Donor Fat-Based Stem Cells May Provide Augmented Healing of Rectovaginal Fistulas of Crohn’s Disease Patients


Fistulas are openings in organ systems that connect with another system. They usually result from wounds or erosions in the lining of a tube or duct that gets deeper and deeper and eventually opens into another tube or duct. Physical injuries can cause fistulas, but so can diseases such as Crohn’s disease. Anal fistulas result from erosions of the rectum that open to the outside and are typically very painful and do not readily heal.

Damián García-Olmo and his colleagues at the Universidad Autónoma de Madrid have conducted several clinical trials that have examined the ability of adipose-derived stem cells (ASCs) to facilitate the healing of fistulas in Crohn’s disease patients. A phase I study, which primarily examines safety, was published in 2005 (see García-Olmo D., et al., Dis Colon Rectum 2005; 48:1416-1423). According to this study, “No adverse effects were observed in any patient at the end of the follow-up period (minimum follow-up, 12 months; maximum follow-up, 30 months; follow-up average, 22 months).” The Phase II study was published in 2009 (García-Olmo, D., et al., Dis Colon Rectum 2009; 52:79-86). According to the results of this study, fistula healing was observed in 71 percent of patients who were treated with ASCs in combination with fibrin glue compared with 16 percent of patients who received fibrin glue alone. Quality of life scores were also higher in patients who received ASCs than in those who received fibrin glue alone. Once again, the stem cell treatments were well tolerated. The third study was a multicenter, randomized, single-blind clinical trial that enrolled 200 adult patients from 19 centers that were randomly assigned to three groups. The first group received 20 million stem cells (group A, 64 patients). The second group received 20 million adipose-derived stem cells plus fibrin glue (group B, 60 patients). The third group received only fibrin glue (group C, 59 patients). In treatment of anal fistulas in Crohn’s disease patients, a dose of 20 or 60 million adipose-derived stem cells alone or in combination with fibrin glue were demonstrably safe and did promote healing. However, there were no statistically significant differences between the three groups once the 3 groups were compared.

These studies suggest that stem cells from fat might have a place in the treatment of fistulas in Crohn’s disease patients. The application of the stem cells is feasible and safe, and requires no new equipment or skill. The stem cells also might augment the healing of these fistulas.

Unfortunately, anal fistulas are not the only type of fistulas that Crohn’s disease patients can experience. Female Crohn’s disease patients can have fistulas that open from their rectum into their birth canal. These rectovaginal fistula can deposit the contents of the gastrointestinal tract into the lower reproductive tract. While Crohn’s disease is not the only cause rectovaginal fistulas, Crohn’s disease patients are at higher risks for complications, which include: loss of control over stool deposition (fecal incontinence), hygiene problems combined with recurrent vaginal or urinary tract infections, inflammation of the birth canal and skin around the anus (perineum), abscess formation, which can become life-threatening if not treated, and recurrence of the fistula. Surgical treatment of rectovaginal fistulas requires that the tissue be free of inflammation before surgery, which can take time and cause extensive amounts of patient suffering.

Garcia-Olmo and his colleagues have conducted a small phase I-IIa clinical trial to evaluate the possibility of banked fat-based stem cells to treat recto-vaginal fistulas in female Crohn’s patients. This study has several limitations because it is so small and they have to exclude at least half of the participants because of complications beyond their control. Therefore, this study is not statistically significant. However, it does show what might be the beginnings of a stem-based treatment for this horrid condition.

The design of the study included 11 subjects who were initially enrolled in the study, but one of those recruited patients did not meet the criteria for the study. Therefore, ten subjects, all of whom suffered from Crohn’s disease and had rectovaginal fistulas were treated with 20 million fat-based stem cells that had been donated by a healthy volunteer in addition to surgical repair of their fistulas. These donated fat-based stem cells were provided by a Spanish biotechnology company called Cellerix S.L. Three months after this stem cell treatment, two patients were healed and the other either were given an additional treatment of 40 million fat-based stem cells. Of this group, four were healed. However, five of these patients experienced severe flare-ups of their Crohn’s disease that required treatment with biological agents, which disqualified these patients from further consideration from this study. The biological agents used to treat the Crohn’s disease flare-ups are very powerful medicines and can significantly influence the outcome of this study. Thus half of the subjects in this study had to be excluded. Of the five subjects that remained, 3 showed healing of their fistulas, and 2 did not.

