Conversion of the liver into a biofactory for DNaseI using adeno-associated virus vector gene transfer reduces neutrophil extracellular traps in a model of Systemic Lupus Erythematosus

Adeno-associated virus (AAV) vectors are proving to be clinically transformative tools in the treatment of monogenic genetic disease. Rapid ongoing development of this technology promises to not only increase the number of monogenic disorders amenable to this approach, but also to bring diseases with complex multigenic and non-genetic aetiologies within therapeutic reach. Here we explore the broader paradigm of converting the liver into a biofactory for systemic output of therapeutic molecules using AAV-mediated delivery of DNaseI as an exemplar. DNaseI can clear neutrophil extracellular traps (NETs), which are nuclear-protein structures possessing anti-microbial action that are also involved in the pathophysiology of clinically troubling immune-mediated diseases. However, a translational challenge is short half-life of the enzyme in vivo (<5 hours). The current study demonstrates that AAV-mediated liver-targeted gene transfer stably induces serum DNaseI activity to >190-fold above physiological levels. In lupus-prone mice (NZBWF1) activity was maintained for longer than 6 months, the latest time point tested, and resulted in a clear functional effect with reduced renal presence of neutrophils, NETs, IgG and complement C3. However, treatment in this complex disease model did not extend life-span, improve serological endpoints or preserve renal function indicating there are elements of pathophysiology not accessible to DNaseI in the NZBWF1 model. We conclude that a translational solution to the challenge of short half-life of DNaseI is AAV-mediated gene delivery and that this may be efficacious in treating disease where NETs are a dominant pathological mechanism.

Animal Models of ANCA Associated Vasculitis

Anti-neutrophil cytoplasmic antibody (ANCA) associated vasculitis (AAV) is a rare and severe autoimmune multisystemic disease. Its pathogenesis involves multiple arms of the immune system, as well as complex interactions between immune cells and target organs. Experimental animal models of disease can provide the crucial link from human disease to translational research into new therapies. This is particularly true in AAV, due to low disease incidence and substantial disease heterogeneity. Animal models allow for controlled environments in which disease mechanisms can be defined, without the clinical confounders of environmental and lifestyle factors. To date, multiple animal models have been developed, each of which shed light on different disease pathways. Results from animal studies of AAV have played a crucial role in enhancing our understanding of disease mechanisms, and have provided direction toward newer targeted therapies. This review will summarize our understanding of AAV pathogenesis as has been gleaned from currently available animal models, as well as address their strengths and limitations. We will also discuss the potential for current and new animal models to further our understanding of this important condition.

Natural killer cell function predicts severe infection in kidney transplant recipients

The aim of this study was to determine if natural killer cell number (CD3^- /CD16^± /CD56^± ) and cytotoxic killing function predicts severity and frequency of infection in kidney transplant recipients. A cohort of 168 kidney transplant recipients with stable graft function underwent assessment of natural killer cell number and functional killing capacity immediately prior to entry into this prospective study. Participants were followed for 2 years for development of severe infection, defined as hospitalization for infection. Area under receiver operating characteristic (AUROC) curves were used to evaluate the accuracy of natural killer cell number and function for predicting severe infection. Adjusted odds ratios were determined by logistic regression. Fifty-nine kidney transplant recipients (35%) developed severe infection and 7 (4%) died. Natural killer cell function was a better predictor of severe infection than natural killer cell number: AUROC 0.84 and 0.75, respectively (P = .018). Logistic regression demonstrated that after adjustment for age, transplant function, transplant duration, mycophenolate use, and increasing natural killer function (odds ratio [OR] 0.82, 95% confidence interval [CI] 0.74-0.90; P < .0001) but not natural killer number (OR 0.96, 95% CI 0.93-1.00; P = .051) remained significantly associated with a reduced likelihood of severe infection. Natural killer cell function predicts severe infection in kidney transplant recipients.

