They discovered a previously unknown group of regulatory T cells linked to the disease and DNA features that affect patients’ response to treatment
A team of scientists and doctors from the SingHealth Duke-NUS Academic Medical Centre (AMC) has uncovered a new group of regulatory T (Treg) cells and DNA features associated with juvenile idiopathic arthritis (JIA), the most common form of arthritis among children under the age of 16. Their findings could potentially enhance diagnosis of the disease and prediction of therapy outcomes for improved treatment successes.
JIA is a disease of the immune system that causes inflammation leading to pain, stiffness and swelling in patients’ joints. It affects around one in 1,000 children in the world.
Juvenile arthritis has no cure and young patients can only alleviate pain or prevent joint deterioration through use of medication or therapy. In advancing care for JIA, researchers are keen to identify the culprit cells or genetic signatures behind the disease in order to tackle it.
In its first discovery, the SingHealth Duke-NUS AMC research team identified a previously unknown group of Treg cells that is associated with inflammation in JIA. Treg cells are a subset of white blood cells that regulate the body’s immune system. When the body has an imbalanced number of Treg cells, its immune tolerance can fail and experience autoimmune disorders such as arthritis.
The team found that the identified Treg cells play a role in JIA progression. During the active disease stage of JIA, these cells expand, grow in number, re-circulate through inflamed areas of patients’ body, and migrate to the connective tissue of patients’ joints. Additionally, a larger quantity of these cells can be found in JIA patients who cannot control arthritis inflammation and are unresponsive to therapy as compared to those who are.
"Clinicians could potentially use this novel group of cells as a marker to diagnose JIA in patients, as well as to predict or monitor patients’ responsiveness to therapy. Importantly, these cells are readily detectable in patients’ bloodstream, allowing for any clinical tests to be minimally invasive and pain-free for patients," said Professor Salvatore Albani, Director, SingHealth Translational Immunology and Inflammation Centre (STIIC), Professor, Duke-NUS Medical School and Senior Clinician Scientist, KK Women’s and Children’s Hospital (KKH), who is the principal investigator of the study.
 
2nd discovery: Patients’ DNA affects JIA treatment outcomes
Currently, only about one-third of JIA patients get better after medication or therapy, while the rest continue to see their condition flare up even after treatment.
To accurately predict treatment outcomes, the research team studied JIA patients’ treatment responses and found that epigenetics – or individuals’ DNA and the way each body uses its genes – determined one’s clinical "fate". In other words, the key is not in individuals’ genetic make-up but rather, in how their bodies employ genes. Even patients with identical genetic backgrounds could experience different clinical outcomes based on their DNA features that activate genes differently.
One of the research paper’s co-author, Associate Professor Thaschawee Arkachaisri, Head & Senior Consultant, Rheumatology and Immunology Service, KKH and Associate Professor, Duke-NUS, said "These discoveries could enable doctors to predict treatment responses and personalise treatment for patients. This is especially relevant for difficult JIA cases which may require more complex therapies, and is important to help save time and money, prevent treatment complications and ultimately, improve care outcomes."
The team’s findings are also relevant for adult rheumatoid arthritis, a similar autoimmune condition that affects one in 100 adults in the world.

EurekAlert
www.eurekalert.org/pub_releases/2017-07/s-ssp071317.php

Ortho Clinical Diagnostics (Ortho) and EKF Diagnostics (EKF) recently announced an agreement that allows Ortho customers to access EKF’s Stanbio Chemistry Beta-Hydroxybutyrate (BHB) LiquiColor^® assay. This is an important marker used in conjunction with clinical findings and other lab tests for the diagnosis and management of ketoacidosis and its main causative factor, diabetic ketoacidosis (DKA). The high-quality, fully automated assay is now available for use on Ortho’s VITROS^® 4600 Chemistry System and the VITROS^® 5600 Integrated System.

