Immunostimulatory capacity of dental casting alloys on endotoxin responsiveness.

STATEMENT OF PROBLEM: Oral metal exposure has been associated with systemic and local adverse reactions, probably due to elemental release from the alloys. Although supraphysiological concentrations of salts from dentally applied metals can activate innate cells through TLR4 (Ni, Co, Pd) and TLR3 (Au), whether direct exposure to solid alloys can also trigger innate immune reactivity is still unknown. PURPOSE: The purpose of this in vitro study was to determine whether dental cast alloy specimens can activate innate cells and influence their responsiveness to bacterial endotoxin. MATERIAL AND METHODS: Human monocyte-derived dendritic cells (MoDC) and THP-1 cells were cultured on top of different alloy specimens (Ni-Cr, Co-Cr, Pd-Cu, Pd-Ag, Ti-6Al-4V, amalgam, gold, and stainless steel) or in alloy-exposed culture medium with or without endotoxin (lipopolysaccharide [LPS]; Escherichia coli 055:B5). Interleukin-8 (IL-8) production was used as the parameter for innate stimulation and evaluated by enzyme-linked immunosorbent assay after 24 hours of culture. The statistical significance of the effects of various casting alloys on the secretion of IL-8 was analyzed by using the nonparametric Wilcoxon rank sum test (α=.05). RESULTS: Dental cast alloys induced IL-8 production in MoDC and THP-1 cells, with Au and Pd-Cu providing the strongest stimulation. The alloy-exposed culture media tested contained sufficient stimulatory metal ions to induce detectable IL-8 production in THP-1 cells, except for the Ni-Cr and stainless steel exposed media. Au and Pd-Cu alloys were also most effective in potentiating LPS responsiveness as measured by IL-8 production. CONCLUSIONS: Using an in vitro culture system to expose MoDC and THP-1 cells to different alloy specimens this study showed that contact with the solid alloys, in particular when they contain Pd or Au, can trigger innate immune responses and augment responsiveness to bacterial endotoxin.

Metal ions potentiate microglia responsiveness to endotoxin.

Oral metal exposure has been associated with diverse adverse reactions, including neurotoxicity. We showed previously that dentally applied metals activate dendritic cells (MoDC) via TLR4 (Ni, Co, Pd) and TLR3 (Au). It is still unknown whether the low levels of dental metals reaching the brain can trigger local innate cells or prime them to become more responsive. Here we tested whether dentally applied metals (Cr, Fe, Co, Ni, Cu, Zn, Au, Hg) activate primary human microglia in vitro and, as a model, monocytic THP-1-cells, in high non-toxic as well as near-physiological concentrations. In addition the effects of 'near-physiological' metal exposure on endotoxin (LPS) responsiveness of these cells were evaluated. IL-8 and IL-6 production after 24h was used as read out. In high, non-toxic concentrations all transition metals except Cr induced IL-8 and IL-6 production in microglia, with Ni and Co providing the strongest stimulation. When using near-physiological doses (up to 10× the normal plasma concentration), only Zn and Cu induced significant IL-8 production. Of note, the latter metals also markedly potentiated LPS responsiveness of microglia and THP-1 cells. In conclusion, transition metals activate microglia similar to MoDCs. In near-physiological concentrations Zn and Cu are the most effective mediators of innate immune activation. A clear synergism between innate responses to Zn/Cu and LPS was observed, shedding new light on the possible relation between oral metal exposure and neurotoxicity.

Serological Screening for Celiac Disease in Adult Chinese Patients With Diarrhea Predominant Irritable Bowel Syndrome.

