Comparison of the Peritoneal Cancer Index and Dutch region count as tools to stage patients with peritoneal metastases of colorectal cancer.

BACKGROUND: Extent of peritoneal metastases (PM) is among the most powerful prognostic factors for survival after cytoreductive surgery (CRS). This study aimed to compare the Peritoneal Cancer Index (PCI) and the Dutch region count as tools for staging PM of colorectal cancer. The Dutch region count is a simpler classification that distinguishes seven rather than 13 abdominal regions. Presence or absence of PM is recorded. METHODS: This was a retrospective cohort study in two tertiary referral centres in the Netherlands. Consecutive patients with colorectal PM who were intentionally treated with CRS and subsequent hyperthermic intraperitoneal chemotherapy in 2016 and 2017 were included. The PCI and Dutch region count were both recorded during laparotomy. Correlation between scoring tools was calculated using Spearman's rank correlation coefficient. Diagnostic values were calculated for different cut-off values of the PCI, alongside the Dutch region count. The correlation of both scores was determined for the exploration and validation cohorts separately. RESULTS: In the exploration and validation cohorts, 73 and 85 patients respectively were included. Spearman's correlation coefficients of 0·897 and 0·961 were observed for continuous scores of the Dutch region count and PCI in the exploration and validation group respectively. A cut-off value of 20 for the PCI score and 5 for the Dutch region count showed 91·9 and 94·5 per cent sensitivity, and 81·8 and 91·7 per cent specificity, respectively. CONCLUSION: The Dutch region count correlated well with the PCI score, and may help to simplify reporting of the extent of peritoneal disease.

ANTECEDENTES: La extensión de las metástasis peritoneales (peritoneal metastases, PM) es uno de los factores pronósticos más importantes para la supervivencia después de la cirugía citorreductora (cytoreductive surgery, CRS). El objetivo de este estudio fue comparar el índice de carcinomatosis peritoneal (Peritoneal Cancer Index, PCI) y el recuento holandés por regiones como herramientas para la estadificación de las PM del cáncer colorrectal. El recuento holandés por regiones es una clasificación más simple que distingue 7 regiones abdominales en lugar de 13. En dichas regiones abdominales se registró la presencia o ausencia de PM. MÉTODOS: Se llevó a cabo un estudio de cohortes retrospectivo en dos centros de referencia terciarios en los Países Bajos. Se incluyeron pacientes consecutivos con PM de origen colorrectal que fueron tratados con CRS seguida de quimioterapia intraperitoneal hipertérmica (hyperthermic intraperitoneal chemotherapy, HIPEC) en 2016 y 2017. Durante la laparotomía se recogieron datos del índice PCI y de la clasificación de las regiones abdominales. Se utilizó el coeficiente de correlación de Spearman para analizar la correlación entre estas dos herramientas de puntuación. Se calculó la precisión diagnóstica en función de diferentes umbrales del índice PCI junto con los datos del recuento por regiones. Asimismo, se calcularon las correlaciones entre ambas puntuaciones en las cohortes de exploración y validación por separado. RESULTADOS: Se incluyeron 73 pacientes en la cohorte de exploración y 85 en la de validación. Los coeficientes de correlación de Spearman eran de 0,987 para puntuaciones continuas del recuento holandés por regiones abdominales y del PCI en la cohorte de exploración y de 0,961 en la cohorte de validación. Los umbrales de corte de 20 para el índice PCI y de 5 para el recuento por regiones demostraron sensibilidades de 91,9% y 94,5%, y especificidades de 81,8% y 91,7%, respectivamente. CONCLUSIÓN: El recuento holandés por regiones abdominales se correlacionó bien con el PCI y puede ser útil para simplificar la extensión de la enfermedad peritoneal.

Effect of intraperitoneal chemotherapy concentration on morbidity and survival.

