A high mucosal blocking score is associated with HIV protection.

BACKGROUND: Early steps of HIV infection are mediated by the binding of the envelope to mucosal receptors as α4ß7 and the C-type lectins DC-SIGN and langerin. Previously Env-specific B-cell responses have been reported in highly exposed seronegative individuals (HESN). METHOD: Here, we studied gp120-specific antibodies ability to block HIV interaction with α4ß7, DC-SIGN and/or langerinin HESN. New cell-based assays were developed to analyze whether antibodies that can alter gp120 binding to α4ß7, DC-SIGN and/or langerin are induced in HESN. A mucosal blocking score (MBS) was defined based on the ability of antibodies to interfere with gp120/α4ß7, gp120/DC-SIGN, and gp120/langerin binding. A new MBS was evaluated in a cohort of 86 HESN individuals and compared with HIV+ patients or HIV- unexposed healthy individuals. RESULTS: Antibodies reducing gp120 binding to both α4ß7 and DC-SIGN were present in HESN serum but also in mucosal secretions, whereas antibodies from HIV+ patients facilitated gp120 binding to DC-SIGN. Any correlation was observed between MBS and the capacity of antibodies to neutralize infection of α4ß7 CD4+ T cells with primary isolates. CONCLUSIONS: MBS is significantly associated with protection in HESN and might reflect altered HIV spreading to mucosal-associated lymphoid tissues.

Neutralizing and Targeting Properties of a New Set of α4ß7-Specific Antibodies Are Influenced by Their Isotype.

The homing of lymphocytes to the mucosa is mainly controlled by α4ß7 integrin, and it is amplified during gut chronic inflammation, as occurs with HIV and/or inflammatory bowel diseases. We designed and applied an improved immunization strategy based on an innovative selection process to isolate new α4ß7 lymphocyte-specific monoclonal antibodies that are able to prevent their migration into inflamed gut tissues and/or to counteract HIV infection in vitro. First, 5 monoclonal antibodies (1 IgA, 1 IgM, and 4 IgGs) were selected based on their capacity to recognize α4 or ß7 homodimers and α4ß7 heterodimers in transfected human cells. Their ability to block gp120/α4ß7 or MAdCAM-1/α4ß7 interactions was then measured in vitro with human T and B lymphocytes. In vitro, the anti-α4ß7 IgA isotype was found to have the highest affinity for the α4ß7 heterodimer, and it significantly reduced HIV replication in retinoic acid-treated α4ß7 CD4 human T cells. This α4ß7-specific IgA also displayed a high avidity for human and mouse α4ß7 lymphocytes in both mouse and human inflammatory colitis tissues. These new antibodies, and in particular those with mucosa-targeting isotypes such as IgA, could therefore be potential novel therapeutic tools for treating HIV and inflammatory bowel disease.

First Membrane Proximal External Region-Specific Anti-HIV1 Broadly Neutralizing Monoclonal IgA1 Presenting Short CDRH3 and Low Somatic Mutations.

Mucosal HIV-1-specific IgA have been described as being able to neutralize HIV-1 and to block viral transcytosis. In serum and saliva, the anti-HIV IgA response is predominantly raised against the envelope of HIV-1. In this work, we describe the in vivo generation of gp41-specific IgA1 in humanized α1KI mice to produce chimeric IgA1. Mice were immunized with a conformational immunogenic gp41-transfected cell line. Among 2300 clones screened by immunofluorescence microscopy, six different gp41-specific IgA with strong recognition of gp41 were identified. Two of them have strong neutralizing activity against primary HIV-1 tier 1, 2, and 3 strains and present a low rate of somatic mutations and autoreactivity, unlike what was described for classical gp41-specific IgG. Epitopes were identified and located in the hepted repeat 2/membrane proximal external region. These Abs could be of interest in prophylactic treatment to block HIV-1 penetration in mucosa or in chronically infected patients in combination with antiretroviral therapy to reduce viral load and reservoir.

Major influence of CD4 count at the initiation of cART on viral and immunological reservoir constitution in HIV-1 infected patients.

