Spatial characterization of interface dermatitis in cutaneous lupus reveals novel chemokine ligand-receptor pairs that drive disease

Chemokines play critical roles in the recruitment and activation of immune cells in both homeostatic and pathologic conditions. Here, we examined chemokine ligand-receptor pairs to better understand the immunopathogenesis of cutaneous lupus erythematosus (CLE), a complex autoimmune connective tissue disorder. We used suction blister biopsies to measure cellular infiltrates with spectral flow cytometry in the interface dermatitis reaction, as well as 184 protein analytes in interstitial skin fluid using Olink targeted proteomics. Flow and Olink data concordantly demonstrated significant increases in T cells and antigen presenting cells (APCs). We also performed spatial transcriptomics and spatial proteomics of punch biopsies using digital spatial profiling (DSP) technology on CLE skin and healthy margin controls to examine discreet locations within the tissue. Spatial and Olink data confirmed elevation of interferon (IFN) and IFN-inducible CXCR3 chemokine ligands. Comparing involved versus uninvolved keratinocytes in CLE samples revealed upregulation of essential inflammatory response genes in areas near interface dermatitis, including AIM2. Our Olink data confirmed upregulation of Caspase 8, IL-18 which is the final product of AIM2 activation, and induced chemokines including CCL8 and CXCL6 in CLE lesional samples. Chemotaxis assays using PBMCs from healthy and CLE donors revealed that T cells are equally poised to respond to CXCR3 ligands, whereas CD14+CD16+ APC populations are more sensitive to CXCL6 via CXCR1 and CD14+ are more sensitive to CCL8 via CCR2. Taken together, our data map a pathway from keratinocyte injury to lymphocyte recruitment in CLE via AIM2-Casp8-IL-18-CXCL6/CXCR1 and CCL8/CCR2, and IFNG/IFNL1-CXCL9/CXCL11-CXCR3.

Lesional CD8+ T-Cell Number Predicts Surgical Outcomes of Melanocyte-Keratinocyte Transplantation Surgery for Vitiligo

The melanocyte-keratinocyte transplantation procedure (MKTP) treats stable and recalcitrant vitiligo. Despite careful selection of candidates based on clinical stability, the success of the procedure is unpredictable. The aim of our study was to define the immunological profile of stable vitiligo lesions undergoing MKTP and correlate them with clinical outcomes. We included 20 MKTP candidates with vitiligo and a patient with piebaldism as a control. Prior to MKTP, T-cell subsets and chemokines in the recipient skin were measured by flow cytometry and ELISA. During MKTP, melanocytes in the donor skin were quantified by flow cytometry. After MKTP, patients were followed for 12 months and repigmentation was assessed clinically and by ImageJ analysis of clinical photographs. Baseline immunologic biomarkers, duration of clinical stability, and transplanted melanocyte number were correlated to postsurgical repigmentation scores. CD8+ T cells were elevated in 43% of the clinically stable vitiligo lesions. CD8+ T-cell number negatively correlated with postsurgical repigmentation scores (r = -0.635, P = 0.002). Duration of clinical stability, skin chemokines, and transplanted melanocyte number did not influence postsurgical repigmentation. This study demonstrates that CD8+ T-cell number correlates negatively with success of postsurgical repigmentation and can be a biomarker to identify ideal surgical candidates.

More than a virus: a qualitative study of the social implications of hepatitis B infection in China

Background

China has the largest absolute number of people living with hepatitis B with up to 300,000 people estimated to die each year from hepatitis B related diseases. Despite advances in immunisation, clinical management, and health policy, there is still a lack of accessible and affordable health care for people with hepatitis B. Through in-depth interviews, this study identifies the personal, social and economic impact of living with hepatitis B and considers the role of stigma and discrimination as barriers to effective clinical management of the disease.

Methods

Semi-structured qualitative interviews were held with 41 people living with hepatitis B in five Chinese cities. Participants were recruited through clinical and non-government organisations providing services to people with hepatitis B, with most (n = 32) being under the age of 35 years.

Results

People living with hepatitis B experience the disease as a transformative intergenerational chronic infection with multiple personal and social impacts. These include education and employment choices, economic opportunities, and the development of intimate relationships. While regulations reducing access to employment and education for people with hepatitis B have been repealed, stigma and discrimination continue to marginalise people with hepatitis B.

Conclusions

Effective public policy to reduce morbidity and mortality associated with hepatitis B needs to address the lived impact of hepatitis B on families, employment and educational choices, finances, and social marginalisation.