BACKGROUND: Selected patients with colorectal peritoneal metastases are treated with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). The concentration of intraperitoneal chemotherapy reflects the administered dose and perfusate volume. The aim of this study was to calculate intraperitoneal chemotherapy concentration during HIPEC and see whether this was related to clinical outcomes. METHODS: An observational multicentre study included consecutive patients with colorectal peritoneal metastases who were treated with CRS-HIPEC between 2010 and 2018 at three Dutch centres. Data were retrieved from prospectively developed databases. Chemotherapy dose and total circulating volumes of carrier solution were used to calculate chemotherapy concentrations. Postoperative complications, disease-free and overall survival were correlated with intraoperative chemotherapy concentrations. Univariable and multivariable logistic regression, Cox regression and survival analyses were performed. RESULTS: Of 320 patients, 220 received intraperitoneal mitomycin C (MMC) and 100 received oxaliplatin. Median perfusate volume for HIPEC was 5·0 (range 0·7-10·0) litres. Median intraperitoneal chemotherapy concentration was 13·3 (range 7·0-76·0) mg/l for MMC and 156·0 (91·9-377·6) mg/l in patients treated with oxaliplatin. Grade III or higher complications occurred in 75 patients (23·4 per cent). Median overall survival was 36·9 (i.q.r. 19·5-62·9) months. Intraperitoneal chemotherapy concentrations were not associated with postoperative complications or survival. CONCLUSION: CRS-HIPEC was performed with a wide variation in intraperitoneal chemotherapy concentrations that were not associated with complications or survival.

ANTECEDENTES: Ciertos pacientes seleccionados con metástasis peritoneales de cáncer colorrectal (peritoneal metastases, PM) se tratan con cirugía citorreductora (cytoreductive surgery, CRS) y quimioterapia intraperitoneal hipertérmica (hyperthermic intraperitoneal chemotherapy, HIPEC). La concentración de quimioterapia intraperitoneal refleja la dosis administrada y el volumen perfundido. El objetivo de este estudio fue calcular la concentración de quimioterapia intraperitoneal durante HIPEC y evaluar si ello se relacionaba con los resultados clínicos. MÉTODOS: Estudio observacional multicéntrico en el que se incluyeron pacientes consecutivos con PM de cáncer colorrectal que fueron tratados con CRS-HIPEC entre 2010 y 2018 en tres centros holandeses. Se obtuvieron los datos a partir de bases de datos mantenidas de forma prospectiva. La dosis de quimioterapia y los volúmenes circulantes totales de solución de perfusión se usaron para calcular las concentraciones de quimioterapia. Las complicaciones postoperatorias y las supervivencias libre de enfermedad y global se correlacionaron con las concentraciones de quimioterapia intraoperatoria. Se realizaron regresiones logísticas univariable y multivariable, regresión de Cox y análisis de supervivencia. RESULTADOS: De 320 pacientes, 220 recibieron mitomicina C intraperitoneal (MMC) y 100 oxaliplatino (OXA). El volumen medio de perfusión para HIPEC fue 5,0 L (rango 0,7-10,0). La mediana de concentración intraperitoneal del agente quimioterápico fue de 13,3 mg/L (rango 7,0-76,0) para MMC y 156,0 mg/L (rango 91,9 - 377,6) en pacientes tratados con OXA. Las complicaciones de grado 3 o mayores ocurrieron en 23,4% (n = 75). La mediana de supervivencia global fue de 36,9 meses (rango intercuartílico 19,5-62,9). Las concentraciones de quimioterapia intraperitoneal no se asociaron con las complicaciones postoperatorias ni con la supervivencia. CONCLUSIÓN: La CRS-HIPEC se realizó con una amplia variación en las concentraciones de quimioterapia intraperitoneal que no se asociaron con las complicaciones ni con la supervivencia.

Factors influencing long-term survival after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for pseudomyxoma peritonei originating from appendiceal neoplasms.

Background: Pseudomyxoma peritonei (PMP) is a rare disease, most commonly of appendiceal origin. Treatment consists of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC). The aim of this study was to identify prognostic factors for recurrence and survival. Methods: This was an observational study using a prospectively designed database containing consecutive patients with PMP originating from the appendix, undergoing CRS-HIPEC at a tertiary referral centre between 1996 and 2015. Histopathological slides were reassessed. Cox regression was used for multivariable analyses. Results: Of 225 patients identified, 36 (16·0 per cent) were diagnosed with acellular mucin, 149 (66·2 per cent) had disseminated peritoneal adenomucinosis (DPAM) and 40 (17·8 per cent) had peritoneal mucinous carcinomatosis (PMCA). The 5-year overall survival (OS) rates were 93, 69·8 and 55 per cent respectively. Recurrence was observed in 120 patients (53·3 per cent), 39 of whom (17·3 per cent) were treated with a second CRS-HIPEC procedure. Factors independently associated with poor disease-free survival were six or seven affected regions (hazard ratio (HR) 6·01, 95 per cent c.i. 2·04 to 17·73), incomplete cytoreduction (R2a resection: HR 1·67, 1·05 to 2·65; R2b resection: HR 2·00, 1·07 to 3·73), and more than threefold raised carcinoembryonic antigen (CEA) and/or carbohydrate antigen (CA) 19-9 level (HR 2·31, 1·30 to 4·11). Factors independently associated with poorer OS were male sex (HR 1·74, 1·09 to 2·77), incomplete cytoreduction (R2a resection: HR 1·87, 1·14 to 3·08; R2b resection: HR 2·28, 1·19 to 4·34), and more than threefold raised CEA and/or CA19-9 level (HR 2·89, 1·36 to 6·16). Conclusion: CEA and CA19-9 levels raised more than threefold above the upper limit identify patients with PMP of appendiceal origin and poorer survival.

