Promoter methylation analysis of WNT/β-catenin signaling pathway regulators to detect adenocarcinoma or its precursor lesion of the cervix

OBJECTIVE

Cervical adenocarcinoma (AdCA) and adenocarcinoma in situ (ACIS) are frequently missed in cytology-based screening programs. Testing for high-risk human papillomavirus (hrHPV) improves their detection, but novel ACIS/AdCA specific biomarkers are needed to increase specificity for these lesions. Novel markers may be deduced from the WNT/β-catenin signaling pathway, which is aberrantly activated during cervical carcinogenesis.

METHODS

Promoter methylation of nine WNT-antagonists (APC, AXIN2, DKK3, SFRP2, SFRP4, SFRP5, SOX17, WIF1 and WNT5A) was evaluated by methylation-specific PCR (MSP) on a small series of cervical tissue specimens, including AdCA and SCC. To estimate the diagnostic potential of the genes most frequently methylated in AdCA an extended series of ACIS, AdCA, CIN3, SCC, and normal cervical tissue specimens (n=131) as well as 49 hrHPV-positive scrapings were analyzed by quantitative MSP (qMSP).

RESULTS

The frequency of DKK3 and SFRP2 methylation was significantly higher in AdCA compared to SCC, i.e. 82% vs. 18% (p<0.01) and 84% vs. 39% (p<0.01), respectively, while SOX17 methylation frequency was significantly higher in SCC than AdCA, i.e. 89% vs. 62% (p<0.05). Methylation of WIF1 was common in both AdCA (71%) and SCC (54%). Methylation frequencies ranged from 4% to 55% in precursor lesions and from 0% to 5% in normal biopsies. When tested on HPV-positive cervical scrapings, qMSP of the best ACIS/AdCA discriminator genes, i.e. DKK3 and SFRP2, detected all women with underlying ACIS/AdCA, compared to 3% of controls.

CONCLUSIONS

DKK3 and SFRP2 promoter methylation is highly indicative for the presence of ACIS/AdCA, thereby providing promising triage markers for HPV-positive women at risk of ACIS/AdCA.

Treatment assessment by monitoring parasite load in skin biopsies from patients with cutaneous leishmaniasis, using quantitative nucleic acid sequence-based amplification

BACKGROUND

Current diagnostic methods for cutaneous leishmaniasis (CL) have low sensitivity or are not useful for treatment follow-up. We previously described the quantitative nucleic acid sequence-based amplification (QT-NASBA) method as a sensitive and specific assay for detection and quantification of Leishmania parasites in skin biopsies. This assay could be a valuable instrument for monitoring response to treatment of CL and identifying treatment failures at an early stage.

AIM

QT-NASBA results of skin biopsies at the end and 6 weeks after treatment from patients with proven CL on various treatment regimens were compared with clinical outcome.

METHODS

The QT-NASBA assay measured the parasite load in skin biopsies before, at the end and 6 weeks after treatment. The results were compared with treatment outcome (clinical cure, delayed healing response or treatment failure) up to 6 months after treatment.

RESULTS

In total, 137 skin biopsies were obtained from 53 patients. A positive QT-NASBA result 6 weeks after treatment was significantly associated with treatment failure/delayed healing up to 6 months (P < 0.001). The positive predictive value (PPV) was 100% and the negative predictive value (NPV) was 92% (95% CI 82-100%). QT-NASBA results at the end of treatment and clinical outcome showed a less significant association (P < 0.05), with a PPV of 46% (95% CI 16-75% and an NPV of 89% (95% CI 79-99%).

CONCLUSIONS

The QT-NASBA assay is a useful instrument to monitor parasite load in skin biopsies of patients with CL 6 weeks after treatment and can help to predict clinical outcome.

Diagnosis of canine leishmaniasis in the endemic area of Belo Horizonte, Minas Gerais, Brazil by parasite, antibody and DNA detection assays

Canine leishmaniasis caused by Leishmania chagasi (L. infantum) is found throughout the South American continent, including Brazil, and dogs are considered to be the main reservoir host for this parasite. To support the implementation of a diagnostic protocol for surveillance of the disease in the region of Belo Horizonte (Minas Gerais, Brazil) we have compared the sensitivity and specificity of two serological tests, indirect immunofluorescent antibody test (IFAT) and direct agglutination test (DAT), with the combination of direct microscopy-culture-PCR as the gold standard, using samples obtained from 103 dogs in the city of Belo Horizonte, Minas Gerais. The currently used standard serodiagnostic test, IFAT, had a sensitivity of 100% and its specificity was 74% compared to the gold standard of the study. The sensitivity and specificity of the DAT were 100% and 91%, respectively. On the basis of this study it is recommended to change from the IFAT to DAT for the serodiagnosis of canine leishmaniasis because of the superior specificity of the test combined with its user-friendliness.

Quantification of the response to miltefosine treatment for visceral leishmaniasis by QT-NASBA

A male patient with psoriatic arthritis and visceral Leishmania infantum infection was treated with oral miltefosine 50 mg three times a day for 4 weeks at the Academic Medical Center, Amsterdam, The Netherlands. Miltefosine plasma concentrations were measured with liquid chromatography/mass spectrometry. The parasite load was followed by quantitative nucleic acid sequence-based amplification (QT-NASBA) assay in blood. Miltefosine elicited a prompt therapeutic effect. After an initial worsening of symptoms and an increase of QT-NASBA values during the first week, recovery was rapidly achieved. QT-NASBA values declined exponentially and were negative after 6 weeks. Miltefosine plasma concentrations continued to accumulate during the 4 weeks of treatment. The terminal elimination half-life was 14.8 days.