Contribution of chemotherapy mobilization to disease control in multiple myeloma treated with autologous hematopoietic cell transplantation.

In patients with multiple myeloma (MM) undergoing autologous hematopoietic cell transplantation (auto-HCT), peripheral blood progenitor cells may be collected following mobilization with growth factor alone (GF) or cytotoxic chemotherapy plus GF (CC+GF). It is uncertain whether the method of mobilization affects post-transplant outcomes. We compared these mobilization strategies in a retrospective analysis of 968 patients with MM from the Center for International Blood and Marrow Transplant Research database who received an auto-HCT in the US and Canada between 2007 and 2012. The kinetics of neutrophil engraftment (⩾0.5 × 10(9)/L) was similar between groups (13 vs 13 days, P=0.69) while platelet engraftment (⩾20 × 10(9)/L) was slightly faster with CC+GF (19 vs 18 days, P=0.006). Adjusted 3-year PFS was 43% (95% confidence interval (CI) 38-48) in GF and 40% (95% CI 35-45) in CC+GF, P=0.33. Adjusted 3-year OS was 82% (95% CI 78-86) vs 80% (95% CI 75-84), P=0.43 and adjusted 5-year OS was 62% (95% CI 54-68) vs 60% (95% CI 52-67), P=0.76, for GF and CC+GF, respectively. We conclude that MM patients undergoing auto-HCT have similar outcomes irrespective of the method of mobilization and found no evidence that the addition of chemotherapy to mobilization contributes to disease control.

Cellular immunotherapy for plasma cell myeloma.

Allogeneic hematopoietic cell transplantation for plasma cell myeloma can lead to graft-vs-myeloma immunity and long-term survivorship, but limited efficacy and associated toxicities have prevented its widespread use. Cellular immunotherapies seek to induce more specific, reliable and potent antimyeloma immune responses with less treatment-related risk than is possible with allogeneic transplantation. Strategies under development include infusion of vaccine-primed and ex vivo expanded/costimulated autologous T cells after high-dose melphalan, genetic engineering of autologous T cells with receptors for myeloma-specific epitopes, administration of DC/plasma cell fusions and administration expanded marrow-infiltrating lymphocytes. In addition, novel immunomodulatory drugs such as inhibitors of the programmed death-1 T cell regulatory pathway may synergize with cellular immunotherapies.

Trimming the fat: obesity and hematopoietic cell transplantation.

Obesity, increasing worldwide, is common in patients undergoing hematopoietic cell transplantation (HCT). This complex physiological state may alter the outcome of cancer therapies by many mechanisms including direct effects on pathogenesis, host responses to disease and altered pharmacology of chemotherapy. Obesity has been associated with multiple adverse health outcomes. Reports of obese patients undergoing HCT are challenging to interpret because of the heterogeneity of obesity definitions, underlying diseases, graft sources and chemotherapy regimens employed. Compared with normal-weight patients, it appears that obese patients undergoing allogeneic HCT have a higher risk of non-relapse mortality and inferior survival whereas those receiving autologous HCT appear to have equivalent outcomes. These findings are also difficult to interpret because there is no consistent standard for calculating chemotherapy dose in this group and future studies on specific regimens in this population are urgently needed. Patients who have undergone bariatric surgery may be at risk for unexpected events because of impaired nutritional state and altered pharmacokinetics of oral drugs. We recommend that future studies utilize more consistent and biologically relevant definitions of obesity and that the pharmacokinetics and pharmacodynamics of specific conditioning regimens be studied. Until more evidence is available, a rationale is presented for dosing based on adjusted body weight. Moreover, recommendations are provided to guide future research efforts based on more definitive measurements of body fat and its distribution available through modern quantitative imaging techniques using dual energy X-ray absorptiometry or magnetic resonance imaging scanning.

High-dose corticosteroids with or without etanercept for the treatment of idiopathic pneumonia syndrome after allo-SCT.

