Patient-Reported Outcomes Correlate With Microbial Community Composition Independent of Mucosal Inflammation in Pediatric Inflammatory Bowel Disease.

BACKGROUND: Inflammatory bowel diseases (IBDs) involve an aberrant host response to intestinal microbiota causing mucosal inflammation and gastrointestinal symptoms. Patient-reported outcomes (PROs) are increasingly important in clinical care and research. Our aim was to examine associations between PROs and fecal microbiota in patients 0 to 22 years of age with IBD. METHODS: A longitudinal, prospective, single-center study tested for associations between microbial community composition via shotgun metagenomics and PROs including stool frequency and rectal bleeding in ulcerative colitis (UC) and abdominal pain and stool frequency in Crohn's disease (CD). Mucosal inflammation was assessed with fecal calprotectin. A negative binomial mixed-effects model including clinical characteristics and fecal calprotectin tested for differentially abundant species and metabolic pathways by PROs. RESULTS: In 70 CD patients with 244 stool samples, abdominal pain correlated with increased relative abundance of Haemophilus and reduced Clostridium spp. There were no differences relative to calprotectin level. In 23 UC patients with 76 samples, both rectal bleeding and increased stool frequency correlated with increased Klebsiella and reduced Bacteroides spp. Conversely, UC patients with lower calprotectin had reduced Klebsiella. Both UC and CD patients with active symptoms exhibited less longitudinal microbial community stability. No differences in metabolic pathways were observed in CD. Increased sulfoglycolysis and ornithine biosynthesis correlated with symptomatic UC. CONCLUSIONS: Microbial community composition correlated with PROs in both CD and UC. Metabolic pathways differed relative to PROs in UC, but not CD. Data suggest that microbiota may contribute to patient symptoms in IBD, in addition to effects of mucosal inflammation.

Microbial Shifts and Shorter Time to Bowel Resection Surgery Associated with C. difficile in Pediatric Crohn's Disease.

BACKGROUND: Clostridioides difficile infection and colonization are common in pediatric Crohn's disease (CD). Our aims were to test the relationship between C. difficile positivity and bowel resection surgery and to characterize microbial shifts associated with C. difficile carriage and surgery. METHODS: A retrospective single-center study of 75 pediatric CD patients tested for association between C. difficile carriage and bowel resection surgery. A prospective single-center study of 70 CD patients utilized C. difficile testing and shotgun metagenomic sequencing of fecal samples to define microbiota variation stratified by C. difficile carriage or history of surgery. RESULTS: The rate of bowel resection surgery increased from 21% in those without C. difficile to 67% in those with (P = 0.003). From a Kaplan-Meier survival model, the hazard ratio for time to first surgery was 4.4 (95% CI, 1.2-16.2; P = 0.00) in patients with positive C. difficile testing in the first year after diagnosis. Multivariable logistic regression analysis confirmed this association (odds ratio 16.2; 95% CI, 2.2-120; P = 0.006). Larger differences in microbial abundance and metabolic pathways were observed in patients with prior surgery than in those with C. difficile carriage. Depletion of Alistipes and Ruminococcus species and reduction in methionine biosynthesis were noted in patients with both C. difficile carriage and past surgery. CONCLUSIONS: A positive C. difficile test during the first year after diagnosis is associated with decreased time to first bowel resection surgery in pediatric Crohn's disease. Depletion of beneficial commensals and methionine biosynthesis in patients with C. difficile carriage may contribute to increased risk for surgery.

Multi-omics of the gut microbial ecosystem in inflammatory bowel diseases.

