Emerging treatments for complex perianal fistula in Crohn’s disease

Local injection of infliximab in severe fistulating perianal Crohn's disease: an open uncontrolled study

BACKGROUND

Perianal fistulas are frequent complications of Crohn's disease. Intravenous infliximab can control perianal disease and promote perianal fistula closure. Perifistular infliximab injections have been proposed for patients who are intolerant or unresponsive to intravenous therapy. The aim of this study was to assess the long-term efficacy of surgical treatment combined with local infliximab therapy.

METHODS

A prospective cohort study was designed. Twelve patients with Crohn's disease and high/complex transphincteric and intrasphincteric perianal fistulas refractory to other treatment were submitted to core-out fistulectomies, plus perifistular injections of infliximab (20-25 mg in 15-20 ml of 5% glucose) every 4-6 weeks. The main outcome measure was the clinical closure of all perianal fistulas. A 95% confidence interval was calculated for short- and long-term fistula closure rates.

RESULTS

None of the procedures were associated with local or systemic adverse effects. Four patients did not complete treatment, two because of relapse of intestinal symptoms, which required intravenous infliximab. In one case, treatment with intravenous infliximab was complicated by a hypersensitivity reaction. Eight patients continued treatment until all perianal fistulas were closed and setons were removed (median: 5 sessions). Persistent closure was observed in seven (87.5%, 95% CI: 47.4-99.6) of the eight patients 12 months after completion of treatment and in five (62.5%; 95% CI: 24.5-91.5) of eight at the end of follow-up (range: 19-43 months, median: 35 months).

CONCLUSIONS

The cohort we examined is small, but fistulectomy combined with repeated perifistular injections of infliximab appears to be safe and may help in fistula healing. However, in most patients, permanent closure of all fistulas is not achieved.

Human adipose-derived stem cells impair natural killer cell function and exhibit low susceptibility to natural killer-mediated lysis

Human adipose-derived stem cells (hASCs) have been successfully used in treating numerous diseases. However, several aspects need to be considered, particularly in the context of allogeneic cell therapy. To better understand hASCs-host interactions, we studied the phenotype of hASCs and their modulatory effect on natural killer (NK) cells by using bone marrow-mesenchymal stem cells (hBM-MSCs) as a reference. The hASCs displayed a lower susceptibility to NK cell-mediated lysis and a lower expression of ligands for DNAM-1 when compared with hBM-MSCs. Moreover, here we demonstrated that hASCs and hBM-MSCs can modulate NK cells through the action of soluble factors such as indoleamine 2,3-dioxygenase. Altogether, these results suggest that for an adoptive cell therapy based on the transfer of allogeneic hASCs, the NK-hASCs crosstalk will not result in an immediate recognition of the transferred cells. Thus, hASCs may remain in the tissue long enough to balance the immune response before being cleared.

Once fat was fat and that was that: our changing perspectives on adipose tissue

Abstract

Past civilisations saw excess body fat as a symbol of wealth and prosperity as the general population struggled with food shortages and famine. Nowadays it is recognised that obesity is associated with co-morbidities such as cardiovascular disease and diabetes. Our views on the roll of adipose tissue have also changed, from being solely a passive energy store, to an important endocrine organ that modulates metabolism, immunity and satiety. The relationship between increased visceral adiposity and obesity-related co-morbidities has lead to the recognition that variation in fat distribution contributes to ethnic differences in the prevalence of obesity-related diseases. Our current negative view of adipose tissue may change with the use of pluripotent adipose-derived stromal cells, which may lead to future autologous stem cell therapies for bone, muscle, cardiac and cartilage disorders. Here, we briefly review the concepts that adipose tissue is an endocrine organ, that differences in body fat distribution underline the aetiology of obesity-related co-morbidities, and the use of adipose-derived stem cells for future therapies.

Endoanal ultrasonography may distinguish Crohn's anal fistulae from cryptoglandular fistulae in patients with Crohn's disease: a cross-sectional study

BACKGROUND

The aim of the study was a cross-sectional investigation into the types of anal fistulae in patients with Crohn's disease using 3-dimensional endoanal ultrasonography.

METHODS

The study population consisted of 45 patients with established Crohn's disease referred in a 2-year period for treatment of anal fistula. The fistulae were classified according to the presence of three criteria: 1. bifurcation or secondary extension; 2. cross-sectional width ≥ 3 mm; and 3. content of hyperechoic secretions.

RESULTS

The fistulae of 24 patients (53%) satisfied two or three criteria and were classified as true Crohn's fistulae, while the fistulae of 21 patients satisfied one or none of the criteria and were the cryptoglandular type. The fistulae in the two or three criteria group had been in existence for 8.4 years on average and those in the cryptoglandular group for 4.5 years on average (P = 0.283). The corresponding numbers of previous operations for fistula were 5.7 (range 0-32) and 1.5 (range 0-6), respectively (P = 0.0211). The presence of colitis or proctitis was similar across the groups, but the perianal Crohn's disease activity index was higher with a Crohn's type of fistula (P = 0.0097). Also, a larger proportion had been treated with anti-TNF-monoclonal antibody (0.0169).