The authors present the data as a “final efficacy rate of 60%.” However, given the high rate of exclusion and the very low numbers of subjects in this study, all we can say with any confidence is that based on the previous successes of this treatment in other studies, there is precedent for such a technique to be safe and somewhat effective, and that the data in this study are in a favorable direction. However, that’s about it.

One feature of this study that differs from the other clinical trials done by this same group is that the previous studies utilized the patient’s own fat-based stem cells, whereas this study used stem cells from a healthy donor. The authors stress that this modification greatly simplifies the procedure and decreases its expense. Because of the ease of the treatments, it reduces postoperative hospitalization and is minimally invasive. This new trial suggests that further work is warranted and the results or even minimally hopeful.

This work was published in the journal Stem Cells Translational Medicine 2016; 5(11): 1441-1446.

ASTIC Clinical Trial Fails to Show Clear Advantage to Hematopoietic Stem Cell Transplantation as a Treatment for Crohn’s Disease


Patients with Crohn’s disease (CD) sometimes suffer from daily bouts of stomach pain and diarrhea. These constant gastrointestinal episodes can prevent them from absorbing enough nutrition to meet their needs, and, consequently, they can suffer from weakness, fatigue, and a general failure to flourish.

To treat Crohn’s disease, physicians use several different types of drugs. First there are the anti-inflammatory drugs, which include oral 5-aminosalicylates such as sulfasalazine (Azulfidine), which contains sulfur, and mesalamine (Asacol, Delzicol, Pentasa, Lialda, Apriso). These drugs, have several side effects, but on the whole are rather well tolerated. If these don’t work, then corticosteroids such as prednisone are used. These have a large number of side effects, including a puffy face, excessive facial hair, night sweats, insomnia and hyperactivity. More-serious side effects include high blood pressure, diabetes, osteoporosis, bone fractures, cataracts, glaucoma and increased chance of infection.

If these don’t work, then the stronger immune system suppressors are brought out. These drugs have some very serious side effects. Azathioprine (Imuran) and mercaptopurine (Purinethol) are two of the most widely used of this group. If used long-term, these drugs can make the patient more susceptible to certain infections and cancers including lymphoma and skin cancer. They may also cause nausea and vomiting. Infliximab (Remicade), adalimumab (Humira) and certolizumab pegol (Cimzia) are the next line of immune system suppressors. These drugs are TNF inhibitors that neutralize an immune system protein known as tumor necrosis factor (TNF). These drugs are also associated with certain cancers, including lymphoma and skin cancers. The next line of drugs include Methotrexate (Rheumatrex), which is usually used to treat cancer, psoriasis and rheumatoid arthritis, but methotrexate also quells the symptoms of Crohn’s disease in patients who don’t respond well to other medications. Short-term side effects include nausea, fatigue and diarrhea, and rarely, it can cause potentially life-threatening pneumonia. Long-term use can lead to bone marrow suppression, scarring of the liver and sometimes to cancer. You will need to be followed closely for side effects.

Then there are specialty medicines for patients who do not respond to other medicines or who suffer from openings in their lower large intestines to the outside world (fistulae). These include cyclosporine (Gengraf, Neoral, Sandimmune) and tacrolimus (Astagraf XL, Hecoria). These have the potential for serious side effects, such as kidney and liver damage, seizures, and fatal infections. These medications are definitely cannot be used for long period of time as their side effects are too dangerous.