Inflammatory bowel diseases, which include Crohn's disease and ulcerative colitis, affect several million individuals worldwide. Crohn's disease and ulcerative colitis are complex diseases that are heterogeneous at the clinical, immunological, molecular, genetic, and microbial levels. Individual contributing factors have been the focus of extensive research. As part of the Integrative Human Microbiome Project (HMP2 or iHMP), we followed 132 subjects for one year each to generate integrated longitudinal molecular profiles of host and microbial activity during disease (up to 24 time points each; in total 2,965 stool, biopsy, and blood specimens). Here we present the results, which provide a comprehensive view of functional dysbiosis in the gut microbiome during inflammatory bowel disease activity. We demonstrate a characteristic increase in facultative anaerobes at the expense of obligate anaerobes, as well as molecular disruptions in microbial transcription (for example, among clostridia), metabolite pools (acylcarnitines, bile acids, and short-chain fatty acids), and levels of antibodies in host serum. Periods of disease activity were also marked by increases in temporal variability, with characteristic taxonomic, functional, and biochemical shifts. Finally, integrative analysis identified microbial, biochemical, and host factors central to this dysregulation. The study's infrastructure resources, results, and data, which are available through the Inflammatory Bowel Disease Multi'omics Database ( http://ibdmdb.org ), provide the most comprehensive description to date of host and microbial activities in inflammatory bowel diseases.

Genetic and Transcriptomic Variation Linked to Neutrophil Granulocyte-Macrophage Colony-Stimulating Factor Signaling in Pediatric Crohn's Disease.

BACKGROUND: Granulocyte-macrophage colony-stimulating factor auto-antibodies (GMAbs) suppress neutrophil-extrinsic GM-CSF signaling and increase risk for stricturing behavior in Crohn's disease (CD). We aimed to define clinical, genomic, and functional associations with neutrophil-intrinsic GM-CSF signaling. METHODS: Missense mutations in CSF2RA, CSF2RB, JAK2, STAT5A, and STAT5B were identified using whole-exome sequencing in 543 pediatric inflammatory bowel disease (IBD) patients. Neutrophil-intrinsic GM-CSF signaling was defined using the GM-CSF-induced STAT5 stimulation index (GMSI) in 180 pediatric IBD patients and 26 non-IBD controls. Reduced GM-CSF signaling (GMSI-Lo) was defined as the 20th percentile within the control group. Variation in neutrophil phospho-protein abundance, bacterial killing, and the global pattern of gene expression with the GMSI was determined. RESULTS: We validated 18 potentially damaging missense mutations in CSF2RA and CSF2RB. CSF2RA A17G carriage increased from 10% in those with intact neutrophil GMSI to 32% in those with low GMSI (P = 0.02). The frequency of reduced Staphylococcus aureus killing increased from 17% in those with intact neutrophil GMSI to 35% in GMSI-Lo neutrophils (P = 0.043). Crohn's disease neutrophils with low GMSI exhibited specific alterations in phospho-protein networks and genes regulating cytokine production, wound healing, and cell survival and proliferation. Stricturing behavior increased from 7% in patients with both low GMAb and intact GMSI to 64% in patients with both elevated GMAb and low GMSI (P < 0.0001). CONCLUSIONS: Low/normal neutrophil-intrinsic GM-CSF signaling is associated with CSF2RA missense mutations, alterations in gene expression networks, and higher rates of disease complications in pediatric CD.

Clinical and Genomic Correlates of Neutrophil Reactive Oxygen Species Production in Pediatric Patients With Crohn's Disease.