Idiopathic Pneumonia Syndrome (IPS) is a common complication after allo-SCT and results in high mortality rates. Conventional treatment for IPS typically includes supportive care and high-dose corticosteroids (CS). Data suggests that TNF-α is important in the pathogenesis of IPS and that the TNF-α inhibitor etanercept may be useful for IPS treatment. We performed a retrospective comparison of consecutive patients treated at our center for IPS with CS only from 1999 to 2003 (group 1, n=22) or CS plus etanercept from 2004 to 2007 (group 2, n=17). In all, 18% of patients in group 1 vs 53% in group 2 were successfully taken off respiratory support and discharged from the hospital (P=0.039). OS was significantly better for recipients of CS plus etanercept (P=0.003). The estimated survival at 28 days and 2 years after IPS was 36.4% (95% CI 17-56%) and 9.1% (95% CI 2-25%) for group 1 and 88.2% (95% CI 61-97%) and 18% (95% CI 4-38%) for group 2, respectively. Our retrospective comparison suggests that the addition of etanercept to CS for IPS improves response rates and OS. However, outcomes remain limited in both groups, highlighting the need for more effective interventions to treat early and late complications of IPS.

Hematopoietic cell transplantation for primary plasma cell leukemia: results from the Center for International Blood and Marrow Transplant Research.

There are limited data on hematopoietic cell transplantation (HCT) in primary plasma cell leukemia (pPCL), an aggressive plasma cell disorder. We report outcomes of 147 patients with pPCL receiving autologous (n=97) or allogeneic (n=50) HCT within 18 months after diagnosis between 1995 and 2006. Median age was 56 years and 48 years for autologous HCT and allogeneic HCT, respectively. Progression-free survival (PFS) at 3 years was 34% (95% confidence interval (CI), 23-46%) in the autologous group and 20% (95% CI, 10-34%) in the allogeneic group. Cumulative incidence of relapse at 3 years was 61% (95% CI, 48-72%) in the autologous group and 38% (95% CI, 25-53%) in the allogeneic group. Overall survival (OS) at 3 years was 64% (95% CI, 52-75%) in the autologous group and 39% (95% CI, 26-54%) in the allogeneic group. Non-relapse mortality (NRM) at 3 years was 5% (95% CI, 1-11%) in the autologous group and 41% (95% CI, 28-56%) in the allogeneic group. The encouraging OS after autologous HCT, establishes the safety and feasibility of this consolidative treatment option after initial induction therapy for pPCL. Allogeneic HCT, although associated with a significantly lower relapse rate, carries a much higher risk of NRM and no OS benefit.

Stem cell collection in patients with multiple myeloma: impact of induction therapy and mobilization regimen.

Lenalidomide is an active treatment for multiple myeloma (MM) and is increasingly used as part of the initial treatment of this disease. Recent reports have suggested decreases in the number of CD34+ cells collected and increases in the failure rate among patients whose initial therapy contained lenalidomide when mobilized with G-CSF alone. A retrospective data analysis of 364 patients with MM who underwent stem cell mobilization and attempted harvest at the Hospital of the University of Pennsylvania between January 2002 and December 2007 was performed. Forty-three of the patients received lenalidomide in their induction regimen, and were mobilized with either CY and G-CSF or G-CSF alone. The number of apheresis cycles and the failure rate were lower, whereas the mean number of collected stem cells was higher in patients who were mobilized with CY and G-CSF in comparison with G-CSF alone. This suggests that lenalidomide does not prevent the harvest of adequate numbers of CD34 cells for autologous stem cell transplant, but mobilization with G-CSF and CY may be required to obtain adequate numbers of stem cells. Finally, in our study, the number of lenalidomide cycles did not correlate with stem cell yield.

Second auto-SCT is safe and effective salvage therapy for relapsed multiple myeloma.

Therapeutic options for patients with multiple myeloma whose disease has relapsed after a prior auto-SCT include novel biologic therapies, traditional chemotherapy or a second transplant, with no clear standard of care. Few published studies address the safety and efficacy of a second auto-SCT for relapsed disease. We reviewed the Abramson Cancer Center experience with salvage auto-SCT for relapsed multiple myeloma. Forty-one patients had received a salvage auto-SCT at our institution; the median time between transplants was 37 months (range 3-91). The overall response rate in assessable patients was 55%, and treatment-related mortality was 7%. With a median follow-up time of 15 months, the median PFS was 8.5 months and the median overall survival (OS) was 20.7 months. In a multivariate analysis of OS, independent prognostic factors were >or=5 prior lines of therapy and time to progression after initial auto-SCT of

EBV PCR in the diagnosis and monitoring of posttransplant lymphoproliferative disorder: results of a two-arm prospective trial.

