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HSS Uses Grant to Test New MRI Techniques & Biomarkers for Arthritis Prevention Treatments

In recent years, researchers have been frustrated because there are no tools to identify early stages of osteoarthritis and thus no good way to test therapies for preventing or slowing the disease. Now, three institutions have been awarded $1 million from the Arthritis Foundation to validate the use of new MRI (magnetic resonance imaging) techniques and newly identified biomarkers to solve this vexing problem. Hospital for Special Surgery in New York City, University of California-San Francisco (UCSF), and Mayo Clinic in Rochester, Minnesota will share the $1 million.

“There is no magic bullet for treatment of osteoarthritis yet, but once we have a potential oral drug, therapeutic injection, or surgery for treating the disease, we will need a way to identify patients who might need it and follow their response to the treatment,” said Scott Rodeo, M.D., orthopedic surgeon and co-chief of the sports medicine and shoulder service at Hospital for Special Surgery (HSS) and co-principal investigator of the tripartite grant. “Using X-rays to measure joint space narrowing is the gold standard for assessing the presence and progression of osteoarthritis, but X-rays are next to worthless for detecting the early changes of arthritis. This study will help us understand the early factors that lead to the degenerative changes in ACL (anterior cruciate ligament) injured knees.”

Acute ACL injury is a major risk factor for developing osteoarthritis. In the past several years, researchers have discovered that long before osteoarthritic changes in joint space can be detected on X-ray, biochemical changes can be detected in cartilage using newer quantitative MRI techniques. Many studies have also shown that ACL injury is associated with quantifiable changes in biochemical biomarkers that can be detected in synovial fluid (joint fluid), blood, and urine.

The Arthritis Foundation grant will be distributed over one year and then the three grant recipients have made an institutional commitment to provide annual patient follow up after that. Each institution will recruit 25 patients who are at a maximum of 14 days out from tearing their ACL. Patients will be evaluated at baseline, six weeks, six months, 12 months and yearly thereafter with traditional MRI and newer MRI techniques.

Specifically, the new quantitative MRI techniques, developed by researchers at HSS and UCSF, measure T1ρ and T2 values of articular cartilage and the meniscus. Articular cartilage is the smooth cushion that lines the end of the bones where they meet at the joints. The meniscus is a knee structure that spans and cushions the space between the joint surfaces of the thighbone and shinbone. In scientific speak, T1ρ measures proteoglycan depletion, and T2 evaluates abnormal collagen orientation. Proteoglycans are conjugates of proteins and long carbohydrate molecules joined together with sugars.

“Imagine you are playing basketball and you jump up to make a basket, your ability to withstand the load when you come down is a function of proteoglycan,” said Hollis Potter, M.D., chief of the division of magnetic resonance imaging, director of research in the Department of Radiology and Imaging at HSS. “If you pivot and throw the ball to someone else, your ability for your cartilage to withstand that load is a function of the collagen. You need both to be healthy.” Dr. Potter is the HSS site leader of the grant.

At each time point that researchers collect MRI data, they will also collect samples of synovial fluid, blood, and urine from patients and evaluate knee function using surveys such as the Knee Outcome Survey, international knee documentation committee (IKDC) evaluation forms, and Marx Activity Level. These surveys gauge whether a patient has knee impairment; the degree of symptoms such as knee swelling and pain; and how much knee impairment impacts overall well-being, daily living, work, and athletic and social activities. The majority of participants in the study will undergo ACL reconstruction, and surgeons will evaluate these patients arthroscopically at the time of the operation. Clinicians will correlate fluid biomarkers and quantitative MRI results with traditional imaging, clinical, and functional outcomes.

Osteoarthritis is an extremely heterogeneous disorder in terms of the factors that contribute to the loss of joint function. Researchers need to be able to identify where a patient is in the progression of the disease to be able to target specific processes that are responsible for the symptoms and loss of joint function.

“Not everyone who has an ACL tear will develop osteoarthritis, but some do,” said Dr. Rodeo. “The goal is to identify biomarkers that reflect alterations in the joint environment that may be predictive of developing arthritis.” Once these are identified, researchers can test therapies to slow or prevent the disease, which can be crippling and lead to disability.

“There remain many unanswered questions regarding the optimal care of patients with ACL injuries,” said Steven Goldring, M.D., Chief Scientific Officer, St. Giles Chair, Hospital for Special Surgery. “This study is a paradigm of interdisciplinary research that brings together experts in orthopedics, radiology and basic science from multiple leading medical centers with the single goal of developing the most effective therapies to improve outcomes in patients with ACL injuries. The Arthritis Foundation should be congratulated in initiating this groundbreaking program.”

ACL ruptures affect roughly 1 in 3,000 people per year in the United States alone. The cumulative population risk of an ACL injury in people between the ages of 10 and 64 years has been estimated to be 5%, but could be considerably higher. More than 175,000 ACL reconstructions are performed each year in the United States at a cost of $2 billion. Participation in sports that involve pivoting including soccer, basketball, football, and skiing put individuals at higher risk for tearing their ACL.

Source: EurekAlert!

Comprehensive Parkinson’s Biomarker Test Has Prognostic and Diagnostic Value, Penn Medicine Team Reports

Perelman School of Medicine researchers at the University of Pennsylvania report the first biomarker results reported from the Parkinson’s Progression Markers Initiative (PPMI), showing that a comprehensive test of protein biomarkers in spinal fluid have prognostic and diagnostic value in early stages of Parkinson’s disease. The study is reported in JAMA Neurology.

Compared to healthy adults, the study found that people with early Parkinson’s had lower levels of amyloid beta, tau and alpha synuclein in their spinal fluid. In addition, those with lower concentrations of tau and alpha synuclein had greater motor dysfunction. And early Parkinson’s patients with low levels of amyloid beta and tau were more likely to be classified as having the postural instability-gait disturbance- dominant (PIGD) motor type of disease, where falling, freezing, and walking difficulty are common.