BACKGROUND & AIMS: Individuals with monogenic disorders of phagocyte function develop chronic colitis that resembles Crohn's disease (CD). We tested for associations between mutations in genes encoding reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidases, neutrophil function, and phenotypes of CD in pediatric patients. METHODS: We performed whole-exome sequence analysis to identify mutations in genes encoding NADPH oxidases (such as CYBA, CYBB, NCF1, NCF2, NCF4, RAC1, and RAC2) using DNA from 543 pediatric patients with inflammatory bowel diseases. Blood samples were collected from an additional 129 pediatric patients with CD and 26 children without IBD (controls); we performed assays for neutrophil activation, reactive oxygen species (ROS) production, and bacteria uptake and killing. Whole-exome sequence analysis was performed using DNA from 46 of the children with CD to examine associations with NADPH gene mutations; RNA sequence analyses were performed using blood cells from 46 children with CD to test for variations in neutrophil gene expression associated with ROS production. RESULTS: We identified 26 missense mutations in CYBA, CYBB, NCF1, NCF2, and NCF4. Patients with CD who carried mutations in these genes were 3-fold more likely to have perianal disease (P = .0008) and stricturing complications (P = .002) than children with CD without these mutations. Among patients with CD with none of these mutations, 9% had undergone abdominal surgery; among patients with mutations in these NADPH oxidase genes, 31% had undergone abdominal surgery (P = .0004). A higher proportion of neutrophils from children with CD had low ROS production (47%) than from controls (15%) among the 129 patients tested for ROS (P = .002). Minor alleles of the NADPH genes were detected in 7% of children with CD whose neutrophils produced normal levels of ROS vs 38% of children whose neutrophils produced low levels of ROS (P = .009). Neutrophils that produced low levels of ROS had specific alterations in genes that regulate glucose metabolism and antimicrobial responses. CONCLUSIONS: We identified missense mutations in genes that encode NADPH oxidases in children with CD; these were associated with a more aggressive disease course and reduced ROS production by neutrophils from the patients.

Dynamics of metatranscription in the inflammatory bowel disease gut microbiome.

Inflammatory bowel disease (IBD) is a group of chronic diseases of the digestive tract that affects millions of people worldwide. Genetic, environmental and microbial factors have been implicated in the onset and exacerbation of IBD. However, the mechanisms associating gut microbial dysbioses and aberrant immune responses remain largely unknown. The integrative Human Microbiome Project seeks to close these gaps by examining the dynamics of microbiome functionality in disease by profiling the gut microbiomes of >100 individuals sampled over a 1-year period. Here, we present the first results based on 78 paired faecal metagenomes and metatranscriptomes, and 222 additional metagenomes from 59 patients with Crohn's disease, 34 with ulcerative colitis and 24 non-IBD control patients. We demonstrate several cases in which measures of microbial gene expression in the inflamed gut can be informative relative to metagenomic profiles of functional potential. First, although many microbial organisms exhibited concordant DNA and RNA abundances, we also detected species-specific biases in transcriptional activity, revealing predominant transcription of pathways by individual microorganisms per host (for example, by Faecalibacterium prausnitzii). Thus, a loss of these organisms in disease may have more far-reaching consequences than suggested by their genomic abundances. Furthermore, we identified organisms that were metagenomically abundant but inactive or dormant in the gut with little or no expression (for example, Dialister invisus). Last, certain disease-specific microbial characteristics were more pronounced or only detectable at the transcript level, such as pathways that were predominantly expressed by different organisms in patients with IBD (for example, Bacteroides vulgatus and Alistipes putredinis). This provides potential insights into gut microbial pathway transcription that can vary over time, inducing phenotypical changes that are complementary to those linked to metagenomic abundances. The study's results highlight the strength of analysing both the activity and the presence of gut microorganisms to provide insight into the role of the microbiome in IBD.

Familial Association of Granulocyte-Macrophage Colony-Stimulating Factor Autoantibodies in Inflammatory Bowel Disease.

OBJECTIVES: Elevated granulocyte-macrophage colony-stimulating factor auto-antibodies (GM-CSF Ab) are associated with increased intestinal permeability and stricturing behavior in Crohn disease (CD). We tested for familial association of serum GM-CSF Ab level in CD and ulcerative colitis (UC) families. METHODS: Serum GM-CSF Ab concentration was determined in 230 pediatric CD probands and 404 of their unaffected parents and siblings, and 45 UC probands and 71 of their unaffected parents and siblings. A linear mixed effects model was used to test for familial association. The intra-class correlation coefficient (ICC) was used to determine the degree of association of the serum GM-CSF Ab level within families in comparison with the degree of association among families. RESULTS: The median (IQR) serum GM-CSF Ab concentration was higher in CD probands than in UC probands (1.5 [0.5,5.4] µg/mL vs 0.7 [0.3, 1.6] µg/mL, P = 0.0002). The frequency of elevated serum GM-CSF Ab concentration ≥1.6 µg/mL was increased in unaffected siblings of CD probands with elevated GM-CSF Ab, compared with unaffected siblings of CD probands without elevated GM-CSF Ab (33% vs 13%, respectively, P = 0.04). A similar result was observed within UC families. In families of CD patients, the mean (95th CI) ICC was equal to 0.153 (0.036, 0.275), P = 0.001, whereas in families of UC patients, the mean (95th CI) ICC was equal to 0.27 (0.24, 0.31), P = 0.047. CONCLUSIONS: These data confirmed familial association of serum GM-CSF Ab levels. This could be accounted for by either genetic or environmental factors shared within the family.

