More Than Half of All ACL Reconstructions Could Be Avoided, Five-Year Follow-Up Study Shows

Another Human-Based Study, and I’ve Been Proving This in Canine Cases For Over 10 Years-

From RehabDeb: This report is from human medical research, however Colorado State University has since conducted some animal studies. I would love to conduct studies with advanced exercise physiology protocol that I have been using for over 20 years even with my own pets before doing “official” vet med work. I look forward to when I have resources to do those studies.

When I began independent practice in 2007, I used my accumulated research studies, experience, and knowledge begun decades before my work in veterinary medicine in order to create some simple functional exercise and drill protocol. These programs benefited hundreds of my pet patients whose people opted to not pursue surgery. I have used these programs for both cats and dogs.

In every case where people follow my protocol (and where there are no extenuating circumstances), the pets have stabilized the knee or other joint with muscle growth and strength and with proper scar tissue (sometimes we want some scar tissue).

These pets have also functioned very well after rehabilitation. You may do all this work in the home environment with no dependence on specialized equipment in a clinic. There is no need for specialized equipment when we are drawing from centuries of known exercise physiology.

My programs for conservative (no surgery) treatment are clinically and anecdotally successful. This means that clients and veterinarians do the work and get good results. You can too, if you want to do the work 🙂

Jan. 30, 2013 — In the summer of 2010, researchers from Lund University in Sweden reported that 60 per cent of all anterior cruciate ligament (ACL) reconstructions could be avoided in favour of rehabilitation. The results made waves around the world, and were met with concerns that the results would not hold up in the long term. Now the researchers have published a follow-up study that confirms the results from 2010 and also show that the risk of osteoarthritis and meniscal surgery is no higher for those treated with physiotherapy alone.

“We have continued with our study and for the first time are able to present a five-year follow-up on the need for and results of ACL surgery as compared with physiotherapy. The British Medical Journal published the findings and they are basically unchanged from 2010.

This will no doubt surprise many people, as we have not seen any difference in the incidence of osteoarthritis,” says Richard Frobell, one of the researchers behind the study, who is an associate professor at Lund University and a clinician at the orthopaedic department, Helsingborg Hospital.

Richard Frobell explains that the research group’s results from 2010, which were published in the New England Journal of Medicine, caused a stir and questions were raised as to whether it was possible to say that an operation would not be needed in the long term.

Half of the patients who were randomly assigned not to undergo reconstructive surgery have had an operation in the five years since, after they experienced symptoms of instability.

“In this study, there was no increased risk of osteoarthritis or meniscal surgery for ACL injury treated with physiotherapy alone compared to treated with surgery. Neither was there any difference in patients’ experiences of function, activity level, quality of life, pain, symptoms or general health,” says Richard Frobell.

“The new report shows that there was no difference in any outcome between those who had operations straight away, those who had operations later, and those who did not have an operation at all.

“The message to the medical experts who are treating young, active patients with ACL injuries is that it may be better to start by considering rehabilitation rather than operating straight away.

In Sweden, over 5000 people every year suffer an anterior cruciate ligament injury, mainly young people involved in sport. There are different schools of treatment and Sweden stands out with treatment that is in line with the results of the study.

“On an international front, almost all of those with ACL injuries have operations. In Sweden, just over half have surgery, but in southern Sweden we have been working for many years to use advanced rehabilitation training as the first method of treatment. Our research so far has confirmed that we are right in not choosing to operate on these injuries immediately. Longer-term follow-up is important to look more closely at the development of osteoarthritis in particular,” says Richard Frobell.

KANON, Knee ACL NON-operative versus operative treatment is the name of the research group. They are now moving on to the next stage. This year, the third part of the study will begin, following up the patients ten years after acl injury.

Richard Frobell has also entered into a collaboration with researchers at the School of Economics and Management at Lund University. He is evaluating the health economics aspects of different treatment methods for ACL injury.

