“Ultrasensitive Reactive C-Protein As an Affordable Biomarker of Quantitative Expression of the BCR-ABL Transcript in Chronic Myeloid Leukemia. an Exploratory Study.”

Abstract

INTRODUCTIONReal-time PCR (PCRq) quantification of the BCR-ABL transcript is the most reliable response marker in Chronic Myeloid Leukemia (CML), its levels have proven prognostic implications. However, in some centers it is still a difficult diagnostic tool to access. The ultrasensitive C reactive protein (pcrU) is an exquisite marker of inflammation and contextually the increased activity of the BCR-ABL transcript is associated with an inflammatory state mediated among others by IL-6. Here we explore the association between the molecular response (RM) induced with Imatinib mesylate and the serum levels of pcrU as a possible biomarker of leukemic activity.OBJECTIVETo explore the association between the quantitative expression of the BCR-ABL transcript and the serum levels of pcrU by turbidimetry.PATIENTS AND METHODS15 patients with CML were studied, in 14 of them the BCR-ABL transcript was determined after 1 year of treatment by PCRq together with the serum levels of pcrU, any inflammatory state present during the sampling was ruled out. As a control 1 patient was studied at diagnosis as described.RESULTSThere is a significant concordance between molecular status and serum levels of pcrU in 13 of the 15 patients studied (87% true negatives and 13% false positives). Table 1. When the diagnostic test was performed to evaluate pcrU as a possible MRI biomarker, we observed that it presents a sensitivity of 100%, specificity 84.6% (in an area under the curve of 93%), Positive Predictive Value (PPV) 50% and Negative Predictive Value (NPV) 100%. The probability index (+) = 6.5 (IC95%: 1.8 to 23.2), while the probability index (-) = 0.DISCUSSIONThe inflammation promoted by the tumor and the escape of the immunologically mediated tumor destruction, have been recognized as the hallmark of cancer and the myeloid cells are key players in this process. Therefore, the detection of an ultrasensitive biomarker of inflammation theoretically has the potential to detect leukemic activity. In this exploratory study a remarkable association was found between the molecular status and the levels of pcrU, making an extension of this study a goal to be pursued. DisclosuresBest:Novartis: Consultancy; AbbVie: Consultancy. Gomez-Almaguer:AbbVie: Consultancy; Novartis: Consultancy.