Celiac disease (CD) is common in Caucasians, but thought to be rare in Asians. Our aim was to determine the prevalence of CD in Chinese patients with chronic diarrhea predominant irritable bowel syndrome (IBS-D).From July 2010 to August 2012, 395 adult patients with IBS-D and 363 age and sex-matched healthy controls were recruited in Zhongnan Hospital of Wuhan University and Xiaogan Central Hospital in Hubei province, central China. Patients with IBS-D were diagnosed according to the Rome III criteria. Serum Immunoglobulin (IgA/IgG) anti-human tissue transglutaminase (anti-htTG)-deamidated gliadin peptide (DGP) antibodies were measured in a single ELISA (QUANTA Lite h-tTG/DGP Screen). Upper endoscopy with duodenal biopsies and HLA-DQA1 and HLA-DQB1 genotyping were performed in seropositive subjects and a gluten-free diet was prescribed.Seven IBS-D patients (7/395, 1.77%) and 2 healthy controls (2/363, 0.55%), were positive for anti-htTG/DGP antibodies. Of these 9 cases, 1 was lost to follow-up, 3 were suspected to have CD and 5 were eventually diagnosed as CD with intestinal histological lesions classified as Marsh Type II in 2 and Type III in 3. Of these 5 diagnosed CD patients, 4 (4/395, 1.01%) were from the IBS-D group and 1 (1/363, 0.28%) from the healthy control had asymptomatic CD. Two Type III CD patients with relatively high titers in the serologic assay were homozygous and heterozygous for haplotype HLA-DQA1*03-DQB1*03:03 (HLA-DQ9.3), respectively.In the present study, CD was present in 1.01% of patients with IBS-D and in 0.28% of the control group. We like to suggest that the haplotype HLA-DQA1*03-DQB1*03:03 (HLA-DQ9.3), which is common in Chinese, is a new susceptibility factor for CD in China. Larger screening and genetic studies are needed in the Chinese population of different regions.

Dental metal-induced innate reactivity in keratinocytes.

Gold, nickel, copper and mercury, i.e. four metals frequently used in dental applications, were explored for their capacity to induce innate immune activation in keratinocytes (KC). Due to their anatomical location the latter epithelial cells are key in primary local irritative responses of skin and mucosa. Fresh foreskin-derived keratinocytes and skin and gingiva KC cell lines were studied for IL-8 release as a most sensitive parameter for NF-kB activation. First, we verified that viral-defense mediating TLR3 is a key innate immune receptor in both skin- and mucosa derived keratinocytes. Second, we found that, in line with our earlier finding that ionized gold can mimic viral dsRNA in triggering TLR3, gold is very effective in KC activation. It would appear that epithelial TLR3 can play a key role in both skin- and mucosa localized irritation reactivities to gold. Subsequently we found that not only gold, but also nickel, copper and mercury salts can activate innate immune reactivity in keratinocytes, although the pathways involved remain unclear. Although current alloys have been optimized for minimal leakage of metal ions, secondary factors such as mechanical friction and acidity may still facilitate such leakage. Subsequently, these metal ions may create local irritation, itching and swelling by triggering innate immune reactions, potentially also facilitating the development of metal specific adaptive immunity.

Continuing the quest for autoimmunity due to oral metal exposure.

AIM: The role of metal exposure in the development of autoimmune disease (AID) is still controversial. Here, we studied the relationship between oral metal exposure, metal allergy and autoimmunity. METHODS: A mixed population (n = 78) of non-allergic volunteers, metal-allergic patients and patients with oral problems putatively due to metal alloys was evaluated for oral Ni, Pd, Au and Hg exposure and skin hypersensitivity. Clinical autoimmune parameters were based on medical histories; additionally, serum levels of the four most common autoantibodies were measured. RESULTS: Skin hypersensitivity, as seen mainly for Ni and/or Pd, was not positively associated with autoimmune parameters. In contrast, metal hypersensitive individuals showed an extremely low frequency of thyroid autoantibodies (3% vs 20% in non-hypersensitive controls). Next, the relation between metal exposure and autoimmunity was evaluated in individuals >35 years (n = 58), since from that age on metal exposure had plateaued and was not correlated with age. In this subgroup, oral Ni exposure was associated (p < 0.01) with self-reported AID, irrespective of autoantibody levels. These unexpected findings warrant further confirmation in a larger test group. Of note, oral Pd, Au or Hg contacts were not associated with any of the clinical or serological autoimmune phenomena tested. CONCLUSION: The results of this study support the view that development of metal contact allergies may prevent autoimmune activation, and, second, that oral exposure to Pd, Au or Hg does not facilitate the development of AID.