Can immune biomarkers predict infections in solid organ transplant recipients? A review of current evidence

Despite improvements in graft survival, solid organ transplantation is still associated with considerable infection induced morbidity and mortality. If we were able to show that serious infection risk was associated with excessive suppression of immune capacity, we would be justified in "personalizing" the extent of immunosuppression by carefully monitored reduction to see if we can improve immune compromize without increasing the risk of rejection. Reliable biomarkers are needed to identify this patients at an increased risk of infection. This review focuses on the currently available evidence in solid organ transplant recipients for immune non-pathogen specific biomarkers to predict severe infections with the susceptibility to particular pathogens according to the component of the immune system that is suppressed. This review is categorized into immune biomarkers representative of the humoral, cellular, phagocytic, natural killer cell and complement system. Biomarkers humoral and cellular systems of the that have demonstrated an association with infections include immunoglobulins, lymphocyte number, lymphocyte subsets, intracellular concentrations of adenosine triphosphate in stimulated CD4⁺ cells and soluble CD30. Biomarkers of the innate immune system that have demonstrated an association with infections include natural killer cell numbers, complement and mannose binding lectin. Emerging evidence shows that quantification of viral nucleic acid (such as Epstein Barr Virus) can act as a biomarker to predict all-cause infections. Studies that show the most promise are those in which several immune biomarkers are assessed in combination. Ongoing research is required to validate non-pathogen specific immune biomarkers in multi-centre studies using standardized study designs.

Delayed Diagnosis and Complications of Predominantly Antibody Deficiencies in a Cohort of Australian Adults

Background

Predominantly antibody deficiencies (PADs) are the most common type of primary immunodeficiency in adults. PADs frequently pass undetected leading to delayed diagnosis, delayed treatment, and the potential for end-organ damage including bronchiectasis. In addition, PADs are frequently accompanied by comorbid autoimmune disease, and an increased risk of malignancy.

Objectives

To characterize the diagnostic and clinical features of adult PAD patients in Victoria, Australia.

Methods

We identified adult patients receiving, or having previously received immunoglobulin replacement therapy for a PAD at four hospitals in metropolitan Melbourne, and retrospectively characterized their clinical and diagnostic features.

Results

179 patients from The Royal Melbourne, Alfred and Austin Hospitals, and Monash Medical Centre were included in the study with a median age of 49.7 years (range: 16–87 years), of whom 98 (54.7%) were female. The majority of patients (116; 64.8%) met diagnostic criteria for common variable immunodeficiency (CVID), and 21 (11.7%) were diagnosed with X-linked agammaglobulinemia (XLA). Unclassified hypogammaglobulinemia (HGG) was described in 22 patients (12.3%), IgG subclass deficiency (IGSCD) in 12 (6.7%), and specific antibody deficiency (SpAD) in 4 individuals (2.2%). The remaining four patients had a diagnosis of Good syndrome (thymoma with immunodeficiency). There was no significant difference between the age at diagnosis of the disorders, with the exception of XLA, with a median age at diagnosis of less than 1 year. The median age of reported symptom onset was 20 years for those with a diagnosis of CVID, with a median age at diagnosis of 35 years. CVID patients experienced significantly more non-infectious complications, such as autoimmune cytopenias and lymphoproliferative disease, than the other antibody deficiency disorders. The presence of non-infectious complications was associated with significantly reduced survival in the cohort.

Conclusion

Our data are largely consistent with the experience of other centers internationally, with clear areas for improvement, including reducing diagnostic delay for patients with PADs. It is likely that these challenges will be in part overcome by continued advances in implementation of genomic sequencing for diagnosis of PADs, and with that opportunities for targeted treatment of non-infectious complications.

Seroresponses and safety of 13-valent pneumococcal conjugate vaccination in kidney transplant recipients

BACKGROUND

Conjugated pneumococcal vaccine is recommended for kidney transplant recipients, however, their immunogenicity and potential to trigger allograft rejection though generation of de novo anti-human leukocyte antigen antibodies has not been well studied.

METHODS

Clinically stable kidney transplant recipients participated in a prospective cohort study and received a single dose of 13-valent conjugate pneumococcal vaccine. Anti-pneumococcal IgG was measured for the 13 vaccine serotypes pre and post vaccination and functional anti-pneumococcal IgG for 4 serotypes post vaccination. Anti-human leukocyte antigen antibodies antibodies were measured before and after vaccination. Kidney transplant recipients were followed clinically for 12 months for episodes of allograft rejection or invasive pneumococcal disease.