Journal References

  • R. B. Frobell, H. P. Roos, E. M. Roos, F. W. Roemer, J. Ranstam, L. S. Lohmander. Treatment for acute anterior cruciate ligament tear: five year outcome of randomised trial. BMJ, 2013; 346 (jan24 1): f232 DOI:10.1136/bmj.f232
  • Richard B. Frobell, Ewa M. Roos, Harald P. Roos, Jonas Ranstam, L. Stefan Lohmander. A Randomized Trial of Treatment for Acute Anterior Cruciate Ligament Tears.New England Journal of Medicine, 2010; 363 (4): 331 DOI:10.1056/NEJMoa0907797

From ScienceDaily

Physical Therapy as Effective as Surgery for Torn Meniscus and Arthritis of the Knee, (Human) Study Suggests

Just One of Many Studies Published on This Topic-

My programs for conservative (no surgery) treatment are clinically and anecdotally successful. So, this means that clients and veterinarians do the work and get good results.

Physical Therapy as Effective as Surgery for Torn Meniscus and Arthritis of the Knee, (Human) Study Suggests –

“Surgery may not always be the best first course of action.

A physical therapist, in many cases, can help patients avoid the often unnecessary risks and expenses of surgery. To reinforce that, this study should help change practice in the management of symptomatic meniscal tears in patients with knee osteoarthritis.” Mar. 21, 2013 — A New England Journal of Medicine (NEJM) study showing that physical therapy is just as effective as surgery in patients with meniscal tears and arthritis of the knee should encourage many health care providers to reconsider their practices in the management of this common injury, according to the American Physical Therapy Association (APTA).

The study, published March 19, showed no significant differences in functional improvement after 6 months between patients who underwent surgery with postoperative physical therapy and those who received standardized physical therapy alone.

“This study demonstrates what physical therapists have long known,” explained APTA President Paul A. Rockar Jr, PT, DPT, MS. “Surgery may not always be the best first course of action. A physical therapist, in many cases, can help patients avoid the often unnecessary risks and expenses of surgery. This study should help change practice in the management of symptomatic meniscal tears in patients with knee osteoarthritis.”

According to lead physical therapist for the trial and American Physical Therapy Association (APTA) member Clare Safran-Norton, PT, PhD, OCS, “our findings suggest that a course of physical therapy in this patient population may be a good first choice since there were no group differences at 6 months and 12 months in this trial.

These findings should help surgeons, physicians, physical therapists, and patients in decision-making regarding their treatment options.”

Researchers at 7 major universities and orthopedic surgery centers around the country studied 351 patients aged 45 years or older who had a meniscal tear and mild-to-moderate osteoarthritis of the knee. Patients were randomly assigned to groups who received either surgery and postoperative physical therapy or standardized physical therapy. Within 6-12 months, patients who had physical therapy alone showed similar improvement in functional status and pain as those who had undergone arthroscopic partial meniscectomy surgery. Furthermore, patients who were given standardized physical therapy — individualized treatment and a progressive home exercise program — had the option of “crossing over” to surgery if substantial improvements were not achieved. In this situation, thirty percent of patients crossed over to surgery during the first 6 months. At 12 months these patients reported similar outcomes as those who initially had surgery. Seventy percent of patients remained with standardized physical therapy.

According to an accompanying editorial in NEJM,”millions of people are being exposed to potential risks associated with a treatment [surgery] that may or may not offer specific benefit, and the costs are substantial.” Physical therapist and APTA member Mary Ann Wilmarth, PT, DPT, MS, OCS, MTC, Cert MDT, chief of physical therapy at Harvard University, said, “Physical therapists are experts in improving mobility and restoring motion. The individualized treatment approach is very important in the early phases of rehabilitation in order to achieve desired functional outcomes and avoid setbacks or complications.”

Story Source:

The above story is reprinted from materials provided by American Physical Therapy Association. Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:
Jeffrey N. Katz, Robert H. Brophy, Christine E. Chaisson, Leigh de Chaves, Brian J. Cole, Diane L. Dahm, Laurel A. Donnell-Fink, Ali Guermazi, Amanda K. Haas, Morgan H. Jones, Bruce A. Levy, Lisa A. Mandl, Scott D. Martin, Robert G. Marx, Anthony Miniaci, Matthew J. Matava, Joseph Palmisano, Emily K. Reinke, Brian E. Richardson, Benjamin N. Rome, Clare E. Safran-Norton, Debra J. Skoniecki, Daniel H. Solomon, Matthew V. Smith, Kurt P. Spindler, Michael J. Stuart, John Wright, Rick W. Wright, Elena Losina. Surgery versus Physical Therapy for a Meniscal Tear and Osteoarthritis. New England Journal of Medicine, 2013; : 130318220107009 DOI:10.1056/NEJMoa1301408