Increased IgA glycoprotein-2 specific antibody titres in refractory celiac disease.

BACKGROUND & AIMS: In most cases celiac disease (CD) is successfully treated with a gluten-free diet (GFD). However, some patients become refractory to the GFD. Refractory CD (RCD) patients have an increased risk for developing enteropathy associated T-cell lymphoma and early diagnosis is therefore of importance. Currently, RCD diagnosis relies on endoscopy and adequate serological markers are lacking. Antibodies against glycoprotein-2 (GP2A) were described in Crohn's disease (CrD) and active CD but not in ulcerative colitis (UC), suggesting this is a specific marker for small intestinal lesions. METHODS: Sera obtained from patients visiting our outpatient clinic for routine serological tests for diagnosis and/or follow-up of inflammatory bowel disease (n=78), active CD (n=45), GFD (n=34) and RCD (n=15) were analysed for GP2A titres. RESULTS: Increased GP2A-IgA levels in CrD and active CD as compared to controls (p<0.001) and lack thereof in UC was confirmed. However, we could not confirm the association with small bowel localization within the CrD patient group. Within CD patients, we demonstrated a significant decrease of GP2A-IgA titres upon a GFD and increased levels in RCD patients as compared to patients on a GFD. Although GP2A-IgA was not associated with the degree of villous atrophy, GP2A-IgA levels were able to distinguish RCD patients from GFD patients (ROC AUC=0.79, p=0.002). CONCLUSION: Follow-up of GP2A-IgA titres in CD patients on a GFD may help to identify patients at risk for developing RCD.

Consumption of gluten with gluten-degrading enzyme by celiac patients: a pilot-study.

AIM: To assesses the safety and efficacy of Aspergillus niger prolyl endoprotease (AN-PEP) to mitigate the immunogenic effects of gluten in celiac patients. METHODS: Patients with initial diagnosis of celiac disease as confirmed by positive serology with subtotal or total villous atrophy on duodenal biopsies who adhere to a strict gluten-free diet (GFD) resulting in normalised antibodies and mucosal healing classified as Marsh 0 or I were included. In a randomised double-blind placebo-controlled pilot study, patients consumed toast (approximately 7 g/d gluten) with AN-PEP for 2 wk (safety phase). After a 2-wk washout period with adherence of the usual GFD, 14 patients were randomised to gluten intake with either AN-PEP or placebo for 2 wk (efficacy phase). Measurements at baseline included complaints, quality-of-life, serum antibodies, immunophenotyping of T-cells and duodenal mucosa immunohistology. Furthermore, serum and quality of life questionnaires were collected during and after the safety, washout and efficacy phase. Duodenal biopsies were collected after the safety phase and after the efficacy phase. A change in histological evaluation according to the modified Marsh classification was the primary endpoint. RESULTS: In total, 16 adults were enrolled in the study. No serious adverse events occurred during the trial and no patients withdrew during the trial. The mean score for the gastrointestinal subcategory of the celiac disease quality (CDQ) was relatively high throughout the study, indicating that AN-PEP was well tolerated. In the efficacy phase, the CDQ scores of patients consuming gluten with placebo or gluten with AN-PEP did not significantly deteriorate and moreover no differences between the groups were observed. During the efficacy phase, neither the placebo nor the AN-PEP group developed significant antibody titers. The IgA-EM concentrations remained negative in both groups. Two patients were excluded from entering the efficacy phase as their mucosa showed an increase of two Marsh steps after the safety phase, yet with undetectable serum antibodies, while 14 patients were considered histologically stable on gluten with AN-PEP. Also after the efficacy phase, no significant deterioration was observed regarding immunohistological and flow cytometric evaluation in the group consuming placebo compared to the group receiving AN-PEP. Furthermore, IgA-tTG deposit staining increased after 2 wk of gluten compared to baseline in four out of seven patients on placebo. In the seven patients receiving AN-PEP, one patient showed increased and one showed decreased IgA-tTG deposits. CONCLUSION: AN-PEP appears to be well tolerated. However, the primary endpoint was not met due to lack of clinical deterioration upon placebo, impeding an effect of AN-PEP.