BACKGROUND: A persistent immune activation is observed in gut during HIV-1 infection, which is not completely reversed by a combined antiretroviral therapy (cART). The impact of the time of cART initiation may highly influence the size of the viral reservoir and the ratio of CD4(+)/CD8(+) T cells in the gut. In this study, we analyzed the characteristics of HIV rectal reservoir of long-term treated patients, regarding their blood CD4(+) T cells count at the time of cART initiation. RESULTS: Twenty-four consenting men were enrolled: 9 exhibiting a CD4(+) T cells count >350/mm(3) ("high-level CD4 group") and 15 < 350/mm(3) ("low-level CD4 group") in blood, at the start of cART. An immunophenotypical analysis of T and B cells subpopulations was performed in blood and rectal biopsies. HIV cell-associated DNA loads and qualitative intra-cellular RNA were determined in both compartments. The ratio of CD4(+)/CD8(+) T cells was significantly decreased in the blood but not in the rectum of the "low-level CD4 group" of patients. The alteration in ß7(+) CD4(+) T cells homing was higher in this group and was correlated to a low ratio of CD4(+)/CD8(+) T cells in blood. An initiation of cART in men exhibiting a low-level CD4 count was also associated with an alteration of B cells maturation. HIV blood and gut DNA reservoirs were significantly lower in the "high-level CD4 group" of men. A high HIV DNA level was associated to a detectable intracellular HIV RNA in rectum. CONCLUSIONS: An early initiation of cART could significantly preserve gut immunity and limit the viral reservoir constitution.

Brief Report: A High Rate of ß7+ Gut-Homing Lymphocytes in HIV-Infected Immunological Nonresponders is Associated With Poor CD4 T-Cell Recovery During Suppressive HAART.

OBJECTIVE: Correlation between GALT homing markers on lymphocytes and the low blood CD4 T-cell reconstitution in immunological nonresponders (INRs) has been studied. DESIGN: Thirty-one INRs, 19 immunological responders (IRs), and 12 noninfected controls were enrolled in this study. INRs were defined by an undetectable plasma viral load RNA less than 40 copies per milliliter and CD4 T-cell count <500 cells per cubic milliliter in at least 3 years. METHODS: A complete peripheral and mucosal lymphocyte immunophenotyping was performed on these patients with a focus on the CCR9, CCR6, and α4ß7 gut-homing markers. RESULTS: A highly significant upregulation of α4ß7 on INRs peripheral lymphocytes compared with that of IRs has been observed. This upregulation impacts different lymphocyte subsets namely CD4, CD8, and B lymphocytes. The frequency of ß7 Th17 and Treg cells are increased compared with IRs and healthy controls. The frequency of ß7 CD8 T cells in the blood is negatively correlated with integrated proviral DNA in rectal lymphoid cells in contrast to ß7 CD4 T cells associated with HIV integration. CONCLUSIONS: Alteration of lymphocyte homing abilities would have deleterious effects on GALT reconstitution and could participate to HIV reservoir constitution. These results emphasize the great interest to consider α4ß7-targeted therapy in INR patients to block homing of lymphocytes and/or to directly impair gp120-α4ß7 interactions.

Comparison of Screening Dilution and Automated Reading for Antinuclear Antibody Detection on HEP2 Cells in the Monitoring of Connective Tissue Diseases.

