The aim of the study was to assess the possible association among cervical HPV infection, levels of lymphocyte subsets and NK receptor expression in SLE patients.
Methods We have conducted a pilot study that included 15 patients that fulfilled the proposed criteria of the ACR for the classification of SLE. Disease activity was measured using SLEDAI, Patients under immunosuppressive therapy were receiving prednisone (4.65±1.55 mg/day), mycophenolate mofetil (0.5 and 1g/day) and methotrexate (2.07±0.69 mg/day). No patients under biological agent treatment were included in this study. Age and gender matched healthy volunteers were also included as a control group. Patients and controls were subjected to conventional colposcopic evaluation. Cervical scrape specimens were collected from endocervix, transported in a liquid preservative solution and used for HPV DNA detection by PCR. Peripheral blood mononuclear cells (PBMC) were isolated from all individuals and the lymphocytes subsets were analyzed by flow cytometry using the following mAbs: isotype-matched negative controls, anti-CD3, -CD4, -CD8, -CD19 and -CD56. For the detection of NK cell receptors expression, three-color flow cytometric analysis was performed by labeling PBMC with mAbs anti-CD56, anti-CD3 and anti-NKp30, -NKp46, -NKG2A, -NKG2D, -CD16 or -ILT2.
Results Women included in the study were classified in three groups: 1) SLE patients without HPV infection (SLE), 2) SLE patients with HPV infection (SLE+HPV), and 3) Healthy controls. We found significantly higher levels of CD4+ T cells in SLE+HPV patients compared with healthy controls (p=0.0039). It is worth mention that these patients had active disease. Similar frequencies of CD8+ T cells, B lymphocytes and NK cells were observed in the three groups studied. No differences were observed regarding the expression of the NK cell receptors analyzed.
Conclusions Our data suggest that levels of CD4+ T cells are markedly increased in SLE patients infected with HPV compared with healthy controls. Despite this fact, the impaired cellular response observed in SLE patients might contribute to increase the risk of HPV infection. In addition, high inflammatory burden observed in patients with active disease might also contribute to the risk of acquiring HPV infection. Because a small number of patients were included a larger prospective study is needed to confirm these preliminary results.
Baranda L. et al.Decreased blood levels of B Lymphocytes and NK cells in patients with SLE infected with HPV.Arch Dermatol Res 2013;305:117.
Disclosure of Interest None declared