If the patient still does not experience any relief, then two humanized mouse monoclonal antibodies natalizumab (Tysabri) and vedolizumab (Entyvio). Both of these drugs bind to and inhibit particular cell adhesion molecules called integrins, and in doing so prevent particular immune cells from binding to the cells in the intestinal lining. Natalizumab is associated with a rare but serious risk of a brain disease that usually leads to death or severe disability called progressive multifocal leukoencephalopathy. In fact, so serious are the side effects of this medicine that patients who take this drug must be enrolled in a special restricted distribution program. The other drug, vedolizumab, works in the same way as natalizumab but does not seem to cause this brain disease. Finally, a drug called Ustekinumab (Stelara) is usually used to treat psoriasis. Studies have shown it’s useful in treating Crohn’s disease and might useful when other medical treatments fail. Ustekinumab can increase the risk of contracting tuberculosis and an increased risk of certain types of cancer. Also there is a risk of posterior reversible encephalopathy syndrome. More common side effects include upper respiratory infection, headache, and tiredness.

If this litany of side effects sounds undesirable, then maybe a cell-based treatment can help Crohn’s patients. To that end, a clinical trial called the Autologous Stem Cell Transplantation International Crohn’s Disease or ASTIC trial was conducted and its results were published in the December 15th, 2015 edition of the Journal of the American Medical Association.

The ASTIC trial enrolled 45 Crohn’s disease patients, all of whom underwent stem cell mobilization with cyclophosphamide and filgrastim, and were then randomly assigned to immediate stem cell transplantation (at 1 month) or delayed transplantation (at 13 months; control group).  Blood samples were drawn and mobilized stem cells were isolated from the blood.  In twenty-three of these patients, their bone marrow was partially wiped out and reconstituted by means of transplantations with their own bone marrow stem cells. The other 22 patients were given standard Crohn disease treatment (corticosteroids and so on) as needed.

The bad news is that hematopoietic stem cell transplantations (HSCT) were not significantly better than conventional therapy at inducing sustained disease remission, if we define remission as the patient not needing any medical therapies (i.e. drugs) for at least 3 months and no clear evidence of active disease on endoscopy and GI imaging at one year after the start of the trial. All patients in this study had moderately to severely active Crohn’s disease that was resistant to treatment, had failed at least 3 immunosuppressive drugs, and whose disease that was not amenable to surgery.  All participants in this study had impaired function and quality of life.  Also, the stem cell transplantation procedure, because it involved partially wiping out the bone marrow, cause considerable toxicities.

Two patients who underwent HSCT (8.7%) experienced sustained disease remission compared to one control patient (4.5%). Fourteen patients undergoing HSCT (61%) compared to five control patients (23%) had discontinued immunosuppressive or biologic agents or corticosteroids for at least 3 months. Eight patients (34.8%) who had HSCTs compared to two (9.1%) patients treated with standard care regimens were free of the signs of active disease on endoscopy and radiology at final assessment.

However, there were 76 serious adverse events in patients undergoing HSCT compared to 38 in controls, and one patient undergoing HSCT died.

So increased toxicities and not really a clear benefit to it; those are the downsides of the ASCTIC study.  An earlier report of the ASTIC trial in 2013, while data was still being collected and analyzed was much more sanguine.  Christopher Hawkey, MD, from the University of Nottingham in the United Kingdom said this: “Some of the case reports are so dramatic that it’s reasonable to talk about this being a cure in those patients.”  These words came from a presentation given by Dr. Hawkey at Digestive Disease Week 2013.  Further analysis, however, apparently, failed to show a clear benefit to HSCT for the patients in this study.  It is entirely possible that some patients in this study did experience significant healing, but statistically, there was no clear difference between HSCT and conventional treatment for the patients in this study.

The silver lining in this study, however, is that compared to the control group, significantly more HSCT patients were able to stop taking all their immunosuppressive therapies for the three months prior to the primary endpoint. That is a potential upside to this study, but it is unlikely for most patients that this upside is worth the heightened risk of severe side effects. An additional potential upside to this trial is that patients who underwent HSCT showed greater absolute reduction of clinical and endoscopic disease activity. Again, it is doubtful if these potential benefits are worth the higher risks for most patients although it might be worth it for some patients.