BACKGROUND: Indirect immunofluorescence plays a major role in the detection of antinuclear antibodies (ANAs) and follow-up of their titers in the context of connective tissue diseases. Given the numerous unfavorable features of the conventional manual reading of HEP2 slides (need of time and expert morphologists for the reading, lack of standardization, subjectivity of the interpretation), the biomedical industry has developed automated techniques of slide preparation and microscope reading. METHODS: We collected 49 sera beforehand analyzed by the conventional reading of slides. They were prepared again by QUANTA-Lyser(®) and reanalyzed in four different conditions: two dilutions of screening (1/40 and 1/80), two different systems of analysis, NOVA View(®) automated reading (INOVA Diagnostics), then confirmation by the operator, and conventional manual reading by two different qualified operators. The analysis was realized in blind of the first interpretation and clinical diagnosis. The sera were classified in four groups, on the basis of the results of the first analysis: negative sera (titer < 1/160; 11 patients), low positives (titer at 1/160; 18 patients), moderated positives (titers between 1/320 and 1/640; 10 patients), and strong positives (titers between 1/1,280 and 1/2,560; 10 patients). RESULTS: Among the 49 patients, 13 presented a connective tissue disease including 4 systemic scleroderma (SS), 3 rheumatoid arthritis (RA), 2 Goujerot-Sjogren (GS), 2 systemic lupus erythematosus (SLE), 1 polymyositis (PM), 1 Raynaud's syndrome (RS), and 1 CREST syndrome. One patient presented both an SLE and an SS. Regarding the screening dilution, the 1/40 dilution is less specific than the 1/80 dilution for both the systems of analysis (5.6% vs. 16.7% for the manual reading, and 27.8% vs. 50% for the automated reading). It also generates statistically more false positives (P = 0.037 for the conventional analysis and P = 0.003 for the automated system). The automated NOVA View(®) reading of slides allows a gain in specificity for both dilutions, and also statistically less false positives (P = 0.002 at the 1/40 and P = 0.0006 at the 1/80), and detriment of the sensitivity at the highest dilution (84.6% vs. 92.3% with manual reading). Thus, according to our analysis of 49 sera, the automated NOVA View(®) system of reading of slides at the dilution 1/80 seems to be a successful condition for the detection of ANAs on HEP2 cells, close to the significance (P = 0.067). CONCLUSION: The automated NOVA View(®) reading of slides allows saving time, and an improvement in the standardization. Nevertheless, it requires a confirmation by a qualified operator, to interpret mixed patterns in particular.

A Difficult and Rare Diagnosis of Autoimmune Enteropathy in a Patient Affected by Down Syndrome.

Patients with Down syndrome are more susceptible to autoimmune pathologies, in particular endocrine or digestive diseases such as celiac disease. Autoimmune enteropathy is another form of digestive autoimmune disease, non-gluten-dependant, more often diagnosed in male neonates with immunodysregulation and polyendocrinopathy such as the Immunodysregulation, Polyendocrinopathy, Enteropathy, X-linked syndrome. It also exists in the adult, but this pathology is less known and therefore frequently under-diagnosed. Clinical manifestations are similar to celiac disease, but not improved after a gluten-free diet. Autoimmune enteropathy is frequently associated with other autoimmune diseases, such as thyroiditis, myasthenia gravis, lupus or immune deficiencies, as Common Variable Immunodeficiency. Pathological analysis of intestinal biopsies can frequently distinguish autoimmune enteropathy and celiac disease. Autoimmune enteropathy usually has an important lymphoplasmacytic infiltration of the mucosa and a lack of intraepithelial lymphocytes in the gastrointestinal mucosal surface, while celiac disease usually has a polymorph infiltration of the mucosa and an important intraepithelial lymphocytes infiltration. Nevertheless, the two pathological patterns may overlap. Here we report the first case of a patient with Down syndrome associated to autoimmune enteropathy (initially diagnosed as celiac disease), chronic pancreatitis and cutaneous lupus erythematosus. Even if autoimmune pathologies are much more common in patients with Down syndrome, we would like to report on this rare and original association found in our patient.

Delivery of antigen to nasal-associated lymphoid tissue microfold cells through secretory IgA targeting local dendritic cells confers protective immunity.

BACKGROUND: Transmission of mucosal pathogens relies on their ability to bind to the surfaces of epithelial cells, to cross this thin barrier, and to gain access to target cells and tissues, leading to systemic infection. This implies that pathogen-specific immunity at mucosal sites is critical for the control of infectious agents using these routes to enter the body. Although mucosal delivery would ensure the best onset of protective immunity, most of the candidate vaccines are administered through the parenteral route. OBJECTIVE: The present study evaluates the feasibility of delivering the chemically bound p24gag (referred to as p24 in the text) HIV antigen through secretory IgA (SIgA) in nasal mucosae in mice. RESULTS: We show that SIgA interacts specifically with mucosal microfold cells present in the nasal-associated lymphoid tissue. p24-SIgA complexes are quickly taken up in the nasal cavity and selectively engulfed by mucosal dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin-positive dendritic cells. Nasal immunization with p24-SIgA elicits both a strong humoral and cellular immune response against p24 at the systemic and mucosal levels. This ensures effective protection against intranasal challenge with recombinant vaccinia virus encoding p24. CONCLUSION: This study represents the first example that underscores the remarkable potential of SIgA to serve as a carrier for a protein antigen in a mucosal vaccine approach targeting the nasal environment.

