Prediction of a positive circumferential resection margin at surgery following neoadjuvant chemotherapy for adenocarcinoma of the oesophagus

Background

A positive circumferential resection margin (CRM) has been associated with higher rates of locoregional recurrence and worse survival in oesophageal cancer. The aim of this study was to establish if clinicopathological and radiological variables might predict CRM positivity in patients who received neoadjuvant chemotherapy before surgery for oesophageal adenocarcinoma.

Methods

Multivariable analysis of clinicopathological and CT imaging characteristics considered potentially predictive of CRM was performed at initial staging and following neoadjuvant chemotherapy. Prediction models were constructed. The area under the curve (AUC) with 95% confidence intervals (c.i.) from 1000 bootstrapping was assessed.

Results

A total of 223 patients were included in the study. Poor differentiation (odds ratio (OR) 2·84, 95 per cent c.i. 1·39 to 6·01) and advanced clinical tumour status (T3-4) (OR 2·93, 1·03 to 9·48) were independently associated with an increased CRM risk at diagnosis. CT-assessed lack of response (stable or progressive disease) following chemotherapy independently corresponded with an increased risk of CRM positivity (OR 3·38, 1·43 to 8·50). Additional CT evidence of local invasion and higher CT tumour volume (14 cm3) improved the performance of a prediction model, including all the above parameters, with an AUC (c-index) of 0·76 (0·67 to 0·83). Variables associated with significantly higher rates of locoregional recurrence were pN status (P = 0·020), lymphovascular invasion (P = 0·007) and poor response to chemotherapy (Mandard score 4-5) (P = 0·006). CRM positivity was associated with a higher locoregional recurrence rate, but this was not statistically significant (P = 0·092).

Conclusion

The presence of advanced cT status, poor tumour differentiation, and CT-assessed lack of response to chemotherapy, higher tumour volume and local invasion can be used to identify patients at risk of a positive CRM following neoadjuvant chemotherapy.

Patient-derived xenografts effectively capture responses to oncology therapy in a heterogeneous cohort of patients with solid tumors

Background

While patient-derived xenografts (PDXs) offer a powerful modality for translational cancer research, a precise evaluation of how accurately patient responses correlate with matching PDXs in a large, heterogeneous population is needed for assessing the utility of this platform for preclinical drug-testing and personalized patient cancer treatment.

Patients and methods

Tumors obtained from surgical or biopsy procedures from 237 cancer patients with a variety of solid tumors were implanted into immunodeficient mice and whole-exome sequencing was carried out. For 92 patients, responses to anticancer therapies were compared with that of their corresponding PDX models.

Results

We compared whole-exome sequencing of 237 PDX models with equivalent information in The Cancer Genome Atlas database, demonstrating that tumorgrafts faithfully conserve genetic patterns of the primary tumors. We next screened PDXs established for 92 patients with various solid cancers against the same 129 treatments that were administered clinically and correlated patient outcomes with the responses in corresponding models. Our analysis demonstrates that PDXs accurately replicate patients' clinical outcomes, even as patients undergo several additional cycles of therapy over time, indicating the capacity of these models to correctly guide an oncologist to treatments that are most likely to be of clinical benefit.

Conclusions

Integration of PDX models as a preclinical platform for assessment of drug efficacy may allow a higher success-rate in critical end points of clinical benefit.

Impact of incremental circumferential resection margin distance on overall survival and recurrence in oesophageal adenocarcinoma

Background

Previous analyses of the oesophageal circumferential resection margin (CRM) have focused on the prognostic validity of two different definitions of a positive CRM, that of the College of American Pathologists (tumour at margin) and that of the Royal College of Pathologists (tumour within 1 mm). This study aimed to analyse the validity of these definitions and explore the risk of recurrence and survival with incremental tumour distances from the CRM.

Methods

This cohort study included patients who underwent resection for adenocarcinoma of the oesophagus between 2000 and 2014. Kaplan-Meier and Cox regression analyses were performed to determine the hazard ratio (HR) with 95 per cent confidence intervals for recurrence and mortality in CRM increments: tumour at the cut margin, extending to within 0·1-0·9, 1·0-1·9, 2·0-4·9 mm, and 5·0 mm or more from the margin.

