Ildikó Márton

Progressive increase of human papillomavirus carriage rates in potentially malignant and malignant oral disorders with increasing malignant potential

INTRODUCTION We investigated the potential role of human papillomaviruses (HPVs) in potentially malignant oral disorders, oral leukoplakia (OL) and oral lichen planus (OLP), and in oral squamous cell cancer (OSCC) in an Eastern Hungarian population with a high incidence of OSCC. METHODS Excised tumor samples (65 OSCC patients) and exfoliated cells from potentially malignant lesions (from 44 and 119 patients with OL and OLP, respectively) as well as from healthy controls (72 individuals) were analysed. OLPs were classified based on clinical appearance, 61 patients had erosive-atrophic lesions (associated with higher malignancy risk, EA-OLP) and 58 had non-erosive non-atrophic lesions (with lower risk of becoming malignant, non-EA-OLP), respectively. Exfoliated cells collected from apparently healthy mucosa accompanied each lesion sample. HPV was detected by MY/GP polymerase chain reaction (PCR) and genotyped by restriction analysis of amplimers. Copy numbers in lesions were determined using real-time PCR. Prevalence rates, copy number distributions, and association with risk factors and diseases were analysed using chi-square test, t-test, and logistic regression, respectively. RESULTS We detected HPVs significantly more frequently in lesions than in controls (P < or = 0.001 in all comparisons). HPV prevalence increased gradually with increasing severity of lesions (32.8, 40.9, and 47.7% in OLP, OL, and OSCC, respectively). Copy number distribution patterns roughly corresponded to prevalence rates, but OLP and OL were comparable. HPV prevalence differed significantly between EA-OLP and non-EA-OLP groups (42.6 vs. 22.4%); EA-OLP group showed a prevalence similar to that found in OL. CONCLUSION HPVs may be involved in the development or progression of not only OSCC but also of potentially malignant oral lesions.

Overlapping Protective and Destructive Regulatory Pathways in Apical Periodontitis

INTRODUCTION Protective and destructive immunoreactions take place simultaneously in apical periodontitis. However, the same reactions defending the periapical area from infection-derived damage may also result in host tissue injury. METHODS The inflammatory reaction of the periapical tissues is self-limited. Regeneration of the injured tooth-supporting structures may follow elimination of the causative microbial irritation. RESULTS Recent experimental and clinical observations have identified important interplay between positive and negative regulatory pathways. A network of stimulatory and inhibitory feedback loops may influence the intensity of the defense and inflammatory responses and the balance between bone resorption and regeneration, resulting in lesion expansion or healing of apical periodontitis. CONCLUSIONS We critically discuss research data on regulatory mechanisms that control the activity of host effector cells and signaling molecules during interactions with pathogenic microbes.

Prevalence and Activity of Epstein-Barr Virus and Human Cytomegalovirus in Symptomatic and Asymptomatic Apical Periodontitis Lesions

INTRODUCTION Apical periodontitis is a polymicrobial inflammation with a dominant flora of opportunistic Gram-negative bacteria; however, a pathogenic role of human herpesviruses such as Epstein-Barr virus (EBV) and human cytomegalovirus (HCMV) has been implicated recently. The aims of this study were to determine the prevalence, activity, and disease association of EBV and HCMV in apical periodontitis in an Eastern Hungarian population. METHODS Forty samples with apical periodontitis (17 symptomatic and 23 asymptomatic) and 40 healthy pulp controls were collected. EBV and HCMV prevalences were measured by polymerase chain reaction (PCR) detection of the viral DNA and viral activity was tested by reverse-transcription PCR amplification of viral messenger RNA. RESULTS EBV DNA and EBNA-2 messenger RNA were found in apical periodontitis lesions at significantly (p < 0.0001) higher frequencies (72.5% and 50%, respectively) than in controls (both 2.5%). The occurrence of HCMV infection was rare in both apical lesions (10%) and controls (0%). The presence of EBV DNA in apical lesions was associated significantly with large (> or = 5 mm) lesion size (p = 0.02) but not with symptoms (p = 0.30). Symptomatic manifestation was significantly associated with the co-occurrence (odds ratio [OR], 8.80; 95% confidence interval [CI], 1.69-45.76) but not the sole occurrences of EBNA-2 messenger RNA (OR, 2.29; 95% CI, 0.48-11.06) and large lesion size (OR, 4.02; 95% CI, 0.81-19.89). CONCLUSION EBV infection is a frequent event in apical periodontitis, whereas the involvement of HCMV still remains to be elucidated. This study showed that symptomatic manifestation was likely to occur if a large-sized apical periodontitis lesion is aggravated with active EBV infection.