RESULTS

Forty-five kidney transplant recipients participated. Median days between pre and post vaccination serology was 27 (range 21-59). Post vaccination, there was a median 1.1 to 1.7-fold increase in anti-pneumococcal IgG antibody concentrations for all 13 serotypes. Kidney transplant recipients displayed a functional antibody titer ≥1:8 for a median of 3 of the 4 serotypes. Post vaccination, there were no de novo anti-human leukocyte antigen antibodies, no episodes of biopsy proven rejection or invasive pneumococcal disease.

CONCLUSION

A single dose of 13-valent conjugate pneumococcal vaccine elicits increased titers and breadth of functional anti-pneumococcal antibodies in kidney transplant recipients without stimulating rejection or donor-specific antibodies.

Local IL-17 Production Exerts a Protective Role in Murine Experimental Glomerulonephritis

IL-17 is a pro-inflammatory cytokine implicated in the pathogenesis of glomerulonephritis and IL-17 deficient mice are protected from nephrotoxic nephritis. However, a regulatory role for IL-17 has recently emerged. We describe a novel protective function for IL-17 in the kidney. Bone marrow chimeras were created using wild-type and IL-17 deficient mice and nephrotoxic nephritis was induced. IL-17 deficient hosts transplanted with wild-type bone marrow had worse disease by all indices compared to wild-type to wild-type bone marrow transplants (serum urea p<0.05; glomerular thrombosis p<0.05; tubular damage p<0.01), suggesting that in wild-type mice, IL-17 production by renal cells resistant to radiation is protective. IL-17 deficient mice transplanted with wild-type bone marrow also had a comparatively altered renal phenotype, with significant differences in renal cytokines (IL-10 p<0.01; IL-1β p<0.001; IL-23 p<0.01), and macrophage phenotype (expression of mannose receptor p<0.05; inducible nitric oxide synthase p<0.001). Finally we show that renal mast cells are resistant to radiation and produce IL-17, suggesting they are potential local mediators of disease protection. This is a novel role for intrinsic cells in the kidney that are radio-resistant and produce IL-17 to mediate protection in nephrotoxic nephritis. This has clinical significance as IL-17 blockade is being trialled as a therapeutic strategy in some autoimmune diseases.

Endogenous IL-17A promotes pristane-induced systemic autoimmunity and experimental lupus nephritis (BA4P.218)

IL-17A is increased in serum and in kidney biopsies from patients with lupus nephritis, but direct evidence of pathogenicity is less well established. These studies sought to define the role of IL-17A in experimental lupus induced by the administration of pristane to WT and IL-17A-/- mice. Local and systemic immune responses were assessed after 6 days and 8 weeks, and autoimmunity, glomerular inflammation and renal injury were determined at 7 months. Peritoneal IL-17A production increased significantly 6 days after pristane injection, with innate cells (neutrophils and macrophages) being the predominant source of IL-17A. After 8 weeks, while systemic IL-17A was still readily detected in WT mice, IFN-γ and TNF were diminished in IL-17A-/- mice. Seven months after pristane, humoral autoimmunity was diminished in IL-17A-/- mice, with decreased serum lgG and anti-dsDNA antibody titers. Renal inflammation and injury was less in the absence of IL-17A. Compared to WT mice, glomerular IgG, complement deposition, glomerular CD4+ T cells and intrarenal pro-inflammatory mediator expression were decreased in IL-17A-/- mice. WT mice developed progressive albuminuria, but albuminuria (7 months: WT 271±56, IL-17A 88±16μg/day; P&lt;0.05) and histological abnormalities were attenuated in IL-17A-/- mice. Therefore, IL-17A is required for the full development of systemic autoimmunity and experimental lupus nephritis. Early in the development of autoimmunity, innate immune cells produce IL-17A.