Differential IL-13 production by small intestinal leukocytes in active coeliac disease versus refractory coeliac disease.

A small fraction of coeliac disease (CD) patients have persistent villous atrophy despite strict adherence to a gluten-free diet. Some of these refractory CD (RCD) patients develop a clonal expansion of lymphocytes with an aberrant phenotype, referred to as RCD type II (RCDII). Pathogenesis of active CD (ACD) has been shown to be related to gluten-specific immunity whereas the disease is no longer gluten driven in RCD. We therefore hypothesized that the immune response is differentially regulated by cytokines in ACD versus RCDII and investigated mucosal cytokine release after polyclonal stimulation of isolated mucosal lymphocytes. Secretion of the T(H)2 cytokine IL-13 was significantly higher in lamina propria leukocytes (LPLs) isolated from RCDII patients as compared to LPL from ACD patients (P = 0.05). In patients successfully treated with a gluten-free diet LPL-derived IL-13 production was also higher as compared to ACD patients (P = 0.02). IL-13 secretion correlated with other T(H)2 as well as T(H)1 cytokines but not with IL-10 secretion. Overall, the cytokine production pattern of LPL in RCDII showed more similarities with LPL isolated from GFD patients than from ACD patients. Our data suggest that different immunological processes are involved in RCDII and ACD with a potential role for IL-13.

Transition metal sensing by Toll-like receptor-4: next to nickel, cobalt and palladium are potent human dendritic cell stimulators.

BACKGROUND: Nickel was recently identified as a potent activator of dendritic cells through ligating with human Toll-like receptor (TLR)-4. OBJECTIVES: Here, we studied an extended panel of transition metals neighbouring nickel in the periodic table of elements, for their capacity to activate human monocyte-derived dendritic cells (MoDCs). METHODS: The panel included chromium, cobalt, and palladium, all of which are known to be frequent clinical sensitizers. MoDC activation was monitored by assessment of release of the pro-inflammatory mediator interleukin (IL)-8, a major downstream result of TLR ligation. Results The data obtained in the present study show that cobalt and palladium also have potent MoDC-activating capacities, whereas copper and zinc, but not iron and chromium, have low but distinct MoDC-activating potential. Involvement of endotoxin contamination in MoDC activation was excluded by Limulus assays and consistent stimulation in the presence of polymyxin B. The critical role of TLR4 in nickel-induced, cobalt-induced and palladium-induced activation was confirmed by essentially similar stimulatory patterns obtained in an HEK293 TLR4/MD2 transfectant cell line. CONCLUSIONS: Given the adjuvant role of costimulatory danger signals, the development of contact allergies to the stimulatory metals may be facilitated by signals from direct TLR4 ligation, whereas other metal sensitizers, such as chromium, may rather depend on microbial or tissue-derived cofactors to induce clinical sensitization.

A prospective longitudinal study on endocrine dysfunction following treatment of laryngeal or hypopharyngeal carcinoma.

OBJECTIVES: The incidences of hypo(para)thyroidism were assessed prospectively in 137 consecutive patients with laryngeal (84.7%) or hypopharyngeal (15.3%) carcinoma who were treated with surgery and/or radiotherapy between 2004 and 2006. MATERIAL AND METHODS: Laboratory studies were performed in patients before primary or salvage treatment of a laryngeal or hypopharyngeal carcinoma and were repeated 6, 12, 18 and 24months after treatment. All patients were evaluated for the development of hypo(para)thyroidism, and the presence of autoantibodies. The association of hypothyroidism was analyzed against several patient parameters including tumor and treatment characteristics. RESULTS: The incidence of hypothyroidism following treatment of laryngeal and hypopharyngeal carcinoma was 47.4%: 27.7% subclinical hypothyroidism and 19.7% clinical hypothyroidism. The median time to develop hypothyroidism was 10months. The incidence of hypoparathyroidism was 7.3%. Univariate analysis showed that patients with laryngectomy, hemithyroidectomy, neck dissection, paratracheal lymph node dissection and radiotherapy had a higher risk of developing hypothyroidism. Multivariate analysis showed laryngectomy, hemithyroidectomy, neck dissection and age to be predictive factors for the development of hypothyroidism. The combination of surgery and radiotherapy increased this risk. Hemithyroidectomy was the most important risk factor. CONCLUSION: The incidence rate of hypothyroidism after treatment for laryngeal or hypopharyngeal cancer in this largest prospective study is high (47.4%), especially after combination treatment. Based on the intervals between treatment and the development of hypothyroidism, thyroid testing before treatment, every 3months during the first year, every 6months the second year and annually thereafter is recommended as screening procedure.