Results

A total of 444 patients were included in the study. Kaplan-Meier and unadjusted analyses showed a significant incremental improvement in overall survival (P < 0·001) and recurrence (P for trend < 0·001) rates with increasing distance from the CRM. Tumour distance of 2·0 mm or more remained a significant predictor of survival on multivariable analysis (HR for risk of death 0·66, 95 per cent c.i. 0·44 to 1·00). Multivariable analysis of overall survival demonstrated a significant difference between a positive and negative CRM with the Royal College of Pathologists' definition (HR 1·37, 1·01 to 1·85), but not with the College of American Pathologists' definition (HR 1·22, 0·90 to 1·65).

Conclusion

This study demonstrated an incremental improvement in survival and recurrence rates with increasing tumour distance from the CRM.

Acquired erythropoietic uroporphyria secondary to myelodysplastic syndrome with chromosome 3 alterations: a case report

Congenital erythropoietic porphyria is a rare autosomal recessive disease caused by a deficiency of uroporphyrinogen III synthase, owing to mutations in UROS in chromosome 10. Occasionally, patients show a mild, late-onset disease, without germline UROS mutations, associated with haematological malignancies. We report a 65-year-old patient with photosensitivity, overexcretion of porphyrins and thrombocytopenia. Bone marrow analysis gave a diagnosis of myelodysplastic syndrome (MDS) with the presence of a derivative chromosome 3, possibly due to an inversion including 3q21 and 3q26 break points. After allogeneic stem-cell transplantation, complete remission of MDS and uroporphyria was achieved. To our knowledge, this is the first reported case of acquired erythropoietic uroporphyria associated with MDS, with chromosome 3 alterations.

Bevacizumab and Combination Chemotherapy in rectal cancer Until Surgery (BACCHUS): a phase II, multicentre, open-label, randomised study of neoadjuvant chemotherapy alone in patients with high-risk cancer of the rectum

BACKGROUND

In locally advanced rectal cancer (LARC) preoperative chemoradiation (CRT) is the standard of care, but the risk of local recurrence is low with good quality total mesorectal excision (TME), although many still develop metastatic disease. Current challenges in treating rectal cancer include the development of effective organ-preserving approaches and the prevention of subsequent metastatic disease. Neoadjuvant systemic chemotherapy (NACT) alone may reduce local and systemic recurrences, and may be more effective than postoperative treatments which often have poor compliance. Investigation of intensified NACT is warranted to improve outcomes for patients with LARC. The objective is to evaluate feasibility and efficacy of a four-drug regimen containing bevacizumab prior to surgical resection.

METHODS/DESIGN

This is a multi-centre, randomized phase II trial. Eligible patients must have histologically confirmed LARC with distal part of the tumour 4-12 cm from anal verge, no metastases, and poor prognostic features on pelvic MRI. Sixty patients will be randomly assigned in a 1:1 ratio to receive folinic acid + flurourcil + oxaliplatin (FOLFOX) + bevacizumab (BVZ) or FOLFOX + irinotecan (FOLFOXIRI) + BVZ, given in 2 weekly cycles for up to 6 cycles prior to TME. Patients stop treatment if they fail to respond after 3 cycles (defined as ≥ 30 % decrease in Standardised Uptake Value (SUV) compared to baseline PET/CT). The primary endpoint is pathological complete response rate. Secondary endpoints include objective response rate, MRI tumour regression grade, involved circumferential resection margin rate, T and N stage downstaging, progression-free survival, disease-free survival, overall survival, local control, 1-year colostomy rate, acute toxicity, compliance to chemotherapy.

DISCUSSION

In LARC, a neoadjuvant chemotherapy regimen - if feasible, effective and tolerable would be suitable for testing as the novel arm against the current standards of short course preoperative radiotherapy (SCPRT) and/or fluorouracil (5FU)-based CRT in a future randomised phase III trial.

TRIAL REGISTRATION

Clinical trial identifier BACCHUS: NCT01650428.

Rectal tumour volume (GTV) delineation using T2-weighted and diffusion-weighted MRI: Implications for radiotherapy planning

PURPOSE

To compare the rectal tumour gross target volume (GTV) delineated on T2 weighted (T2W MRI) and diffusion weighted MRI (DWI) images by two different observers and to assess if agreement is improved by DWI.

