Mycophenolate Mofetil Impairs the Integrity of Colonic Anastomosis

DOES THE ASSOCIATION OF TACROLIMUS AND MYCOPHENOLATE MOFETIL CHANGE THE HEALING OF THE ABDOMINAL WALL? STUDY IN RATS SUBMITTED TO ISCHEMIA AND KIDNEY REPERFUSION

BACKGROUND

Tacrolimus and mycophenolate mofetil are immunosuppressive agents widely used on the postoperative period of the transplants.

AIM

To evaluate the influence of the association of them on the abdominal wall healing in rats.

METHODS

Thirty-six Wistar rats were randomly assigned in three groups of 12. On the early postoperative period, four of the control group and three of the experimental groups died. The three groups were nominated as follow: control group (GC, n=8); group I (GI, n=11, standard operation, mycophenolate mofetil and tacrolimus); group II (GII, n=10, standard operation, mycophenolate mofetil and tacrolimus). The standard operation consisted of right total nephrectomy and 20 min ischemia of the left kidney followed by reperfusion. Both NaCl 0.9% and the immunosuppressive agents were administered starting on the first postoperative day and continuing daily until the day of death on the 14th day. On the day of their deaths, two strips of the anterior abdominal wall were collected and submitted to breaking strength measurement and histological examination.

RESULTS

There were no significant differences in wound infection rates (p=0,175), in the breaking strength measurement and in the histological examination among the three groups.

CONCLUSION

The combination of the immunosuppressive agents used in the study associated with renal ischemia and reperfusion does not interfere in the abdominal wall healing of rats.

Glucagon-Like Peptide-2 Analogue ZP1849 Augments Colonic Anastomotic Wound Healing

Background

The enteroendocrine hormone glucagon-like peptide- (GLP-) 2 is a potent trophic factor in the gastrointestinal tract. The GLP-2 receptor (GLP-2R) is expressed in the stroma of the large bowel wall, which is the major therapeutic target area to prevent anastomotic leakage. We investigated the efficacy of the long-acting GLP-2 analogue ZP1849 on colonic anastomotic wound healing.

Methods

Eighty-seven male Wistar rats were stratified into four groups and received daily treatment with vehicle or ZP1849 starting one day before (day -1) end-to-end anastomosis was constructed in the left colon on day 0, and on days 0 (resected colon segment), 3, and 5, gene expressions of GLP-2R, Ki67, insulin-like growth factor- (IGF-) 1, type I (COL1A1) and type III (COL3A1) procollagens, cyclooxygenase- (COX-) 1, COX-2, and matrix metalloproteinase- (MMP-) 7 were quantified by RT-qPCR. Breaking strength, myeloperoxidase (MPO), transforming growth factor- (TGF-) β1, and soluble collagen proteins were measured on days 3 and 5.

Results

ZP1849 treatment increased Ki67 (P < 0.0001) and IGF-1 (P < 0.05) mRNA levels in noninjured colon day 0, and postoperatively in the anastomotic wounds compared to vehicle-treated rats. ZP1849-treated rats had increased (P = 0.042) anastomotic breaking strength at day 5 compared with vehicle. COL1A1 and COL3A1 mRNA levels (P < 0.0001) and soluble collagen proteins (P < 0.05) increased from day 3 to day 5 in ZP1849-treated rats, but not in vehicle-treated rats. COX-2 mRNA and MPO protein levels decreased from day 3 to day 5 (P < 0.001) in both groups. ZP1849 treatment reduced TGF-β1 protein levels on day 5 (P < 0.001) but did not impact MMP-7 transcription.

Conclusions

The GLP-2 analogue ZP1849 increased breaking strength, IGF-1 expression, and cell proliferation, which may be beneficial for colonic anastomotic wound healing.