Diabetic ketoacidosis is a serious complication that can lead to a disruption of chemical balance in the body, and can be fatal if left undiagnosed. EKF’s enzymatic Beta-Hydroxybutyrate (BHB) assay is used primarily for determining both the presence and degree of ketosis in suspected diabetic ketoacidosis cases. The BHB assay produces a quantitative value that is specific to the BHB ‘ketone body’. These qualities make the BHB assay the new clinical diagnostic standard of care for ketone testing.

“Ortho is committed to delivering a broad menu of assays to our customers in the clinical lab, whether through in-house development or collaborations like the one with EKF,” said Ortho’s chief Operating Officer Robert Yates.

Ortho and EKF are collaborating to provide the BHB assay as a validated MicroTip Partnership Assay (MPA) application in the U.S. and Canada. This MPA utilizes the User Defined Assay (UDA) feature, which provides the capability to program assay parameters as defined in the EKF Stanbio Assay Application Sheet. The Beta-Hydroxybutyrate LiquiColor^® assay has been CLIA classified by the U.S. Food and Drug Administration (FDA) as a MODERATE complexity assay on the VITROS^® 4600 Chemistry System and VITROS^® 5600 Integrated System.

“Diabetic ketoacidosis is a serious condition, and our collaboration with Ortho Clinical Diagnostics will help to deliver the important BHB assay to their existing customers” said EKF’s Diagnostics Head of Sales, Gilbert Mejia.

EKF Diagnostics’ Stanbio Chemistry portfolio is a broad range of liquid-stable reagents, calibrators, standards and controls. LiquiColor^® and Liqui-UV^® reagents are designed for maximum stability, ease-of-use and are optimized for today’s chemistry analyzers. In addition to its BHB test for ketosis, EKF continues to build on its successful range of esoteric reagents.

 

www.orthoclinicaldiagnostics.comwww.ekfdiagnostics.com

A consortium including St. Jude Children’s Research Hospital and the Children’s Oncology Group has performed an unprecedented genomic sequencing analysis of hundreds of patients with T-lineage acute lymphoblastic leukaemia (T-ALL). The results provide a detailed genomic landscape that will inform treatment strategies and aid efforts to develop drugs to target newly discovered mutations.
The data will also enable researchers to engineer better mouse models to probe the leukaemia’s aberrant biological machinery.
The project’s 39 researchers were led by Charles Mullighan, M.D., MBBS, a member of the St. Jude Department of Pathology, with co-corresponding authors Jinghui Zhang, Ph.D., chair of the St. Jude Department of Computational Biology, and Stephen Hunger, M.D., of the Children’s Hospital of Philadelphia.
"This first comprehensive and systematic analysis in a large group of patients revealed many new mutations that are biologically significant as well as new drug targets that could be clinically important," Mullighan said. "Leukaemias typically arise from multiple genetic changes that work together. Most previous studies have not had the breadth of genomic data in enough patients to identify the constellations of mutations and recognize their associations."
T-ALL is a form of leukaemia in which the immune system’s T cells acquire multiple mutations that freeze the cells in an immature stage, causing them to accumulate in the body. ALL is the most common type of childhood cancer, affecting about 3,000 children nationwide each year. T-ALL constitutes about 15 percent of those cases. While about 90 percent of children with ALL can be cured, many still relapse and require additional treatment.
The multi-institutional effort involved sequencing the genomes of 264 children and young adults with T-ALL—the largest such group ever analysed. The study involved sophisticated analysis of multiple types of genomic data, led by Yu Liu, Ph.D., a postdoctoral fellow in Zhang’s Computational Biology laboratory and first author of the study. Their analyses identified 106 driver genes—those whose mutations trigger the malfunctions that block normal T cell development and give rise to cancer. Half of those mutated genes had not been previously identified in childhood T-ALL.
The study enabled the researchers to compare the frequencies of mutations among patients whose cancerous cells were sequenced at the same detailed level, Mullighan said. Also important, he said, was that all the patients had uniform treatment, which enabled the researchers to draw meaningful associations between the genetics of their cancer and the response to different treatments. Such associations will enable better diagnosis and treatment of T-ALL with existing drugs.
Researchers analysed the cancerous T cells as well as those that treatments had rendered non-cancerous. Comparing the two populations of cells could reveal valuable clues about why specific treatments were successful in thwarting particular cancer-causing mutations.
The findings revealed significant unexpected findings. "We went into this study knowing that we didn’t know the full genomic landscape of T-ALL," Hunger said. "But we were surprised that over half of the new targets and mutations were previously unrecognized. It was particularly unexpected and very striking that some mutations were exclusively found in some subtypes of T-ALL, but not others."
Cancers are driven by mutations in genes that are the blueprint for protein enzymes in signaling pathways in cells—the biological equivalent of circuits in a computer. While a cancer may arise from an initial founding mutation, that mutation triggers a cascade of other mutations that help drive the cancer.
The new genomic analysis confirmed that T-ALL was driven by mutations in known signalling pathways, including JAK–STAT, Ras and PTEN–PI3K.
However, the new analysis identified many more genetic mutations in those known pathways. The findings offered more targets for drugs to shut down the aberrant cells. "So the frequency of the patients that are potentially amenable to these targeted approaches is higher than we appreciated before," Mullighan said.
The researchers also found cases in which the same T-ALL subtype had mutations in different pathways triggered by the same cancer-causing founding mutation. "We believe this finding suggests we can target such subtypes with an inhibitor drug for one of the pathways, and it’s likely to be effective," Mullighan said.
The multitude of new mutations uncovered in the new study will also enable researchers to use genetic engineering to create mouse models that more accurately reflect human cancer, he said. Such models are invaluable for understanding the biological machinery of T-ALL, as well as testing new drug strategies. "We now have a launching pad, if you will, to design mouse models that include multiple genetic mutations to more faithfully reflect the leukemias we see in humans," Mullighan said.