T cell profiling reveals high CD4+CTLA-4 + T cell frequency as dominant predictor for survival after prostate GVAX/ipilimumab treatment.

Immune checkpoint blockade enhances antitumor responses, but can also lead to severe immune-related adverse events (IRAE). To avoid unnecessary exposure to these potentially hazardous agents, it is important to identify biomarkers that correlate with clinical activity and can be used to select patients that will benefit from immune checkpoint blockade. To understand the consequences of CTLA-4 blockade and identify biomarkers for clinical efficacy and/or survival, an exploratory T cell monitoring study was performed in a phase I/II dose escalation/expansion trial (n = 28) of combined Prostate GVAX/ipilimumab immunotherapy. Phenotypic T cell monitoring in peripheral blood before and after Prostate GVAX/ipilimumab treatment revealed striking differences between patients who benefited from therapy and patients that did not. Treatment-induced rises in absolute lymphocyte counts, CD4(+) T cell differentiation, and CD4(+) and CD8(+) T cell activation were all associated with clinical benefit. Moreover, significantly prolonged overall survival (OS) was observed for patients with high pre-treatment frequencies of CD4(+)CTLA-4(+), CD4(+)PD-1(+), or differentiated (i.e., non-naive) CD8(+) T cells or low pre-treatment frequencies of differentiated CD4(+) or regulatory T cells. Unsupervised clustering of these immune biomarkers revealed cancer-related expression of CTLA-4(+) in CD4(+) T cells to be a dominant predictor for survival after Prostate GVAX/ipilimumab therapy and to thus provide a putative and much-needed biomarker for patient selection prior to therapeutic CTLA4 blockade.

Serum parameters in the spectrum of coeliac disease: beyond standard antibody testing--a cohort study.

BACKGROUND: Invasive techniques are still required to distinguish between uncomplicated and complicated forms of CD. METHODS: We set out to investigate the potential use of novel serum parameters, including IL-6, IL-8, IL-17, IL-22, sCD25, sCD27, granzyme-B, sMICA and sCTLA-4 in patients diagnosed with active CD, CD on a GFD, Refractory coeliac disease (RCD) type I and II, and enteropathy associated T-cell lymphoma (EATL). RESULTS: In both active CD and RCDI-II elevated levels of the proinflammatory IL-8, IL-17 and sCD25 were observed. In addition, RCDII patients displayed higher serum levels of soluble granzyme-B and IL-6 in comparison to active CD patients. In contrast, no differences between RCDI and active CD or RCDII were observed. Furthermore, EATL patients displayed higher levels of IL-6 as compared to all other groups. CONCLUSIONS: A series of novel serum parameters reveal distinctive immunological characteristics of RCDII and EATL in comparison to uncomplicated CD and RCDI.

[Non-responsive coeliac disease: what to do?]. / Als coeliakie niet beter wordt.

Coeliac disease (CD) is the most common cause of villous atrophy and is increasingly recognized. The majority of CD patients responds to a gluten-free diet (GFD). However, some patients experience persistence or recurrence of symptoms despite a GFD. These patients require further diagnostic workup. We describe a 62-year-old female with recurring symptoms attributed to refractory coeliac disease (RCD) type I. A 66-year-old patient with a similar history had aberrant intraepithelial lymphocytes characteristic for RCD type II in her duodenum. Furthermore, in a third CD patient described here, microscopic colitis was responsible for diarrhoea that persisted despite strict dietary adherence. Microscopic colitis is strongly associated with CD and should be considered in patients with this disease. On the basis of these three illustrative case studies, we discuss the causes of non-responsive CD and their respective diagnostic workup.

Clinical practice : coeliac disease.