Giant Gastric Ulcers: An Unusual Culprit

Mycophenolate Mofetil (MMF) is routinely used immunosuppressant in solid organ transplantation is commonly associated with several gastrointestinal (GI) side effects. Here we present a case of giant gastric ulcer of 5 cm from MMF use post cardiac transplant. CASE DESCRIPTION: A 56-year-old male with history of severe ischemic cardiomyopathy post heart transplant was on immunosuppression with MMF, tacrolimus and prednisone for 5 months. He presented with severe epigastric pain and intermittent episodes of melena for 1 month. His pain radiated to back that is worsened with eating. Associated with loss of appetite, vomiting and 16-pound weight loss in 3 months. He never smoked, drank alcohol or used over the counter pain medications. He was profoundly anemic requiring blood transfusions. EGD performed demonstrated very large clean-based ulcer of 5 cm diameter in the body, smaller ulcer of 8 mm diameter in pre-pyloric region and 5-10 small aphthous ulcers in the gastric body and fundus. Gastric biopsies taken from the ulcer were negative for Helicobacter pylori, cytomegalovirus and malignancy. Flexible sigmoidoscopy revealed non-bleeding inflamed internal hemorrhoids. Consequently, MMF was discontinued and switched to azathioprine. He was treated with twice daily proton pump inhibitor therapy with resolution of abdominal pain, improved appetite and weight gain. DISCUSSION: MMF is well known for common GI side-effects such as nausea, diarrhea, vomiting, ulcers, abdominal pain and rarely gastrointestinal bleeding. Few studies reported 3 to 8% incidence of ulcer perforation and GI bleeding within 6 months. Risk of gastroduodenal erosions is nearly 1.83 times for MMF, with the highest lesions associated with MMF-tacrolimus-corticosteroid combination treatment as seen in our patient. Hypothesis is that GI tract is vulnerable because of dependence of enterocytes on de novo synthesis of purines, which is disrupted by MMF. Typically, upper GI mucosal injuries of mucosal irritation leading to esophagitis, gastritis and/or ulcers are seen. Endoscopy is both diagnostic and therapeutic if bleeding gastric ulcers are noted. Minor complications improve with reduction of drug dose or use of enteric coated preparation if feasible. Discontinuation of the drug is main stay in the management of MMF related ulcer disease. Simple medical treatment with either H2-receptor antagonists, proton-pump inhibitors, coating agents, prostaglandins or combination has proven effective in most cases. Considering excellent results with medical management of ulcer, role of surgery is limited.

The effect of gender on early colonic anastomotic wound healing

PURPOSE

Clinically, male patients subjected to colorectal surgery are more prone to develop anastomotic leakage than female patients by unknown mechanisms. Our aim was to investigate the impact of gender on anastomotic wound healing using an experimental model.

METHODS

One-layer colonic anastomosis was constructed in 8-week-old 28 male and 32 female Sprague-Dawley rats. Animals of one group (n = 30) were sacrificed immediately after surgery day 0 and the other group (n = 30) on postoperative day 3. Anastomotic breaking strength, total collagen (hydroxyproline), soluble collagen (Sircol), matrix metalloproteinase (MMP)-9, and transforming growth factor (TGF)-β1 were measured.

RESULTS

The anastomotic breaking strength decreased from day 0 to day 3 with no significant gender differences either in the extent of decline (P = 0.122) or absolute day 3 strengths (P = 0.425). Analogously, total collagen concentration in the anastomotic wounds decreased postoperatively and were lower (P = 0.043) in the male compared with the female rats on day 3. MMP-9 levels increased in the anastomoses postoperatively, but they did not differ (P = 0.391) between male and female animals. Soluble collagen levels were lower in the day-3 anastomoses of male versus female rats (P = 0.015) and correlated positively with total TGF-β1 levels (r_S = 0.540, P = 0.006). Although TGF-β1 tended to be lower in male compared with the female rats, the differences did not reach statistical significance.

CONCLUSION

Our findings point towards a less favorable collagen metabolism in colonic anastomoses of male compared with female rats during early wound healing.

Duodenal leaks after pancreas transplantation with enteric drainage - characteristics and risk factors

Pancreas-kidney transplantation with enteric drainage has become a standard treatment in diabetic patients with renal failure. Leaks of the graft duodenum (DL) remain a significant complication after transplantation. We studied incidence and predisposing factors of DLs in both simultaneous pancreas-kidney (SPK) and pancreas after kidney (PAK) transplantation. Between January 2002 and April 2013, 284 pancreas transplantations were performed including 191 SPK (67.3%) and 93 PAK (32.7%). Patient data were analyzed for occurrence of DLs, risk factors, leak etiology, and graft survival. Of 18 DLs (incidence 6.3%), 12 (67%) occurred within the first 100 days after transplantation. Six grafts (33%) were rescued by duodenal segment resection. Risk factors for a DL were PAK transplantation sequence (odds ratio 3.526, P = 0.008) and preoperative immunosuppression (odds ratio 3.328, P = 0.012). In the SPK subgroup, postoperative peak amylase as marker of preservation/reperfusion injury and recipient pretransplantation cardiovascular interventions as marker of atherosclerosis severity were associated with an increased incidence of DLs. CMV-mismatch constellations showed an increased incidence in the SPK subgroup, however without significance probability. Long-term immunosuppression in PAK transplantation is a major risk factor for DLs. Early surgical revision offers the chance of graft rescue.