Therefore, when HSCT was compared with conventional therapy, there was no statistically significant improvement in sustained disease remission at 1 year. Furthermore, HSCT was associated with significant toxicity. Overall, despite some potential upside to HSCT observed in this study, the authors, I think rightly, conclude that their data do not support the widespread use of HSCT for patients with refractory Crohn’s disease.

Could HSCT help some Crohn’s patients more than others? That is a very good question that will need far more work with defined patient populations to answer.  Perhaps further work will ferret out the benefits HSCT has for some Crohn’s disease patients relative to others.

The ASTIC trial was a collaborative project between the European Society for Blood and Marrow Transplantation (EBMT) and the European Crohn’s and Colitis Organization (ECCO) and was funded by the Broad Medical Foundation and the Nottingham Digestive Diseases Centers.

Laboratory-Grown Intestine Shows Promise in Mice and Dogs


David Hackam is a pediatric surgeon at the Johns Hopkins Children’s Center. Unfortunately, Dr. Hackam spends a good deal of his time removing dead sections of intestine from sick babies, but he would deeply love to be able to do more than just take out intestines but actually replace the dead or dying intestinal tissue. It is that desire that has driven Hackam and his colleagues to grow intestines in the laboratory.

They begin with stem cells taken from the small intestines of human infants and mice and apply them to intestine-shaped scaffolds. The stem cells dig in, grow and form mini-intestines that just might be able to treat disorders like necrotizing enterocolitis and Crohn’s disease someday. Transplantation experiments in laboratory animals have shown that this laboratory-grown tissue and scaffolding are not rejected, but integrate into the tissues of the animals. Experiments in dogs have shown that the scaffold allowed dogs to heal from damage to the colon lining, essentially restoring healthy bowel function.

The study is a “great breakthrough,” says Hans Clevers, a stem cell biologist at the Hubrecht Institute in Utrecht, the Netherlands, who was not involved in the new research. Clevers and his colleagues were the first to identify stem cells in the intestine, and his lab developed the technique Hackam’s team used to grow intestinal tissue.

Making replacement organs by growing cells on scaffolds molded into the shape of the organ is not a new idea, since other researchers have used exactly this technique to make bladders and blood vessels. However, the laboratory-grown intestines made by Hackam and his group come closer to the shape and structure of a natural intestine than anything created in the laboratory before. In previous experiments carried out in other laboratories, the gut lining has been grown on flat scaffolds or in culture flasks. Under these conditions, the tissue tends to roll up into little balls that have the absorptive surface on the inside. Hackam and his coworkers, however, overcame this problem by using a scaffold fabricated from materials similar to surgical sutures. This material can be molded into any desired intestinal size and shape, and in Hackam’s hands, the scaffolds formed a true tube-shaped (like a real gut), with tiny projections on the inner surface that can help the tissue form functional small intestinal villi (the small fingers of tissue that increase the surface area of the intestine to increase nutrient absorption. “They can now make sheets of cells that can be clinically managed,” Clevers says. “Surgeons can handle these things and just stick them in.”

To grow the gut lining in the lab, the researchers painted the scaffold with a sticky collagen-rich substance and then dripped onto it a solution of stem cells from the small intestine. This concoction was grown in a culture system for a week. Interestingly, Hackam and his team found that if they added connective tissue cells, immune cells, and probiotics (bacteria that help maintain a healthy gut), all of these things helped the stem cells mature and differentiate.

Hackam’s group also sutured intestines grown from mouse stem cells into the tissue surrounding the abdominal organs of the mouse. The lab-grown intestines developed their own blood supply and normal gut structures despite the fact that they were not connected to the animals’ digestive tract. “Using the mouse’s own stem cells, we can actually create something that looks just like the native intestine,” Hackam says. The next step, he says, is “to hook it up.”