Diffusion-weighted MRI assessment of the peritoneal cancer index before cytoreductive surgery.

BACKGROUND: Patients with limited peritoneal metastases from colorectal cancer may be candidates for an aggressive surgical approach including cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC). Selection is based on surgical inspection during laparoscopy or laparotomy. The aim of this study was to investigate whether diffusion-weighted MRI (DW-MRI) can be used to select patients for CRS-HIPEC. METHODS: This was a prospective study at a tertiary referral centre. Patients with confirmed or suspected colorectal peritoneal metastases scheduled for exploratory laparotomy or laparoscopy were eligible. Two radiologists assessed the peritoneal cancer index (PCI) on CT (CT-PCI) and DW-MRI (MRI-PCI). The reference standard was PCI at surgery. Radiologists were blinded to the surgical PCI and to each other's findings. The main outcome was the accuracy of DW-MRI in predicting whether patients had resectable disease (PCI less than 21) or not. RESULTS: Fifty-six patients were included in the study, of whom 49 could be evaluated. The mean(s.d.) PCI at surgery was 11·27(7·53). The mean MRI-PCI was 10·18(7·07) for reader 1 and 8·59(7·08) for reader 2. Readers 1 and 2 correctly staged 47 of 49 and 44 of 49 patients respectively (accuracy 96 and 90 per cent). Both readers detected all patients with resectable disease with a PCI below 21 at surgery (sensitivity 100 per cent). No patient was overstaged. The intraclass correlation (ICC) between readers was excellent (ICC 0·91, 95 per cent c.i. 0·77 to 0·96). MRI-PCI had a stronger correlation with surgical PCI (ICC 0·83-0·88) than did CT-PCI (ICC 0·39-0·44). CONCLUSION: DW-MRI is a promising non-invasive tool to guide treatment selection in patients with peritoneal metastases from colorectal cancer.

Molecular and cellular signatures underlying superior immunity against Bordetella pertussis upon pulmonary vaccination.

This corrects the article DOI: 10.1038/mi.2017.81.

Histopathological and molecular classification of colorectal cancer and corresponding peritoneal metastases.

BACKGROUND: Patients with colorectal peritoneal carcinomatosis have a very poor prognosis. The recently developed consensus molecular subtype (CMS) classification of primary colorectal cancer categorizes tumours into four robust subtypes, which could guide subtype-targeted therapy. CMS4, also known as the mesenchymal subtype, has the greatest propensity to form distant metastases. CMS4 status and histopathological features of colorectal peritoneal carcinomatosis were investigated in this study. METHODS: Fresh-frozen tissue samples from primary colorectal cancer and paired peritoneal metastases from patients who underwent cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy were collected. Histopathological features were analysed, and a reverse transcriptase-quantitative PCR test was used to assess CMS4 status of all collected lesions. RESULTS: Colorectal peritoneal carcinomatosis was associated with adverse histopathological characteristics, including a high percentage of stroma in both primary tumours and metastases, and poor differentiation grade and high-grade tumour budding in primary tumours. Furthermore, CMS4 was significantly enriched in primary tumours with peritoneal metastases, compared with unselected stage I-IV tumours (60 per cent (12 of 20) versus 23 per cent; P = 0.002). The majority of peritoneal metastases (75 per cent, 21 of 28) were also classified as CMS4. Considerable intrapatient subtype heterogeneity was observed. Notably, 15 of 16 patients with paired tumours had at least one CMS4-positive tumour location. CONCLUSION: Significant enrichment for CMS4 was observed in colorectal peritoneal carcinomatosis. Surgical relevance Cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) improves survival of selected patients with colorectal peritoneal carcinomatosis, but recurrence is common. Histopathological and molecular analysis of colorectal peritoneal carcinomatosis could provide clues for development of novel therapies. In this study, colorectal peritoneal carcinomatosis was found to be enriched for tumours with high stromal content and CMS4-positive status. To further improve prognosis for patients with colorectal peritoneal carcinomatosis, therapies that target tumour-stroma interaction could be added to CRS-HIPEC.