CONCLUSIONS

Endoanal ultrasonography was capable of discerning two subgroups of fistula in Crohn's patients. These groups were clinically different indicating that the prospect of surgical cure is also different.

Perianal Crohn’s disease: Is there something new?

Perianal lesions are common in patients with Crohn’s disease, and display aggressive behavior in some cases. An accurate diagnosis is necessary for the optimal management of perianal lesions. Treatment of perianal Crohn’s disease includes medical and/or surgical options. Recent discoveries in the pathogenesis of this disease have led to advances in medical and surgical therapy with good results. Perianal lesions in Crohn’s disease remain a challenging aspect for both gastroenterologists and surgeons and lead to a greatly impaired quality of life for all patients affected by this disease. A multidisciplinary approach is mandatory to obtain the best results.

Immunopathological characteristics of cryptoglandular and Crohn's anorectal fistulas

Anorectal fistulas are quite common proctologic disorders. They can be either of cryptoglandular origin or can be associated with Crohn's disease and chronic ileocolitis. Mechanical obstruction and local infections are prime causes of this pathological condition. Genetic predisposition and inadequate immune response with overproduction of pro-inflammatory cytokines appear prominently in the course of Crohn's disease. Interferon-gamma, a Th1 type cytokine, reflecting the engagement of cellular immune mechanisms, is the first to be produced in the intestinal mucosa. The inflammatory process in the colon mucosa induced by the abundant microbial flora is sustained and turned chronic by the gradual elevation of the local TNF-a and regulatory cytokines levels (interleukin-10, transforming growth factor-beta). The number of activated local memory T cells CD4+CD45RBl0 increases significantly. The regulatory CD4+CD25+ T lymphocytes producing interleukin-10 increase also trying to counterbalance the cytokine reaction. The chronic inflammatory infiltrates of the colon mucosa are represented by lymphocytes, plasma cells, macrophages. The long-term activation of macrophages by the released interferon-gamma leads to tissue damage and potentiation of angiogenesis--a risk factor for carcinoma development. Management of anorectal abscesses and fistulas is complex aiming to alleviate the symptoms, prevent relapses, reduce the risk of sphincter damage and improve quality of life. The main approach (surgery) should be combined with antimicrobial infection control and immunomodulation by intravenous or local administration of anti-TNF-alpha antibodies.

Porcine dermal collagen matrix injection may enhance flap repair surgery for complex anal fistula

INTRODUCTION

The use of biomaterials to treat anal fistula has drawn great interest. More recently, a porcine dermal matrix injection has been proposed as infill biomaterial to treat fistulas.

METHODS

We propose a novel approach consisting in non-cutting seton positioning followed by flap repair associated with dermal matrix injection into the fistula tracts after several weeks.

RESULTS

We report our experience with this two-staged procedure on 11 consecutive patients with recurrent high trans-sphincteric fistulas with a minimum follow-up of 6 months.

CONCLUSIONS

In our experience, this two-stage approach seems to be safe and effective.

Current treatment of rectovaginal fistula in Crohn’s disease

Rectovaginal fistula (RVF) continues to be the most difficult perianal manifestation of Crohn’s disease to treat. This devastating and disabling complication has a significant impact on patients’ quality of life and presents unique management challenges. Current therapeutic approaches include many medical therapeutics and surgical treatments with a wide range of success rates reported. However, current evidence is lacking to support any recommendation. The choice of repair depends on various patient and disease factors and basic surgical tenets. In this article, we review the current options to consider in the treatment of Crohn’s-related RVF, and try to evaluate their effects on fistulae closure and quality of life.

Clinical and preclinical translation of cell-based therapies using adipose tissue-derived cells

Adipose tissue is now recognized as an accessible, abundant, and reliable site for the isolation of adult stem cells suitable for tissue engineering and regenerative medicine applications. The past decade has witnessed an explosion of preclinical data relating to the isolation, characterization, cryopreservation, differentiation, and transplantation of freshly isolated stromal vascular fraction cells and adherent, culture-expanded, adipose-derived stromal/stem cells in vitro and in animal models. This body of work has provided evidence supporting clinical translational applications of adipose-derived cells in safety and efficacy trials. The present article reviews the case reports and phase I-III clinical evidence using autologous adipose-derived cells that have been published, to date, in the fields of gastroenterology, neurology, orthopedics, reconstructive surgery, and related clinical disciplines. Future directions and challenges facing the field are discussed and evaluated.

The adipose-derived stem cell: looking back and looking ahead

In 2002, researchers at UCLA published a manuscript in Molecular Biology of the Cell describing a novel adult stem cell population isolated from adipose tissue-the adipose-derived stem cell (ASC). Since that time, the ASC has gone on to be one of the most popular adult stem cell populations currently being used in the stem cell field. With multilineage mesodermal potential and possible ectodermal and endodermal potentials also, the ASC could conceivably be an alternate to pluripotent ES cells in both the lab and in the clinic. In this retrospective article, a historical perspective on the ASC is given together with exciting new applications for the stem cell being considered today.