Before “hooking it up,” Hackam needed to be sure that the scaffold could be tolerated in living animals. Therefore he tested the new scaffold in dogs. He removed sections of large intestinal lining and replaced it with pieces of scaffolding. The dogs made a complete recovery: their gut lining regrew onto the scaffold and functioned normally to absorb water from the colon. After a few weeks, the scaffolding had completely dissolved and was replaced with normal connective tissue. “The scaffold was well tolerated and promoted healing by recruiting stem cells,” Hackam says. “[The dogs] had a perfectly normal lining after 8 weeks.”

This technique could help more than just dogs and mice, but could aid human patients. According to Hackam, scaffolds could be custom-designed for individual human patients to replace a portion of an intestine or the entire organ. This could be a revolutionary treatment for patients with necrotizing enterocolitis, a condition that destroys intestinal tissue in about 12% of premature babies in the United States. It could also potentially repair the intestines of patients with Crohn’s disease, an inflammatory bowel disorder that can have life-threatening complications and that affects more than 500,000 people in the United States. However, these lab-grown intestines must pass several other tests before they are ready for human clinical trials, Hackam cautions.

The first test that these laboratory-grown intestines must pass is the absorption test. Laboratory-grown small intestines must be transplanted into live animals and they must properly absorb food. Also, the technology that is used will also require some adjustments. For example, Mari Sogayar, a molecular biologist at the University of São Paulo in Brazil, points out that the collagen product that helps the stem cells stick to the scaffold is not meant for use in people. In the next experiments, Hackam says, the researchers plan to use a surgical-grade alternative.

“I take care of children who have intestinal deficiencies, eating deficiencies, and they are very much at wits’ end,” Hackam says. “I think what we can offer in the scientific community is a path toward something that one day will help a child.”

Pregnancy and Delivery Unaffected in Women Patients With Crohn’s Disease Who Were Treated With Fat-Based Stem Cells


Fat is a readily accessible source of mesenchymal stem cells (MSCs). When fat is extracted by liposuction, the result is a so-called stromal vascular fraction (SVF) that contains a mishmash of mast cells (important in allergies), blood vessel-making cells, blood vessel-associated cells, fibroblasts, and MSCs. These adipose-derived stem cells (ASCs) as they are called, can be relatively easily prepared once the SVF is digested by enzymes, and centrifuges. The living adult MSCs are then rather easily identified because they adhere to plastic tissue culture plates.

Fat-based MSCs have been used in clinical studies to help heal patients with Crohn’s disease who have “fistulas.”  For a picture of a fistula, see here.  Crohn’s disease (CD) is one of a group of gastrointestinal diseases known as IBDs or inflammatory bowel diseases. CD features inflammation of any part of the GI tract, and this inflammation can affect multiple layers of the GI tract. Fistulas form when a hole is eroded through the GI tract and into another organ system. For example, in women, the rectum and erode and form an opening in the vagina. Alternatively, an opening can appear in some place other than the anus. Because of the repeated irritation and extensive inflammation of these lesions, they tend to not heal.

Beginning in 2003, Damián García-Olmo and his team at the Jiménez Diaz Foundation University Hospital in Madrid, Spain have tested the efficacy of fat-based stem cells in treating patients with CD-based fistulas.  The results have been encouraging and highly positive, since ASCs promote healing of the fistulas and decrease recovery time (see de la Portilla F, et al. (2013) Int J Colorectal Dis 28:313–323; García-Olmo D, et al. (2003) Int J Colorectal Dis 18:451–454; García-Olmo D, et al. (2005) Dis Colon Rectum 48:1416–1423; Garcia-Olmo D, et al. (2009) Dis Colon Rectum 52:79–86).

Recently, Garcia-Olmo and his colleagues examined data from several their patients who went on to become pregnant after their treatment with fat-based stem cells and even given birth. This study, which was published in the June 2015 edition of Stem Cells Translational Medicine, examined six patients from these previous clinical trials who were successfully treated with fat-based stem cells, had satisfactory resolution and healing of their lesions, and then went on to become pregnant and give birth.

Of the five women examined in this study, one was treated for rectovaginal and perinatal fistulas, two for rectovaginal fistulas only, and two others for perianal fistulas only. All women received 2 doses of 20 million and 40 million stem cells at three-four-month intervals. One patient, however, received 2 doses of 6.6 million and 20 million stem cells nine months apart.