MATERIAL AND METHODS

27 consecutive patients (15 male, range 27.1-88.8 years, mean 66.9 years) underwent 1.5T MRI prior to chemoradiation (45Gy in 25 fractions; oral capecitabine 850mg/m(2)), including axial T2W MRI (TR=6600ms, TE=90ms) and DWI (TR=3000ms, TE=77ms, b=0, 100, 800s/mm(2)). 3D tumour volume (cm(3)) was measured by volume of interest (VOI) analysis by two independent readers for the T2W MRI and b800 DWI axial images, and the T2W MRI and DWI volumes compared using Mann-Whitney test. Observer agreement was assessed using Bland-Altman statistics. Significance was at 5%.

RESULTS

Artefacts precluded DWI analysis in 1 patient. In the remaining 26 patients evaluated, median (range) T2W MRI MRI and DWI (b=800s/mm(2)) 3D GTVin cm(3) were 33.97 (4.44-199.8) and 31.38 (2.43-228), respectively, for Reader One and 43.78 (7.57-267.7) and 42.45 (3.68-251) for Reader Two. T2W MRI GTVs were slightly larger but not statistically different from DWI volumes: p=0.52 Reader One; p=0.92 Reader Two. Interobserver mean difference (95% limits of agreement) for T2W MRI and DWI GTVs were -9.84 (-54.96 to +35.28) cm(3) and -14.79 (-54.01 to +24.43) cm(3) respectively.

CONCLUSION

Smaller DWI volumes may result from better tumour conspicuity but overall observer agreement is not improved by DWI.

Association of leisure time physical activity and sports competition activities with high blood pressure levels: study carried out in a sample of Portuguese children and adolescents

BACKGROUND

A better understanding of the different domains and characteristics of children's and adolescent's physical activity (PA) could be a strategy to clarify the association of this behaviour with the early development of cardiovascular risk factors.

OBJECTIVES

To examine the relationship between leisure time physical activity (LTPA) and sports competition activities (SCA) with high blood pressure (HBP) levels in a sample of children and adolescents from Porto, Portugal.

STUDY DESIGN

This is a cross-sectional study, which comprised 503 boys and 572 girls, aged 8-17 years old. LTPA and SCA were assed by self-reported. Students were assigned as active and non-active in SCA or LTPA according to their self-reported participation. Participants were classified as HBP when they are above of the last quartile for systolic and/or diastolic BP adjusted for gender and age.

RESULTS

Do not be engaged in LTPA (OR: 1.47; 95% CI: 1.12; 1.93) and SCA (OR: 1.36; 95% CI: 1.02; 1.81) was significantly associated with the likelihood of being HBP. However, when cardiorespiratory fitness (CRF) (OR: 1.23; 95% CI: 0.91; 1.67) and body mass index (BMI) (OR: 1.31; 95% CI: 0.98; 1.75) were included on SCA model, the association between SCA with HBP did not showed significant results.

CONCLUSION

Children and adolescents who are not engaged in SCA or LTPA are more likely to be classified as having HBP; however, the relationship between SCA and HBP was dependent of CRF and BMI. Further, PA strategies should take these differences on the relationship between HBP, SCA and LTPA.

Relationship between human tumour angiogenic profile and combretastatin-induced vascular shutdown: an exploratory study

Combretastatin-A4-phosphate (CA4P) acts most effectively against immature tumour vasculature. We investigated whether histological angiogenic profile can explain the differential sensitivity of human tumours to CA4P, by correlating the kinetic changes demonstrated by dynamic MRI (DCE-MRI) in response to CA4P, with tumour immunohistochemical angiogenic markers. Tissue was received from 24 patients (mean age 59, range 32–73, 18 women, 6 men). An angiogenic profile was performed using standard immunohistochemical techniques. Dynamic MRI data were obtained for the same patients before and 4 h after CA4P. Three patients showed a statistically significant fall in K^trans following CA4P, and one a statistically significant fall in IAUGC₆₀. No statistically significant correlations were seen between the continuous or categorical variables and the DCE-MRI kinetic parameters other than between ang-2 and K^trans (P=0.044). In conclusion, we found no strong relationships between changes in DCE-MRI kinetic variables following CA4P and the immunohistochemical angiogenic profile.