Molecular and cellular signatures underlying superior immunity against Bordetella pertussis upon pulmonary vaccination.

Mucosal immunity is often required for protection against respiratory pathogens but the underlying cellular and molecular mechanisms of induction remain poorly understood. Here, systems vaccinology was used to identify immune signatures after pulmonary or subcutaneous immunization of mice with pertussis outer membrane vesicles. Pulmonary immunization led to improved protection, exclusively induced mucosal immunoglobulin A (IgA) and T helper type 17 (Th17) responses, and in addition evoked elevated systemic immunoglobulin G (IgG) antibody levels, IgG-producing plasma cells, memory B cells, and Th17 cells. These adaptive responses were preceded by unique local expression of genes of the innate immune response related to Th17 (e.g., Rorc) and IgA responses (e.g., Pigr) in addition to local and systemic secretion of Th1/Th17-promoting cytokines. This comprehensive systems approach identifies the effect of the administration route on the development of mucosal immunity, its importance in protection against Bordetella pertussis, and reveals potential molecular correlates of vaccine immunity to this reemerging pathogen.

Safety of intraperitoneal Mitomycin C versus intraperitoneal oxaliplatin in patients with peritoneal carcinomatosis of colorectal cancer undergoing cytoreductive surgery and HIPEC.

BACKGROUND: Colorectal peritoneal carcinomatosis (PC) is commonly treated with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). There is an ongoing international debate about which intraperitoneal chemotherapeutic agent is preferred, Mitomycin C (MMC) or oxaliplatin. We questioned whether the type of chemotherapeutic agent influenced postoperative complication rates or short-term survival. METHODS: In this retrospective cohort study patients with colorectal PC who underwent CRS-HIPEC between January 2010 and December 2016 were included. Until March 2014 patients had preferentially been treated with MMC and thereafter with oxaliplatin in an iso-osmotic glucose/electrolyte dialysis (Dianeal®) carrier solution. Main outcomes were postoperative complications, disease free survival (DFS) and overall survival (OS). Survival analyses and multivariable analyses were performed. RESULTS: One hundred four patients received MMC and 73 patients oxaliplatin. Postoperative complications did not differ between groups (44.2% (MMC) versus 43.8% (oxaliplatin); P = 0.958). Median DFS was 12.5 months (IQR 6.4-32.4) in the MMC-group and 13.1 months (IQR 6.1-NA) in the oxaliplatin-group (P = 0.669). Median OS was 37.2 months (IQR 17.2-NA) in the MMC-group and 29.4 months (IQR 17.0-NA) in the oxaliplatin-group (P = 0.764). The type of chemotherapeutic agent did not influence OS in multivariable analysis (oxaliplatin versus MMC HR 1.09 (95%CI 0.58-2.06)). The HIPEC-phase was shorter for oxaliplatin (median 32 (IQR 31-34) versus 91 min (IQR 90-92) for MMC (P < 0.001)). CONCLUSION: Intraperitoneal oxaliplatin reduced the chemoperfusion time when compared to intraperitoneal MMC without adversely influencing complication rates or short-term survival. It may therefore be the preferential drug in CRS-HIPEC procedures for colorectal PC.

Adaptive immune response to whole cell pertussis vaccine reflects vaccine quality: A possible complementation to the Pertussis Serological Potency test.