UNLABELLED: Coeliac disease (CD) is an immune-mediated systemic condition elicited by gluten and related prolamines in genetically predisposed individuals and characterised by gluten-induced symptoms and signs, specific antibodies, a specific human leukocyte antigen (HLA) type and enteropathy. The risk of coeliac disease is increased in first-degree relatives, certain syndromes including Down syndrome and autoimmune disorders. It is thought to occur in 1 in 100-200 individuals, but still only one in four cases is diagnosed. Small-bowel biopsy is no longer deemed necessary in a subgroup of patients, i.e. when all of the following are present: typical symptoms or signs, high titres of and transglutaminase antibodies, endomysial antibodies, and HLA-type DQ2 or DQ8. In all other cases, small-bowel biopsy remains mandatory for a correct diagnosis. Therapy consists of a strictly gluten-free diet. This should result in complete disappearance of symptoms and of serological markers. Adequate follow-up is considered essential. CONCLUSION: Although small-bowel biopsy may be omitted in a minority of patients, small-bowel biopsy is essential for a correct diagnosis of CD in all other cases. Diagnostic work-up should be completed before treatment with gluten-free diet instituted.

Origin and immunophenotype of aberrant IEL in RCDII patients.

OBJECTIVES: Aberrant intra-epithelial lymphocytes (IELs) are the hallmark of refractory coeliac disease type II RCDII and considered a premalignant cell population from which aggressive enteropathy-associated T cell lymphoma (EATL) can evolve. The aim of this study was to gain further insight in the origin and characteristics of aberrant IELs by analysing T-cell receptor (TCR) rearrangements, and by immunophenotypic analysis of aberrant IELs. DESIGN: Duodenal biopsies from 18 RCDII patients and three RCDII cell lines were analysed for the presence of TCR delta, gamma, and beta rearrangements. In addition, IELs isolated from biopsies derived from RCDII patients were phenotypically analysed. RESULTS: Aberrant IELs showed an upregulated expression of granzyme B and decreased expression of PCNA. TCR rearrangements in the aberrant IEL population in biopsies of RCDII patients were heterogenic, which is most likely due to a variation in maturity. Similarly, RCDII cell lines displayed a heterogenic TCR rearrangement pattern. CONCLUSION: Aberrant IELs originate from deranged immature T lymphocytes and display clear differentiation to a cytotoxic phenotype. Aberrant IELs displayed different stages of maturity between RCDII patients, of which only the patients harbouring the most mature aberrant IEL population developed an EATL.

Combined immunotherapy with granulocyte-macrophage colony-stimulating factor-transduced allogeneic prostate cancer cells and ipilimumab in patients with metastatic castration-resistant prostate cancer: a phase 1 dose-escalation trial.

BACKGROUND: The granulocyte-macrophage colony-stimulating factor-transduced allogeneic prostate cancer cells vaccine (GVAX) has antitumour activity against prostate cancer; preclinical studies have shown potent synergy when combined with ipilimumab, an antibody that blocks cytotoxic T-lymphocyte antigen 4. We aimed to assess the safety of combined treatment with GVAX and ipilimumab in patients with metastatic castration-resistant prostate cancer (mCRPC). METHODS: We did an open-labelled, single-centre, dose-escalation study of ipilimumab concurrent with a fixed dose of GVAX, with a subsequent expansion phase, both at the VU University Medical Centre (Amsterdam, Netherlands). Eligible patients had documented mCRPC and had not been previously treated with chemotherapy. All patients received a 5×10(8) cell priming dose of GVAX intradermally on day 1 with subsequent intradermal injections of 3×10(8) cells every 2 weeks for 24 weeks. The vaccinations were combined with intravenous ipilimumab every 4 weeks. We enrolled patients in cohorts of three; each cohort received an escalating dose of ipilimumab at 0·3, 1·0, 3·0, or 5·0 mg/kg. Our primary endpoint was safety. This study is registered with ClinicalTrials.gov, number NCT01510288. FINDINGS: We enrolled 12 patients into our dose-escalation cohort. We did not record any severe immune-related adverse events at the first two dose levels. At the 3·0 mg/kg dose level, one patient had grade 2 and two patients grade 3 hypophysitis; at the 5·0 mg/kg dose level, two patients had grade 3 hypophysitis and one patient developed grade 4 sarcoid alveolitis (a dose-limiting toxic effect). Due to observed clinical activity and toxic events, we decided to expand the 3·0 mg/kg dose level, rather than enrol a further three patients at the 5·0 mg/kg level. 16 patients were enrolled in the expansion cohort, two of whom developed grade 2 hypophysitis, three colitis (one grade 1 and two grade 2), and one grade 3 hepatitis--all immune-related adverse events. The most common adverse events noted in all 28 patients were injection-site reactions (grade 1-2 events seen in all patients), fatigue (grade 1-2 in 20 patients, grade 3 in two), and pyrexia (grade 1-2 in 15 patients, grade 3 in one). 50% or greater declines in prostate-specific antigen from baseline was recorded in seven patients (25%); all had received 3·0 mg/kg or 5·0 mg/kg ipilimumab. INTERPRETATION: GVAX combined with 3·0 mg/kg ipilimumab is tolerable and safe for patients with mCRPC. Further research on the combined treatment of patients with mCRPC with vaccination and ipilimumab is warranted. FUNDING: Cell Genesys Inc, Prostate Cancer Foundation, Dutch Cancer Society (KWF-VU 2006-3697), and Foundation Stichting VUmc Cancer Center Amsterdam.