Effects of immunosuppressive therapy on wound healing

Immunosuppressive therapy is increasingly being used in clinical practice and has been shown to affect wound healing to varying degrees. This article looks at the effects of the newer immunosuppressive agents on wound healing. It is shown that wound healing is impaired via different mechanisms. Some of the animal and human studies are reviewed in more detail. It is shown that some of the newer agents affect wound healing to such an extent that reduction or avoidance of these drugs until complete wound healing is achieved is advocated. More research is required for these newer agents to determine the most appropriate time to introduce them.

Temporal expression of cytokines in rat cutaneous, fascial, and intestinal wounds: a comparative study

BACKGROUND

Previous studies have shown that healing in intestinal wounds is proportionally faster than skin. Cytokines and growth factors play a major role in these coordinated wound-healing events. We hypothesized that this more rapid intestinal healing is due to an early upregulation of proinflammatory cytokines (IL-1beta, TNF-alpha, and IFN-gamma), followed by increases in the expression of the anti-inflammatory cytokine IL-10 and growth factor TGF-beta.

METHODS

Four wounds (skin, fascia, small intestinal, and colonic anastomosis) were created in each of 48 juvenile male Sprague Dawley rats; tissue samples of each site were harvested at 0, 1, 3, 5, 7, and 14 days postoperatively (n = 8/group) and levels of IL-1beta, IFN-gamma, TNF-alpha, IL-10 and TGF-beta expression from each site were measured using ELISA kits.

RESULTS

IL-1beta expression peaked earlier in small-intestinal and colonic wounds when compared to skin or fascia (e.g., small intestine: day 3 and colon day 5, P < 0.05 by ANOVA). Post-wounding levels of TNF-alpha were elevated in fascial wounds, but decreased in small-intestinal and colonic wounds. IFN-gamma levels were not significantly altered in any wounds. IL-10 showed a similar downregulation pattern in all wounds, while TGF-B levels were decreased in colonic and fascial wounds, but relatively unchanged in SI and skin.

CONCLUSIONS

An earlier peak in IL-1beta levels and a consistent decrease in TNF-alpha were seen in healing intestinal tissues; but no clear pattern of increased anti-inflammatory or regulatory cytokines was seen, which might explain the earlier healing of intestinal tissues. Additional studies are required to determine the role of individual cytokines, or the intrinsic reactivity of the tissues may explain the site specific differences of healing rates in different tissues.

A prospective open-label study of mycophenolate mofetil for the treatment of diffuse systemic sclerosis

OBJECTIVE

To evaluate the efficacy and safety of mycophenolate mofetil for the treatment of SSc.

METHODS

We recruited 15 patients with dcSSc to take part in an open-label study using mycophenolate mofetil to treat their disease over a 12-month period. The primary outcome measure was the modified Rodnan skin score (mRSS), whereas secondary outcomes included the Medsger severity score, pulmonary function studies, 2D echocardiograms and the Short Form Health Survey (SF)-36 questionnaire.

RESULTS

The mRSS significantly improved in those patients who tolerated the medication for >3 months (P < 0.0001), and there was a statistically significant improvement in the Medsger severity scores of the general (P = 0.05), peripheral vascular involvement (P = 0.05) and skin (P = 0.0003) scores. The SF-36 scores improved (P = 0.05) and the pulmonary function studies showed a trend towards improvement, though not of statistical significance. The mean pulmonary artery pressure by 2D echocardiography did not change.

CONCLUSIONS

In this prospective open-label study of mycophenolate mofetil for the treatment of dcSSc, we observed significant improvements in skin scores, peripheral vascular involvement and patient-perceived health status. Pulmonary function studies did not worsen as expected, but instead showed a trend towards improvement. Controlled trials are needed to further investigate this trend for improved pulmonary function studies.

Insulin-like growth factor I improves aspects of mycophenolate mofetil-impaired anastomotic healing in an experimental model

Background

Patients taking immunosuppressants after transplantation may require intestinal surgery. Mycophenolate mofetil (MMF) has been found to impair the healing of colonic anastomoses in rats. This study examined whether insulin-like growth factor (IGF) I prevents MMF impairment of anastomotic healing.

Methods

Sixty-three rats were divided into three groups (MMF, MMF/IGF and control). Animals underwent a sigmoid colon anastomosis with a 6/0 suture, and were killed on days 2, 4 and 6 after surgery. Investigations included bursting pressure measurement, morphometric analysis, and assessment of mucosal proliferation by 5-bromo-2′-deoxyuridine and Ki67 immunohistochemistry of the anastomoses.