The fertility of these women and their pregnancies were unaffected by their previous cell therapies. There were no signs of treatment-related malformations in the babies they delivered, and their bodies did not show any identifiable signs of structural abnormalities as a result of the stem cell treatments. It must be said, that all four women who delivered healthy babies (one of them even had twins) elected for Caesarian sections. The fifth woman, unfortunately, miscarried twice, both times during the first trimester.

However, even though this represents a small data set, this study does strongly suggest that injection of a patient’s own fat-based stem cells does not negatively affect a woman’s ability to conceive, the course of her pregnancy, or the health of her baby.

A Patient’s Own Stem Cells Treats Their Crohn’s Disease


Stem cells isolated from the fat of patients with Crohn’s disease, an inflammatory disease of the bowel, relieved them from fistulas, which are a common, and potentially dangerous side effect of the disease. This is according to the results of a phase 2 clinical trial published in the latest issue of STEM CELLS Translational Medicine (SCTM).

Patients with Crohn’s disease suffer from a painful, chronic disease in which the body’s immune system attacks its own gastrointestinal tract. In Crohn’s patients, inflammation within the bowel can sometimes extend completely through the intestinal wall and create a what is known as a “fistula.”. Fistulas are abnormal connections between the intestine and another organ or even the skin. If left untreated, a fistula can become infected and form an abscess that can be life threatening.

Chang Sik Yu, M.D., Ph.D., of the Asan Medical Center in Seoul, Korea, who is a senior author of the SCTM paper, describes the results of a clinical trial that was conducted in collaboration with four other hospitals in South Korea. According to Dr. Yu: “Crohn’s fistula is one of the most distressing diseases as it decreases patient’s quality of life and frequently recurs. It has been reported to occur in up to 38 percent of Crohn’s patients and over the course of the disease, 10 to 18 percent of them must undergo a proctectomy, which is a surgical procedure to remove the rectum.”

Overall, the treatments currently available for Crohn’s fistula remain unsatisfactory because they fail to achieve complete closure, lower recurrence of the fistulas and do not limit adverse effects, Dr. Yu said. Given the challenges and unmet medical needs in Crohn’s fistula, attention has turned to stem cell therapy as a possible treatment.

Several studies, including those undertaken by Dr. Yu’s team, have shown that mesenchymal stem cells (MSCs) do indeed improve Crohn’s disease and Crohn’s fistula. Their phase II trial enrolled 43 patients for a term of one year, over the period from January 2010 to August 2012. These patients received injections of their own fat-based MSCs, and 82 percent of them experienced complete closure of fistula eight weeks after the final ASC injection. 75 percent of the trial participants remained fistula-free two years later.

“It strongly demonstrated MSCs derived from ASCs are a safe and useful therapeutic tool for the treatment of Crohn’s fistula,” Dr. Yu said.

The latest study was intended to evaluate the long-term outcome by following 41 of the original 43 patients for yet another year. Dr. Yu reported, “Our long-term follow-up found that one or two doses of autologous ASC therapy achieved complete closure of the fistulas in 75 percent of the patients at 24 months, and sustainable safety and efficacy of initial response in 83 percent. No adverse events related to ASC administration were observed. Furthermore, complete closure after initial treatment was well sustained.”

“These results strongly suggest that autologous ASCs may be a novel treatment option for Crohn’s fistulae,” he said.

“Stem cells derived from fat tissue are known to regulate the immune response, which may explain these successful long-term results treating Crohn’s fistulae with a high risk of recurrence,” said Anthony Atala, M.D., Editor-in-Chief of STEM CELLS Translational Medicine and director of the Wake Forest Institute for Regenerative Medicine.

Treating Crohn’s Disease Fistulas with Fat Stem Cells


All of us have probably heard of Crohn’s disease or have probably known someone with Crohn’s disease. While the severity of this disease varies from patient to patient, some people with Crohn’s disease simply cannot get a break.