Arthritis

Physical Therapy as Effective as Surgery for Torn Meniscus and Arthritis of the Knee, (Human) Study Suggests

“Surgery may not always be the best first course of action. A physical therapist, in many cases, can help patients avoid the often unnecessary risks and expenses of surgery. This study should help change practice in the management of symptomatic meniscal tears in patients with knee osteoarthritis.” Mar. 21, 2013 — A New England Journal of Medicine (NEJM) study showing that physical therapy is just as effective as surgery in patients with meniscal tears and arthritis of the knee should encourage many health care providers to reconsider their practices in the management of this common injury, according to the American Physical Therapy Association (APTA).

The study, published March 19, showed no significant differences in functional improvement after 6 months between patients who underwent surgery with postoperative physical therapy and those who received standardized physical therapy alone.

“This study demonstrates what physical therapists have long known,” explained APTA President Paul A. Rockar Jr, PT, DPT, MS. “Surgery may not always be the best first course of action. A physical therapist, in many cases, can help patients avoid the often unnecessary risks and expenses of surgery. This study should help change practice in the management of symptomatic meniscal tears in patients with knee osteoarthritis.” According to lead physical therapist for the trial and American Physical Therapy Association (APTA) member Clare Safran-Norton, PT, PhD, OCS, “our findings suggest that a course of physical therapy in this patient population may be a good first choice since there were no group differences at 6 months and 12 months in this trial. These findings should help surgeons, physicians, physical therapists, and patients in decision-making regarding their treatment options.” Researchers at 7 major universities and orthopedic surgery centers around the country studied 351 patients aged 45 years or older who had a meniscal tear and mild-to-moderate osteoarthritis of the knee. Patients were randomly assigned to groups who received either surgery and postoperative physical therapy or standardized physical therapy. Within 6-12 months, patients who had physical therapy alone showed similar improvement in functional status and pain as those who had undergone arthroscopic partial meniscectomy surgery. Patients who were given standardized physical therapy — individualized treatment and a progressive home exercise program — had the option of “crossing over” to surgery if substantial improvements were not achieved. Thirty percent of patients crossed over to surgery during the first 6 months. At 12 months these patients reported similar outcomes as those who initially had surgery. Seventy percent of patients remained with standardized physical therapy. According to an accompanying editorial in NEJM,”millions of people are being exposed to potential risks associated with a treatment [surgery] that may or may not offer specific benefit, and the costs are substantial.” Physical therapist and APTA member Mary Ann Wilmarth, PT, DPT, MS, OCS, MTC, Cert MDT, chief of physical therapy at Harvard University, said, “Physical therapists are experts in improving mobility and restoring motion. The individualized treatment approach is very important in the early phases of rehabilitation in order to achieve desired functional outcomes and avoid setbacks or complications.”

Story Source: The above story is reprinted from materials provided by American Physical Therapy Association. Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:
Jeffrey N. Katz, Robert H. Brophy, Christine E. Chaisson, Leigh de Chaves, Brian J. Cole, Diane L. Dahm, Laurel A. Donnell-Fink, Ali Guermazi, Amanda K. Haas, Morgan H. Jones, Bruce A. Levy, Lisa A. Mandl, Scott D. Martin, Robert G. Marx, Anthony Miniaci, Matthew J. Matava, Joseph Palmisano, Emily K. Reinke, Brian E. Richardson, Benjamin N. Rome, Clare E. Safran-Norton, Debra J. Skoniecki, Daniel H. Solomon, Matthew V. Smith, Kurt P. Spindler, Michael J. Stuart, John Wright, Rick W. Wright, Elena Losina. Surgery versus Physical Therapy for a Meniscal Tear and Osteoarthritis. New England Journal of Medicine, 2013; : 130318220107009 DOI:10.1056/NEJMoa1301408
Note: If no author is given, the source is cited instead.