Directing vaccine immune responses to mucosa by nanosized particulate carriers encapsulating NOD ligands.

Mucosal surfaces are a major portal of entry for many pathogens that are the cause of infectious diseases. Therefore, effective vaccines that induce a protective immune response at these sites are much needed. However, despite early success with the live attenuated oral polio vaccine over 50 years ago, only a few new mucosal vaccines have been subsequently licensed. Development of new adjuvants, comprising antigen delivery platforms and immunostimulatory molecules, are critical for the successful development of new mucosal vaccines. Among them, biodegradable nanoparticle delivery systems are promising and NOD-like receptors are considered as potential new targets for immunostimulatory molecules. In this work, different NOD1 and NOD2 ligands were encapsulated in polylactic acid (PLA) nanoparticles, coated with HIV-1 gag p24 antigen. We showed that these new formulations are able to induce proliferation of HIV-specific T cells from HIV(+) individuals as well as autophagy. In vivo, these formulations highly enhanced p24-specific systemic and mucosal immune responses in mice not only after mucosal administration but also after immunization via the parenteral route. Our results provide a rational approach for combining nanosized particulate carriers and encapsulated NOD receptor ligands as potent synergistic tools for induction of specific mucosal immunity.

[Targeting and role of α4ß7 integrin in the pathophysiology of IBD and HIV infection]. / Rôle et ciblage de l'intégrine α4ß7 dans la physiopathologie des MICI et de l'infection par le VIH.

Integrins are a large family of heterodimeric cell adhesion molecules that are key regulators in multiple biological functions. They orchestrate cell-cell and cell-extracellular matrix (ECM) adhesive interactions from embryonic development to mature tissue function, and are thus involved in cell migration, proliferation, differentiation, and survival. As such, they are also involved in human diseases, such as thrombotic diseases, inflammation, cancer, fibrosis and infectious diseases. Integrins are exciting pharmacological targets because they are exposed on the cell surface. Indeed, several compounds have been developed that block integrins function, and five have been approved as therapeutic drugs for use in clinic. This review will detail the role of α4ß7, an integrin of particular relevance for mucosal diseases such as IBD (inflammatory bowel disease) and also, as reported more recently, HIV infection.

Loss of heterozygosity in tumor tissue in hormonal receptor genes is associated with poor prognostic criteria in breast cancer.

The estrogen receptors (ESRα and ß) and the androgen receptor (AR) mediate genomic and non-genomic effects on breast tumor growth and proliferation. We analyzed 101 breast cancer patients for allelic loss in microsatellites located in regulatory regions of the ESRs and AR genes in breast cancer tumors. The loss of heterozygosity (LOH) at these loci was found in 36.2% of tumor tissues (ductal carcinoma cases), for 19% of cases at the ESRα locus, for 16% at the ESRß locus, and for 10% at the AR locus. The LOH in at least one of the two ESR loci was correlated to poor prognosis criteria: ESR-negative status (P = 0.007), PR-negative status (P = 0.003), high Scarff-Bloom-Richardson (SBR) grade (P = 0.0007), high MIB-1 proliferation index (P = 0.02), and diminished apoptosis potential (TP53-positive status, P = 0.018). When AR was also considered, the LOH in at least one of the three loci was associated with ESR-negative status (P = 0.036), PR-negative status (P = 0.027), high SBR grade (P = 0.005), high mitotic index (P = 0.0002), TP53-positive status (P = 0.029), and proliferating index (high MIB-1, P = 0.03). Allelic loss was observed in 26% of normal tissue adjacent to tumor with LOH at the ESRα locus and in 7.1% of tumors with LOH at the ESRß locus. The LOH in tumor tissue in the regulatory regions of ESRα, ESRß, and AR genes has potentially synergistic effects on tumor proliferation, histological aggressiveness, down-regulation of ESRα and progesterone receptor (PR) genes, and is an early genetic alteration in cancer that is possibly involved in passage to estrogen independence.