A review of new agents evaluated against pediatric acute lymphoblastic leukemia by the Pediatric Preclinical Testing Program

Acute lymphoblastic leukemia (ALL) in children exemplifies how multi-agent chemotherapy has improved the outcome for patients. Refinements in treatment protocols and improvements in supportive care for this most common pediatric malignancy have led to a cure rate that now approaches 90%. However, certain pediatric ALL subgroups remain relatively intractable to treatment and many patients who relapse face a similarly dismal outcome. Moreover, survivors of pediatric ALL suffer the long-term sequelae of their intensive treatment throughout their lives. Therefore, the development of drugs to treat relapsed/refractory pediatric ALL, as well as those that more specifically target leukemia cells, remains a high priority. As pediatric malignancies represent a minority of the overall cancer burden, it is not surprising that they are generally underrepresented in drug development efforts. The identification of novel therapies relies largely on the reappropriation of drugs developed for adult malignancies. However, despite the large number of experimental agents available, clinical evaluation of novel drugs for pediatric ALL is hindered by limited patient numbers and the availability of effective established drugs. The Pediatric Preclinical Testing Program (PPTP) was established in 2005 to provide a mechanism by which novel therapeutics could be evaluated against xenograft and cell line models of the most common childhood malignancies, including ALL, to prioritize those with the greatest activity for clinical evaluation. In this article, we review the results of >50 novel agents and combinations tested against the PPTP ALL xenografts, highlighting comparisons between PPTP results and clinical data where possible.

CCR4+T cell recruitment to the skin in mycosis fungoides: potential contributions by thymic stromal lymphopoietin and interleukin-16

Mycosis fungoides (MF) is characterized by skin accumulation of CCR4+CCR7- effector memory T cells; however the mechanism for their recruitment is not clearly identified. Thymic Stromal Lymphopoietin (TSLP) is a keratinocyte-derived cytokine that triggers Th2 immunity and is associated with T cell recruitment to the skin in atopic dermatitis. Interleukin-16 (IL-16) is a chemoattractant and growth factor for CD4+T cells. We hypothesized that TSLP and IL-16 could contribute to recruitment of malignant T cells in MF. We found elevated TSLP and IL-16 in very early stage patients' plasma and skin biopsies, prior to elevation in CCL22. Both TSLP and IL-16 induced migratory responses of CCR4+TSLPR+CD4+CCR7-CD31+cells, characteristic of malignant T cells in the skin. Co-stimulation also resulted in significant proliferative responses. We conclude that TSLP and IL-16, expressed at early stages of disease, function to recruit malignant T cells to the skin and contribute to their enhanced proliferation.

Regulation of cellular processes by interleukin-16 in homeostasis and cancer

Interleukin-16 (IL-16) is generated as a precursor molecule that is cleaved by caspase-3 to produce a pro-IL-16 molecule that functions as a regulator of T cell growth, and a secreted peptide that functions as a CD4 and/or CD9 ligand for induction of cell motility and activation. IL-16 has been predominantly studied as a contributing factor in the orchestration of an immune response; however, more recently IL-16 bioactivity has been closely associated with the progression of a number of different cancers. While the association between IL-16 plasma levels and tumor progression has been reported for many types of cancer, the mechanism for IL-16 involvement has been partially elucidated for three of the cancer types, cutaneous T cell lymphoma (CTCL), multiple myeloma (MM), and breast cancer. The mechanism for promoting cell growth is different in each of these cancers and involves a sequence mutation in the pro-molecule facilitating decreased p27(KIP1) levels in CTCL; over expression of the secreted IL-16 molecule to induce proliferation in CTCL T cells, and plasma cells in MM; and increased secreted IL-16 acting to recruit CD4+ pro-tumor macrophages in breast cancer. This article will review the cellular process for generating IL-16, the biological activities for both the pro- and secreted forms of the protein, and then the mechanism by which these forms contribute to cancer progression. As a soluble cytokine the ability to reduce or eliminate IL-16 synthesis through siRNA approaches or bioactivity through the use of neutralizing antibody treatment may represent a novel therapeutic approach.

CXCR3 chemokine receptor-ligand interactions in the lymph node optimize CD4+ T helper 1 cell differentiation

Differentiation of naive CD4(+) T cells into T helper (Th) cells is a defining event in adaptive immunity. The cytokines and transcription factors that control Th cell differentiation are understood, but it is not known how this process is orchestrated within lymph nodes (LNs). Here we have shown that the CXCR3 chemokine receptor was required for optimal generation of interferon-γ (IFN-γ)-secreting Th1 cells in vivo. By using a CXCR3 ligand reporter mouse, we found that stromal cells predominately expressed the chemokine ligand CXCL9 whereas hematopoietic cells expressed CXCL10 in LNs. Dendritic cell (DC)-derived CXCL10 facilitated T cell-DC interactions in LNs during T cell priming while both chemokines guided intranodal positioning of CD4(+) T cells to interfollicular and medullary zones. Thus, different chemokines acting on the same receptor can function locally to facilitate DC-T cell interactions and globally to influence intranodal positioning, and both functions contribute to Th1 cell differentiation.