FcγRIIB regulates T cell autoreactivity, ANCA production and neutrophil activation to suppress anti-myeloperoxidase glomerulonephritis (THER5P.834)

Anti-neutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis involves innate and adaptive immune cells in the induction of autoimmunity and in autoimmune effector responses. Most Fcγ receptors (FcγRs) activate immune cells, but FcγRIIB, found in humans and mice on B cells and innate cells, is an inhibitory receptor. These studies tested the hypothesis that endogenous FcγRIIB negatively regulates autoreactivity and effector responses in experimental anti-myeloperoxidase (MPO) glomerulonephritis, using wild type and FcγRIIB-/- mice. After MPO immunization, FcγRIIB-/- mice developed higher MPO-ANCA titers and increased anti-MPO T cell responses. Transfer of FcγRIIB deficient dendritic cells loaded with a nephritogenic MPO peptide (MPO409-428) into wild type mice induced stronger autoimmunity than dendritic cells derived from wild type mice. Transferring anti-MPO antibodies into LPS primed mice resulted in increased glomerular neutrophil accumulation and injury in FcγRIIB-/- mice, showing a role for FcγRIIB in suppressing neutrophil activation. Inducing active autoimmunity to MPO followed by triggering T cell mediated glomerular injury by transfer of subnephritogenic doses of LPS and anti-MPO antibodies resulted in more disease in FcγRIIB-/- mice. Therefore endogenous FcγRIIB negatively regulates anti-MPO autoimmunity and glomerulonephritis via dendritic cells, B cells and neutrophils to limit MPO-ANCA production, T cell responses and neutrophil activation.

Epitope specificity determines pathogenicity and detectability in ANCA-associated vasculitis

Anti-neutrophil cytoplasmic antibody-associated (ANCA-associated) small vessel necrotizing vasculitis is caused by immune-mediated inflammation of the vessel wall and is diagnosed in some cases by the presence of myeloperoxidase-specific antibodies (MPO-ANCA). This multicenter study sought to determine whether differences in ANCA epitope specificity explain why, in some cases, conventional serologic assays do not correlate with disease activity, why naturally occurring anti-MPO autoantibodies can exist in disease-free individuals, and why ANCA are undetected in patients with ANCA-negative disease. Autoantibodies from human and murine samples were epitope mapped using a highly sensitive epitope excision/mass spectrometry approach. Data indicated that MPO autoantibodies from healthy individuals had epitope specificities different from those present in ANCA disease. Importantly, this methodology led to the discovery of MPO-ANCA in ANCA-negative disease that reacted against a sole linear sequence. Autoantibodies against this epitope had pathogenic properties, as demonstrated by their capacity to activate neutrophils in vitro and to induce nephritis in mice. The confounder for serological detection of these autoantibodies was the presence of a fragment of ceruloplasmin in serum, which was eliminated in purified IgG, allowing detection. These findings implicate immunodominant epitopes in the pathology of ANCA-associated vasculitis and suggest that autoantibody diversity may be common to other autoimmune diseases.

The immunodominant CD4+ T cell epitope of myeloperoxidase induces cell mediated injury in murine anti-myeloperoxidase glomerulonephritis (159.14)

Microscopic polyangiitis, characterized by pathogenic autoantibodies to neutrophil cytoplasmic proteins (ANCA), including myeloperoxidase (MPO), frequently targets the glomerulus. Although the pathogenicity of ANCA has been established, the role of CD4+ cells, cell mediated effector responses and MPO T cell epitopes are not known. By screening overlapping peptides of 20aa spanning the entire MPO molecule, we identified an immunodominant MPO CD4+ cell epitope (MPO409-428). Immunization with MPO409-428 induced disease similar to that seen with whole MPO when disease was triggered with anti-glomerular basement membrane antibodies. A CD4+ MPO409-428 specific clone transferred into Rag1-/- mice induced necrotizing glomerulonephritis with renal impairment when MPO409-428 was planted in glomeruli, or when whole MPO was deposited in glomeruli after neutrophil recruitment induced by transfer of anti-MPO antibodies with LPS. MPO409-428 also induced biologically active anti-MPO antibodies in mice. The MPO409-428 T cell epitope has a minimum immunogenic core region of 11 aa, MPO415-426, with several critical residues. These studies identify an immunodominant MPO T cell epitope and redefine how effector responses induce injury in MPO-ANCA associated microscopic polyangiitis. ANCA activate neutrophils not only induce injury, but also lodge the autoantigen MPO in glomeruli, where autoreactive CD4+ cells act to induce delayed-type hypersensitivity like necrotizing glomerular lesions.

