Chronic Lymphocytic Leukemia (CLL) is a malignant disease which usually affects mid-aged men and women. It has drawn significant academic efforts from scientist who had engaged in drastic measures to invent new methods of treatment. The most critical issue is lower rates of specificity of drugs to non-cancerous cells, which makes early diagnosis of cancer vital to the long life of patients. Specifically, early diagnosis of mutation in DNA would contribute to treatment significantly.
Dr. Ali Asghar Ensafi, the head of research group, provided some detail about the research; “electrochemical diagnostic methods presents advantages over other methods; it is highly sensitive and cheaply carried out,” he added. “A bio-sensor capable of diagnosis and distinguishing between these two types of CLL was reported. The biosensor was developed by modifying a gold electrode with gold nanoparticles (AuNPS) followed by coating of ZAP70 oligonucleotide probe on the surface to detect specific sequence of ZAP70 gene. ZAP70 could predict the IgVH mutation status and is a good marker for differentiating Ig-mutated and Ig-unmutated CLL and serve as prognostic marker,” he said further.
“We focused on achieving hybridization between probe and its complementary sequence. Hybridization between probe and target was determined with electrochemical impedance spectroscopy (EIS). Then, our efforts turned to optimize the conditions for the detection of any point mutation and also to maximize the selectivity,” said the researcher.
“In chronic lymphocytic leukemia (CLL), the immunoglobulin heavy-chain variable (IgVH) region may be mutated (Ig-mutated CLL) or unmutated (Ig-unmutated CLL); and the presence or absence of mutations in this region of CLL cells distinguishes two clinically distinct forms. It is important for physicians to distinguish between patients with Ig-unmutated CLL, where typically have more indolent disease with median survivals close to 25 years, and Ig-mutated CLL, where have more aggressive disease with median survivals around eight years,” Ensafi further detailed.
“Experimental results illustrated that the nanostructured biosensor clearly discriminates between mutated and non-mutated CLL and predict the IgVH mutation status, which it has been considered as the single most informative stage independent prognostic factor in CLL,” he concluded.
The report of this research was published as ‘A novel diagnostic biosensor for distinguishing immunoglobulin mutated and unmutated types of chronic lymphocytic leukemia’ in Biosensors and Bioelectronics, Volume 77, 15 March 2016, Pages 409–415, accessed (abstract) here.
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