Potential role of TSLP and IL-16 for migration and proliferation in Mycosis Fungoides T cells (161.15)

Mycosis Fungoides is a cutaneous T cell lymphoma disease characterized by CCR4+ T cells in skin plaques. While CCL22/CCR4 has been implicated, the mechanism for recruitment and expansion is not well understood. We have now identified elevated levels of IL-16 and thymic stromal lymphopoietin (TSLP) in the sera and skin of MF patients and investigated the potential role of these cytokines. Sera levels showed a stage-dependent increase of TSLP (3 fold versus control), and consistently, stage independent, elevated IL-16 levels. The source appears to be the skin, as both were positive compared with staining of normal skin. MF T cells expressed higher levels of TSLP receptor and expression correlated with CCR4 expression. In vitro migration studies indicated a 210% and 230% increase in migration to IL-16 and TSLP respectively. Pre-treatment of IL-16 prior to TSLP induced migration increased the migratory response to 280%, suggesting an additive effect. Addressing T cell proliferation, we determined that TSLP and IL-16 separately had minimal effects on proliferation however in combination proliferation increased 3 fold versus stimulated control T cells. Taken together our findings indicate the potential role of IL-16 and TSLP to recruit and expand MF T cells at sites of plaque formation in MF. Co-expression of TSLPR and CCR4 suggests a possible mechanism that at least in part would account for the prevalence of CCR4+ T cells in the skin of MF.

Loss of nuclear pro-IL-16 facilitates cell cycle progression in human cutaneous T cell lymphoma

Cutaneous T cell lymphomas (CTCLs) represent a heterogeneous group of non-Hodgkin lymphomas that affect the skin. The pathogenesis of these conditions is poorly understood. For example, the signaling mechanisms contributing to the dysregulated growth of the neoplastic T cells are not well defined. Here, we demonstrate that loss of nuclear localization of pro-IL-16 facilitates CTCL cell proliferation by causing a decrease in expression of the cyclin dependent-kinase inhibitor p27Kip1. The decrease in p27Kip1 expression was directly attributable to an increase in expression of S-phase kinase-associated protein 2 (Skp2). Regulation of Skp2 is in part attributed to the nuclear presence of the scaffold protein pro-IL-16. T cells isolated from 11 patients with advanced CTCL, but not those from healthy controls or patients with T cell acute lymphocytic leukemia (T-ALL), demonstrated reduction in nuclear pro-IL-16 levels. Sequence analysis identified the presence of mutations in the 5' end of the PDZ1 region of pro-IL-16, a domain required for association of pro-IL-16 with the nuclear chaperone HSC70 (also known as HSPA8). HSC70 knockdown led to loss of nuclear translocation by pro-IL-16 and subsequent increases in Skp2 levels and decreases in p27Kip1 levels, which ultimately enhanced T cell proliferation. Thus, our data indicate that advanced CTCL cell growth is facilitated, at least in part, by mutations in the scaffold protein pro-IL-16, which directly regulates Skp2 synthesis.

Interleukin-16 as a marker of Sézary syndrome onset and stage

INTRODUCTION

Sézary syndrome is one of the most common forms of cutaneous T cell lymphoma (CTCL). It is characterized by skin infiltration of malignant T cells. We examined interleukin-16, a potent T cell chemoattractant and cell-cycle regulator, as a prospective marker of disease onset and stage.

METHODS

The correlation of total intracellular interleukin-16 and surface CD26 was studied by flow cytometry. Confocal microscopy was performed to determine localization of interleukin-16 at different stages of the disease. The levels of interleukin-16 in plasma and culture supernatants were examined by enzyme-linked immunoassay. Additionally, lymphocytes from stage IB patients were cultured in the presence of interleukin-16 alone and in combination with interleukin-15, and their ability to survive and proliferate was determined by cell counts and [3H]TdR incorporation.

RESULTS

The data indicate that loss of both nuclear and intracellular pro-interleukin-16 highly correspond to disease stage, with a concomitant increase in secreted mature interleukin-16 in both culture supernatants and patients' plasma that peaks at stage IB. Loss of intracellular interleukin-16 strongly corresponded to loss of surface CD26, which has been shown to occur with more advanced stage of CTCL. Nuclear translocation of pro-interleukin-16 was not observed in late stages of Sézary syndrome, indicating this loss is not reversible.

CONCLUSIONS

We propose that it is feasible to use plasma levels of IL-16 as a potential diagnostic marker of Sézary syndrome and to use loss of intracellular IL-16 as a prognostic indicator of disease severity and stage.