Cell mediated injury in autoimmune anti-glomerular basement membrane disease is defined by a critical T cell epitope in humanized mice (123.33)

Human anti-glomerular basement membrane (GBM) disease has strong associations with HLA DRB1*1501. The target autoantigen is the non-collagenous domain of the α3 chain of Type IV collagen, α3(IV)NC1. T cell epitopes of α3(IV)NC1 were identified by immunizing mouse MHC-/-, HLA DRB1*1501 transgenic (1501tg) mice with overlapping 20mers. They defined a HLA DRB1*1501 restricted epitope (aa128-147) not reactive in HLA DRB1*0101 transgenic (0101tg) or C57BL/6 mice. 1501tg mice were immunized with α1(IV)NC1, α3(IV)NC1 or α1/α3 chimeric molecules, made by inserting the α3 aa17-31 (C2) or aa127-141 (C6) into the non-immunogenic α1 backbone. 1501tg mice immunized with α3(IV)NC1 or C6 responded to aa128-147 but not to aa8-27, but α1(IV)NC1 or C2-immunized mice did not respond to either peptide. CD4+ T cell clones, made from 1501tg mice and transferred into naive 1501tg mice, induced disease with necrotizing and crescentic glomeruli, albuminuria and renal failure, and glomerular CD4+ T cell and macrophage infiltrates. To determine if immunization with the restricted epitope causes disease, 1501tg or 0101tg mice were crossed with FcγRIIB-/- mice (Fcγ receptors are implicated in disease susceptibility). Immunization with either whole α3(IV)NC1 or the identified restricted epitope induced glomerulonephritis in 1501tg.FcγRIIB-/- mice but not in 0101tg.FcγRIIB-/- mice. These studies demonstrate that T cell responses in anti-GBM disease are defined by a HLA DRB1*1501 restricted T cell epitope.

Model for the correction of motion-induced phase errors in multishot diffusion-weighted-MRI of the head: are cardiac-motion-induced phase errors reproducible from beat-to-beat?

In diffusion-weighted imaging, multishot acquisitions are problematic due to intershot inconsistencies of the phase caused by motion during the diffusion-encoding gradients. A model for the motion-induced phase errors in diffusion-weighted-MRI of the brain is presented, in which rigid-body and nonrigid-body motion are separated. In the model, it is assumed that nonrigid-body motion is due to cardiac pulsation, and that the motion patterns are repeatable from beat-to-beat. To test the validity of this assumption, the repeatability of nonrigid-body motion-induced phase errors is quantified in three healthy volunteers. Nonrigid-body motion-induced phase was found to significantly correlate (P < 0.05) with pulse-oximeter waveforms in ~83% of the pixels tested across all slices and subjects.

Inventory management

A critical aspect of blood transfusion is the timely provision of high quality blood products. This task remains a significant challenge for many blood services and blood systems reflecting the difficulty of balancing the recruitment of sufficient donors, the optimal utilization of the donor's gift, the increasing safety related restrictions on blood donation, a growing menu of specialized blood products and an ever-growing imperative to increase the efficiency of blood product provision from a cost perspective. As our industry now faces questions about our standard practices including whether or not the age of blood has a negative impact on recipients, it is timely to take a look at our collective inventory management practices. This International Forum represents an effort to get a snap shot of inventory management practices around the world, and to understand the range of different products provided for patients. In addition to sharing current inventory management practices, this Forum is intended to foster an exchange of ideas around where we see our field moving with respect to various issues including specialty products, new technologies, and reducing recipient risk from blood transfusion products.

Bactericidal activity of neutrophils with reduced oxidative burst from adults with bronchiectasis

Recent work has shown that the most common abnormality on screening of immune function in cohort of adult subjects with bronchiectasis was a low neutrophil oxidative burst. To assess the functional significance of a low oxidative burst in subjects with idiopathic bronchiectasis. Neutrophils with a low oxidative burst were obtained from six bronchiectasis patients and assessed for their ability to kill Staphylococcus aureus. The results were compared with those obtained using neutrophils from 12 healthy controls subjects and control neutrophils treated with dimethylthiourea (DMTU), an inhibitor of the oxidative burst. The results showed that the bronchiectasis subjects had significantly reduced killing of bacteria compared with controls (p<0.001). The addition of DMTU to neutrophils of control subjects significantly impaired both the oxidative burst and bactericidal activity. The addition of interferon-gamma enhanced oxidative burst in both groups. Abnormal neutrophil function in some subjects with bronchiectasis may account for their high rate of infection.