Whole cell Bordetella pertussis (wP) vaccines are still used in many countries to protect against the respiratory disease pertussis. The potency of whole-cell pertussis vaccine lots is determined by an intracerebral challenge test (the Kendrick test). This test is criticized due to lack of immunological relevance of the read-out after an intracerebral challenge with B. pertussis. The alternative in vivo test, which assesses specific antibody levels in serum after wP vaccination, is the Pertussis Serological Potency test (PSPT). Although the PSPT focuses on a parameter that contributes to protection, the protective immune mechanisms after wP vaccination includes more elements than specific antibody responses only. In this study, additional parameters were investigated, i.e. circulating pro-inflammatory cytokines, antibody specificity and T helper cell responses and it was evaluated whether they can be used as complementary readout parameters in the PSPT to assess wP lot quality. By deliberate manipulation of the vaccine preparation procedure, a panel of high, intermediate and low quality wP vaccines were made. The results revealed that these vaccines induced similar IL-6 and IP10 levels in serum 4h after vaccination (innate responses) and similar antibody levels directed against the entire bacterium. In contrast, the induced antibody specificity to distinct wP antigens differed after vaccination with high, intermediate and low quality wP vaccines. In addition, the magnitude of wP-induced Th cell responses (Th17, Th1 and Th2) was reduced after vaccination with a wP vaccine of low quality. T cell responses and antibody specificity are therefore correlates of qualitative differences in the investigated vaccines, while the current parameter of the PSPT alone was not sensitive enough to distinguish between vaccines of different qualities. This study demonstrates that assessment of the magnitude of Th cell responses and the antigen specificity of antibodies induced by wP vaccination could form valuable complementary parameters to the PSPT.

[Impaired immunity: risk groups and consequences for general practice]. / Verminderde afweer.

- Due to medication use, comorbidities and/or age, an increasing number of patients have an impaired immunity to infection.- Impaired immunity may lead to an increased risk of (opportunistic) infection, complications from infections, and difficulties in the diagnosis of infections.- Guided by clinical parameters, a general practitioner can classify an impaired immunity as 'clinically irrelevant', 'limitedly relevant' or 'potentially serious'.- Tocilizumab impairs the production of CRP, which makes it unreliable as an infection parameter.- In case of a suspected infection in patients with severe immunosuppression, it will often be necessary to consult a specialist as quickly as possible about further diagnostic procedures and the need for, type and administration route of antimicrobials.- In patients with an impaired immunity, adaptation of the antibiotic policy and prophylactic measures, such as vaccination, may be indicated.- Patients with (functional) asplenia should immediately start antibiotic treatment in case of fever, pending clinical evaluation by a physician.

Inactivated influenza vaccine adjuvanted with bacterium-like particles induce systemic and mucosal influenza A virus specific T-cell and B-cell responses after nasal administration in a TLR2 dependent fashion.

BACKGROUND: Nasal vaccination is considered to be a promising alternative for parenteral vaccination against influenza virus as it is non-invasive and offers the opportunity to elicit strong antigen-specific responses both systemic and locally at the port of entry of the pathogen. Previous studies showed that non-living bacterium-like particles (BLPs) from the food-grade bacterium Lactococcus lactis are effective stimulators of local and systemic immune responses when administered intranasally. Moreover, in vitro, BLPs specifically interact with human Toll-like receptor 2 (TLR2), suggestive of a role for TLR2 dependent immune activation by BLPs. METHODS: In the present study, we examined the role of TLR2 in vivo in immune activation after nasal administration of BLP mixed with split influenza vaccine (BLP-SV) of influenza A virus (IAV) using TLR2 knockout mice. RESULTS: The systemic Th1 cell and subsequent B-cell responses induced after intranasal BLP-SV vaccination depended on the interaction of BLPs with TLR2. Notably, the BLP-SV-induced class switch to IgG2c depended on the interaction of BLP with TLR2. Local induced IAV-specific Th1 cell responses and the mucosal B-cell responses also depended on interaction of BLP with TLR2. Strongly reduced SIgA levels were observed in TLR2 knockout mice both in the nasal and vaginal lavages. In addition, detailed analysis of the T-cell response revealed that nasal BLP-SV vaccination promoted Th1/Th17 immune responses that coincided with increased IAV-specific IgG2c antibody production. DISCUSSION: Altogether these results indicate that nasal BLP-SV vaccination induces IAV-specific T-cell and B-cell responses, both systemically and at the site of virus entry in a TLR2-dependent manner.

Protection against allergic airway inflammation during the chronic and acute phases of Trichinella spiralis infection.