G-CSF increases the number of peripheral blood dendritic cells CD16+ and modifies the expression of the costimulatory molecule CD86+

Dendritic cells (DC) play a key role in initiating immune reactions after allogeneic stem cell transplantation. The two main peripheral blood DC populations are myeloid (DC1) and lymphoplasmacytoid (DC2). A new subset of myeloid DC, expressing CD16, has been identified. We analyzed the number and CD86 expression of DC subsets in peripheral blood of 18 healthy donors, before and after granulocyte colony-stimulating factor (G-CSF) and in the inoculum of allogeneic peripheral blood transplants (allo-PBT; n=100) and allogeneic bone marrow transplants (allo-BMT; n=22). Granulocyte colony-stimulating factor administration increased the median number of DC1 (P=0.0007), of DC2 (P<0.0001) and of DC CD16+ (P=0.0001). Granulocyte colony-stimulating factor administration was also associated with a significant decrease of CD86 expression on DC1 (P=0.0003) and with a trend for an increase on DC CD16+ (P=0.07). Recipients of allo-PBT received similar quantities of DC1 and higher doses of DC2 and DC CD16+ than recipients of allo-BMT (P=0.5; P=0.0001; P<0.0001, respectively). Granulocyte colony-stimulating factor modifies the number of DC in peripheral blood and the expression of the costimulatory molecule CD86. This resulted in a different composition of DC2 and especially of DC CD16+ in the harvests, which might explain some of the differences observed in allogeneic reactions after allo-PBT with respect to allo-BMT.

The use of temozolomide in recurrent malignant gliomas

Gliomas are the most common primary intracerebral tumours and over 60% of these are malignant. Standard treatment in the UK for patients with a good performance status consists of surgery and postoperative radiotherapy, however, recurrence is almost inevitable. Treatment of recurrent malignant gliomas (MG) is limited to further surgery, chemotherapy and novel biological therapies. The response rate to standard chemotherapy protocols for recurrent MG is less than 30%. Temozolomide (Temodar-US, Temodal-Rest of World) is an oral alkylating agent with a similar chemical structure to dacarbazine, and has recently been licensed in the UK for second line treatment of recurrent MG. Several phase II studies and one randomised trial suggest that Temozolomide improves time to progression and quality of life but not overall survival. The drug is well tolerated with dose limiting myelosuppression and thrombocytopenia occurring in less than 10% of patients at current dosage schedules. A randomised trial comparing Temozolomide with best first line adjuvant chemotherapy (PCV) is about to start recruiting patients. Further clinical studies investigating its role in neoadjuvant treatment or in combination with radiotherapy or other chemotherapeutic approaches are ongoing.

Pegylated liposomal doxorubicin (Caelyx) in recurrent ovarian cancer

Epithelial ovarian cancer (EOC) is the most common gynaecological malignancy in the Western world and a leading cause of death. Patients with relapsed EOC are incurable and therefore the toxicity of palliative chemotherapy and effects on health-related Quality of Life are important factors. Several newer cytotoxic agents have been used in these patients. Pegylated liposomal doxorubicin (Caelyx) has a different spectrum of activity from standard doxorubicin with response rates up to 25% in these patients and a low toxicity profile. In addition it is non cross resistant with platinum compounds. In a randomised phase III trial (n=474) of Caelyx versus Topotecan there were no significant differences in response rates, time to progression, overall survival or quality of life. Patients receiving Topotecan had more side effects requiring admission to hospital. Caelyx is a valuable therapy in platinum resistant patients with an efficacy equivalent to Topotecan but at a lower cost when side-effects and admission costs are included.

The evidence-based use of induction chemotherapy in breast cancer

The use of induction chemotherapy, also known as pre-operative or neoadjuvant chemotherapy has been studied in a number of randomised trials. Response rates are generally high, ranging from 70-90%, which allows for the downstaging of primary tumours and breast conservation surgery. Conserving surgery as opposed to mastectomy in this setting appears to be safe, effective and improves quality of life, although there is a suggestion of a small increase in local recurrence rate. Data from the randomised trials presented in this review shows that the use of induction chemotherapy neither prolongs nor decreases overall or disease free survival when compared with the same chemotherapy given in an adjuvant setting. There is a direct correlation between response of a primary breast tumour to induction chemotherapy and patient outcome, probably because this approximates the effect of induction chemotherapy on micrometastases which are present at presentation in many patients with apparently localised primary breast cancers. A pathological complete response after surgery is an excellent predictor of long term outcome, and is more likely to be seen in smaller tumours. Induction chemotherapy can be used as an in vivo measure of tumour response to treatment. This allows a further option of switching cytotoxic drugs in apparently resistant tumours.