Here is a second report of the same issue:

Medscape Medical News from the:

American Academy of Orthopaedic Surgeons (AAOS) 2013 Annual Meeting
This coverage is not sanctioned by, nor a part of, the American Academy of Orthopaedic Surgeons.

Medscape Medical News > Conference News
Physical Therapy as Effective as Surgery for Meniscal Tear

Medscape Medical News from the: American Academy of Orthopaedic Surgeons (AAOS) 2013 Annual Meeting Physical Therapy as Effective as Surgery for Meniscal Tear Kathleen Louden Mar 20, 2013 CHICAGO, Illinois — Patients with knee osteoarthritis and a meniscal tear who received physical therapy without surgery had good functional improvement 6 months later, and outcomes did not differ significantly from patients who underwent arthroscopic partial meniscectomy, a new clinical trial shows. In the Meniscal Tear in Osteoarthritis Research (METEOR) trial, both groups of patients improved substantially in function and pain. This finding, presented here at the American Academy of Orthopaedic Surgeons 2013 Annual Meeting and published online simultaneously in the New England Journal of Medicine, provides “considerable reassurance regarding an initial nonoperative strategy,” the investigators report. Patients with a meniscal tear and osteoarthritis pose a treatment challenge because it is not clear which condition is causing their symptoms,” principal investigator Jeffrey Katz, MD, from Brigham and Women’s Hospital in Boston, Massachusetts, told Medscape Medical News. “These data suggest that there are 2 reasonable pathways for patients with knee arthritis and meniscal tear,” Dr. Katz explained. “We hope physicians will use these data to help patients understand their choices.” In an accompanying editorial, clinical epidemiologist Rachelle Buchbinder, PhD, from the Monash University School of Public Health and Preventive Medicine in Victoria, Australia, said that “these results should change practice. Currently, millions of people are being exposed to potential risks associated with a [surgical] treatment that may or may not offer specific benefit, and the costs are substantial.” These results should change practice. The METEOR trial enrolled 351 patients from 7 medical centers in the United States. Eligible patients were older than 45 years, had osteoarthritic cartilage change documented with magnetic resonance imaging, and had at least 1 symptom of meniscal tear, such as knee clicking or giving way, that lasted at least 1 month despite drug treatment, physical therapy, or limited activity. In this intent-to-treat analysis, investigators randomly assigned 174 patients to arthroscopic partial meniscectomy plus postoperative physical therapy and 177 to physical therapy alone. The physical therapy in both regimens was a standardized 3-stage program that allowed patients to advance to the next intensity level at their own pace, Dr. Katz explained. The program involved 1 or 2 sessions a week for about 6 weeks and home exercises. The average number of physical therapy visits was 7 in the surgery group and 8 in the nonsurgery group. Investigators evaluated patients 6 and 12 months after randomization. The primary outcome was the between-group difference in change in physical function score from baseline to 6 months, assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). At baseline, demographic characteristics and WOMAC physical function scores were similar in the 2 groups. At 6 months, improvement in the WOMAC function score was comparable in the 2 groups. The mean between-group difference of 2.4 points was not statistically significant after analysis of covariance. There was also no significant difference between groups in pain improvement or frequency of adverse events. METEOR: Mean Improvement in Osteoarthritis Index at 6 Months Treatment Group Mean Improvement (Points) 95% Confidence Interval Surgery plus physical therapy 20.9 17.9–23.9 Physical therapy 18.5 15.6–21.5 There was 1 death in each group, and 8 patients in the nonsurgery group and 13 in the surgery group withdrew in the first 6 months of the study. Patients in the nonsurgery group were allowed to cross over to the surgical group at any time. Within 6 months, 30% of patients did so. “They were not doing very well,” Dr. Katz said. His team is still analyzing the reasons these patients did not benefit from intensive physical therapy. The 12-month results were similar to the 6-month results. In addition, by 12 months, outcomes for the crossover patients and for those in the original surgery group were similar. Meeting delegate John Mays, MD, an orthopaedic surgeon practicing in Bossier City, Louisiana, who was asked by Medscape Medical News to comment on the findings, said most patients don’t choose physical therapy. “In the real world, most people want a quick fix” and choose surgery, he noted. Dr. Mays said he would have liked to have seen a group of patients who underwent surgery but did not receive postoperative physical therapy. He explained that his patients with osteoarthritis and meniscal tear rarely get physical therapy after arthroscopic meniscectomy; they most often do home-based exercises. He added that “most insurance plans have limits on the number of physical therapy sessions they allow.” This study is funded by the National Institute of Arthritis and Musculoskeletal and Skin Diseases. Dr. Katz, Dr. Buchbinder, and Dr. Mays have disclosed no relevant financial relationships. N Engl J Med. Published online March 19, 2013. Abstract, Editorial American Academy of Orthopaedic Surgeons (AAOS) 2013 Annual Meeting: Abstract SE67. Presented March 19, 2013.