Increased prevalence of luminal narrowing and stricturing identified by enterography in pediatric Crohn's disease patients with elevated granulocyte-macrophage colony stimulating factor autoantibodies.

BACKGROUND: Crohn's disease (CD) patients with elevated granulocyte-macrophage colony-stimulating factor autoantibodies (GM-CSF Ab) are more likely to develop stricturing behavior requiring surgery. Computed tomography or magnetic resonance enterography (CTE or MRE) may detect luminal narrowing (LN) before stricture development. The objective of this study was to determine whether CD patients with elevated GM-CSF Ab (≥1.6 µg/mL) have a higher prevalence of LN and stricturing on CTE or MRE. METHODS: A single-center, cross-sectional study of 153 pediatric patients with CD and control subjects undergoing diagnostic CTE or MRE. Examinations were evaluated for disease activity using a novel scoring system and for the presence of LN, stricture, intra-abdominal abscess, or fistulae. Dichotomous outcomes were compared with respect to antibody status (high or low) using Fisher's exact test and logistic regression, whereas continuous outcomes were evaluated using unpaired t test. RESULTS: GM-CSF Ab were elevated in CD patients (n = 114) with a median (interquartile range) GM-CSF Ab level of 2.3 µg/mL (0.5-6.6 µg/mL) compared with 0.6 µg/mL (0.3-1.3 µg/mL) in healthy and disease control subjects (n = 39) (P = 0.001). Ileal disease location was more common in CD patients with high GM-CSF Ab (P < 0.001). LN increased from 39% in CD patients with low GM-CSF Ab to 71% in those with high levels (P = 0.004) and remained significantly associated with high GM-CSF Ab in a multivariate logistic model, which included age, gender, small bowel location, and duration of disease. Stricturing prevalence on CTE or MRE examination increased from 4% in CD patients with low GM-CSF Ab to 19% in those with high GM-CSF Ab (P = 0.03). CONCLUSIONS: Pediatric CD patients with high GM-CSF Ab levels have a higher prevalence of LN on CTE or MRE. Further study will be needed to determine whether medical therapy will reduce progression to stricturing behavior in these patients.

A multidisciplinary clinical program is effective in stabilizing BMI and reducing transaminase levels in pediatric patients with NAFLD.

BACKGROUND AND AIM: Weight loss is an effective treatment for children with nonalcoholic fatty liver disease (NAFLD), but it is extremely difficult to achieve outside of an intensive weight management program. We hypothesized that one can achieve success in improving NAFLD and weight-related outcomes in a structured and focused multidisciplinary clinical program feasible to implement in a gastroenterology clinic. METHODS: We prospectively tracked the clinical status of our patients enrolled in a multidisciplinary program of dietary and exercise advice through an institutional review board-approved NAFLD registry. Each patient met with a gastroenterologist and dietitian every 3 months for 30 minutes to set individualized goals and monitor progress. RESULTS: A total of 108 children have been enrolled in the registry, and of the 83 that were eligible for 1-year follow-up and included in the analysis, 39 patients returned, resulting in a 47% follow-up rate. These 39 patients showed statistically significant improvements in mean BMI z score (-0.1 U, P < 0.05), total (-11 mg/dL, P < 0.05) and low-density lipoprotein (9 mg/dL, P < 0.05) cholesterol, and serum alanine aminotransferase levels (-36 U/L) and aspartate aminotransferase levels (-22 U/L) levels. CONCLUSIONS: A clinically feasible multidisciplinary program for obese pediatric patients with NAFLD stabilized BMI z score and significantly improved aminotransferase levels at 1-year follow-up.