While EBV PCR is used in the management of PTLD, the optimal primer set, relative importance of intracellular versus free plasma EBV, and the baseline profile in an organ transplant population remains unclear. We performed a prospective 2-arm trial utilizing an EBV PCR panel measuring LMP-1, EBER-1 and EBNA-1 in both free plasma as well as intracellular whole blood. Control Arm A consisted of 31 lung transplant patients and Arm B consisted of 35 transplant patients being evaluated for possible PTLD. In Arm A, 1/31 (3%) patients developed a transient plasma EBV load. Thirteen of 31 (42%) had detectable intracellular EBV. In Arm B, 17 (49%) patients were diagnosed with PTLD. Thirteen (76%) had EBV-positive PTLD with 12/13 (92%) having detectable EBV by PCR. The EBV PCR panel had a high sensitivity (92%), specificity (72%), positive predictive value (PPV) (71%) and negative predictive value (NPV) (93%) for diagnosing EBV-positive PTLD and followed patients' clinical course well (p < 0.001). Comparing the individual PCR assays, plasma EBNA PCR was superior with high sensitivity (77%), specificity (100%), PPV (100%) and NPV (86%). We conclude that EBV PCR is a useful test for managing PTLD patients. While plasma EBNA PCR is the best single assay for diagnosing and monitoring PTLD, the complete PCR panel is superior for ruling out its presence.

Intracellular polyamine levels of intestinal epithelial cells in inflammatory bowel disease.

Polyamines and their acetylated derivatives are a prerequisite for cellular metabolism and considered to be essential for proliferation and differentiation of the rapidly renewing intestinal mucosa. However, their role during mucosal inflammation is less clear. Polyamine concentrations were determined in isolated colonic epithelial cells (CECs) from endoscopic biopsies from 26 patients with inflammatory bowel disease (IBD) and 40 controls as well as colon samples from mice with and without acute or chronic dextran sodium sulfate (DSS)-induced colitis. In patients with ulcerative colitis, CEC spermidine and N8-acetylspermidine levels were significantly enhanced and spermine levels were reduced compared with healthy controls. A correlation of polyamine levels of patients with IBD with their corresponding inflammatory index revealed that increased concentrations of spermidine, N8-acetylspermidine, and N1-acetylspermine were found in CECs from the most severe inflamed mucosal areas. Using acute and chronic DSS colitis as a model of mucosal inflammation, we found enhanced levels of spermidine and spermine in acute colitis, whereas in chronic inflammation, CEC spermine concentrations were decreased. Our data indicate a lack of the anti-inflammatory polyamine spermine in severe ulcerative colitis and chronic DSS colitis, which may aggravate the disease. Increased spermidine and N8-acetylspermidine levels reflect increased uptake and metabolism likely due to accelerated proliferation and regeneration of CECs.

Interferon gamma downregulates IL-8 production in primary human colonic epithelial cells without induction of apoptosis.

BACKGROUND: In acute or chronic inflammatory bowel disease (IBD) interferon gamma (IFNgamma) is still considered to be an important pro-inflammatory mediator. In the present study we investigated the impact of IFNgamma on interleukin-8 (IL-8) production as a read-out for cell activation in intestinal epithelial cell (IEC) lines and primary human colonic epithelial cells (CEC). METHODS: Primary cultures of human CEC were established from the mucosa of patients without inflammatory disease. CEC, HT-29 or Caco-2 cells were incubated with either IFNgamma, tumor necrosis factor (TNF)alpha or IL-10. IL-8 and IL-1Ra secretion was determined by ELISA. Competicon PCR was used for quantification of IL-8mRNA. Apoptosis was quantified by propidium iodine incorporation and fluorescence activated cell sorting (FACS) analysis. RESULTS: In contrast to HT-29 cells in primary human CEC 100 U/ml IFNgamma inhibited IL-8 secretion significantly to 70+/-15% of unstimulated primary CEC (p<0.005) more effectively than IL-10 (87+/-21% versus unstimulated cells, n.s.). In HT-29 cells, IL-8 secretion was induced to 405+/-101% of unstimulated cells. In Caco-2 cells, IFNgamma had no significant effect on IL-8 secretion. The effect in HT-29 and CEC was concentration dependent. In primary CEC, 200 U/ml IFNgamma further reduced IL-8 secretion to 48+/-18% of unstimulated CEC (p<0.05). Whereas IL-8 mRNA was strongly upregulated in HT-29 cells, no upregulation or even a downregulation was found in CEC. Pre-incubation with 100 U/ml IFNgamma did not increase the susceptibility to apoptosis mediated by anti-Fas antibody (CH-11) in primary CEC, whereas HT-29 cells showed increased rates of apoptosis after priming with IFNgamma. CONCLUSION: In contrast to HT-29, IFNgamma downregulated IL-8 secretion and did not induce IL-8 mRNA expression in primary human CEC. This effect was not due to induction of apoptosis.