Cell-free RNA content in urine as a possible molecular diagnostic tool for clear cell renal cell carcinoma.

There is limited research on cell-free RNA (cf-RNA) in the urine of cancer patients. The present study was performed to detect the cf-RNA in the urine of patients with clear cell renal cell carcinoma (ccRCC). Ninety-five urine samples from ccRCC patients and 50 urine samples from control subjects were analyzed. The cf-RNA integrity index was calculated by using quantitative real-time RT-PCR assays of the small-sized fragment (106 bp) and the big-sized fragment (416 bp) in GAPDH mRNA. The initial analysis showed that cf-RNA was stable and detectable in the urine. The mean cf-RNA integrity index was significantly lower in the urine of ccRCC patients (mean: 0.07, 95%CI: 0.05-0.10) when compared with the urine from control subjects (mean: 0.25, 95%CI: 0.16-0.33) (p < 0.001). The value of the area under the receiver-operating characteristic curve by using the cf-RNA integrity index for the diagnosis of ccRCC was 0.858 with a sensitivity of 68.0% and a specificity of 92.6%. Moreover, the small-sized VEGF mRNA fragment (98 bp) was detected in 31 of 50 urine samples of patients with ccRCC and in only 2 of 50 urine samples of control subjects (p < 0.001) while the detection of the big-sized (420 bp) VEGF mRNA fragment was an infrequent event. Our findings suggest that the small-sized cf-RNA in urine was more abundant in cancer patients. The tumor-related gene VEGF mRNA fragment was detectable in the urine of cancer patients. Our finding may provide a new molecular assay for the diagnosis of renal cell carcinoma.

Secretory IgA as a vaccine carrier for delivery of HIV antigen to M cells.

HIV transmission and spread in the host are based on the survival of the virus or infected cells present in mucosal secretions, and the virus' ability to cross the epithelial barrier and access immune target cells, which leads to systemic infection. Therefore, HIV-specific immunity at mucosal sites is critical for control of infection. Although mucosal delivery would ensure the best onset of protective immunity, most candidate vaccines are administered through the parenteral route. Remarkably, secretory IgA (SIgA) interacts specifically with mucosal microfold (M) cells present in gut-associated lymphoid tissues. Here we evaluate the feasibility of delivering chemically bound p24HIV antigen via SIgA into the intestinal mucosae in mice. After oral administration, p24-SIgA complexes are quickly delivered into the tissue and selectively captured by CX3CR1(+) dendritic cells. Oral immunization with p24gag linked to SIgA (p24-SIgA) adjuvanted with E. coli heat labile enterotoxin (HLT) elicits both humoral and cellular immune responses against p24 at the systemic and mucosal levels and induces efficient protection against rectal challenge with a recombinant vaccinia virus encoding gag. This is the first study which underscores the remarkable potential of SIgA to serve as a vaccine carrier for an HIV antigen in mucosal administration targeting the gastrointestinal environment.

Prevention and treatment of postoperative Crohn's disease recurrence with anti-TNF therapy: a meta-analysis of controlled trials.

BACKGROUND: The magnitude of the efficacy of anti-tumour necrosis factor (TNF) therapy in preventing and treating postoperative Crohn's disease recurrence has yet to be determined. METHODS: We searched MEDLINE, the Cochrane Library, and EMBASE. The primary endpoints, and clinical and endoscopic recurrence, were analysed using the Mantel-Haenszel and DerSimonian and Laird methods. RESULTS: Nine controlled trials (n=362) that evaluated the efficacy of anti-TNF therapy in preventing (n=7) or treating (n=2) postoperative recurrence were included. Anti-TNF therapy was more effective at preventing (n=6) endoscopic recurrence than the control arms (odds ratio 0.05; 95% confidence interval 0.02-0.13, P<0.0001; NNT=1.9). Anti-TNF therapy was more effective at preventing (n=5) clinical recurrence than the control arms (odds ratio 0.10; 95% confidence interval 0.05-0.21, P<0.0001; NNT=2.4). Anti-TNF therapy was more effective than control arms at treating endoscopic postoperative recurrence (n=2; odds ratio 16.64; 95% confidence interval 2.51-110.27, P<0.004; NNT=2.3). Neither heterogeneity nor publication bias was observed. CONCLUSION: Anti-TNF agents may be more effective in preventing clinical and endoscopic postoperative Crohn's disease recurrence than control treatment (thiopurines or mesalamine). Efficacy in treating postoperative Crohn's disease recurrence will require further investigation. Large randomised controlled trials are awaited.