More Than Half of All ACL Reconstructions Could Be Avoided, Five-Year Follow-Up Study Shows

(From RehabDeb: This report is from human medical research, however animal studies are currently being conducted at Colorado State University. When I began animal rehab in 2005, I developed some protocol for people to use to benefit their animals if they did not want surgery for their pet, even though I was working at the time in a surgery specialty hospital. When I began independent practice in 2007, I took years of accumulated research, experience, and knowledge and created some simple functional exercise and drill protocol that has benefited hundreds of my canine patients whose people opted to not pursue surgery. That protocol and some other papers citing surgery text recommendations may be found elsewhere on this site-see the index to the right. In every case where my protocol has been followed (and there are no extenuating circumstances), the pets have stabilized the joint with muscle and scar tissue, and they have functioned very well. This work is all done in the home environment with no dependence on specialized equipment…no need when we are drawing from centuries of known exercise physiology and dynamic principles of body function. Blessings-)

Jan. 30, 2013 — In the summer of 2010, researchers from Lund University in Sweden reported that 60 per cent of all anterior cruciate ligament (ACL) reconstructions could be avoided in favour of rehabilitation. The results made waves around the world, and were met with concerns that the results would not hold up in the long term. Now the researchers have published a follow-up study that confirms the results from 2010 and also show that the risk of osteoarthritis and meniscal surgery is no higher for those treated with physiotherapy alone.

“We have continued with our study and for the first time are able to present a five-year follow-up on the need for and results of ACL surgery as compared with physiotherapy. The findings have been published in the British Medical Journal and are basically unchanged from 2010. This will no doubt surprise many people, as we have not seen any difference in the incidence of osteoarthritis,” says Richard Frobell, one of the researchers behind the study, who is an associate professor at Lund University and a clinician at the orthopaedic department, Helsingborg Hospital.

Richard Frobell explains that the research group’s results from 2010, which were published in the New England Journal of Medicine, caused a stir and questions were raised as to whether it was possible to say that an operation would not be needed in the long term.

Half of the patients who were randomly assigned not to undergo reconstructive surgery have had an operation in the five years since, after experiencing symptoms of instability.

“In this study, there was no increased risk of osteoarthritis or meniscal surgery if the ACL injury was treated with physiotherapy alone compared with if it was treated with surgery. Neither was there any difference in patients’ experiences of function, activity level, quality of life, pain, symptoms or general health,” says Richard Frobell.

“The new report shows that there was no difference in any outcome between those who were operated on straight away, those who were operated on later and those who did not have an operation at all. The message to the medical experts who are treating young, active patients with ACL injuries is that it may be better to start by considering rehabilitation rather than operating straight away.”

In Sweden, over 5 000 people every year suffer an anterior cruciate ligament injury — mainly young people involved in sport. There are different schools of treatment and Sweden stands out with treatment that is in line with the results of the study.

“On an international front, almost all of those with ACL injuries are operated on. In Sweden, just over half are operated on, but in southern Sweden we have been working for many years to use advanced rehabilitation training as the first method of treatment. Our research so far has confirmed that we are right in not choosing to operate on these injuries immediately. Longer-term follow-up is important, however, if we are to look more closely at the development of osteoarthritis in particular,” says Richard Frobell.

The research group, whose study is called KANON, Knee ACL NON-operative versus operative treatment, is now moving on to the next stage. This year, the third part of the study will begin, following up the patients ten years after anterior cruciate ligament injury.