BACKGROUND: Modulation of the host immune response by helminths has been reported to be essential for parasite survival and also to benefit the host by suppressing inflammatory diseases such as allergies. We have previously shown that excretory-secretory products of Trichinella spiralis muscle larvae have immunomodulatory properties and induce in vitro the expansion of CD4(+) CD25(+) FOXP3(+) Treg cells in a TGF-ß-dependent manner. OBJECTIVE: We aimed at determining the effect of the acute (intestinal) and the chronic (muscle) phase of T. spiralis infection on experimental allergic airway inflammation (EAAI) to Ovalbumin (OVA) and the involvement of Treg cells. METHODS: The chronic phase was established before OVA-sensitization/challenge and the acute phase at two-time points, before and after OVA-sensitization. Mice were infected with 400 T. spiralis larvae and after euthanasia different pathological features of EAAI were measured. Adoptive transfer of CD4(+) T cells from Trichinella infected mice to OVA sensitized/challenged recipients was also performed. RESULTS: We found that the chronic as well as the acute phase of Trichinella infection suppress EAAI as indicated by reduction in airway inflammation, OVA-specific IgE levels in sera, Th2-cytokine production and eosinophils in bronchoalveolar lavage. This protective effect was found to be stronger during the chronic phase and to be associated with increased numbers of splenic CD4(+) CD25(+) FOXP3(+) Treg cells with suppressive activity. Adoptive transfer of splenic CD4(+) T cells from chronically infected mice with elevated numbers of Treg cells resulted in partial protection against EAAI. CONCLUSIONS AND CLINICAL RELEVANCE: These results demonstrate that the protective effect of T. spiralis on EAAI increases as infection progresses from the acute to the chronic phase. Here, Treg cells may play an essential role in the suppression of EAAI. Elucidating the mechanisms and molecular helminth structures responsible for this regulatory process is relevant to develop alternative tools for preventing or treating allergic asthma.

Mycobacterial and mouse HSP70 have immuno-modulatory effects on dendritic cells.

Previously, it has been shown that heat shock protein 70 (HSP70) can prevent inflammatory damage in experimental autoimmune disease models. Various possible underlying working mechanisms have been proposed. One possibility is that HSP70 induces a tolerogenic phenotype in dendritic cells (DCs) as a result of the direct interaction of the antigen with the DC. Tolerogenic DCs can induce antigen-specific regulatory T cells and dampen pathogenic T cell responses. We show that treatment of murine DCs with either mycobacterial (Mt) or mouse HSP70 and pulsed with the disease-inducing antigen induced suppression of proteoglycan-induced arthritis (PGIA), although mouse HSP70-treated DCs could ameliorate PGIA to a greater extent. In addition, while murine DCs treated with Mt- or mouse HSP70 had no significantly altered phenotype as compared to untreated DCs, HSP70-treated DCs pulsed with pOVA (ovalbumin peptide 323-339) induced a significantly increased production of IL-10 in pOVA-specific T cells. IL-10-producing T cells were earlier shown to be involved in Mt HSP70-induced suppression of PGIA. In conclusion, this study indicates that Mt- and mouse HSP70-treated BMDC can suppress PGIA via an IL-10-producing T cell-dependent manner.

T cell receptor (TCR) signal strength controls arthritis severity in proteoglycan-specific TCR transgenic mice.

T cell receptor transgenic (TCR-Tg) mice specific for the arthritogenic 5/4E8 epitope in the G1 domain of cartilage proteoglycan were generated and back-crossed into arthritis-prone BALB/c background. Although more than 90% of CD4(+) T cells of all TCR-Tg lines were 5/4E8-specific, one (TCR-TgA) was highly sensitive to G1-induced or spontaneous arthritis, while another (TCR-TgB) was less susceptible. Here we studied whether fine differences in TCR signalling controlled the onset and severity of arthritis. Mice from the two TCR-Tg lines were immunized side by side with purified recombinant human G1 (rhG1) domain for G1 domain of cartilage proteoglycan (PG)-induced arthritis (GIA). TCR-TgA mice developed severe and early-onset arthritis, whereas TCR-TgB mice developed weaker arthritis with delayed onset, although TCR-TgB CD4(+) T cells expressed approximately twice more TCR-Vß4 chain protein. The more severe arthritis in TCR-TgA mice was associated with higher amounts of anti-G1 domain-specific antibodies, larger numbers of B cells and activated T helper cells. Importantly, TCR-TgB CD4(+) T cells were more sensitive to in vitro activation-induced apoptosis, correlating with their higher TCR and CD3 expression and with the increased TCR signal strength. These findings indicate that TCR signal strength determines the clinical outcome of arthritis induction: 'optimal' TCR signal strength leads to strong T cell activation and severe arthritis in TCR-TgA mice, whereas 'supra-optimal' TCR signal leads to enhanced elimination of self-reactive T cells, resulting in attenuated disease.