Mannose lipoarabinomannan from Mycobacterium tuberculosis inhibits T cell migration to sphingosine-1-phosphate and promotes trapping of T cells in lung draining lymph nodes. (40.3)

Humans and mice that have been infected with Mycobacterium tuberculosis (MTB) develop lymphadenopathy in lung draining lymph nodes. To determine a possible mechanism for this, we examined human and mouse T cell migration to the lymph node chemoattractant CCL21 and to sphingosine-1-phosphate (S1P) following exposure to various TB components. Mannose lipoarabinomannan (ManLAM), a glycolipid from the MTB cell wall, did not alter T cell migration to CCL21; however, ManLAM did significantly inhibit T cell migration to S1P. As S1P is the primary factor required for egress from lymph nodes, this suggested a potential mechanism. To determine whether this effect could be established in vivo ManLAM was administered intratracheally to C57BL/6J mice. Accumulation of T cells was detected in lung-draining lymph nodes within 24 hr with a four to five fold increase in total T cell numbers. Accumulation patterns were similar to mice that had been infected with Erdman TB for 4 weeks, as both groups exhibited a preferential trapping of Th1 cells. Our data provide evidence that ManLAM may be a primary factor for MTB-associated lymphadenopathy during MTB infection. We hypothesize that alteration in T cell homing patterns induced by ManLAM would affect normal host immune responses and thus potentially facilitate infection by the bacterium.

Mannose lipoarabinomannan from Mycobacterium tuberculosis promotes production of soluble TNF Receptors I & II. (40.4)

Serum and BAL fluid from mice that had been infected with Erdman Mycobacterium tuberculosis (MTB) for 6 months were analyzed with an in-house multiplex ELISA system. Out of the panel of cytokines tested, the cytokines that exhibited the largest increase in both serum and BAL as compared with uninfected mice were soluble TNF Receptors I & II. This is consistent with current literature demonstrating that soluble TNF Receptors increase over time during TB infection. To determine the potential source of the TNFRs as well to identify the stimulant, murine T cells were treated ex-vivo with a panel of MTB components. It was determined that the MTB cell wall component Mannose lipoarabinomannan (ManLAM) (10 or 100ng/ml) was able to induce a significant increase in sTNFRI & II following treatment overnight. To confirm the ability of ManLAM alone to induce TNFRs, serum and BAL from mice that had received 25ug purified ManLAM intratracheally exhibited elevated sTNFRI & II 24h following instillation. ManLAM was not able to induce increases in TNF alpha in vitro or in vivo, which is consistent with current literature. These data indicate the ability of ManLAM alone to induce elevated soluble TNFR production from T cells, thereby shifting the balance between TNF alpha and TNF soluble receptors. Based on the role of TNF in granuloma formation and maintenance during MTB infection, this could potentially contribute to the inability of mice to form proper granulomas.

IL-16 Mediates CD4 T Lymphocyte Accumulation in the lymph nodes by desensitizing S1P1 (134.1)

IL-16 is a cytokine generated at sites of inflammation. Originally characterized as a CD4 ligand that induces migration, it is now known that IL-16 can alter TCR-induced cell activation and inhibit many chemokine receptors via cross-receptor desensitization. Previous work has demonstrated that stimulation by HIV-1 gp120 results in greater CCL21 induced migration with concomitant inhibition of sphingosine-1-phosphate (S1P) induced migration. Injection of gp120 into SCIDhu mice resulted in sequestration of CD4+ T cells within lymph nodes. We now investigated whether a natural ligand for CD4, IL-16, could similarly affect T cell homing. We found that IL-16 could not augment CCL21; however, was capable of inhibiting S1P induced migration. This effect was dependent on p56lck signaling and did not affect S1P receptor expression. IL-16 intratracheal instillation resulted in initial recruitment of CD4+ cells into the lung with subsequent recruitment into lung draining lymph nodes. Instillation of eotaxin-2 resulted in lung accumulation but not lymph node accumulation of T cells. The effect by IL-16 was CD4 dependent as no accumulation was seen using CD4-/- mice. Accumulation within the nodes occurred 2 h post instillation and resolved by 24 h. We propose that this is the first description of cytokine desensitization of S1P stimulation and further, suggests an additional mechanism by which IL-16 can regulate recruitment of cells and mediate the inflammatory process.

Paraoxonase 2 (PON2) polymorphisms and development of renal dysfunction in type 2 diabetes: UKPDS 76

AIMS/HYPOTHESIS

Identification of variants predicting development of renal dysfunction would offer substantial clinical benefits. There is evidence that coding non-synonymous variants in the gene encoding paraoxonase 2 (PON2) are associated with nephropathy in both type 1 and type 2 diabetes.

METHODS

We examined the relationship between variation at the C311S and A148G polymorphisms (together with PON2 intronic variant rs12704795) and indices of renal dysfunction (progression to micro- and macroalbuminuria, plasma creatinine increases) in 3,374 newly diagnosed type 2 diabetic subjects from the UK Prospective Diabetes Study followed prospectively (median 14.0 years), using proportional hazards models, adjusted for sex, ethnicity and other known or putative risk factors.

RESULTS

rs12704795 genotypes were associated with differing rates of development of microalbuminuria (relative risk [RR] for CC vs AA homozygotes 0.68 [95% CI 0.54-0.87], p=0.002) but not other measures of worsening renal function. Heterozygotes for C311S were more likely to develop microalbuminuria (RR=1.31 [95% CI 1.11-1.54], p=0.001) but less likely to double creatinine levels during follow-up (RR=0.49 [95% CI 0.27-0.89], p=0.02). There was no corroboration of this latter association for related outcomes and no prior evidence supports heterosis effects at this locus.