Inducible CD40 expression mediates NFkappaB activation and cytokine secretion in human colonic fibroblasts.

BACKGROUND: CD40 has been shown to be a functional activation antigen on a variety of cell types involved in immune responses. As intestinal fibroblasts and myofibroblasts may play a role during mucosal inflammation, we investigated the functional consequences of CD40 induction in primary cultures of human colonic fibroblasts. METHODS: Primary colonic lamina propria fibroblasts (PCLF) were isolated from endoscopic biopsies and surgical specimens. Cultures were used between passages 3 and 9. CD40 surface display was determined by FACS analysis and mRNA expression by reverse transcription-polymerase chain reaction. Secretion of cytokines was determined by ELISA. Nuclear factor kappaB (NFkappaB) activation was shown by electrophoretic mobility shift assay (EMSA). RESULTS: After priming with interferon gamma (IFN-gamma) (200 U/ml) for 72 hours, five of eight tested PCLF cultures showed induction of CD40 surface display (up to 10-fold). Induction of CD40 mRNA expression was demonstrated by semiquantitative polymerase chain reaction. In the responder-PCLF cultures, IFN-gamma alone caused a 1.5-5-fold increase in interleukin (IL)-8 secretion. Addition of 1 ng/ml CD40L was sufficient to achieve a further increase in IL-8, IL-6, or monocyte chemotactic protein 1 (MCP-1) secretion (2.5-18-fold of controls). Incubation with CD40L alone without priming with IFN-gamma had no effect. The proteasome inhibitor N-acetyl-leucinyl-leucinyl-norleucinal (ALLN 100 microM) reduced IFN-gamma/CD40L mediated cytokine induction, suggesting participation of NFkappaB, which was directly demonstrated by EMSA. CD4+ T cells induced MCP-1 secretion by PCLF, which was prevented by addition of an excess of CD40-IgG fusion protein. CD40 expression on PCLF could also be demonstrated in vivo by immunohistochemistry. CONCLUSION: The CD40-CD40L pathway augments mucosal inflammatory responses via mucosal PCLF. CD40-CD40L mediated T cell/PCLF interactions could play an important role during intestinal mucosal inflammation.

Regulation of migration of human colonic myofibroblasts.

BACKGROUND AND AIM: The migration of mesenchymal cells to areas of mucosal or submucosal tissue damage is an essential factor for wound healing in the intestine. Thus far, neither migration inducing factors nor signal transduction cascades involved in the migration of colonic myofibroblasts (CMF) have been studied in detail. METHODS: Primary CMF were isolated from the mucosa of surgical specimens or endoscopic biopsies. Migration assays of CMF were performed in the modified 48-well Boyden chamber. Secreted growth factors were quantified by ELISA. RESULTS: CMF secrete autocrine or paracrine migration stimulating factors. Culture supernatant of CMF collected after 24, 48, and 72 h ( = conditioned media) stimulated the migration of CMF (48.9+/-4.5; 60.3+/-5.3 and 67.8+/-6.4 cells/hpf, respectively). Heating of conditioned media to 95 degrees C or addition of cycloheximide during the conditioning period abolished migration. Addition of PDGF-AB (2.5-50 ng/ml) or IGF-I (10-300 ng/ml) to CMF conditioned media further increased the migration of CMF to a maximum of 177 and 160%, respectively, when compared to the migration induced by conditioned medium alone. Addition of EGF (2.5-50 ng/ml) or TGF-beta1 (1-50 microg/ml) caused an increased CMF migration up to 139 and 128%, respectively. MCP-1 (5-50 ng/ml) and bFGF (10-200 ng/ml) had no effect on CMF migration. CONCLUSION: The growth factors PDGF-AB, IGF-I, EGF and TGF-beta1 stimulate the migration of CMF. However, factors secreted by CMF are essential for their ability to migrate in response to these growth factors. The identification of physiologically relevant migration inducing factors may help to elucidate the network of interactions and the complex mechanisms involved in intestinal wound healing or fibrosis.

Monocyte differentiation in intestine-like macrophage phenotype induced by epithelial cells.

