Analysis of TaqMan Array Cards Data by an Assumption-Free Improvement of the maxRatio Algorithm Is More Accurate than the Cycle-Threshold Method

<div><p>Quantitative PCR diagnostic platforms are moving towards increased sample throughput, with instruments capable of carrying out thousands of reactions at once already in use. The need for a computational tool to reliably assist in the validation of the results is therefore compelling. In the present study, 328 residual clinical samples provided by the Public Health England at Addenbrooke's Hospital (Cambridge, UK) were processed by TaqMan Array Card assay, generating 15 744 reactions from 54 targets. The amplification data were analysed by the conventional cycle-threshold (CT) method and an improvement of the <i>maxRatio</i> (MR) algorithm developed to filter out the reactions with irregular amplification profiles. The reactions were also independently validated by three raters and a consensus was generated from their classification. The inter-rater agreement by Fleiss' kappa was 0.885; the agreement between either CT or MR with the raters gave Fleiss' kappa 0.884 and 0.902, respectively. Based on the consensus classification, the CT and MR methods achieved an assay accuracy of 0.979 and 0.987, respectively. These results suggested that the assumption-free MR algorithm was more reliable than the CT method, with clear advantages for the diagnostic settings.</p></div

Drug-Induced Colon Injury

Drug-induced injury of the colon is a relatively frequent though underestimated event. The histological manifestations are very variable and frequently mimic other disease entities with different etiologies. The pathologist should try to give to the clinician indications concerning a possible drug-related etiology of the injury, with a specification of the drug involved, if feasible. Careful clinicopatho-logical confrontation is important to distinguish drug-related injury from other diseases of the colon. The following section provides an overview of the different patterns that can be encountered in drug-induced colon injury, their relation to specific medications, and the possible differential diagnosis