Significance of oral Candida infections in children with cancer

Candidiasis is common in children with cancer, particularly during periods of severe immunosuppression and neutropenia. Our aim was to study the microbiological changes in the oral cavity of children with newly diagnosed cancer. The study group consisted of 30 consecutive children and adolescents, 16 with acute lymphoblastic leukemia and 14 with solid tumors. Oral cultures to detect fungi and bacteria were conducted for all patients before treatment, during and after neutropenic episodes. In 23 patients developing fever simultaneous throat, urine and blood sampling was carried out. No pathogens were found in the cultures taken before the outset (30 cultures) or after recovery from (30 cultures) the neutropenic episodes. In the 45 oral cultures taken during the neutropenic episodes 38 (84.4%) proved positive. Fungi were the most frequently isolated oral pathogens: 33/38 yeast and 6/38 bacterial infections were identified. There was no association between the underlying malignancy and the occurrence of the positive cultures. Of the 30 patients, all 23 (76.7%) who have developed moderate-to-severe neutropenia, developed oral fungal colonization or clinically obvious fungal infection at least on one occasion during the study. In addition to oral samples, fungi were identified in 9/23 pharyngeal swabs, 6/23 urine and 1/23 blood cultures. The initial fungal pathogen was exclusively (33/33)Candida albicans. In extended severe neutropenic states,C. albicans was replaced by non-albicans species (C. kefyr, C. lusitaniae, C. sake, C. tropicalis) in 5 patients between 4 to 6 days of the neutropenic episodes. Four of the nonalbicansCandida strains were resistant to azole-type antifungal agents. Neutropenic episodes of children with cancer are associated with an increased risk of developing oral and even systemic infections withC. albicans that can be replaced by azole-resistant nonalbicans strains in prolonged neutropenia contributing to morbidity of these patients.

High co-prevalence of genogroup 1 TT virus and human papillomavirus is associated with poor clinical outcome of laryngeal carcinoma

Background: The aetiology and factors leading to the progression of laryngeal cancer are still unclear. Although human papillomavirus (HPV) has been suggested to play a role, reports concerning the effect of HPV infection on tumour development are controversial. Recently, transfusion transmitted virus (TTV) was suggested to play a role in certain infections as a causative or coinfecting agent. Aims: To investigate whether the development and progression of laryngeal squamous cell carcinoma is associated with coinfection with TTV and HPV. Methods: The prevalence of TTV and HPV was investigated using the polymerase chain reaction in tissue samples from 40 healthy individuals, 10 patients with recurrent papillomatosis, five patients with papillomatosis with malignant transformation, and 25 patients with laryngeal carcinoma. The obtained prevalence data were compared and analysed statistically. Results: In the 11 patients with carcinoma who had metastasis or relapse there was a high rate of coinfection with genogroup 1 TTV and HPV (eight of 11), whereas in the 14 without tumour progression no coinfection was found. Coinfection was associated with significantly lower tumour free survival in patients with carcinoma (p < 0.001). Furthermore, four of five patients who had papillomatosis with malignant transformation were coinfected with genogroup 1 TTV and HPV. Conclusions: Although the nature of cooperation between HPV and TTV needs to be investigated further, coinfection with genogroup 1 TTV and HPV appears to be associated with poor clinical outcome in laryngeal cancer.