CONCLUSIONS/INTERPRETATION

We conclude that the PON2 variants typed in this study have, at best, a small effect on the risk of renal dysfunction in type 2 diabetes.

IHC for Her2 with CBE356 antibody is a more accurate predictor of Her2 gene amplification by FISH than HercepTest in breast carcinoma

BACKGROUND

Her2 (c-erbB-2/neu) overexpression in breast carcinoma predicts response to the anti-Her2 monoclonal antibody, trastuzumab, and is associated with a poor prognosis. When considering patients for trastuzumab treatment, Her2 protein expression is measured by imunohistochemistry (IHC) and, where staining is equivocal, by fluorescence in situ hybridisation (FISH) detection of Her2 gene amplification.

AIMS

To compare IHC using CBE356 with IHC using the Food and Drug Administration approved HercepTesttrade mark.

METHODS

CBE356 and HercepTest were analysed using 167 FISH characterised breast carcinomas. Immunohistochemical expression of Her2 was measured semiquantitatively. Sensitivity, specificity, predictive values, and overall accuracy were calculated for both IHC methods using gene amplification by FISH as the end point, and IHC and FISH assays were tested in Kaplan-Meier survival analysis.

RESULTS

The accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of CBE356 positive (2+ and 3+) cases were 94%, 89%, 95%, 84%, and 97%, respectively, and of HercepTest positive (2+ and 3+) cases were 91%, 66%, 98%, 92%, and 91%, respectively. A positive result with CBE356, HercepTest, or FISH was associated with significantly decreased overall survival (log rank p = 0.005, p = 0.0017, and p = 0.0005, respectively).

CONCLUSIONS

Positive IHC staining for Her2 using CBE356 is 3% more accurate and 23% more sensitive at predicting Her2 gene amplification by FISH than positive staining with HercepTest. Negative IHC using CBE356 antibody is 6% more likely to represent a truly negative result than negative staining with HercepTest. Overall, CBE356 was a more accurate predictor of Her2 gene amplification by FISH than HercepTest.

BMP signaling components are expressed in human fracture callus

Of the various growth factors involved in the healing response after a fracture, bone morphogenetic proteins (BMPs) are emerging as key modulators. BMPs exert their effects by binding to a complex of type I and type II receptors leading to the phosphorylation of specific downstream effector proteins called Smads. The current study examined the presence of BMP signaling components in human callus obtained from five nascent malunions undergoing fracture fixation. These callus samples represented various stages of bone healing and a mixture of endochondral and intramembraneous bone healing. We performed immunohistochemistry on the callus, using antibodies for BMP (BMP-2,-3,-4,-7), their receptors (BMPR-IA, -IB, -II), and phosphorylated BMP receptor-regulated Smads (pBMP-R-Smads). Active osteoblasts showed fairly consistent positive staining for all BMPs that were examined, with the immunoreactivity most intense for BMP-7 and BMP-3. Immunostaining for BMPs in osteoblasts appeared to colocalize with the expression of BMPR-IA, -IB, and -II. Positive immunostaining for pBMP-R-Smads suggests that the BMP receptors expressed in these cells are activated. Staining for BMPs in cartilage cells was variable. The immunostaining appeared stronger in more mature cells, whereas staining for BMP receptors in cartilage cells was less ubiquitous. However, the expression of pBMP-R-Smads in cartilage cells suggests active signal transduction. Fibroblast-like cells also had a variable staining pattern. Overall, our findings indicate the presence of BMPs, their various receptors, and activated forms of receptor-regulated Smads in human fracture callus. To the best of our knowledge, this is the first study that documents the expression of these proteins in human fracture tissue. Complete elucidation of the roles of BMP in bone formation will hopefully lead to improved fracture healing care.

Evaluating HER2 amplification and overexpression in breast cancer

The development of Herceptin (Trazumatab) makes testing for HER2 status important for choosing optimal therapy in breast cancer. This study addresses the precision, accuracy, and reproducibility of HER2 assays. HER2 was assessed retrospectively by immunohistochemistry (IHC) with Dako 'Herceptest', by IHC with the monoclonal antibody CB11, and by fluorescence in situ hybridization (FISH, PathVysion), in a series of 216 formalin-fixed breast carcinomas including 191 for which quantitative HER2 data from radioimmunohistochemistry (Q-IHC) were available. All tests were scored independently by two observers. Positivity rates varied between Herceptest (12.6%), FISH (19.4%), and CB11 IHC (28.5%). Kappa values showed that IHC-based tests were more susceptible to inter-observer variation (kappa=0.67 and 0.74 for Herceptest and CB11, respectively) than FISH (kappa=0.973). Overall test accuracy (see the Materials and methods section) for CB11 IHC (83.8%) was lower than Herceptest (87.4%) or FISH (93.2%). FISH predicted p185 HER2 overexpression (determined by Q-IHC) better (concordance index C.Ind. 0.90) than CB11 IHC (C.Ind.=0.85) or Herceptest (C.Ind.=0.81). Of 42 cases with gene amplification by FISH, 67% were positive in the Herceptest (2+ or 3+) vs. 83% with CB11. Of 174 cases negative by FISH, 96% were negative in the Herceptest and 68% with CB11. In conclusion, FISH is the most accurate, reproducible, and precise predictor of HER2 overexpression in routine diagnostic laboratories.