Macrophages in normal colonic mucosa show a specific and distinct phenotype with low expression of the typical monocyte/macrophage surface antigens CD14, CD16, and CD11b and T-cell costimulatory molecules. A method for the in vitro induction of a macrophage phenotype similar to this intestinal phenotype is presented. Multicellular spheroids (MCSs) of intestinal epithelial cell (IEC) and control cell lines were cocultured with elutriated monocytes. Surface antigen expression was analyzed by immunohistochemistry and flow cytometry. Interleukin (IL)-1beta mRNA was measured by quantitative PCR. Monocytes adhered and infiltrated the MCSs within 24 h. In the MCSs of all IEC lines, the typical monocyte/macrophage surface antigens CD14, CD16, CD11b, and CD11c, which are detectable after 24 h of coculture by immunohistochemistry and flow cytometry, were down-regulated after 7 days (e.g., for CD14 at 24 h, expression was 86% of CD33+ cells; at day 7, it was 11%). A clear decrease of lipopolysaccharide (LPS)-stimulated IL-1beta transcription in monocytes cocultured with IEC MCSs could be observed during the 7-day period. For the first time an intestine-like macrophage-phenotype could be induced in vitro. Interactions with IECs play an essential role during this differentiation, which is of functional relevance, e.g., for LPS-induced cytokine secretion.

Differential activation of cytokine secretion in primary human colonic fibroblast/myofibroblast cultures.

BACKGROUND: Fibroblasts and myofibroblasts are known to secrete a wide spectrum of cytokines, but the individual spectrum is tissue-specific. We investigated the effect of cell activation on cytokine secretion of isolated human colonic fibroblasts/myofibroblasts from control patients and patients with mucosal inflammation. METHODS: Primary cultures of human colonic submucosal fibroblasts/myofibroblasts were incubated with IL-1alpha (100 U/ml), IL-Ibeta (10 ng/ml), IL-10 (10 ng/ml), TNF (10 ng/ml), PMA (10 ng/ml), LPS (50 ng/ml), IL-4 (10 ng/ml), or a combination of IL-1 and TNF. Secreted cytokines were determined by ELISA. NF-kappaB activation was demonstrated by electrophoretic mobility-shift assays (EMSA). RESULTS: Incubation of colonic fibroblasts/myofibroblasts with IL-1, LPS, TNF and PMA induced secretion of IL-6, IL-8, M-CSF and GM-CSF. IL-8 and IL-6 secretion could be stimulated by IL-1alpha, IL-1beta, TNF, PMA and LPS within 6 h of incubation. IL-6 secretion was stimulated from 0.5 +/- 0.01 pg/h x microg fibroblast protein to 18.5 +/- 2.6 pg/h x microg fibroblast protein with IL-1beta (P < 0.01). IL-8 secretion was stimulated from 1.0 +/- 0.1 pg/h x microg fibroblast protein to 41.1 +/- 3.6 pg/h x microg (P < 0.005). IL-4 and IL-10 did not change cytokine secretion significantly. No significant differences between cultures from normal and inflamed mucosa were observed. TNF and IL-1 induced NF-kappaB activation. ALLN, a proteasome and NF-kappaB activation inhibitor, reduced TNF-mediated IL-8, GM-CSF and M-CSF induction significantly, whereas induction of IL-6 secretion remained unchanged. CONCLUSION: Human colonic myofibroblasts can secrete large amounts of IL-6, IL-8, M-CSF and GM-CSF upon stimulation. The induction of IL-8, M-CSF and GM-CSF, but not of IL-6 secretion, is mediated mainly by NF-kappaB activation. The cytokine profile and the total amounts of cytokines released suggest that colonic myofibroblasts can play a role in leukocyte recruitment and during mucosal inflammation. They therefore have to be regarded as an important part of the mucosal immune system.

Human intestinal epithelial cells secrete interleukin-1 receptor antagonist and interleukin-8 but not interleukin-1 or interleukin-6.