Expression on human eosinophils of CD148: a membrane tyrosine phosphatase. Implications in the effector function of eosinophils

The role of protein tyrosine phosphatases (PTP) is crucial in regulating the phosphorylation status of cells. CD148 is a recently described membrane-type PTP. In this study, we have demonstrated that this molecule is expressed on human eosinophils and eosinophilic cell line EoL-3. Interestingly, our data also showed that this molecule acts as a transduction molecule on these cells. Thus, the crosslinking of CD148 was able to induce the degranulation and the induction of superoxide anion generation. By using specific inhibitor and by western blotting, we have shown that tyrosine kinase activation is involved in this transduction pathway. In addition, we have shown the presence of a serine/threonine kinase activity associated with CD148. In conclusion, the activation capacity of CD148 on eosinophils suggests a potential role of this molecule on inflammatory diseases, such as allergic and parasitic diseases, associated with eosinophilia.

Novel molecular mechanisms of dendritic cell-induced T cell activation

In this study we have re-examined the molecular mechanisms involved in activation of T cells by dendritic cells (DC). Human peripheral blood DC (PBDC) were derived by 2 h adhesion followed by 7 day culture in a combination of granulocyte macrophage colony stimulating factor and IL-4, and depletion of residual T and B cells. These PBDC were used to induce autologous T cell proliferation in a CD3-dependent response, and antibodies against CD11a/18 and CD86 were used as control inhibitors of accessory function. Antibodies against five of the cell surface molecules that we have recently identified on the surface of DC, CD13, CD87, CD98, CD147 and CD148, and an antibody which recognizes a molecule that has not as yet been identified, all inhibited the CD3-induced T cell proliferation. These findings were observed not only when antibodies were present throughout the culture, but also when they were prepulsed on to the surface of the DC, suggesting the inhibition was mediated via the antigen-presenting cells rather than the T cell. The same set of antibodies also inhibited an allospecific mixed lymphocyte reaction, confirming that the inhibitory effect was not dependent on the use of a CD3 antibody as the stimulating agent. All the antibodies of known specificity inhibited both CD4 and CD8 T cells equally. Unlike CD87, CD98 and CD147 antibodies, which inhibited activation of both CD45RA (naive) T cells and CD45RO (memory) T cells, CD13 and CD148 appeared to be involved in activation of naive cells only. The molecules identified in this study have not previously been demonstrated to play a role as accessory molecules on DC, the cells that are pivotal for immune induction. Therefore they may provide new potential targets for modulation of the immune response at the APC level.

Expression of the membrane protein tyrosine phosphatase CD148 in human tissues

CD148, a receptor-like protein tyrosine phosphatase also known as HPTP-eta/DEP-1, is involved in signal transduction in leucocytes and is thought to contribute to mechanisms of cellular differentiation. We have investigated the in situ expression of CD148 in various fresh-frozen tissues by immunohistology and analyzed its expression on subpopulations of activated peripheral blood leucocytes by flow cytometry. In lymphoid organs, CD148 was found to be widely expressed on B and T cells, granulocytes, macrophages, certain dendritic cells as well as mature thymocytes. The cellular level of CD148 was increased after in vitro activation of peripheral blood leucocytes. Comparative analysis of tissue samples from normal gut and from patients with active Crohn's disease showed that leucocytes expressing CD148 are significantly upregulated in inflamed tissues and that a subset of these cells co-express the activation marker CD25. In non-lymphoid tissues, CD148 was found to be present on many epithelial cell types with glandular and/or endocrine differentiation as well as on fibrocytes, melanocytes and Schwann cells. CD148 expression was maintained also in malignant counterparts of such tissues. However, a marked loss of CD148 immunoreactivity was apparent in some of the investigated high-grade carcinomas. In summary, our results confirm a role of CD148 as a leucocyte activation marker. Among non-hematopoietic cells, CD148 is expressed by characteristic types of epithelial and non-epithelial cells. Downregulation of CD148 might promote dedifferentiation and autonomous growth of such cells in malignant tumors.