St. Jude Children’s Research Hospital
www.stjude.org/media-resources/news-releases/2017-medicine-science-news/genomic-analysis-of-key-acute-leukemia-will-likely-yield-new-therapies.html

Mutations in the gene encoding the enzyme protein tyrosine phosphatase N2 (PTPN2) have been associated with the development of autoimmune disease including Type 1 diabetes, Crohn’s Disease and rheumatoid arthritis.
In important fundamental research, Monash University researchers have identified a crucial part of the enzyme’s role in early T-cell development, and have shown that decreased levels of this enzyme can lead to the type of T-cells that can contribute to the development of autoimmune disease.
Autoimmune diseases represent a broad spectrum of diseases, which arise when immune responses are directed against, and damage, the body’s own tissues. Collectively their incidence exceeds that of cancer and heart disease and they are a leading cause of death and disability, in particular in the Western world.
The Monash Biomedicine Discovery Institute researchers had already shown in studies over the years that decreased levels of PTPN2 result in T-cells attacking the body’s own cells and tissues. 
In a paper they drilled deeper, exploring roles for the enzyme in early T-cell development and the development of particular T-cell subsets (αβ and γδ) implicated in the development of different autoimmune and inflammatory diseases.
By removing the gene coding for PTPN2 in laboratory trials, the scientists found that the developmental process for T-cells was skewed towards the generation of γδ T cells with pro-inflammatory properties that are known to contribute to the development of different diseases including Irritable Bowel Disease, Crohn’s Disease and rheumatoid arthritis.
“This is an important advance in our understanding of critical checkpoints in T-cell development,” lead researcher Professor Tony Tiganis said.
“It helps decide whether the progenitors go on to become T-cells or something else; if they become one type of T-cell or another type,” he said.
As part of the study, the researchers looked at the pathways that PTPN2 regulates.
“There are drugs that target some of these pathways – potentially we might be able to use existing drugs to target these pathways in the context of autoimmune and inflammatory diseases to help a subset of patients with a deficiency in this gene, although that is a long way off,” Professor Tiganis said. 
First author Dr Florian Wiede said, “Understanding the mechanisms that govern early T-cell development and how these are altered in human disease may ultimately afford opportunities for novel treatments. This is very exciting.”

Monash Biomedicine Discovery Institute
www.monash.edu/news/articles/monash-university-scientists-make-critical-insights-into-t-cell-development