Results

The leak rate was three of 21, one of 20 and two of 20 in the MMF, MMF/IGF-I and control groups respectively. Anastomotic bursting pressures were significantly lower in the MMF group than in the control group on days 2 and 4, but there was no significant difference by day 6. Values in the MMF/IGF-I and control groups were similar. Colonic crypt depth was significantly reduced in MMF-treated animals on days 2 and 4, but this impairment was attenuated by IGF-I on day 4. Similarly, IGF-I reduced the negative impact of MMF on mucosal proliferation on days 2 and 6.

Conclusion

Exogenous IGF-I improves some aspects of MMF-impaired anastomotic healing.

Perioperative management of medications for psoriasis and psoriatic arthritis: a review for the dermasurgeon

BACKGROUND

Psoriasis affects an estimated 3% of the world's population. Many are on chronic immunosuppressive therapy for the cutaneous and joint manifestations of this disorder. The management of these medications in the perioperative period is controversial. Psoriasis and psoriatic arthritis medications can affect wound healing, hemostasis, and infection risk during cutaneous surgery.

OBJECTIVES

The objective of this article is to provide a critical review of various medications used for care of the psoriatic patient and their potential effect on cutaneous surgical procedures.

CONCLUSIONS

This review summarizes current understanding of wound healing, hemostatic effects, and infectious risks regarding many psoriasis medications including nonsteroidal anti-inflammatory drugs, cyclooxygenase inhibitors, corticosteroids, various immunosuppressants, and biologic response modifiers. Recommendations vary depending on the agent in question, type of procedure, and comorbid conditions in the patient. Caution is advised when using many of the medications reviewed due to lack of human data of their effects in the perioperative period.

Effect of mycophenolate mofetil on pulmonary function in scleroderma-associated interstitial lung disease

OBJECTIVE

We sought to determine the effectiveness of mycophenolate mofetil (MMF) in scleroderma- associated interstitial lung disease (SSc-ILD).

METHODS

We retrospectively identified patients who met criteria for systemic sclerosis, had evidence of SSc-ILD on chest CT, received > 1 g/d of MMF for >or= 6 months, and had pulmonary function data available. Vital capacity (VC) and diffusion capacity of the lung for carbon monoxide (Dlco) at treatment onset were compared with VC and Dlco values 12 months before and 12 months after treatment onset. Twelve-month values were imputed from regression lines generated using all VC and Dlco measurements made in the 24-month period either prior to or following treatment onset.

RESULTS

Among 13 patients who met inclusion criteria, MMF was associated with a significant improvement in VC (mean, + 159 mL; confidence interval [CI], + 30 to + 289 mL; and + 4% of the predicted normal value; CI, + 2 to + 7%) after 12 months of treatment. In contrast, patients had a significant decrease in VC (mean, - 239 mL; CI, - 477 to - 0.5 mL; and - 5% of the predicted normal value; CI, - 11 to - 0.3%) in the 12 months prior to MMF treatment. Dlco did not change significantly during MMF treatment (mean, + 1% of the predicted normal value; CI, - 2 to + 5%) but decreased significantly in the 12 months prior to treatment (mean, - 5% of the predicted normal value; CI, - 10 to - 1%).

CONCLUSION

These retrospective data suggest MMF improves VC in patients with SSc-ILD.

Functional CD25bright+alloresponsive T cells in fully immunosuppressed renal allograft recipients

BACKGROUND

Evidence from animal studies indicate a crucial role for CD25(bright+) regulatory T cells in transplantation tolerance.

METHODS

To assess whether peripheral CD25(bright+) T cells control immune responses in immunosuppressed kidney transplant patients, we analyzed the suppressive capacities of these cells using mixed lymphocytes reactions.

RESULTS

Allogeneic stimulation of patients peripheral blood mononuclear cells was associated with IL-2 production and T-cell proliferation. Depletion of CD25(bright+) T cells resulted in a 35% (median) higher IL-2 production and a 38% higher proliferative response against third party cells, showing that functional regulatory CD25(bright+) T cells were present (p = 0.03 and 0.02 respectively). In eight out of 11 patients, we also demonstrated regulation activity against donor-activated T cells (p = 0.03). These data were confirmed in coculture experiments with isolated CD25(-/dim) T cells plus CD25(bright+) T cells. At a 1:2 ratio, the CD25(bright+) T cells suppressed the proliferation of CD25(-/dim) donor- and third party-stimulated responder T cells.

CONCLUSIONS

CD25(bright+) T cells with immune regulatory activities against anti-donor-responsive T cells are readily detectable in renal allograft recipients during treatment with full dosage immunosuppression. Whether CD25(bright+) T cells indeed play a role in graft acceptance after organ transplantation in patients remains to be elucidated.