Pharmacokinetic monitoring of mycophenolic acid in heart transplant patients: correlation the side-effects and rejections with pharmacokinetic parameters.

BACKGROUND: Mycophenolate mofetil is a commonly used immunosuppressant in heart transplantation but pharmacokinetic monitoring is not routinely done. We performed a prospective pilot multi-center trial in de-novo heart transplant recipients to evaluate the pharmacokinetics (PK) of mycophenolic acid (MPA) at multiple time points in the first year following transplant.
MATERIAL/METHODS: MPA trough and estimated area-under-the-curve (AUC) values were obtained at multiple visits from 21 enrolled patients. We attempted to correlate the side-effects and rejections with PK parameters.
RESULTS: MPA AUC and trough levels increased modestly over 12 months with substantial inter and intra patient variability. Cardiac rejection was associated with low MPA AUC values with a threshold of <36.2 mg×h/L during the first two post-transplant weeks. A threshold of 2-weeks average MPA trough level of 1.43 mg/L provided a sensitivity 82% and a specificity of 60%.
CONCLUSIONS: Adequate MPA levels are associated with decreased risk of allograft rejection. For patients with Cyclosporine co-immunosuppression, we propose an MPA trough of 1.4 mg/L and an MPA AUC of 36 mg × h/L as threshold values for dose adjustments. We recommend monitoring MPA levels at 1, 2 and 4 weeks, 6 months, 1 year and whenever an unexplained side-effect or allograft rejection occurs. Additional MPA AUC measurements are recommended when trough levels do not explain the clinical picture.

Impact of changing from cyclosporine to tacrolimus on pharmacokinetics of mycophenolic acid in renal transplant recipients with diabetes.

The rate of mycophenolic acid (MPA) absorption after oral administration of mycophenolate mofetil (MMF) is delayed in patients with diabetes. Cyclosporine (CsA) decreases MPA exposure by inhibiting enterohepatic recirculation of MPA/MPA glucuronide, and tacrolimus (TRL) may alter the rate and extent of MPA absorption due to its prokinetic properties especially in patients with diabetic gastroparesis. This study evaluated the effect of changing from CsA to TRL on pharmacokinetics of MPA in stable renal transplant recipients with long-standing diabetes. Eight patients were switched from a stable dose of CsA to TRL while taking MMF 1 g twice daily. The 12-hour steady-state total plasma concentration-time profiles of MPA and MPA glucuronide were obtained after oral administration of MMF on 2 occasions: first while taking CsA and second after changing to TRL. Pharmacokinetic parameters of MPA were calculated by the noncompartmental method. Changing from CsA to TRL resulted in significantly increased MPA exposure (area under the concentration-time curve from 0 to 12 hours, AUC0-12) by 46 +/- 32% (P = 0.012) and MPA predose concentration (C0) by 121 +/- 67% (P = 0.008). The magnitude of change in MPA exposure did not correlate well with MPA-C0 or CsA trough concentration. Switching to TRL had minimal impact on peak concentration of MPA (15.0 +/- 6.9 mg/L with CsA versus 16.1 +/- 9.7 mg/L with TRL, P = 0.773) and time to reach the peak concentration (1.0 +/- 0.4 hours with CsA versus 1.2 +/- 0.8 hours with TRL, P = 0.461). Highly variable and unpredictable changes in MPA exposure among renal transplant patients with diabetes do not support a strategy of preemptively adjusting MMF dose when switching calcineurin inhibitors in this population.

Lack of an effect of oral iron administration on mycophenolic acid pharmacokinetics in stable renal transplant recipients.