Upregulated expression of VLA proteins and CD29 in peripheral blood lymphocytes of chronic alcoholics without ethanol-related diseases

To analyze adhesion molecule expression on peripheral blood mononuclear cells (PBMCs) and on different lymphocyte subpopulations (CD2+, CD8+, CD19+, and CD56+ subsets) in chronic alcoholism, 30 well-nourished chronic alcoholics without ethanol-related diseases and 30 matched controls were included in the study. Adhesion molecules that mediate adhesion to other cells and to extracellular matrix proteins, and whose cellular expression is modified during lymphocyte activation, were selected for study. A detailed clinical evaluation, laboratory analysis, nutritional assessment, and study of adhesion molecule expression was performed. A significant higher expression of CD29 (beta1-integrin) (p = 0.001), VLA-3 (p = 0.002), VLA-4 (p = 0.03), and VLA-5 (p = 0.001) were observed on PBMCs of chronic alcoholics, compared with control subjects, whereas no changes were observed in CD18 (beta2-integrin) and CD50 (ICAM-3) expression. The upregulation of CD29 and VLA proteins only affected T lymphocytes (CD2+/CD8+/CD4+ cells). These data confirm that T cells of chronic alcoholics are basally activated and that changes in adhesion molecule expression on PBMCs may be responsible of disturbances of adhesion processes in chronic alcoholics without ethanol-related diseases.

Nitric oxide production by pig endothelial cells in response to human-derived injury

BACKGROUND

The hyperacute rejection induced by natural antibodies is the first barrier to the success of pig to human organ xenotransplantation. When this barrier is overcome, an infiltrate of mainly monocytes and natural killer cells can be observed. Nitric oxide (NO) has been described to be involved in allo- and xenorejection, and to participate in the regulation of monocyte infiltration in other models.

METHODS

We have studied the capacity of human monocytes and natural antibodies to induce the production of NO by pig endothelial cells, by measuring NO2, a stable end product of NO.

RESULTS

Human monocytes can induce HuProVim (HUP), a pig endothelial line, and "in situ, ex vivo" pig endothelial cells to produce NO2. This NO2 production was inhibited by NG-nitro-L-arginine-methylester and NG-monomethyl-L-arginine, inhibitors of NO production. This induction can be observed even if cells are separated by a semipermeable membrane, which indicates that it is a result of soluble factors. Activated cells continue producing NO after triggering for 1 hr. No NO2 production was observed after activation of HUP cells with recombinant human interleukin (IL)-1alpha, IL-1beta, IL-6, IL-10, transforming growth factor-beta1, IL-2, IL-4, interferon-gamma, or recombinant human tumor necrosis factor-alpha (rhTNF-alpha) alone. Only the combination of rhTNF-alpha+rIL-1alpha or rIL-1beta, and rhTNF-alpha+rIL-1alpha+IFN-gamma induces some NO production. Human natural anti-pig antibodies, which had been described to induce cytoskeleton changes on endothelial cells, do not induce NO production.

CONCLUSIONS

Our data show that human monocytes induce the production of NO by pig endothelial cells. The inducing signal is soluble and cannot be provided by human anti-pig natural antibodies.

Elevated soluble CD27 levels in serum of patients with systemic lupus erythematosus

The CD27 belongs to the NGF-R, a family of type I transmembrane receptors present in most T cells. The soluble form of CD27 can be found in body fluids, and elevation of serum levels is observed in T cell activation. Preliminary studies indicate that measurement of sCD27 levels might be of use in the evaluation of immune responses in vivo. Systemic lupus erythematosus (SLE) is a disease of unknown etiology. T cells from SLE patients have impaired responsiveness to various kinds of stimuli. However, the precise localization of the defect in the activation of SLE remains unclear. In this study we have analyzed the sCD27 serum levels in a SLE population and in a healthy group control. Seventy patients with SLE were prospectively studied. As controls, 20 healthy volunteer blood donors, matched by sex and age, were studied. We developed an enzyme-linked immunosorbent assay (ELISA) to measure sCD27. The mean level (+/-SD) of sCD27 was higher in the SLE patients (48.29 +/- 23.86 u) than that in the control group (36.13 +/- 7.48 u) (P = 0.02). In addition, patients with active SLE revealed higher serum concentration of sCD27 (58.20 +/- 31.06 u) than that of patients in remission (42.77 +/- 16.71 u) (P < 0.01). We found a positive correlation among sCD27 and sCD25 serum levels in SLE patients (r = 0.30, P = 0.01). No significant relation was found for other clinical symptoms or immunological parameters. In conclusion, sCD27 serum levels were increased in SLE patients and this increase was associated with the activity of the disease. Our data are consistent with the hypothesis that the CD27 antigen may constitute a marker of disease activity.