BACKGROUND: There is growing evidence that intestinal epithelial cells (IECs) are involved in the mucosal immune system. AIM: To assess the pattern of cytokines secreted by IECs and lamina propria mononuclear cells (LPMNCs). To achieve this, the expression and secretion of interleukin (IL)-1, IL-1 receptor antagonist (IL-1ra), IL-6, and IL-8 in human primary colonic and ileal IECs and LPMNCs from the same patient were studied. METHODS: IECs and LPMNCs were isolated from surgical specimens or endoscopic biopsy samples. mRNA expression was investigated by northern blot analysis. Secretion of IL-1beta, IL-6, IL-8, and IL-1ra was measured by enzyme linked immunosorbent assay. RESULTS: IL-1ra mRNA levels were higher in IECs than in LPMNCs in all probands. IL-8 mRNA was only present in low amounts in the IECs from two controls. In none of the specimens were IL-1beta and IL-6 mRNA present in IECs. Transcripts encoding IL-1beta, IL-1ra, IL-6, and IL-8 were identified in LPMNC preparations of all specimens. IECs from normal mucosa produced no detectable amounts of IL-1beta or IL-6, whereas LPMNCs did. IECs secreted some IL-8 (65 (9) pg/10(5) cells) but significantly more was generated by LPMNCs (408 (43) pg/10(5) cells, p<0.0001). However, IECs secreted more IL-1ra than did LPMNCs (120 (12) v 94 (11) pg/10(5) cells). In acute inflammation, IEC IL-1ra secretion was significantly increased. A correlation between secreted IL-1ra and the macroscopical degree of inflammation was found in Crohn's disease (r = 0.64, p<0.0001, n = 36) and ulcerative colitis (r = 0. 76, p<0.0001, n = 24). CONCLUSIONS: IECs from normal mucosa express and secrete IL-1ra and low amounts of IL-8, but no IL-1 or IL-6. In inflamed mucosa the secretion of IL-1ra by IECs is slightly increased but may be not sufficient to antagonise the greatly increased production of proinflammatory cytokines by LPMNCs and the IECs themselves.

Post-traumatic stress disorder in cancer: a review.

The stressor criterion for Post-Traumatic Stress Disorder (PTSD) has been recently modified to include life-threatening illnesses, such as cancer, as precipitating traumatic events. We sought to examine the empiric evidence for cancer's inclusion as a traumatic stressor. Nine published studies assessing PTSD in cancer survivors and/or family members were identified in the literature. The studies were predominantly small (n<100) and cross-sectional. Study target groups included one or more of the following: children cancer survivors, parents of pediatric survivors and adult cancer survivors. There was considerable inter- and intra-study variability in the type and stage of cancer diagnosed and in the type of treatment regimens participants had undergone. Only three studies utilized a validated PTSD diagnostic tool to evaluate the disorder. Evidence of full-blown PTSD was found for adults and parents, and for children in all but one instance. These results suggest that a PTSD symptom assessment provides valuable clinical information concerning the post-treatment adjustment of cancer survivors and their immediate family members.

T-cell co-stimulatory molecules are upregulated on intestinal macrophages from inflammatory bowel disease mucosa.

BACKGROUND AND AIMS: Macrophages play an important role during mucosal inflammation in inflammatory bowel disease (IBD). As the co-stimulatory molecules B7-1 (CD80) and B7-2 (CD86) play an integral role in the activation of T cells by antigen-presenting cells (APC) we investigated the surface expression of B7-1 and B7-2 on colonic macrophages from normal and IBD mucosa. METHODS: Intestinal macrophages were isolated from biopsies of 13 control persons and 14 patients with IBD (seven with Crohn's disease (CD); and seven with ulcerative colitis (UC)). Cells were characterized by triple fluorescence flow cytometrical analysis using CD33 as macrophage marker. RESULTS: The expression of B7-1 (CD80) (9.2% +/- 4.2%) and B7-2 (CD86) (15.1% +/- 7.3%) was low on colonic macrophages from normal mucosa, indicating only a low antigen presenting potential. However, on macrophages from IBD colon there was a significant increase in the expression of co-stimulatory molecules (CD80, 33.8% +/- 8.9%, P = 0.00005 vs. control; CD86, 39.9% +/- 8.8%, P = 0.00002). There was no significant difference between CD and UC in the expression of CD80 (CD, 31.3% +/- 6.7%; UC, 34.4% +/- 13.3%) and CD86 (CD, 41.9% +/- 3.8%; UC, 35.6% +/- 13.8%). While in normal mucosa only 10.6% +/- 4.9% of the macrophages expressed CD14, more than 90% of the CD86/CD80 positive cells of the inflamed mucosa were positive for CD14. CONCLUSION: Colonic macrophages from normal mucosa rarely express the co-stimulatory molecules CD80 and CD86. In IBD a new macrophage population is found with high expression of co-stimulatory molecules presumably responsible for the perpetuated immune response.