STUDY OBJECTIVES: To determine if coadministration of polysaccharide iron complex and slow-release ferrous sulfate alter the absorption of mycophenolic acid (MPA), and to examine the potential influence of dosing relative to mycophenolate mofetil (MMF) administration and the effect of immediate- versus sustained-release iron products on the steady-state pharmacokinetics of MPA. DESIGN: Prospective, open-label, three-phase, crossover, steady-state pharmacokinetic study. SETTING: National Institutes of Health-sponsored General Clinical Research Center at a university medical center. PATIENTS: Twelve adult (mean age 50 yrs) renal transplant recipients who were receiving concomitant iron and MMF maintenance therapy. INTERVENTION: Oral iron therapy was coadministered with MMF on days -6-0, MMF was administered alone on days 1-8 (control phase), then oral iron therapy was administered 2 hours after MMF administration on days 9-16. MEASUREMENTS AND MAIN RESULTS: Baseline demographics, concurrent drug regimens, and clinical laboratory values were assessed. Blood samples were obtained at baseline and at 1, 2, 3, 4, 6, 8, and 12 hours after MMF administration on days 0, 8, and 16. The MPA levels were measured by high-performance liquid chromatography. We found no significant differences in the dose-standardized area under the concentration-time curve from 0-12 hours (AUC(0-12)) for MPA between the control phase (39.66 +/- 8.70 mg mg x hr/L) and the concomitant ferrous sulfate or dose-separated ferrous sulfate (37.56 +/- 9.95 or 32.84 +/- 8.43 mg x hr/L, respectively, p>0.05) phases. Dose-standardized AUC(0-12) values for MPA did not significantly differ after the concomitant administration of polysaccharide iron complex from that of the control phase (48.46 +/- 9.68 and 43.80 +/- 9.46 mg x hr/L, respectively, p=0.065). However, the AUC(0-12) for MPA significantly increased when polysaccharide iron complex was administered 2 hours after MMF (53.41 +/- 11.75 mg x hr/L, p=0.012). Maximum concentrations and times to reach maximum concentrations remained consistent across all study phases in each arm of the trial (p>0.05). CONCLUSION: Multiple doses of iron therapy-slow-release ferrous sulfate, or polysaccharide iron complex-did not significantly reduce systemic exposure to MMF, as measured by using AUC(0-12) values.

Atomoxetine in the treatment of binge-eating disorder: a randomized placebo-controlled trial.

OBJECTIVE: Binge-eating disorder (BED) is associated with obesity. Atomoxetine is a highly selective norepinephrine reuptake inhibitor associated with weight loss. The purpose of this study was to evaluate atomoxetine in the treatment of BED. METHOD: In this 10-week, single-center, randomized, double-blind, placebo-controlled, flexible dose (40-120 mg/day) trial, outpatients with DSM-IV-TR BED received atomoxetine or placebo. The primary outcome measure was binge-eating episode frequency. The primary analysis of efficacy was a longitudinal analysis of the intent-to-treat sample, with treatment-by-time interaction as the effect measure. Patients were enrolled from September 2004 through October 2005. RESULTS: Compared with placebo (N = 20), atomoxetine (N = 20) was associated with a significantly greater rate of reduction in binge-eating episode frequency, as well as in binge day frequency, weight, body mass index, and scores on the Clinical Global Impressions-Severity of Illness scale, Yale-Brown Obsessive Compulsive Scale Modified for Binge Eating obsession sub-scale, and Three Factor Eating Questionnaire hunger subscale. The mean (SD) atomoxetine daily dose at endpoint evaluation was 106 (21) mg/day. Four patients (N = 3 receiving atomoxe-tine, N = 1 receiving placebo) discontinued because of adverse events. The reasons for atomoxetine discontinuation were increased depressive symptoms (N = 1), constipation (N = 1), and nervousness (N = 1). CONCLUSION: Atomoxetine was efficacious and fairly well tolerated in the short-term treatment of BED. CLINICAL TRIALS REGISTRATION: ClinicalTrials.gov identifier NCT00327834.