Noninvasive graft flow and patency assessment following minimally invasive direct coronary artery bypass (MIDCAB) grafting

OBJECTIVE

Assessment of graft patency following minimally invasive direct coronary artery bypass (MIDCAB) surgery is essential in order to determine the efficacy of this technique. This study was conducted to evaluate the role of intraoperative and postoperative noninvasive flow and velocity measurements to follow and predict graft performance.

METHODS

Between April 1996 and July 1997, 130 patients had 133 grafts placed using MIDCAB techniques. Intraoperative transit-time ultrasound was used to assess graft patency and flow prior to wound closure. Also, serial transcutaneous doppler examinations were performed to evaluate graft patency on the first postoperative day, at two weeks, and at three months. Peak values for systolic and diastolic waveforms were measured for both flow and velocity, and the diastolic-to-systolic ratio was calculated at each time interval. Recatheterization was performed selectively for inadequate ultrasound flow or doppler velocity, or for patient symptoms.

RESULTS

Seven (5.3 %) grafts developed stenosis or occlusion. When compared to normal grafts, mean intraoperative flows, flow ratios, and velocity ratios were lower. Mean postoperative diastolic peak velocity (DPV) to systolic peak velocity (SPV) ratio remained stable over time for normal grafts; however, grafts with stenosis or occlusion demonstrated a diminished DPV/SPV ratio.

CONCLUSIONS

Intraoperative transit-time ultrasound and outpatient transcutaneous doppler examinations did not reach a predictive value for graft stenosis or occlusion following MIDCAB surgery in this series of patients. However, these data demonstrate trends that may help identify patients at an increased risk for unfavorable events, guiding the use of postoperative recatheterization in such patients.

FRAME annual lecture. The three Rs: a journey or a destination?

It is an honour to have been asked to follow in the footsteps of Professor Russell (1) and deliver the FRAME Annual Lecture. In doing so, I am not speaking in any official capacity. I am speaking as myself: someone who has had a 30-year association with medicine and the biological sciences, who has had more time and reason than most to reflect upon the changes that have taken place during that period, and to think about how things may develop in the future. The views expressed tonight are based upon, and represent, my personal experience, expectations and aspirations.

Lipid vesicle size determines the Th1 or Th2 response to entrapped antigen

Understanding the factors that control the differential induction of Th1 and Th2 responses is a key immunologic objective with profound implications for vaccination and immunotherapy of infectious and autoimmune diseases. Using Ag formulated in lipid vesicles prepared from nonionic surfactants, we describe a novel mechanism influencing the balance of the Th1 or Th2 response. Our results indicate that inoculation of BALB/c mice with vesicles with a mean diameter > or = 225 nm preferentially induces Th1 responses, as characterized by increased titers of IgG2a in plasma and elevated IFN-gamma production by lymph node cells. However, preparation of the same quantity of Ag in vesicles with mean diameter of < or = 155 nm induces a Th2 response, as identified by IgG1 in the absence of IgG2a production and increased lymph node IL-5 production. Although large (> or = 225 nm) vesicles could induce IL-12 production, smaller vesicles (< or = 155 nm) could not. However, small vesicles did induce higher levels of IL-1beta production by macrophages than larger vesicles. The role of IL-12 in this response was confirmed in IL-12-deficient mice, whose spleen cells failed to produce IFN-gamma following in vivo priming with Ag prepared in large vesicles. Our results therefore indicate that macrophages respond to endocytosis of large or small vesicles by producing different patterns of cytokines that can subsequently direct the immune response toward a Th1 or a Th2 phenotype.

Fine-needle aspiration cytology of extranodal lymphoma

The assessment of lymphoproliferative disorders using fine-needle aspiration (FNA) cytology may be problematic particularly when organs other than lymph node are involved. In this report we have reviewed 26 consecutive FNA specimens from superficial extranodal sites which were reported as diagnostic or suggestive of malignant lymphoma. The aspirates were obtained from skin or subcutaneous tissue (ten cases), thyroid (five cases), salivary gland (five cases), breast (four cases), neck, and pharynx (one case each). Ancillary studies including immunocytochemistry, in situ hybridisation to detect immunoglobulin light chain mRNA expression, and polymerase chain reaction for analysis of immunoglobulin heavy chain gene rearrangement were performed in 20, 12, and 7 cases, respectively. Clinicopathologic correlation confirmed the diagnosis of lymphoma in 25/26 aspirates. Nine of the 14 patients whose initial presentation was with an extranodal mass were considered to have primary lymphomas of mucosa-associated lymphoid tissue (MALT) type. In contrast, ten of 11 patients with recurrent extranodal disease had primary nodal type lymphomas. There was one false-positive diagnosis, a neck mass misinterpreted cytologically as B-cell lymphoma which was ultimately shown to be a branchial cyst. FNA cytology supported by appropriate ancillary investigations provides accurate diagnosis in most cases of extranodal lymphoma.