Role of pathogenic oral flora in postoperative pneumonia following brain surgery

BackgroundPost-operative pulmonary infection often appears to result from aspiration of pathogens colonizing the oral cavity. It was hypothesized that impaired periodontal status and pathogenic oral bacteria significantly contribute to development of aspiration pneumonia following neurosurgical operations. Further, the prophylactic effects of a single dose preoperative cefazolin on the oral bacteria were investigated.MethodsA matched cohort of 18 patients without postoperative lung complications was compared to 5 patients who developed pneumonia within 48 hours after brain surgery. Patients waiting for elective operation of a single brain tumor underwent dental examination and saliva collection before surgery. Bacteria from saliva cultures were isolated and periodontal disease was scored according to type and severity. Patients received 15 mg/kg cefazolin intravenously at the beginning of surgery. Serum, saliva and bronchial secretion were collected promptly after the operation. The minimal inhibitory concentrations of cefazolin regarding the isolated bacteria were determined. The actual antibiotic concentrations in serum, saliva and bronchial secretion were measured by capillary electrophoresis upon completion of surgery. Bacteria were isolated again from the sputum of postoperative pneumonia patients.ResultsThe number and severity of coexisting periodontal diseases were significantly greater in patients with postoperative pneumonia in comparison to the control group (p = 0.031 and p = 0.002, respectively). The relative risk of developing postoperative pneumonia in high periodontal score patients was 3.5 greater than in patients who had low periodontal score (p < 0.0001). Cefazolin concentration in saliva and bronchial secretion remained below detectable levels in every patient.ConclusionPresence of multiple periodontal diseases and pathogenic bacteria in the saliva are important predisposing factors of postoperative aspiration pneumonia in patients after brain surgery. The low penetration rate of cefazolin into the saliva indicates that its prophylactic administration may not be sufficient to prevent postoperative aspiration pneumonia. Our study suggests that dental examination may be warranted in order to identify patients at high risk of developing postoperative respiratory infections.

Elevated tumor necrosis factor-alpha expression in periapical lesions infected by Epstein-Barr virus.

INTRODUCTION In apical periodontitis, there is an intense inflammatory response to endodontopathogenic bacteria, an essential component of the pathogenic microbiota. The inflammation can be aggravated by herpesviruses acting as nonessential pathogens in periapical lesions. This study aimed to determine the levels of tumor necrosis factor-alpha (TNF-α) and transforming growth factor-beta (TGF-β) in periapical lesions in relation to local occurrence of Epstein-Barr virus (EBV), human cytomegalovirus (HCMV), human herpesvirus 6 (HHV-6), and human herpesvirus 8 (HHV-8). METHODS Fifty-eight samples with apical periodontitis and 20 clinically healthy gingival control tissues were collected. Viral DNA was determined with nested polymerase chain reaction, and cytokine mRNA expression was detected with real-time polymerase chain reaction assays. RESULTS Periapical lesions harbored EBV (75.9%) and HHV-6 (22.4%) at significantly higher frequencies compared with controls (P < .000001 and P < .05, respectively), whereas HCMV (12%) and HHV-8 (0%) occurred rarely. The median TNF-α expression was 13 times higher (P < .001) and TGF-β expression was 5 times higher in periapical lesions than in controls (P < .001). TNF-α expression was significantly higher in EBV-positive lesions than in EBV-negative lesions (P = .032). Presence of symptoms, lesion size, and infection by HCMV or HHV-6 had no significant association with either TNF-α or TGF-β expression. CONCLUSIONS The herpesviral component of the endodontic microbiota did not correlate with TGF-β expression, whereas EBV infection was associated with a median 1.5 times further elevation of the high TNF-α expression characteristic for periapical lesions.

Human Herpesvirus 8 in Hematologic Diseases

Human herpesvirus type 8 (HHV-8), also known as Kaposi’s sarcoma-associated herpesvirus (KSHV) is a new member of the γ-herpesvirus family. It is an unusual herpesvirus in that it carries a large number of genes that encode oncoproteins or cell signaling proteins. In addition to being the causative agent of both HIV-associated and non-HIV-associated Kaposi’s sarcoma this DNA tumor virus has been implicated in the pathogenesis of several diseases. These include multiple myeloma (MM), Waldenström’s macroglobulinemia (WM), multicentric Castleman’s disease (MCD), body cavity-based lymphoma (BCBL), and various other conditions such as sarcoidosis and pemphigus. While the causative role of the viral infection is fairly certain in the development of BCBL and multicentric Castleman’s disease, HHV-8 may act through a different mechanism to induce plasma cell malignancies. It has been suggested - though the finding is still controversial -that infection of bone marrow stromal dendritic cells by HHV-8 might be a key factor in the etiology and pathogenesis of monoclonal gammopathies. The aim of this review is to provide a short introduction into the tumorigenic potential of HHV-8 as well as to detail the available data and possible mechanisms on the involvement of this virus in different hematologic diseases.