Richard Frobell has also entered into a collaboration with researchers at the School of Economics and Management at Lund University to evaluate the health economics aspects of different treatment methods for ACL injury.

Journal References:

  1. R. B. Frobell, H. P. Roos, E. M. Roos, F. W. Roemer, J. Ranstam, L. S. Lohmander. Treatment for acute anterior cruciate ligament tear: five year outcome of randomised trialBMJ, 2013; 346 (jan24 1): f232 DOI:10.1136/bmj.f232
  2. Richard B. Frobell, Ewa M. Roos, Harald P. Roos, Jonas Ranstam, L. Stefan Lohmander. A Randomized Trial of Treatment for Acute Anterior Cruciate Ligament Tears.New England Journal of Medicine, 2010; 363 (4): 331 DOI:10.1056/NEJMoa0907797

From ScienceDaily

Fat is Pro-Inflammatory! Weight Loss Helps Relieve Pain From Arthritis (among other things!)

Copied from a recent post on the IVAPM*:

“…I would be looking for some of the non-pharmacologic strategies. You have already mentioned an important one, getting the weight off. Adipose tissue is the body’s largest endocrine organ, and it secretes, especially when in excess, a slew of nasty cytokines that essentially bathes the body – including the synovia and joints – in a soup of pro-inflammatory mediators. We have increasingly strong evidence in dogs that nothing more than weight loss will improve comfort and mobility in this species, including excellent one this year where the authors conclude “results indicate that body weight reduction causes a significant decrease in lameness from a weight loss of 6.10% onwards. Kinetic gait analysis supported the results from a body weight reduction of 8.85% onwards. These results confirm that weight loss should be presented as an important treatment modality to owners of obese dogs with OA and that noticeable improvement may be seen after modest weight loss in the region of 6.10 – 8.85% body weight”.”

Weight loss. There is no substitute. • Lago R, Gomez R, et al A new player in cartilage homeostasis: adiponectin induces nitric oxide synthase type II and pro-inflammatory cytokines in chondrocytes. Osteoarthritis Cartilage. 2008 Sep;16(9):1101-9. • Impellizeri JA, Tetrick MA, Muir P. Effect of weight reduction on clinical signs of lameness in dogs with hip osteoarthritis. JAVMA 2000 Apr 1;216(7):1089-91 • Burkholder, 2001 • Mlacnik E, Bockstahler BA, Muller M, et al. Effects of caloric restriction and a moderate or intense physiotherapy program for treatment of lameness in overweight dogs with osteoarthritis. J Am Vet Med Assoc. 2006 Dec 1;229(11):1756-60. • Marshall WG, Hazewinkel, HA, Mullen D, et al. Vet Res Commun. The effect of weight loss on lameness in obese dogs with osteoarthritis. 2010 Mar;34(3):241-53

*International Veterinary Association of Pain Management

Intestinal Bacteria Linked to Rheumatoid Arthritis

From ScienceDaily. com Nov. 5, 2013 — Researchers have linked a species of intestinal bacteria known as Prevotella copri to the onset of rheumatoid arthritis, the first demonstration in humans that the chronic inflammatory joint disease may be mediated in part by specific intestinal bacteria. The new findings by laboratory scientists and clinical researchers in rheumatology at NYU School of Medicine add to the growing evidence that the trillions of microbes in our body play an important role in regulating our health.

Using sophisticated DNA analysis to compare gut bacteria from fecal samples of patients with rheumatoid arthritis and healthy individuals, the researchers found that P. copri was more abundant in patients newly diagnosed with rheumatoid arthritis than in healthy individuals or patients with chronic, treated rheumatoid arthritis. Moreover, the overgrowth of P. copri was associated with fewer beneficial gut bacteria belonging to the genera Bacteroides.