Effect of interferon gamma and CD40 ligation on intracellular monocyte survival of nontypeable Haemophilus influenzae

Nontypeable Haemophilus influenzae (NTHi) is a mucosal pathogen that is a major cause of respiratory infection, including sinusitis, otitis media and bronchitis. This bacterium has evolved a number of mechanisms to facilitate its survival in the human host. Recently it has been recognized that it is capable of intracellular survival in monocytes/macrophages and epithelial cells. Previous work by the authors has demonstrated that the protective response to NTHi is Th1 predominant. This information led to the hypothesis that the intracellular survival of NTHi in human monocytes may be reduced by two key effector mechanisms of Th1-mediated immunity: interferon gamma and ligation of CD40. This study assessed the effect of interferon gamma and ligation of CD40 on the intracellular survival of NTHi in human monocytes. Responses were studied in monocytes from subjects with bronchiectasis and persistent airway infection with NTHi and compared with control subjects. The results demonstrated that different isolates of NTHi were able to survive inside monocytes. Killing of one strain of NTHi could be enhanced by the addition of interferon gamma and CD40 ligation in both control and bronchiectasis subjects. Other strains were more resistant.

Bronchiectasis

Bronchiectasis is generally classified into cystic fibrosis and non-cystic fibrosis bronchiectasis. This review article describes non-cystic fibrosis bronchiectasis in adults. Bronchiectasis can be considered a heterogeneous condition characterized by irreversible airway dilatation with chronic bronchial infection/inflammation. It remains a common condition and is a major cause of respiratory morbidity. Many factors are associated with bronchiectasis, but most commonly patients will have idiopathic disease. Important clinical findings include chronic productive cough, rhinosinusitis, fatigue and bi-basal crackles. Patients have usually had symptoms for many years. Diagnosis is confirmed by high-resolution computed tomography scanning using standardized criteria. Spirometry shows moderate airflow obstruction and there is a high prevalence of bronchial hyperreactivity. The most common pathogens are non-typeable Haemophilus influenzae and Pseudomonas aeruginosa. There may be considerable overlap with other chronic airway diseases. Treatment regimens are still not well defined. Patients tend to have ongoing symptoms and decline in respiratory function despite treatment.

Airway inflammation in asymptomatic children with episodic wheeze

Airway pathologies have been comprehensively researched in adult asthma, but in children, the extent of airway inflammation associated with episodic wheeze, often diagnosed as asthma, has not been fully characterized. It is not clear whether persistent airway inflammation is present in the absence of wheezing symptoms, and there is controversy regarding the role of age and atopy. This study assessed cellular and cytokine markers of airway inflammation in asymptomatic children with a history of episodic wheeze. Children with a history of episodic wheeze and cough (study group) and nonasthmatic patients requiring elective surgery (control group) were recruited. All subjects in the study group had a history of significant episodic wheezing (>2 episodes per year), and used only as-needed beta-agonist treatment. Bronchoalveolar lavage (BAL) was obtained using bronchoscopic lavage (study group) and nonbronchoscopic lavage (control group). Differential cell counts of BAL and flow cytometry were performed to identify T-lymphocyte phenotypes, and intracellular cytokine profiles were measured after phorbol-12-myristate 13-acetate (PMA) stimulation of BAL fluid T-cells. Twenty-one children with a history of 2-12 episodes of wheeze per year and 21 nonasthmatic subjects without respiratory symptoms were recruited. Study and control subjects were matched for age (median age, 5 years) and demographic characteristics. Study subjects had higher IgE levels, but their measurements were still within normal range. No significant differences in BAL differential cell counts were noted, and in both groups, the majority of T-cells were CD3+ CD8+, with a median CD4:CD8 ratio of 0.6. There was no significant difference in T-cell expression of the activation markers HLA-DR and CD25 (IL-2 receptor), or in PMA-induced production of the intracellular cytokines IFN-gamma, IL-2, IL-4, IL-5, and IL-10. The results of this study suggest that significant T-cell-driven airway inflammation is absent in mild or nonatopic, asymptomatic children of this age group who have episodic wheeze. Our findings support asthma management guidelines that do not recommend long-term treatment of this group of patients with anti-inflammatory medications.