Expression and immune recognition of SV40 Tag in transgenic mice that develop metastatic osteosarcomas

Mature adult mice of the C57BL/6-TgN(Amy1TAg)501Knw transgenic mouse lineage, 501, containing a liver α-amylase promoted-SV40 Tag hybrid gene, routinely develop SV40 Tag-induced metastatic osteosarcomas. This form of α-amylase was known to be expressed in the liver, salivary glands, pancreas, and fat. Cells in the normal rib adjacent to the periosteum also express α-amylase suggesting that transgene expression is correctly targeted to generate osteosarcomas. 501 mice express SV40 Tag in the salivary glands but do not develop abnormalities in these organs by the time of their death from SV40-induced osteosarcomas. Mice of the C57BL/6 strain make a strong and effective anti-tumor immune response to SV40 Tag immunization. However, immunization of 501 mice with SV40 Tag early in life does not alter or prevent SV40 Tag-induced osteosarcomagenesis. 501 mice mount a significantly less effective cytotoxic T-lymphocyte response following SV40 Tag immunization while 501 osteosarcoma-derived cells are fully susceptible to SV40 Tag-specific T-cell lysis. This suggests that partial tolerance, not loss of antigen presentation by tumor cells, characterizes this mouse model of endogenous bone tumor development. To determine whether the immune recognition of endogenous SV40 Tag could influence tumorigenesis, the metastatic potential and time of death from tumor was investigated in CD4-null mutant 501 mice and β-2 microglobulin-null mutant 501 mice. The size and number of metastases in these strains and longevity of these strains varied. We suggest that components of both the innate and adaptive immune response control tumor appearance and progression.

Oral health of long‐term childhood cancer survivors

As survival rate of children with cancer improved considerably during the past decades, late effects of antineoplastic therapy gained an increasing importance. Oral and dental care seem to be neglected areas resulting in considerable impairment of quality of life in adolescents and young adults cured from cancer. Even literature data surveying oral and dental status of childrenwith preceding neoplastic and hematologic disease are sparse. Here we report on the oral and dental status of longterm cancer survivors followed-up at the Outpatient Hematology-Oncology Clinic of the Department of Pediatrics, University of Debrecen, Medical and Health Science Center (UDMHSC). Forty-five children in long-term remission, previously treated for neoplastic diseases at the Division of Hematology-Oncology, Department of Pediatrics, UDMHSC were included into the study. The survey was performed in the Institute of Dental Sciences of the UDMHSC. Of the 45 patients, 25 boys and 20 girls, aged 4–25 years (mean 12.9 years), were examined. At the time of diagnosis, the age ranged from 1 to 22 years (mean 6.9 years). Mean survival time was 1–14 years (mean 5.9 years) at the time of the survey. The underlying diseases were 23/45 acute lymphoblastic leukemia, 5/45 acute myeloblastic leukemia, and 17/45 solid tumors. Patients were treated according to standard protocols as accepted by the Hungarian Pediatric Oncology Group (HPOG). In course of the combined cytotoxic treatment, out of 28 patients (ALL, AML) 13 received cranial irradiation (12 and 18 Gy, respectively) in addition to chemotherapy; while out of 17 patients (solid tumors), 11 received additional irradiation (18–40 Gy). The irradiation field of solid tumor patients did not involve the cranium. For each patient, an age and sex-matched control was chosen randomly from kindergarden and school children of similar socio-economic background attending at the Department of Pediatric Dentistry, MHSCUD. Oral and dental status, including X-ray imaging, was assessedwith informed consent. TheDMF numeric scores are generally accepted in the stomatologic literature to quantify the extent of dental disorders [1]. The scores represent the total number of decayed (D), missing (M) or filled (F) permanent teeth (DMF-T) and, allowing a more precise evaluation of dental status, the tooth surfaces (DMF-S). Of these indices, we used the combined DM scores (i.e., the number of decayedþmissing teeth/ surfaces within the denture of a proband) and F scores characteristic for dental pathology and treatment, respectively. In addition to the numeric score system, we also recorded congenital and acquired oral and dental malformations. DMandF data points did not follownormal distribution as checked with Kolmogorov–Smirnov test, therefore, we used nonparametric tests for the further statistical analysis of our data. Differences and correlations were considered significant if P-values were below 0.05. Before testing the difference of DM and F indexes of teeth and surface between patient and control group, we investigated the effect of age to these differences. We found strong and statistically significant, positive correlation between age and the DM differences (Spearman correlation, Corr1⁄4 0.463, P< 0.003 for teeth, Corr1⁄4 0.523, P< 0.001 for surface). To control for this effect of age, we created three age groups: 4–11, 12–15, and 16– 25 years. To check the relevance of these age intervals, we