Zonisamide in the treatment of binge eating disorder with obesity: a randomized controlled trial.

OBJECTIVE: Binge eating disorder (BED) is associated with obesity. Zonisamide is a novel antiepileptic drug associated with weight loss. The purpose of this study was to evaluate zonisa-mide in the treatment of BED associated with obesity. METHOD: In this 16-week, single-center, randomized, double-blind, placebo-controlled, flexible-dose (100-600 mg/day) trial, 60 outpatients with DSM-IV-TR BED received zonisamide (N = 30) or placebo (N = 30). The primary outcome measure was weekly frequency of binge eating episodes. The primary analysis of efficacy was a longitudinal analysis of the intent-to-treat sample, with treatment-by-time interaction as the effect measure. Patients were enrolled from September 5, 2003, through October 1, 2004. RESULTS: Compared with placebo, zonisamide was associated with a significantly greater rate of reduction in binge eating episode frequency (p = .021), body weight (p < .001), BMI (p = .001), and scores on the Clinical Global Impressions-Severity scale (p < .001), Yale-Brown Obsessive Compulsive Scale Modified for Binge Eating (p < .001), and Three Factor Eating Questionnaire disinhibition scales (p < .001). Plasma ghrelin concentrations increased with zonisamide but decreased with placebo (p = .001). The mean (SD) zonisamide daily dose at endpoint evaluation was 436 (159) mg/day. Twelve patients (N = 8 receiving zonisamide, N = 4 receiving placebo) discontinued because of adverse events. The most common reasons for discontinuing zonisamide were accidental injury with bone fracture (N = 2), psychological complaints (N = 2), and cognitive complaints (N = 2). CONCLUSION: Zonisamide was efficacious, but not well tolerated, in the short-term treatment of BED associated with obesity. CLINICAL TRIALS REGISTRATION: ClinicalTrials.gov identifier NCT00221442.

Rabbit antithymocyte globulin versus basiliximab in renal transplantation.

BACKGROUND: Induction therapy reduces the frequency of acute rejection and delayed graft function after transplantation. A rabbit antithymocyte polyclonal antibody or basiliximab, an interleukin-2 receptor monoclonal antibody, is most commonly used for induction. METHODS: In this prospective, randomized, international study, we compared short courses of antithymocyte globulin and basiliximab in patients at high risk for acute rejection or delayed graft function who received a renal transplant from a deceased donor. Patients taking cyclosporine, mycophenolate mofetil, and prednisone were randomly assigned to receive either rabbit antithymocyte globulin (1.5 mg per kilogram of body weight daily, 141 patients) during transplantation (day 0) and on days 1 through 4 or basiliximab (20 mg, 137 patients) on days 0 and 4. The primary end point was a composite of acute rejection, delayed graft function, graft loss, and death. RESULTS: At 12 months, the incidence of the composite end point was similar in the two groups (P=0.34). The antithymocyte globulin group, as compared with the basiliximab group, had lower incidences of acute rejection (15.6% vs. 25.5%, P=0.02) and of acute rejection that required treatment with antibody (1.4% vs. 8.0%, P=0.005). The antithymocyte globulin group and the basiliximab group had similar incidences of graft loss (9.2% and 10.2%, respectively), delayed graft function (40.4% and 44.5%), and death (4.3% and 4.4%). Though the incidences of all adverse events, serious adverse events, and cancers were also similar between the two groups, patients receiving antithymocyte globulin had a greater incidence of infection (85.8% vs. 75.2%, P=0.03) but a lower incidence of cytomegalovirus disease (7.8% vs. 17.5%, P=0.02). CONCLUSIONS: Among patients at high risk for acute rejection or delayed graft function who received a renal transplant from a deceased donor, induction therapy consisting of a 5-day course of antithymocyte globulin, as compared with basiliximab, reduced the incidence and severity of acute rejection but not the incidence of delayed graft function. Patient and graft survival were similar in the two groups. (ClinicalTrials.gov number, NCT00235300 [ClinicalTrials.gov].).