Cutting edge: New chimeric NOD2/TLR2 adjuvant drastically increases vaccine immunogenicity.

TLR ligands are critical activators of innate immunity and are being developed as vaccine adjuvants. However, their usefulness in conjunction with NOD-like receptor agonists remains poorly studied. In this study, we evaluated a new ligand that targets both TLR2 and NOD2 receptors. We assessed its ability to enhance dendritic cell maturation in vitro in addition to improving systemic and mucosal immune responses in mice. The chimeric NOD2/TLR2 ligand induced synergistic upregulation of dendritic cell maturation markers, costimulatory molecules, and secretion of proinflammatory cytokines compared with combinations of separate ligands. Furthermore, when coadministered with biodegradable nanoparticles carrying a model Ag, the ligand was able to induce high Ag-specific IgA and IgG titers at both systemic and mucosal sites after parenteral immunizations. These findings point out the potential utility of chimeric molecules TLR/NOD as adjuvants for vaccines to induce systemic and mucosal immune responses.

Pharmacokinetics in IBD: ready for prime time?

This review discusses the rationale behind recommending immunopharmacological guidance of long-term therapies with anti-TNF-α specific biotherapies. "Arguments why therapeutic decision-making should not rely on clinical outcomes alone are presented. Central to this is that the use of theranostics (i.e., monitoring circulating levels of functional anti-TNF-α drugs and antidrug antibodies) would markedly improve treatment because therapies can be tailored to individual patients and provide more effective and economical long-term clinical benefits while minimising risk of side effects. Large-scale immunopharmacological knowledge of the pharmacokinetics of TNF-α biopharmaceuticals in individual patients would also help industry to develop more effective and safer TNF-α inhibitors" [1].

Recent progress in HIV vaccines inducing mucosal immune responses.

In spite of several attempts over many years at developing a HIV vaccine based on classical strategies, none has convincingly succeeded to date. As HIV is transmitted primarily by the mucosal route, particularly through sexual intercourse, understanding antiviral immunity at mucosal sites is of major importance. An ideal vaccine should elicit HIV-specific antibodies and mucosal CD8⁺ cytotoxic T-lymphocyte (CTL) as a first line of defense at a very early stage of HIV infection, before the virus can disseminate into the secondary lymphoid organs in mucosal and systemic tissues. A primary focus of HIV preventive vaccine research is therefore the induction of protective immune responses in these crucial early stages of HIV infection. Numerous approaches are being studied in the field, including building upon the recent RV144 clinical trial. In this article, we will review current strategies and briefly discuss the use of adjuvants in designing HIV vaccines that induce mucosal immune responses.

Pharmacokinetics of adalimumab in inflammatory bowel diseases: a systematic review and meta-analysis.

BACKGROUND: The aim of this meta-analysis was to explore the magnitude of the association between pharmacokinetics of adalimumab and clinical response in patients with inflammatory bowel disease. METHODS: A literature search was performed up to December 2013. MEDLINE, EMBASE, Cochrane, and meeting abstracts were reviewed. Studies were included if they analyzed the association of trough levels of adalimumab (TRA) or antibodies against adalimumab (AAA) with clinical response in adult or pediatric inflammatory bowel disease. A Mantel-Haenszel pooled risk estimate provided a measure of the association. RESULTS: Fourteen studies enrolling 1941 patients with inflammatory bowel disease were included in the systematic review. Thirteen studies analyzed clinical outcomes according to TRA. In only 1 study, there was no correlation between high TRA and clinical response. Six of the 7 studies reported a negative correlation between AAA and clinical outcomes. Six studies enrolling 536 patients (Crohn's disease [CD] only) met the meta-analysis inclusion criteria. The pooled odds ratio (OR) for loss of clinical response to adalimumab in patients with CD (N = 4) with positive AAAs was 10.15 (95% confidence interval [CI]: 3.90-26.40, P < 0.0001). Patients with CD with TRA over a predefined cutoff were more likely to be in clinical remission with an OR of 2.6 (95% CI: 1.79-3.77, P < 0.0001). The association was stronger if the analysis was limited to the adult population (N = 3, OR: 7.05, 95% CI: 3.58-13.9, P < 0.0001). CONCLUSIONS: The presence of AAA is associated with a higher risk of loss of clinical response to adalimumab, whereas high TRA is associated with greater clinical response rates in CD. More data are needed in ulcerative colitis.

