Sir,In the era following accomplishment of the “Human Genome Project,” molecular diagnostics has been steadily expanding. The driving force behind this rapid expansion could be the need for specific and rapid identification, a first-ranking priority for the treatment and eradication of infectious diseases. Availability of a wide range of modern molecular diagnostic tools, including genomic, proteomic and cytomic technologies, has made clinicians emphasize evidence-based diagnostics. Molecular diagnostics has been extremely successful in the area of infectious diseases, where nucleic acid identification and bacterial and viral genotyping have made rapid progress. Though presently in an embryonic stage, molecular diagnostics has confirmed its usefulness and is likely to provide further major breakthroughs into clinical practice of infectious biology.We examined 1,739 samples, referred to our center during the period January 2004 to March 2010, through quantitative polymerase chain reaction (PCR). A total of 688 samples were screened for hepatitis B virus (HBV); 325 samples, for hepatitis C virus (HCV) RNA; and 726 subjects, for the presence of Mycobacterium tuberculosis complex (MTBC). A higher prevalence of sero-negative pattern, but positive for HBV-DNA, HCV-RNA and reactive MTBC-DNA in gastrointestinal tuberculosis by quantitative PCR was observed, indicating occurrence of occult infections among the subjects [Table 1]. This prompted us to undertake in-depth immunological and molecular characterization of these cases to rule out any false-positive apprehensions.
Table 1
Results of quantitative polymerase chain reaction
Results of quantitative polymerase chain reactionExploring information from the complex interaction of host cellular DNA damage response machinery with viral infection, accumulation of phospho-H2AX foci in peripheral lymphocytes as an early biomarker for characterization of occult viral hepatitis has been proposed.[1] Besides, by applying a novel probe technology based on fluorescence resonance energy transfer (FRET) hybridization, we could characterize the host immune response to HCV genotypes and at the same time delineate the role of occult HCV infection in liver biopsies of patients with cryptogenic cirrhosis who are at increased risk of developing hepatocellular carcinoma.[23] Given the insidious course of, and clinical impediments in treating, gastrointestinal tuberculosis (GITB), we developed a novel combinatorial diagnostic approach for rapid detection and characterization of GITB that not only illustrates increased diagnostic accuracy but also signifies the importance of these molecular assays for better disease management and patient survival.[45] However, to pave the way for successful translation of our findings from bench to bedside, a larger sample size is a requisite.Laboratory research has always provided new technologies and will continue to be the foundation for advances in molecular diagnostics. With time, molecular diagnostics will continue to evolve; not all methods and markers will survive, but those that do will complement rapidly proliferating menu of molecular diagnostic services focused on improving health care and quality of human lives. Clinical utility may not necessarily correspond directly to the quantum of tests performed or the category of the diagnostic services provided. Emphasis on translational research will transform scientific discoveries arising from laboratory into clinical application; however, to flourish, it will require a knowledge-driven ecosystem to provide a continuous feedback loop to accelerate the translation of data into clinical utility.