Critical proinflammatory role of thymic stromal lymphopoietin and its receptor in experimental autoimmune arthritis.

OBJECTIVE: The interleukin-7 (IL-7)-related cytokine thymic stromal lymphopoietin (TSLP) is a potent activator of myeloid dendritic cells, enhancing Th2-mediated hypersensitivity, and it has been implicated in the pathogenesis of atopic diseases. Although intraarticular concentrations of TSLP have been shown to be increased in patients with rheumatoid arthritis (RA), the functional capacities of TSLP in arthritis are poorly studied. The purpose of this study was to investigate the effects of TSLP administration and TSLP receptor deficiency on immune activation, arthritis severity, and tissue destruction in T cell-driven arthritis models of RA. METHODS: Immunopathology was studied in arthritic mice that were given multiple injections of murine recombinant TSLP and in mice that were deficient in the TSLP receptor (TSLPR(-/-)). Arthritis severity and incidence were determined by visual examination of the paws. Joint destruction was determined by assessing radiographs and the immunohistochemistry of ankle joints. Total cellularity and numbers of T cell subsets were assessed. Proinflammatory mediators were measured by multianalyte profiling of serum or paw protein extracts. RESULTS: Administration of TSLP significantly exacerbated the severity of collagen-induced arthritis and the joint damage that was associated with increased T cell activation. Furthermore, TSLPR(-/-) mice had less severe arthritis than did wild-type mice. TSLPR(-/-) mice had diminished concentrations of local proinflammatory and catabolic mediators, including IL-17, IL-1ß, IL-6, basic fibroblast growth factor, and matrix metalloproteinase 9, while levels of the regulatory cytokines IL-10 and IL-13 were increased. CONCLUSION: TSLP and its receptor enhance Th17-driven arthritis and tissue destruction in experimental arthritis. The increased expression of TSLP as well as the increased number of TSLPR-expressing cells in the joints of patients with RA suggest that TSLP and its receptor constitute novel therapeutic targets in RA.

Considerations in the design of vaccines that induce CD8 T cell mediated immunity.

The protective capacity of many currently used vaccines is based on induction of neutralizing antibodies. Many pathogens, however, have adapted themselves in different ways to escape antibody-based immune protection. In particular, for those infections against which conventional neutralizing antibody-based vaccinations appear challenging, CD8 T-cells are considered to be promising candidates for vaccine targeting. The design of vaccines that induce robust and long-lasting protective CD8 T-cell responses however imposes new challenges, as many factors such as kinetics and efficiency of antigen-processing and presentation by antigen presenting cells, T-cell repertoire and cytokine environment during T cell priming contribute to the specificity and functionality of CD8 T-cell responses. In the following, we review the most prominent aspects that underlie CD8 T-cell induction and discuss how this knowledge may help to improve the design of efficient CD8 T-cell inducing vaccines.

Cartilage proteoglycan aggrecan epitopes induce proinflammatory autoreactive T-cell responses in rheumatoid arthritis and osteoarthritis.

OBJECTIVES: To explore potential T-cell epitopes of the core protein of human cartilage proteoglycan aggrecan (PG) in patients with rheumatoid arthritis (RA) or osteoarthritis. METHODS: Peptide-specific T-cell proliferation and cytokine/chemokine production in response to PG-specific peptides were measured in RA and osteoarthritis patients and in healthy controls. RESULTS: Peptides representing amino acid regions 16-39 and 263-282 of PG were most frequently recognised by T cells in a subset of patients with RA or osteoarthritis. Peripheral blood mononuclear cells from these PG-reactive RA and osteoarthritis patients showed increased production of proinflammatory cytokines/chemokines in response to PG peptide stimulation. As PG p263-282 was found to show high sequence homology with Yersinia Yop protein, the corresponding bacterial (Yersinia) peptide was also tested. Remarkably, RA and osteoarthritis patients responding to the Yersinia peptide also responded to p263-282 of PG suggesting a possibility of molecular mimicry in these patients. CONCLUSIONS: These results indicate that PG-specific peptides, located in the G1 domain of PG, can induce (auto)antigenic T-cell responses in RA and osteoarthritis patients. These peptides might thus be involved in the immune pathogenesis and/or cartilage degradation in RA and osteoarthritis.

Inflammatory disease processes and interactions with nutrition.