Crohn’s disease is one of a group of diseases known as IBDs or “Inflammatory Bowel Diseases.” IBDs include Crohn;s disease, which can affect either the small or large intestine and rarely the esophagus and mouth, ulcerative colitis, which is restricted to the large intestine, and other rarer types of IBDs known that include Collagenous colitis, Lymphocytic colitis, Ischaemic colitis, Diversion colitis, Behçet’s disease, and Indeterminate colitis.

Crohn’s disease (CD) involves the patient’s immune system attacking the tissues of the gastrointestinal tract, which leads to chronic inflammation within the bowel. While the exact mechanism by which this disease works is still not completely understood and robustly debated, Crohn’s disease was originally thought to be an autoimmune disease in which the immune system recognizes some kind of surface protein in the gastrointestinal tract as foreign and then attacks it. However, genetic studies of CD, linked with clinical and immunological studies have shown that this is not the case. Instead, CD seems to be due to a poor innate immunity so that the bowel has an accumulation of intestinal contents that breach the lining of the gastrointestinal tract, resulting in chronic inflammation. A seminal paper by Daniel Marks and others in the Lancet in 2006 provided hard evidence that this is the case. When Marks and others tested the white blood cells from CD patients and their ability to react to foreign invaders, those cells were sluggish and relatively ineffective. Therefore, Crohn’s seems to be an overactivity of the acquired immunity to make up for poor innate immunity.

Given all that, one of the biggest, most painful consequences of CD are anal fistulas. If those sound painful it’s because they are. A fistula is a connection between to linings in your body that should not normally be connected. In CD patients, the anus and the attached rectum get kicked about by excessive inflammation and tears occur. These tears heal, but the healing can cause connections between linings that previously did not exist. Therefore fecal material not comes out of the body in more than one place. Sounds disgusting? It gets worse. Those areas that leak feces are not subject to extensive pus formation and they must be fixed surgically. But how do you fix something that is constantly inflamed? It’s an ongoing problem in medicine.

Enter stem cells to the rescue, maybe. In Spain, a multicenter clinical study has just been published that shows that fat-derived mesenchymal stem cells might provide a better way to treat these fistulas in CD patients. Mesenchymal stem cells have the ability to suppress inflammation, and for that reason, they are excellent candidates to accelerate healing in cases such as these.

Galindo and his group took 24 CD patients who had at least one draining fistula (yes, some have more than one) and gave them 20 million fat-derived mesenchymal stem cells. These cells were extracted from someone else, which is an important fact, since liposuction procedures on these patients might have added to their already surfeit of inflammation.

For this treatment, the cells were administered directly on the lesion, which is almost certainly important. If the closing of the fistula was incomplete after 12 weeks, then the patients were given another dose of 40 million fat-derived mesenchymal stem cells right on the lesion. All these patients were followed until week 24 after the initial stem cell administration.

The results were very hopeful. There were no major adverse effects six months after the stem cell treatment. This is a result seen over and over with mesenchymal stem cells – they are pretty safe when administered properly. Secondly, full analysis the data showed that at week 24 69.2% of the patients showed a reduction in the number of draining fistulas. Even more remarkably, 56.3% of the patients achieved complete closure of the treated fistula. That is just over half. Also, 30% of the cases showed complete closure of all existing fistulas. These results are exciting when you consider the criteria they used for complete closure: absence of draining pus through its former opening. complete “re-epithelization” of the tissue, which means that the lining of the tissue is healed, looks normal and is properly attached to the proper neighbors, and magnetic resonance image (MRI) scans of the region must look normal. For these patients, the MRI “Score of Severity,” which is a measure of the structural abnormality of the anal region, showed statistically significant reductions at week 12 with a marked reduction at week 24. Folks that’s good news.

Galindo interprets his results cautiously and notes that this is a small study, which is true. He also states that the goal of this study was to ascertain the safety of this technique, and when it comes to safety, this technique is certainly safe. When it comes to efficacy, another larger study is required that specifically examined the efficacy of this technique. Galindo is, of course, quite correct, but this is certainly a very exciting result, and hopefully these cells will get further chances to “strut their therapeutic stuff.”

