Nucleic Acid Quality Assessment is Critical to the Success of the Oncomine Dx Target Test for Lung Cancer.

BACKGROUND AND OBJECTIVE: The Oncomine Dx Target Test (ODxTT) has been used as a companion diagnostic test for lung cancer. Here, we evaluated whether the amount of nucleic acid and the degree of RNA degradation are related to the success of the ODxTT. METHODS: This study included 223 samples from 218 patients with lung cancer. For all samples, DNA and RNA concentrations were quantified using Qubit, and the degree of RNA degradation was evaluated using the Bioanalyzer. RESULTS: Of the 223 samples, 219 samples were successfully analyzed in the ODxTT and four were not. DNA analysis failed in two samples, which were attributed to low DNA concentrations and both were cytology specimens. Meanwhile, RNA analysis failed in the other two samples. These samples had sufficient amounts of RNA, but it was highly degraded with DV200 (the percentage of RNA fragments > 200 base pairs) less than 30. Compared with RNA samples with DV200 ≥ 30, analysis of RNA with DV200 < 30 yielded significantly fewer reads for the internal control genes. This test showed actionable mutations were identified in 38% (83/218) of all patients and in 46.6% (76/163) of patients with lung adenocarcinoma. CONCLUSIONS: DNA concentration and degree of RNA degradation are key factors determining the success of diagnostic testing by the ODxTT.

[Recurrent idiopathic cerebral infarction in a 5-year-old boy, with emphasis on the importance of platelet aggregation analysis for appropriate selection of anti-platelet drugs].

We present a 5-year-old boy with recurrent idiopathic cerebral infarction in which analysis of platelet hyperaggregability was useful in choosing appropriate anti-platelet drugs. The patient presented with gait disturbance at the age of 5 years and 1 month. Brain MRI demonstrated multiple infarctions in the right thalamus and left cerebellum. There were no apparent underlying diseases including hematological, cardiac and vascular abnormalities. He was diagnosed as idiopathic cerebral infarction. First, we administered ticlopidine and he remained stable with persistent mild intention tremor in the left upper extremity for 4 months. Then he developed the second stroke at the age of 5 years and 5 months, and multiple infarctions in the right celebellum and cerebellar vermis were demonstrated. On platelet aggregation analysis, adenosine diphosphate (ADP)-induced aggregation was inhibited, probably due to ticlopidine administration. Collagen- and epinephrine-induced platelet aggregation showed hyperaggregation, so we started to administer cilostazol, which inhibits only epinephrine-induced hyperaggregation. We also added aspirin, which inhibits collagen-induced hyperaggregation. The combination of anti-platelet drugs inhibited epinephrine-, collagen- and ADP-induced hyperaggregation in this patient. He has been stable on the triple combination of anti-platelet drugs without further episodes of cerebral infarction or transient ischemic attack for 4 years to date. Appropriate selection of anti-platelet therapy was achieved by the simple and repeatable platelet aggregation analyses, which must be considered even in pediatric patients with cerebral infarction.