“Studies in rodent models have clearly shown that the intestinal microbiota contribute significantly to the causation of systemic autoimmune diseases,” says Dan R. Littman, MD, PhD, the Helen L. and Martin S. Kimmel Professor of Pathology and Microbiology and a Howard Hughes Medical Institute investigator.
“Our own results in mouse studies encouraged us to take a closer look at patients with rheumatoid arthritis, and we found this remarkable and surprising association,” says Dr. Littman, whose basic science laboratory at NYU School of Medicine’s Skirball Institute of Biomolecular Medicine collaborated with clinical investigators led by Steven Abramson, MD, senior vice president and vice dean for education, faculty, and academic affairs; the Frederick H. King Professor of Internal Medicine; chair of the Department of Medicine; and professor of medicine and pathology at NYU School of Medicine.

“At this stage, however, we cannot conclude that there is a causal link between the abundance of P. copri and the onset of rheumatoid arthritis,” Dr. Littman says. “We are developing new tools that will hopefully allow us to ask if this is indeed the case.”

The new findings, reported today in the open-access journal eLife, were inspired by previous research in Dr. Littman’s laboratory, collaborating with Harvard Medical School investigators, using mice genetically predisposed to rheumatoid arthritis, which resist the disease if kept in sterile environments, but show signs of joint inflammation when exposed to otherwise benign gut bacteria known as segmented filamentous bacteria.

Rheumatoid arthritis, an autoimmune disease that attacks joint tissue and causes painful, often debilitating stiffness and swelling, affects 1.3 million Americans. It strikes twice as many women as men and its cause remains unknown although genetic and environmental factors are thought to play a role.

The human gut is home to hundreds of species of beneficial bacteria, including P. copri, which ferment undigested carbohydrates to fuel the body and keep harmful bacteria in check. The immune system, primed to attack foreign microbes, possesses the extraordinary ability to distinguish benign or beneficial bacteria from pathogenic bacteria. This ability may be compromised, however, when the gut’s microbial ecosystem is thrown off balance.

“Expansion of P. copri in the intestinal microbiota exacerbates colonic inflammation in mouse models and may offer insight into the systemic autoimmune response seen in rheumatoid arthritis,” says Randy S. Longman, MD, PhD, a post-doctoral fellow in Dr. Littman’s laboratory and a gastroenterologist at Weill-Cornell, and an author on the new study. Exactly how this expansion relates to disease remains unclear even in animal models, he says.

Why P. copri growth seems to take off in newly diagnosed patients with rheumatoid arthritis is also unclear, the researchers say. Both environmental influences, such as diet and genetic factors can shift bacterial populations within the gut, which may set off a systemic autoimmune attack. Adding to the mystery, P. copri extracted from stool samples of newly diagnosed patients appears genetically distinct from P. copri found in healthy individuals, the researchers found.

To determine if particular bacterial species correlate with rheumatoid arthritis, the researchers sequenced the so-called 16S gene on 44 fecal DNA samples from newly diagnosed patients with rheumatoid arthritis prior to immune-suppressive treatment; 26 samples from patients with chronic, treated rheumatoid arthritis; 16 samples from patients with psoriatic arthritis (characterized by red, flaky skin in conjunction with joint inflammation); and 28 samples from healthy individuals.

Seventy-five percent of stool samples from patients newly diagnosed with rheumatoid arthritis carried P. copri compared to 21.4% of samples from healthy individuals; 11.5% from chronic, treated patients; and 37.5% from patients with psoriatic arthritis.

Rheumatoid arthritis is treated with an assortment of medications, including antibiotics, anti-inflammatory drugs like steroids, and immunosuppressive therapies that tame immune reactions. Little is understood about how these medications affect gut bacteria. This latest research offers an important clue, showing that treated patients with chronic rheumatoid arthritis carry smaller populations of P. copri. “It could be that certain treatments help stabilize the balance of bacteria in the gut,” says Jose U. Scher, MD, director of the Microbiome Center for Rheumatology and Autoimmunity at NYU Langone Medical Center’s Hospital for Joint Diseases, and an author on the new study. “Or it could be that certain gut bacteria favor inflammation.”

The researchers plan to validate their results in regions beyond New York, since gut flora can vary across geographical regions, and investigate whether the gut flora can be used as a biological marker to guide treatment. “We want to know if people with certain populations of gut bacteria respond better to certain treatment than others,” says Dr. Scher. Finally, they hope to study people before they develop rheumatoid arthritis to see whether overgrowth of P. copri is a cause or result of autoimmune attacks.