Bariatric surgery improves histological features of nonalcoholic fatty liver disease and liver fibrosis.

Nonalcoholic fatty liver disease (NAFLD) is prevalent in obese patients. We sought to determine the effects of bariatric surgery on the histological features of NAFLD. Two blinded pathologists graded liver biopsies done during bariatric procedures and subsequent operations in 160 patients using the Brunt classification. Data are mean ± SD. Interval between biopsies was 31 ± 26 months. Initial biopsies demonstrated steatosis 77 %, lobular inflammation 39 %, and chronic portal inflammation 56 %. Steatohepatitis was present in 27 %. Grade 2-3 fibrosis was present in 27 %, and cirrhosis was present in one patient. On post-bariatric biopsy, steatosis resolved in 75 %, lobular inflammation resolved in 75 %, chronic portal inflammation resolved in 49 %, and steatohepatitis resolved in 90 %. Fibrosis of any grade resolved in 53 % and improved in another 3 % of patients. Grade 2 fibrosis resolved in 58 %, improved in 3 %, and did not worsen in 11 %. Bridging fibrosis resolved in 29 %, improved in 29 %, and did not worsen in 29 %. Bariatric surgery is associated with resolution of steatosis or steatohepatitis in the majority of patients. More importantly, grade 2 or 3 (bridging) fibrosis is resolved or improved in 60 % of patients. Bariatric surgery should be considered as a treatment of NAFLD in severely obese patients.

From molecular diagnostics to personalized testing.

Gene-based molecular diagnostics is changing the practice of medicine and will continue to do so for the foreseeable future. The major underlying principle of these diagnostic tests is the use of specific nucleic acid sequences as surrogates; amplification of the surrogate markers enables the detection of pathogens or disease-related gene mutations. Gene targets can be amplified by target-, probe- or signal-based methods. Combined use of nucleic acid amplification and enzyme-linked immunosorbent assay with methods such as immuno-polymerase-chain reaction allows us to detect protein at femtogram (10(15) g) levels. A variety of choices are available for the detection of amplified amplicons with the fluorophore-linked nanoparticles as the most sensitive markers. The unique advantages of using covalently-linked nanoparticles include the detection of single molecules, the ability to enrich molecules of interest with unprecedented detection sensitivity (up to zeptogram levels, 10(21) g) and the flexibility of multiple functionalization. Automation appears to be the current trend for high-volume molecular testing of infectious diseases. Molecular profiling of various diseases using genomic or proteomic approaches opens up a molecule wonderland with promise and emergence of new molecular testing that will likely impact the practice of medicine to a greater degree in the future. The future of molecular-based testing and the journey toward personalized testing will be discussed.