Inflammation is a stereotypical physiological response to infections and tissue injury; it initiates pathogen killing as well as tissue repair processes and helps to restore homeostasis at infected or damaged sites. Acute inflammatory reactions are usually self-limiting and resolve rapidly, due to the involvement of negative feedback mechanisms. Thus, regulated inflammatory responses are essential to remain healthy and maintain homeostasis. However, inflammatory responses that fail to regulate themselves can become chronic and contribute to the perpetuation and progression of disease. Characteristics typical of chronic inflammatory responses underlying the pathophysiology of several disorders include loss of barrier function, responsiveness to a normally benign stimulus, infiltration of inflammatory cells into compartments where they are not normally found in such high numbers, and overproduction of oxidants, cytokines, chemokines, eicosanoids and matrix metalloproteinases. The levels of these mediators amplify the inflammatory response, are destructive and contribute to the clinical symptoms. Various dietary components including long chain omega-3 fatty acids, antioxidant vitamins, plant flavonoids, prebiotics and probiotics have the potential to modulate predisposition to chronic inflammatory conditions and may have a role in their therapy. These components act through a variety of mechanisms including decreasing inflammatory mediator production through effects on cell signaling and gene expression (omega-3 fatty acids, vitamin E, plant flavonoids), reducing the production of damaging oxidants (vitamin E and other antioxidants), and promoting gut barrier function and anti-inflammatory responses (prebiotics and probiotics). However, in general really strong evidence of benefit to human health through anti-inflammatory actions is lacking for most of these dietary components. Thus, further studies addressing efficacy in humans linked to studies providing greater understanding of the mechanisms of action involved are required.

Activation of nucleotide oligomerization domain 2 exacerbates a murine model of proteoglycan-induced arthritis.

In addition to its role in innate immunity, nucleotide oligomerization domain 2 (NOD2) has been shown to play a suppressive role in models of colitis. Notably, mutations in NOD2 cause the inherited granulomatous disease of the joints called Blau syndrome, thereby linking NOD2 with joint disease as well. However, the role of NOD2 in joint inflammation has not been clarified. We demonstrate here that NOD2 is functional within the mouse joint and promotes inflammation, as locally or systemically administered muramyl dipeptide (MDP; the NOD2 agonist) resulted in significant joint inflammation that was abolished in NOD2-deficient mice. We then sought to investigate the role of NOD2 in a mouse model of inflammatory arthritis dependent on adaptive immunity using TCR-transgenic mice whose T cells recognized the dominant epitope of proteoglycan (PG). Mice immunized with PG in the presence of MDP developed a more severe inflammatory arthritis and histopathology within the joints. Antigen-specific activation of splenocytes was enhanced by MDP with respect to IFN-gamma production, which would be consistent with the Th1-mediated disease in vivo. Intriguingly, NOD2 deficiency did not alter the PG-induced arthritis, indicating that NOD2 does not play an essential role in this model of joint disease when it is not activated by MDP. In conclusion, we demonstrate that in a model of inflammatory arthritis dependent on T and B cell priming, NOD2 activation potentiates disease. However, the absence of NOD2 does not alter the course of inflammatory arthritis, in contrast to models of intestinal inflammation.

ELISPOT and intracellular cytokine staining: novel assays for quantifying T cell responses in the chicken.

The measurement of T cell responses in chickens, not only for quantitative aspects but also for the qualitative nature of the responses, becomes increasingly important. However, there are very few assays available to measure T cell function. Therefore, we have developed enzyme-linked immunosorbent spot assay (ELISPOT) and an intracellular cytokine staining (ICCS) assay. ELISPOT assay for the detection of chicken interferon-gamma (ChIFN-gamma) production was set up and shown to be reproducible for both polyclonal and antigen-specific stimuli such as Newcastle disease virus (NDV). However, the ELISPOT assay lacks the ability to identify individual cytokine-producing cells. Separation of CD4+ and CD8+ T cell populations gave additional information, but appeared to have the disadvantage of a loss of cell interactions during stimulation. In a further refinement, individual cells were identifiable by ICCS, which gives the possibility to characterize for multiple characteristics, such as cytokine production and phenotype of the cell. Using ICCS, ChIFN-gamma production was evaluated. Although cells were detected at only low frequencies, polyclonal stimulation of peripheral blood mononuclear cell (PBMC) or spleen cells resulted in a significant increase in ChIFN-gamma production by CD4+ and CD8+ cells.