Blood lead in U.K. children--time for a lower action level?

1. Blood lead measurements in samples collected from 660 London schoolchildren during 1991 to 1992 suggest that the blood lead values in children in the U.K. are decreasing. 2. Geometric mean values for blood lead were 0.18 (range 0.05-0.71) micromol/l [3.7 (1. 0-15.0) microgram/dl]. Analysis of variance showed differences between ethnic groups, sex and schools. An age-matched subset of 148 children was compared with 136 children from an earlier study in 1986 and 1987. Trend analysis of the geometric mean lead values showed a negative slope (b=-0.484, P<0.0001), with maximum values of 0.81, 1.00, 0.71 and 0.43 micromol/l (17, 21, 15 and 9 microgram/dl) for the years 1986, 1987, 1991 and 1992 respectively. 3. It is recommended that children in the U.K. being investigated for anaemia, pica, recurrent abdominal pain or a high-risk environment should have blood lead values measured and that the action level for blood lead in children should be decreased from 1.19 micromol/l to 0.48 micromol/l (from 25 microgram/dl to 10 microgram/dl). 4. Guidance is offered to clinicians and other health professionals investigating excessive lead exposure.

Measurement of vitamin D3 metabolites in smelter workers exposed to lead and cadmium

OBJECTIVES

To investigate the effects of lead and cadmium on the metabolic pathway of vitamin D3.

METHODS

Blood and urinary cadmium and urinary total proteins were measured in 59 smelter workers occupationally exposed to lead and cadmium. In 19 of these workers, the plasma vitamin D3 metabolites, (25-hydroxycholecalciferol (25 OHD3), 24R, 25-dihydroxycholecalciferol (24R,25(OH)2D3) and 1 alpha,25-dihydroxycholecalciferol (1 alpha, 25(OH)2D3)) were measured together with blood lead. Vitamin D3 metabolites were measured by radioimmunoassay, (RIA), lead and cadmium by atomic absorption spectrophotometry, and total proteins with a test kit.

RESULTS

Ranges for plasma 25(OH)D3, 24R,25(OH)2D3 and 1 alpha,25(OH)2D3 were 1.0-51.9 ng/ml, 0.6-5.8 ng/ml, and 0.1-75.7 pg/ml, respectively. Ranges for blood lead were 1-3.7 mumol/l, (21-76 micrograms/dl), blood cadmium 6-145 nmol/l, and urinary cadmium 3-161 nmol/l. Total proteins in random urine samples were 2.1-32.6 mg/dl. Concentrations of lead and cadmium in blood showed no correlation (correlation coefficient -0.265) but there was a highly significant correlation between blood and urinary cadmium. Concentrations for 24R,25(OH)2D3 were depressed below the normal range as blood and urinary cadmium increased, irrespective of lead concentrations. High cadmium concentrations were associated with decreased plasma 1 alpha,25(OH)2D3 when lead concentrations were < 1.9 mumol/l and with above normal plasma 1 alpha,25(OH)2D3 when lead concentrations were > 1.9 mumol/l, Kruskal-Wallis analysis of variance (K-W ANOVA) chi 2 = 10.3, p = 0.006. Plasma 25(OH)D3 was negatively correlated with both urinary total proteins and urinary cadmium, but showed no correlation with plasma 24R,25(OH)2D3, 1 alpha,25(OH)2D3, blood lead, or blood cadmium.

CONCLUSION

Continuous long term exposure to cadmium may result in a state of equilibrium between blood and urinary cadmium. Cadmium concentrations in blood could be predicted from the cadmium concentration of the urine, (regression coefficient +0.35 SE 0.077). Exposure to cadmium alone decreased the concentrations of 1 alpha,25(OH)2D3 and 24R,25(OH)2D3, whereas exposure to both cadmium and lead increased the concentrations of 1 alpha,25(OH)2D3. It has been suggested that cadmium and lead interact with renal mitochondrial hydroxylases of the vitamin D3 endocrine complex. Perturbation of the vitamin D metabolic pathway by cadmium may result in health effect, such as osteoporosis or osteomalacia, risks which are possibly increased in the presence of lead.

Fine needle aspiration cytology diagnosis of malignant lymphoma and reactive lymphoid hyperplasia

AIMS

To assess the diagnostic accuracy of lymph node fine needle aspiration (FNA) cytology to distinguish reactive lymphoid hyperplasia from malignant lymphoma, and to evaluate the contribution of ancillary techniques applied to cytological material.