Testing a rating scale of video-taped consultations to assess performance of trainee nurse practitioners in general practice

BACKGROUND

Nurse practitioners (NPs) in the United Kingdom are taking on some of the consultation work previously done by general practitioners (GPs) without there being any established professional standards that they must achieve before doing so. There is a need to develop and test methods of assessing their consultation performance for reasons of professional accreditation and patient safety.

AIMS

1. To make independent summative assessments of trainee nurse practitioners' (TNPs) consultation performance. 2. To assess the validity and reliability of an existing video-taped assessment tool.

METHOD

Four TNPs taking part in the EROS (extended roles of staff) study video recorded seven or eight consecutive consultations with typical patients during one surgery. Each consultation was rated nine times by members of a panel comprising eight independent GP trainers, four NPs and the GPs and TNPs in the EROS practices. A rating scale developed by Cox & Mulholland was used for the purpose.

RESULTS

Eight of the 37 items and four consultations had more than 10% missing data, mean = 7.7 items per rater. Factor analysis yielded a single factor solution explaining 32.6% of the variance and indicated that items could be summed to provide a single score. Internal consistency was high, alpha coefficient = 0.92. Individual differences between raters in scoring consultations were taken into account in providing a score for each consultation. Scores obtained were found to cluster at the positive end of the distribution indicating a high level of performance. Greater differences were found between scorers than between consultations.

CONCLUSIONS

This instrument is appropriate for scoring NP consultations and this small sample was rated as showing a uniformly high standard of performance. Some items could be deleted since they do not feature in the range of consultations currently performed. If this or a similar tool was to be adopted more widely for summative rating purposes then it should be tested rigorously for validity and reliability, training should be given to raters and criteria provided by which to make judgements.

Antithyroid and antiadrenal autoantibodies in antiglomerular basement membrane disease, thin basement membrane disease and Alport syndrome

The basement membranes of the glomerulus, thyroid and adrenal all contain the Goodpasture antigen, the target of autoantibodies in antiglomerular basement membrane (GBM) disease. Antithyroid antibodies can be associated with antiGBM disease, and there have been occasional reports of antithyroid antibodies in Alport syndrome, an inherited kidney disease where the GBM lacks the Goodpasture antigen. The aim of this study was to determine how often antithyroid and antiadrenal autoantibodies occurred in antiGBM disease, Alport syndrome and a related condition, thin basement membrane disease (TBMD). Sera from patients with antiGBM disease (n = 19), Alport syndrome (n = 5) or TBMD (n = 13) were tested for antithyroglobulin, antithyroid microsomal and antiadrenal antibodies. Five of the patients with antiGBM disease (5/19, 26%, P NS) had antimicrosomal, and one had antithyroglobulin, antibodies (1/19, 5%, P NS). No patient with Alport syndrome had antithyroid antibodies. One with TBMD (1/13, 8%, P NS) had antithyroglobulin and antimicrosomal antibodies at titres of 1/400 and 1/25,600, respectively. Both patients with antithyroglobulin antibodies had previously been diagnosed with hypothyroidism. No one with antiGBM disease, Alport syndrome or TBMD had antiadrenal antibodies. Antithyroid microsomal antibodies do not occur significantly more often in patients with antiGBM disease than in normals, and antithyroid and antiadrenal antibodies are not associated with Alport syndrome or TBMD.

Life-threatening sepsis complicating heavy metal chelation therapy with desferrioxamine

A case of severe Yersinia enterocolitica septicemia in a hemodialysis patient receiving desferrioxamine (DFX) therapy is reported. The association between systemic yersiniosis and DFX chelation therapy is reviewed. The increasing application of DFX chelation, in iron overload states and for aluminium overload in dialysis patients, provides an increasing number of patients at risk for this unusual drug side effect. An awareness of the association between Yersinia sepsis and DFX therapy allows appropriate therapeutic intervention which may prove lifesaving.