“Biomarkers for Parkinson’s disease such as these could help us diagnose patients earlier, and we’ve now shown that the simultaneous measurement of a variety of neurodegenerative disease proteins is valuable,” said study senior author Leslie M. Shaw, PhD, professor of Pathology and Laboratory Medicine at Penn Medicine. Dr. Shaw and John Q. Trojanowski, MD, PhD, director of the Penn Udall Center for Parkinson’s Research, are co-leaders of the Bioanalytics Core for the Parkinson’s Progression Markers Initiative, an international observational clinical study sponsored by The Michael J. Fox Foundation for Parkinson’s Research.

The team evaluated spinal fluid collected from baseline visits of the first 102 PPMI participants – 63 with early, untreated Parkinson’s disease and 39 healthy controls. The spinal fluid was evaluated for levels of five biomarkers: amyloid beta, total tau, phosphorylated tau, alpha synuclein and the ratio of total tau to amyloid beta. Spinal fluid measures of amyloid and tau are currently used in research to distinguish Alzheimer’s disease from other neurodegenerative diseases. In contrast to Alzheimer’s, where tau levels are higher than healthy controls, the study found that early Parkinson’s patients had lower levels of tau than healthy controls. One reason, researchers suggest, could be that interactions between tau and alpha synuclein may limit the release of tau into the cerebrospinal fluid of Parkinson’s patients.

“Through PPMI, we are hoping to identify subgroups of Parkinson’s patients whose disease is likely to progress at a different rate, as early as possible,” said Dr. Trojanowski. “Early prediction is critical, for both motor and dementia symptoms.”

The Parkinson’s PIGD motor subtype has been associated with a more rapid cognitive decline as well as greater functional disability. Using the biomarker test, this initial study found that levels of all spinal fluid biomarkers were lower in the PIGD motor subtype than other types of PD as well as healthy controls. In addition, amyloid beta and phosphorylated tau were at lower levels in the PIGD motor subtype, but were no different in tremor or indeterminate subtypes compared to normal controls.

This spinal fluid testing procedure is only being used in research studies, and will be continued to be evaluated and validated in a larger study of the PPMI cohorts.

In addition to leading the Bioanalytics Core of PPMI, Penn’s Parkinson’s Disease and Movement Disorders Center is one of the two dozen trial sites where volunteers are evaluated throughout the PPMI study. The Penn PDMDC has been part of the PPMI group studying people with early Parkinson’s disease as well as healthy adults since 2010, and began enrollment for a new, pre-symptomatic arm of the study in the summer of 2013. The pre-motor arm of PPMI is enrolling participants who do not have Parkinson’s disease and are living with one of three potential risk factors for PD: a reduced sense of smell (hyposmia); rapid eye movement sleep behavior disorder (RBD; a disorder in which the individual acts out his/her dreams); or a mutation in the LRRK2 gene (the single greatest genetic contributor to PD known to date).

“In addition to biomarker tests, validating risk factors could enable earlier detection of the disease and open new avenues in the quest for therapies that could slow or stop disease progression,” said PPMI trial site study leader Matthew Stern, MD, professor of Neurology and director of Penn’s Parkinson’s Disease and Movement Disorders Center.

Study: Association of Cerebrospinal Fluid β-Amyloid 1-42, T-tau, P-tau181, and α-Synuclein Levels With Clinical Features of Drug-Naive Patients With Early Parkinson Disease [JAMA Neurology]

Source: Penn Medicine

Spinal Fluid Biomarkers of AD and Brain Functional Network Integrity on Imaging Studies

Both Aß and tau pathology appear to be associated with default mode network integrity before clinical onset of Alzheimer disease (AD), according to a study by Liang Wang, M.D., and colleagues at Washington University in St. Louis, Missouri.

Accumulation of Aß and tau proteins, the pathologic hallmarks of AD, starts years before clinical onset. Pathophysiological abnormalities in the preclinical phase of AD may be detected using cerebrospinal fluid (CSF) or neuroimaging biomarkers, according to the study background.

A total of 207 older adults with normal cognition participated in the cross-sectional group study. Researchers examined the relationship between default mode network integrity and cerebrospinal fluid biomarkers of Alzheimer disease pathology in cognitively normal older individuals using resting-state functional connectivity magnetic resonance imaging.

According to the study results, decreased cerebrospinal fluid Aß42 and increased cerebrospinal fluid phosphorylated tau181 were independently associated with reduced default mode network integrity, with the most prominent decreases in functional connectivity observed between the posterior cingulate and medial temporal regions (regions of the brain associated with memory). Observed reductions in functional connectivity were unattributable to age or structural atrophy in the posterior cingulate and medial temporal areas.

Study: Cerebrospinal Fluid Aβ42, Phosphorylated Tau181, and Resting-State Functional Connectivity [JAMA Neurology]

Source: EurekAlert!

Combination of Imaging Exams Improves Alzheimer’s Diagnosis

A combination of diagnostic tests, including imaging and cerebrospinal fluid biomarkers can improve prediction of conversion from mild cognitive impairment (MCI) to Alzheimer’s disease, according to a new study published online in the journal Radiology.

Videos: Recent Advances in Biomarkers of Parkinson’s Disease

Presentations from the Covance Symposium Recent Advances in Biomarkers of Parkinson’s Disease at the 2011 Society for Neuroscience Conference is now available to watch on the Covance website. Listen to discussions regarding recent innovations in imaging, genomic, proteomic, and fluid biomarkers of Parkinson’s disease and their potential application to the clinic.