Association between 6-thioguanine nucleotides levels and clinical remission in inflammatory disease: a meta-analysis.

BACKGROUND: A previous meta-analysis suggested that 6-thioguanine nucleotides levels are associated with clinical remission in inflammatory bowel disease. It was criticized because of the relatively small number of patients included in this meta-analysis and heterogeneity between studies. Recent studies provided conflicting results, and the source of those discrepancies has yet to be explored. METHODS: A comprehensive, computerized literature search was conducted in Medline, ISI Web of Science, and EMBASE until December 31, 2012. A combined odd ratio with its 95% confidence interval was calculated using a fixed effects model based on the Mantel-Haenszel method. Between-study heterogeneity was assessed using Cochran's Q statistic. RESULTS: Seventeen studies enrolling 2049 patients with inflammatory bowel disease were analyzed. A significant heterogeneity was found in the overall analysis (P = 0.005). As heterogeneity among studies could be explained by differences in metabolite assay methods, an analysis including only studies using the reference method by Lennard et al (N = 10) was performed, and the pooled odds ratio for clinical remission among patients with 6-thioguanine nucleotides levels over a cut-off value between 230 and 260 pmol/8.10^8 RBC was 3.15 (95% confidence interval, 2.41-4.11). CONCLUSIONS: This meta-analysis clearly establishes an association between 6-thioguanine nucleotides levels and clinical remission rates in patients with inflammatory bowel disease and explains the heterogeneity of results among selected studies. The lack of standardization in 6-thioguanine nucleotides assays is responsible for recent contradictory results. Whether therapeutic drug monitoring of thiopurines should be systematically used in clinical practice in inflammatory bowel disease to improve disease outcomes will require further investigation.

Association between pharmacokinetics of adalimumab and mucosal healing in patients with inflammatory bowel diseases.

BACKGROUND & AIMS: Little is known about the association between pharmacokinetic features of adalimumab and mucosal healing in patients with inflammatory bowel disease (IBD). METHODS: We conducted a cross-sectional study of 40 patients with Crohn's disease (CD) or ulcerative colitis (UC) who received adalimumab maintenance therapy and underwent endoscopic evaluation of disease activity and pharmacokinetic analysis (measurements of trough levels and antibodies against adalimumab). Patients in clinical remission were identified based on CD activity index scores less than 150 or Mayo scores less than 3 (for those with UC). Patients with mucosal healing were identified based on Mayo endoscopic scores less than 2 (for UC) or the disappearance of all ulcerations (for CD). RESULTS: The median trough level of adalimumab was higher in patients in clinical remission (6.02 µg/mL) than in patients with active disease (3.2 µg/mL; P = .012). Trough levels of adalimumab were also higher in patients with mucosal healing (6.5 µg/mL) than in patients without (4.2 µg/mL; P < .005). These results did not vary with type of IBD. On multivariate analysis, trough levels of adalimumab (relative risk, 0.62; 95% confidence interval, 0.40-0.94; P = .026) and duration of adalimumab treatment (relative risk, 0.82; 95% confidence interval, 0.68-0.97; P = .026) were associated independently with healing mucosa. An absence of mucosal healing was associated with trough levels of adalimumab less than 4.9 µg/mL (likelihood ratio, 4.3; sensitivity, 66%; specificity, 85%). CONCLUSIONS: Trough levels of adalimumab are significantly higher in IBD patients who are in clinical remission and in those with mucosal healing. Detection of antibodies against adalimumab predicts a lack of mucosal healing.