Pharmacological induction of interferon type I activity following treatment with rituximab determines clinical response in rheumatoid arthritis.

OBJECTIVE: Despite the fact that rituximab depletes B cells in all treated patients with RA, not all patients show a favourable clinical response. The goal of this study was to provide insight into pharmacological changes in peripheral blood that are associated with clinical response to rituximab. METHODS: Gene expression profiling was performed on peripheral blood RNA of 13 patients with RA (test group) using Illumina HumanHT beadchip microarrays. An independent group of nine patients was used for validation using TaqMan quantitative PCR. Clinical responder status was determined after 6 months using change in 28-joint Disease Activity Score (ΔDAS28) and European League Against Rheumatism (EULAR) response criteria. Significance analysis of microarrays and ontology analysis were used for data analysis and interpretation. RESULTS: Pharmacogenomic analyses demonstrated marked interindividual differences in the pharmacological responses at 3 and 6 months after start of treatment with rituximab. Interestingly, only differences in the regulation of type I interferon (IFN)-response genes after 3 months correlated with the ΔDAS28 response. Good responders (DAS>1.2; n=7) exhibited a selective increase in the expression of type I IFN-response genes, whereas this activity was unchanged or hardly changed in non-responders (DAS<1.2; n=6) (p=0.0040 at a cut-off of 1.1-fold induction). Similar results were obtained using EULAR response criteria. These results were validated in an independent cohort of nine patients (five non-responders and four responders, p=0.0317). CONCLUSIONS: A good clinical response to rituximab in RA is associated with a selective drug-induced increase in type I IFN-response activity in patients with RA. This finding may provide insight in the biological mechanism underlying the therapeutic response to rituximab.

Clinical experience with α-galactosylceramide (KRN7000) in patients with advanced cancer and chronic hepatitis B/C infection.

For over a century, research has sought ways to boost the immune system in order to eradicate tumors and viruses that exist after escaping immunosurveillance. For the treatment of cancer and hepatitis immunotherapeutic strategies have overall had limited clinical success. An urgent need exists therefore to introduce more effective therapeutic approaches. Invariant (i)NKT cells constitute a conserved T lymphocyte lineage with dominant immunoregulatory, antitumor and antiviral effector cell properties. iNKT specifically recognize the glycolipid α-galactosylceramide in the context of CD1d resulting in their activation. Activated iNKT can promote the development of a long-lasting Th1 biased proinflammatory immune response as demonstrated in multiple tumor-metastasis and viral infection models. Here, we will provide a brief overview of the preclinical data of α-galactosylceramide that formed the basis for subsequent clinical trials in patients with advanced cancer and chronic hepatitis B/C, and elaborate on our own clinical experience with α-galactosylceramide in these patient groups.