Efficacy and safety of low-dose valganciclovir in the prevention of cytomegalovirus disease in adult liver transplant recipients.

The efficacy and safety of valganciclovir (VGCV) for cytomegalovirus (CMV) prophylaxis in liver transplant recipients has not been established. We retrospectively compared the efficacy and safety of low-dose oral VGCV (450 mg once daily for 90 days) and standard oral ganciclovir (1 g three times a day for 90 days, GCV) in preventing CMV disease in 109 adult liver transplant recipients who survived at least 1 month between January 2001 and April 2003 (49 GCV and 60 VGCV). The incidence of CMV disease at 1 year post-transplant was similar among patients treated with VGCV and GCV (3% and 4%, respectively). Three of the four CMV disease cases occurred in high-risk recipients with CMV serotype of donor+/recipient- (D+/R-) and all cases presented after completion of CMV prophylaxis, ranging 114-152 days post-transplant. Severe neutropenia was rare, and thrombocytopenia and anemia occurred at similar frequencies with both prophylaxis regimens. In conclusion, a 90-day regimen of low-dose oral VGCV has a similar efficacy and safety profile to high-dose oral GCV in adult liver transplant recipients. D+/R- liver transplant recipients remain at risk of developing CMV disease after completion of antiviral prophylaxis. Additional prospective studies with close monitoring for CMV viremia and drug resistance are needed to further establish the optimal dose and duration of VGCV in liver transplant recipients.

Effect of oral vitamin E and C therapy on calcineurin inhibitor levels in heart transplant recipients.

BACKGROUND: A recent prospective trial demonstrated that oral vitamins C and E retard the early progression of transplant-associated coronary arteriosclerosis; as a result, a number of centers have added these agents to their maintenance regimens. This study reviewed the impact of vitamin E and C supplementation on calcineurin inhibitor trough concentrations. METHODS: A retrospective chart review of the first 29 heart transplant patients prescribed anti-oxidant agents was performed. Twenty-two patients taking cyclosporin A (CsA) and 7 patients taking tacrolimus were prescribed vitamin C (500 mg twice a day) and vitamin E (400 IU twice a day). Serum chemistries and drug levels were measured before and after vitamin therapy was initiated. RESULTS: The baseline CsA trough concentration (mean +/- SD) was 137 +/- 39 ng/ml and it declined to 99 +/- 54 ng/ml (p = 0.007) after anti-oxidant therapy was initiated. The average percentage decrease in the CsA trough concentration was 30%. No significant changes were seen in the patients taking tacrolimus. CONCLUSIONS: These data demonstrate that supplementation with the anti-oxidant agents vitamin C and vitamin E decreases CsA concentrations but does not appear to effect tacrolimus concentrations. Although more detailed pharmacokinetic analysis is necessary to clarify the exact mechanism of this interaction, physicians who take care of transplant recipients should be aware that more frequent CsA concentration monitoring is warranted after initiating these anti-oxidant agents.

Reproduction and transplantation: report on the AST Consensus Conference on Reproductive Issues and Transplantation.

It has been almost 50 years since the first child was born to a female transplant recipient. Since that time pregnancy has become common after transplantation, but physicians have been left to rely on case reports, small series and data from voluntary registries to guide the care of their patients. Many uncertainties exist including the risks that pregnancy presents to the graft, the patient herself, and the long-term risks to the fetus. It is also unclear how to best modify immunosuppressive agents or treat rejection during pregnancy, especially in light of newer agents available where pregnancy safety has not been established. To begin to address uncertainties and define clinical practice guidelines for the transplant physician and obstetrical caregivers, a consensus conference was held in Bethesda, Md. The conferees summarized both what is known and important gaps in our knowledge. They also identified key areas of agreement, and posed a number of critical questions, the resolution of which is necessary in order to establish evidence-based guidelines. The manuscript summarizes the deliberations and conclusions of the conference as well as specific recommendations based on current knowledge in the field.