Top-level MET gene copy number gain defines a subtype of poorly differentiated pulmonary adenocarcinomas with poor prognosis.

BACKGROUND: MET amplifications occur in human tumors, including non-small cell lung cancer (NSCLC). MET inhibitors have demonstrated some clinical activity in MET amplified NSCLC, presumably with a gene dose effect. However, the definition of MET positivity or MET amplification as a potential oncogenic driver is still under debate. In this study, we aimed to establish the molecular subgroup of NSCLC with the highest unequivocal MET amplification level and to describe the prevalence, and histologic and clinical phenotype of this subgroup. METHODS: A total of 373 unselected patients with NSCLC were consecutively tested for MET gene copy number (GCN) by FISH. Mean GCN, MET/CEN7 ratio and other FISH parameters were identified and correlated with morphological and molecular pathological characteristics of the tumors as well as with clinical data. RESULTS: Based on the variability of obtained data a top-level category of MET amplification was newly defined (>90th percentile of average GCN; ≥10 MET gene copies per tumor cell). This criterion was fulfilled in 2% of analyzed tumors. These tumors were exclusively poorly differentiated adenocarcinomas with a predominant solid subtype and pleomorphic features. Rarely, co-alterations were detected (KRAS mutation or MET exon 14 skipping mutation). In this top-level group, there were no EGFR mutations or ALK or ROS1 alterations. The most important clinical feature was a significantly shortened overall survival (HR 3.61; median OS 8.2 vs. 23.6 months). Worse prognosis did not depend on initial stage or treatment. CONCLUSIONS: The newly defined top-level category of MET amplification in NSCLC defines a specific subgroup of pulmonary adenocarcinoma with adverse prognosis and characteristic morphological features. Lower levels of MET gene copy number seem to have probably no specific value as a prognostic or predictive biomarker.

Improved diagnosis of gestational parvovirus B19 infection at the time of nonimmune fetal hydrops.

BACKGROUND: In the diagnosis of parvovirus B19 infection, the detection of virus-specific IgG in the absence of virus-specific IgM is considered to indicate past immunity. METHODS: We determined the diagnostic value of a high-quality B19 IgM EIA, compared with that of a VP1 IgG avidity EIA, a VP2 IgG epitope-type specificity (ETS) EIA, and real-time polymerase chain reaction (PCR) in the diagnosis of maternal B19 infection during nonimmune fetal hydrops. RESULTS: Serum samples from 101 pregnant women with confirmed B19-induced fetal hydrops were collected at the time of invasive prenatal diagnosis. The samples were investigated for B19 IgM, VP1 IgG avidity, and VP2 IgG ETS. With the B19 IgM EIA, 78 women (77.2 %) showed positive results, 15 (14.9%) showed negative results, and 8 (7.9 %) showed equivocal results. According to the combined B19 IgG avidity and IgG ETS EIA results, only 5 (5%) of 101 women were classified as having past immunity. Available serum samples (n = 24) that had nondiagnostic results in the antibody assays were further investigated by PCR. All were B19 DNA positive (mean load, 2.5 x 10(4) genome equivalents/mL; range, 2.5 x 10(3) - 7.8 x 10(6)). CONCLUSIONS: At the time of B19-induced hydrops, detection of B19 DNA in maternal blood had the best diagnostic sensitivity for identifying maternal B19 infection. However, given the long persistence of B19 DNAemia, supplementary measurement of VP1 IgG avidity and VP2 IgG ETS improves the precision of diagnosis and management of pregnant women affected by the B19 virus.

Roche AMPLICOR human papilloma virus (HPV) and LINEAR ARRAY HPV tests will profit from automated DNA extraction.

BACKGROUND: Persistent infection with high risk human papillomavirus (HR-HPV) types is at the origin of cervical cancer in women and HPV-genotyping is considered to be a valuable tool for risk stratification. Its diagnostic relevance will further increase in the context of HPV vaccination which covers the HR-HPV types 16 and 18 only. For rapid screening and genotyping the commercial Roche AMPLICOR and the Roche LINEAR ARRAY (LA) HPV PCR tests are available. However, the manual DNA extraction procedure recommended by the manufacturer is time-consuming and labor-intensive. To improve workflow we evaluated automated DNA extraction by the MagNA Pure LC (MP-LC). CONCLUSION: The AMPLICOR and the LA HPV tests perform equally well with both extraction methods. The MagNA Pure LC provides an automated alternative for processing HPV clinical specimens coupled with the Roche AMPLICOR and LA HPV tests.