Cytokine gene expression and release from epithelial cells. A comparison study between healthy nasal mucosa and nasal polyps

BACKGROUND

Epithelial cells release cytokines and they probably contribute to chronic inflammation detected in bronchial asthma, rhinitis and nasal polyposis.

OBJECTIVES

To investigate the effect of cultures on cytokine gene expression to compare epithelial cell cytokine release by both healthy nasal nucosa (HNM) and nasal polyps (NP), and the modulation by dexamethasone and to investigate which cytokines may promote eosinophil survival.

METHODS

Epithelials cells were cultured to confluence, human epithelial cell conditioned media generated with or without dexamethasone, and supernatants measured by ELISA. Cytokine gene expression was investigated by reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS

Fresh epithelial cells only expressed mRNA for intesleukin-8 (IL-8) and granulocyte macrophage-colony stimulating factor (GM-CSF) while cultured cells expressed mRNA for IL-1 beta, IL-6, IL-8, tumour necrosis factor-alpha (TNF alpha) and GM-CSF. Epithelial cells from NP significantly (P < 0.05) released more IL-8 (25431 +/- 3163 pg/mL), and GM-CSF (1229 +/- 391 pg/mL) than those from HNM (18604 +/- 1723 pg/mL for IL-8; and 611 +/- 98 pg/mL for GM-CSF). Dexamethasone 10 microM inhibited the release of all cytokines, this effect being similar (40-50%) in both HNM and NP, except for IL-6 which was higher in HNM. Eosinophil survival induced by epithelial cell secretions from both HNM and NP was strongly blocked by GM-CSF antibody while it was partially blocked by antibodies to TNF alpha and IL-8.

CONCLUSIONS

These findings suggest that although epithelial cell culture procedures may upregulate cytokine gene expression, nasal polyps may represent a more active inflammatory tissue by releasing more cytokines than healthy nasal mucosa this release being inhibited by steroids; and that, in addition to GM-CSF, other cytokines such as TNF alpha and IL-8, may also be involved in the promotion of eosinophil survival.

Changes in idiotypic predominance in the anti-arsonate response by priming with anti-idiotypic antibodies

The predominant selection of CRI-A-bearing antibodies during the anti-arsonate (ARS) response of A/J mice has been used as a model to analyse the mechanism involved in the process of clonal selection and establishment of predominance. In order to assess the importance of the affinity and adaptability of CRI-A clones in this process, we tested the capability of a minor recurrent idiotype (id-1A3), present in a CRI-Aanti-ARS monoclonal antibody (65-1A3), to develop a normal anti-ARS response. Our results show that the id-1A3 predominance, established by anti-id-1A3 administration was stable during the primary and secondary anti-ARS response and that this predominance occurred concomitantly with low levels of CRI-A. Thus, a change in the idiotype predominance was achieved. In spite of the high levels of id-1A3, the anti-ARS antibody concentration, the affinity values, and the kinetics of the immune response were similar to those of the control group. All these results show that CRI-A clones are not essential in the normal development of the anti-ARS antibody response of A/J mice, and suggest that factors other than affinity could be involved in the establishment of the CRI-A predominance.

Direct measurement of antibody affinity distribution by hapten-inhibition enzyme immunoassay

A rapid, simple and reliable technique for determining the affinities of antibody subpopulations in a complex mixture is described. The principle of this method is that antigen conc can be represented as the amount of antigen immobilized on the polystyrene surface of a microwell containing a fixed vol of diluted antibody. Thus, by measuring the proportion of antibody bound to different wells coated with varying amounts of antigen, it is a straightforward matter to calculate an affinity distribution. We have verified that: (1) the amount of antigen bound to a polystyrene plate is proportional to the concn of antigen used for sensitization and follows a typical saturation curve; (2) the antibodies bound to plates sensitized with low concns of antigen are of higher affinity than those bound to plates sensitized with high concns of antigen; (3) an apparent affinity constant (aK) is defined as the reciprocal concn of free hapten required for 50% inhibition of antibody binding to immobilized antigen; (4) the aK determined by this method is in close agreement with the intrinsic affinity constant (K) measured by fluorescence quenching or the Farr assay; and (5) that during the course of immunization in vivo there is a clear shift to higher-affinity antibody subpopulations.