METHODS

Two hundred and seventy seven consecutive lymph node FNA specimens reported to be consistent with reactive lymphoid hyperplasia (n = 213) or suggestive/diagnostic of malignant lymphoma (n = 64) were reviewed. Follow up data were obtained by case record review or by histological correlation. The value of immunocytochemistry, in situ hybridisation for immunoglobulin light chain mRNA, and polymerase chain reaction (PCR) towards the final clinicopathological diagnosis was assessed in 92, 61, and 45 cases, respectively.

RESULTS

Sixty one of 67 lymphomas and 207 of 209 reactive lymph nodes were accurately diagnosed by FNA cytology. There were six false negative aspirates including three cases of follicular lymphoma, two cases of Hodgkin's disease, and one chronic lymphocytic leukaemia. Two FNA specimens considered suspicious of lymphoma proved reactive on histology or clinical follow up. One metastatic small cell carcinoma was wrongly diagnosed as lymphoma. Ancillary studies contributed to the correct diagnosis in most cases although occasional misleading results were obtained, particularly with PCR.

CONCLUSIONS

FNA cytology accurately distinguished reactive lymphoid hyperplasia from malignant lymphoma in 97% of cases. However, occasional wrong diagnoses occurred owing to sampling error or misinterpretation. Ancillary studies can be applied to cytological samples and contribute to the diagnosis in most cases.

Non-Hodgkin's lymphomas complicating Sjögren's syndrome: can Epstein Barr virus be implicated?

We examined eight (6 parotid, 1 caecum, 1 lymph node) non Hodgkin's Lymphomas (NHL) complicating primary Sjögren's syndrome (SS), four parotid NHL, in patients without SS, and three salivary gland biopsies from SS patients and no NHL, for Epstein Barr virus (EBV), using immunohistochemistry for late membrane protein, in situ hybridisation (ISH) for EBER, and PCR for EBV DNA. Late membrane protein was not detected. In NHL's complicating SS, EBERs were detected in two parotid lymphomas by ISH. EBV DNA was detected in three SS parotid NHL. Cecal and lymph node SS NHL were negative for EBER and EBV DNA. EBV DNA was detected in two non SS NHLs, one expressed EBER. Despite positive EBV DNA results by PCR in three samples expression of EBER was noted in only one by ISH. This was a high grade NHL complicating SS. There was no evidence of EBV in low grade NHLs complicating SS.

Effects of hypoglycaemia: patients' perceptions and experiences

A qualitative study was undertaken to investigate the perceptions and experiences of insulin-treated people with diabetes mellitus. Seven people were randomly selected from an opportunistic sample and interviewed either at home or on hospital premises. The subjects comprised four women and three men (age range 20-72 years). The study found that hypoglycaemia plays a significant role in the lives of these subjects and that concern over having a hypoglycaemic attack is constantly present. All subjects had suffered at least one attack which had potentially serious consequences and six did not always recognize the warning signs of an impending insulin reaction. Only one of the subjects said they would be happy to live alone.

Noradrenaline inhibition of Ca2+ channels and secretion in single patch-clamped insulinoma cells

Noradrenaline effects on voltage-operated calcium channels and exocytosis were studied, for the first time, in single patch-clamped RINm5F insulin-secreting cells. Noradrenaline, despite small and variable inhibition of calcium currents, strongly inhibited the increase in membrane capacitance (a measure of exocytosis) stimulated by both step depolarizations and the calcium ionophore, ionomycin. Noradrenaline similarly inhibited KCl- and ionomycin-induced [3H]serotonin release from RINm5F cell populations. Noradrenaline effects were mediated by PTX-sensitive G proteins. Noradrenaline inhibitory effects on secretion are, therefore, mainly exerted downstream from Ca2+ influx.

Expression of the human heat shock protein 60 in thyroid, pancreatic, hepatic and adrenal autoimmunity

Heat shock proteins (hsps) have been proposed to play a role in autoimmune disease. Their highly conserved nature and role as a common antigenic determinant throughout phylogeny has raised the possibility that they may act as cellular targets of an autoimmune response when their expression is altered in stressed tissue cells. Using an antibody to human hsp60 we have demonstrated a wide tissue distribution in normal tissues, including thymus, the degree of staining reflecting the content of mitochondria in the cells, consistent with the known mitochondrial location of this protein. Enhanced staining was also demonstrated in oncocytes (deeply eosinophilic cells which have greatly increased numbers of mitochondria) in both thyroid and adrenal autoimmune disease and also in unrelated conditions where oncocytic change was identified. No enhancement was demonstrated in target cells in organ specific autoimmune diseases where oncocytic change was not seen, for example islet cells in diabetes and bile duct cells in primary biliary cirrhosis. Thus, no alteration of hsp60 expression was demonstrated which was specific to the autoimmune diseases studied.