See de la Portilla F, et al Expanded allogeneic adipose-derived stem cells (eASCs) for the treatment of complex perianal fistula in Crohn’s disease: results from a multicenter phase I/IIa clinical trial.  Int J Colorectal Dis. 2013 Mar;28(3):313-23. doi: 10.1007/s00384-012-1581-9. Epub 2012 Sep 29.

Stem Cell Therapy for Inflammatory Bowel Disease


Graca Almeida-Porada is professor of regenerative medicine at Wake Forest University in the Wake Forest Baptist’s Institute for Regenerative Medicine. Dr. Almeida-Porta and her colleagues have identified a special population of stem cells in the bone marrow that can migrate to the intestine and regenerate the intestine. Thus this stem population might provide a treatment for inflammatory bowel diseases or IBDs.

Approximately one million Americans have IBDs, and the main IBDs are ulcerative colitis, which is restricted to the large intestine, and Crohn’s disease, which involves the small and large intestine. These IBDs result from the immune system recognizing some component of the gastrointestinal system as foreign. and the immune system then attacks the gastrointestinal system as though it was a foreign invader. The result is chronic inflammation in the gastrointestinal tract, pain, bloody stools, redness and swelling of the bowel, in some severe cases, rupture of the bowel and death.

There are no cures for IDBs, but several drugs that suppress the immune response against the bowel, such as mesalamine (marketed as Asacol), sulfasalazine (Azulfidine), balsalazide (Colazal) and olsalazine (Dipentum) can reduce inflammation and assuage the symptoms of IBDs. However, there is no treatment to replace the damaged and dead cells in the bowel that result from the inflammation. Even though the bowel does regenerate to some degree, these extra bouts of cell proliferation can increase the patient’s risk of colon cancer. Is there a stem cell treatment to regenerate the bowel?

Research from Almeida-Porada’s laboratory has identified stem cells from umbilical cord blood that can make blood vessels that can also migrate to the intestine and liver (Wood JA, et al., Hepatology. 2012 Sep;56(3):1086-96). Now work in her lab has extended this original observations.

“We’ve identified two populations of human cells that migrate to the intestine – one involved in blood vessel formation and the other that can replenish intestinal cells and modulate inflammation,” said Almeida-Porada. She continued: “Our hope is that a mixture of these cells could be used as an injectable therapy to treat IBD.”

These cells would theoretically contribute cells to the intestine and facilitate and induce tissue healing and recovery. The lining of the intestine has one of the highest cellular turnover rates in the body. Intestinal cell types are being renewed weekly from this pool of intestinal cells that are in an area of the intestine known as the crypt.

In this current study, Almeida-Porada’s team used specific cell surface proteins (cell markers) to identify a stem cell population in human bone marrow that possesses the highest potential to migrate to the intestine and thrive in the intestine. These intestine-bound cells expressed high levels of a protein called ephrin type B, which is typically found on the surfaces of cells involved in tissue repair and wound closure.

Ephrin Protein Structure
Ephrin Protein Structure

When these ephrin type B-enriched bone marrow cells were injected into fetal sheep, the bone marrow-derived cells were able to migrate to the intestine and contribute to the growth and development of the sheep intestine.  Interestingly, these cells took up their positions in the intestinal crypts.

Almeida-Porada comment on her work:  “Previous studies in animals have shown that the transplantation of bone-marrow-derived cells can contribute to the regeneration of the gastrointestinal tract in IBD.  However, only small numbers of cells were successfully transplanted using this method.  Our goal with the current study was to identify populations of cells that naturally migrate to the intestine and have the intrinsic ability to restore tissue health.”

While these two studies show that the cells can migrate to and survive in a healthy intestine, the next step will be to determine whether they can survive in an inflamed intestine, like the type found in IBD patients.  In could be that preconditioning of the cells is required, as in the case of stem cell treatments for the heart after a heart attack.