The clinical spectrum of acute glomerulonephritis and lung haemorrhage (Goodpasture's syndrome)

The aetiology, clinical features and outcome of 40 patients presenting with Goodpasture's syndrome (glomerulonephritis with haemoptysis and pulmonary infiltrates) are reviewed. The diseases of the patients studied could be divided into three groups: antiglomerular basement membrane (anti-GBM) antibody-induced disease (7/40); systemic vasculitis (22/40) and idiopathic Goodpasture's syndrome (i.e. no systemic disease or anti-GBM antibody detected) (11/40). Overall mortality was 57.5 per cent (anti-GBM disease 4/7; systemic vasculitis 15/22; and idiopathic Goodpasture's syndrome 4/11). Most patients died of disease progression or infection. End-stage renal failure developed in 26 patients (anti-GBM (7), vasculitis (14) and idiopathic Goodpasture's syndrome (5). End-stage renal failure developed in 23 of 24 patients presenting with a creatinine of greater than 600 microM/l regardless of the aetiology of Goodpasture's syndrome or treatment used. Review of renal histology showed that all had proliferative nephritis, with 80 per cent of patients having more than 30 per cent crescents. Thus Goodpasture's syndrome was associated with a wide variety of underlying disease. It had a poor prognosis, with the degree of renal impairment at presentation, the extent of crescent formation and the nature of the underlying disease being the major determinants of outcome.

De-novo anti-GBM-antibody-induced glomerulonephritis in a renal transplant

We report a case of de-novo anti-glomerular basement membrane antibody induced glomerulonephritis (anti-GBM GN) in a renal cadaveric transplant. The 52 year old male patient had developed end-stage renal failure secondary to malignant hypertension. His initial renal transplant lost function within two months because of severe allograft rejection without evidence of anti-glomerular basement membrane (anti-GBM) antibody formation. Eight months after his second cadaveric transplant he developed the nephrotic syndrome. This was followed by a rapid deterioration in graft function associated with the development of diffuse proliferative glomerulonephritis with 100% crescent formation. Linear staining of the GBM with IgG and C3 and the presence of circulating anti-GBM antibodies confirmed the anti-GBM antibody etiology of the glomerular lesion. Thus anti-GBM antibody induced glomerulonephritis can occur de-novo in a transplanted kidney despite routine immunosuppression. This represents either coincidental autoantibody production after transplantation or specific alloantibody production, stimulated by the introduction, by transplantation, of GBM neoantigens.

The pituitary-testicular axis in men with chronic renal failure

We studied the effects of uremia on the pituitary-testicular axis in 35 men with creatinine clearances less than 4 ml per minute per 1.7m(2). We found significant elevation (p less than 0.001) of plasma luteinizing hormone and follicle-stimulating hormone (p less than 0.005) and subnormal levels of testosterone (p less than 0.005). Testicular histology revealed severe spermatogenic damage. Human chorionic gonadotropin produced a subnormal testosterone response. The initial response of plasma luteinizing hormone and follicle-stimulating hormone to luteinizing-hormone-releasing hormone was normal, but their subsequent decline was prolonged. The suppression of plasma luteinizing hormone levels by testosterone propionate was normal, but the nadir occurred late; the elevated plasma luteinizing hormone level was due to reduced metabolic clearnace and increased production. Chronic renal failure interferes with testicular steroid production and spermatogenesis.

Renin release from isolated rat glomeruli

1. By the use of a mechanical graded sieving technique a high yield of isolated glomeruli has been obtained from rat kidny. 2. Microscopy and renin assay have shown the presence of renin-containing juxtaglomerular cells attached to these glomeruli. 3. The viability of isolated glomeruli has been confirmed by the ability of the cells to survive and divide in tissue culture and by their exclusion of vital dyes. 4. In superfusion after washout of extracellular renin, the glomeruli actively release constant amounts of renin over 3 h in direct proportion to the number of superfused. 5. Decreasing sodium concentration from 140 to 110 mol/l with constant osmolarity of 305 mosmol/l stimulated renin release by a direct effect on juxtaglomerular cells. 6. Catecholamines stimulated renin release in vitro in proportion to the potency of their action on beta-adrenoreceptors. 7. The system of superfusion of isolated glomeruli provides a technique for studying the influence of mediators leading to renin release acting directly on juxtaglomerular cells, independent of pressure change, tubular sodium, the sympathetic nervous system and circulating hormones.