ABC of arterial and vascular disease: vasculitis.
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Biomedical subjects
Publications and source records attributed to D Adu.
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OBJECTIVES: To implement and assess a rules based computerised prescribing system with the aim of improving the safety of prescriptions and the administration of drugs. DESIGN: Analysis of performance of computerised system plus questionnaire survey of users. SETTING: 64 bed renal unit in a teaching hospital. INTERVENTION: : Introduction of the system into routine clinical use. MAIN OUTCOME MEASURES: Number of attempted prescriptions cancelled by the system; proportion of warning messages overridden; users' comparisons of the system with conventional procedures. RESULTS: Between October 1998 and August 1999 the system cancelled 58 (0.07%) out of 87 789 prescriptions on the grounds of clinical safety. In addition, 427 (57%) attempted prescriptions generating high level warnings and 1257 (8%) generating low level warnings were not completed. In a user survey 82% (31/38) of doctors and nurses considered the system to be an improvement on conventional procedures. CONCLUSIONS: The system has contributed to safety and patient care. All prescriptions are complete and legible, and transcription errors have been eliminated. The system assists clinicians when they are writing a prescription by making available information on patients. The system supports clinical decision making and has been well received by doctors, nurses, and pharmacists.
This study assessed whether anti-neutrophil cytoplasmic antibodies (ANCAs) interfere with the safe deletion of neutrophils by apoptosis and phagocytic clearance. Tumor necrosis factor (TNF)-primed neutrophils were incubated with normal IgG (N IgG) or ANCA IgG for up to 36 hours. Compared with N IgG, ANCAs accelerated constitutive apoptosis of TNF-alpha primed neutrophils, as assessed by morphology and confirmed by DNA laddering pattern on gel electrophoresis, and accelerated progression to secondary necrosis. The accelerated apoptosis induced by ANCA was dependent on reactive oxygen species generation, as primed neutrophils from patients with chronic granulomatous disease failed to show an effect of ANCAs on apoptosis. However, there was no change in the rate at which neutrophils exhibited annexin V binding, indicating that externalization of phosphatidylserine was not accelerated by ANCAs. Furthermore, when ANCA-treated primed neutrophils were interacted with human or murine peritoneal macrophages after 12 hours there was significantly less phagocytosis by human macrophages and no difference in phagocytosis by murine peritoneal-derived macrophages when compared with N IgG-treated controls. In conclusion, ANCAs accelerate apoptosis and secondary necrosis in TNF-primed neutrophils by a mechanism dependent on the generation of reactive oxygen species, with uncoupling of nuclear and surface membrane changes, resulting in a "reduced window of opportunity" for phagocytic recognition and engulfment before disintegration.
Neutrophils constitutively express FcgammaRIIa and FcgammaRIIIb receptors. Both receptors exhibit allelic variants which have different quantitative functional capacities: the biallelic FcgammaRIIa-R131 and -H131 alleles, and the neutrophil antigen (NA) NA1/NA2 alleles. ANCA activation of neutrophils requires ligation of FcgammaRIIa receptor, but recent data have shown that ANCA can also bind FcgammaRIIIb receptor. The aim of this study was to determine whether the FcgammaRIIIb polymorphism was a risk factor for the development of ANCA-associated systemic vasculitis, or the associated nephritis. FcgammaRIIIb receptor genotyping was determined by allele-specific polymerase chain reaction. Genomic DNA was extracted from 101 Caucasian patients with ANCA+ vasculitis (of whom 84 had renal disease) and 100 ethnically matched controls. Of the patients with ANCA+ systemic vasculitis, 71 had ANCA with specificity for proteinase 3 and 30 with specificity for myeloperoxidase (MPO). Overall no significant difference in genotype distribution or allele frequencies was found between patients and controls, or between patients with renal disease and controls. However, there was a trend for an increase in homozygosity for the NA1 allele in patients with a vasculitis and this was significant in patients who had anti-MPO antibodies. The FcgammaRIIIb receptor polymorphism is not a major factor predisposing to the development of ANCA+ systemic vasculitis or the associated nephritis. The over-representation of the FcgammaRIIIb homozygous NA1 allele in patients with anti-MPO antibodies may have implications for disease susceptibility.
Intravenous immunoglobulin (IVIg) is a potential alternative treatment for anti-neutrophil cytoplasm antibody (ANCA)-associated systemic vasculitis (AASV) with less toxicity than conventional immunosuppressive agents. This randomized, placebo-controlled trial aimed to investigate the efficacy of a single course of IVIg (total dose 2 g/kg) in previously-treated AASV with persistent disease activity in whom there was an intention to escalate therapy. Vasculitic activity was monitored by the Birmingham vasculitis activity score (BVAS), C-reactive protein (CRP) and ANCA levels. Treatment response was defined as a reduction in BVAS of more than 50% after 3 months, and there was an intention to keep doses of concurrent immunosuppressive drugs unchanged during this period; follow-up continued to 12 months. Seventeen patients were randomized to receive IVIg and 17 to receive placebo. Treatment responses were found in 14/17 and 6/17 of the IVIg and placebo groups, respectively (p=0.015, OR 8.56, 95%CI 1.74-42.2). Following infusion of trial medication, greater falls in CRP were seen at 2 weeks (p=0.02) and 1 month (p=0.04) in the IVIg group. No differences were observed between ANCA levels or cumulative exposure to immunosuppressive drugs, and after 3 months there were no differences in CRP levels or disease activity between the IVIg and placebo groups. Seventeen adverse effects occurred after IVIg and six after placebo: they were mostly mild, although reversible rises in serum creatinine occurred in four from the IVIg group. A single course of IVIg reduced disease activity in persistent AASV, but this effect was not maintained beyond 3 months; mild, reversible side-effects following IVIg were frequent. IVIg is an alternative treatment for AASV with persistent disease activity after standard therapy.
Renal inflammatory conditions are characterized by mononuclear cell recruitment to sites of inflammation. We have developed a modified Stamper-Woodruff assay system to analyze mechanisms of functional T cell adhesion to cryostat sections of renal biopsy material from patients with vasculitic glomerulonephritis (GN) and acute allograft rejection. Peripheral blood T cells adhered to intraglomerular, periglomerular, and tubulointerstitial regions of the cortex. Blocking monoclonal antibodies against tissue expressed ICAM-1, VCAM-1, and the CS-1 domain of fibronectin (CS-1Fn) differentially attenuated T cell adhesion. Glomerular adhesion in vasculitic GN and tubulointerstitial adhesion in acute rejection were particularly sensitive to both anti-ICAM-1 and anti-VCAM-1 antibodies, indicating a prominent role for ICAM-1 and VCAM-1 at glomerular sites in vasculitis and at tubulointerstitial sites in rejection. Furthermore, using KL/4 cells (LFA-1 expressing) and Jurkat cells (VLA-4 expressing), we demonstrated specific LFA-1/ICAM-1- and VLA-4/VCAM-1-mediated interactions within glomerular and tubulointerstitial compartments. Jurkat cells also adhered to VCAM-1-free sites, and binding was inhibitable by anti-CS-1Fn antibody, thereby demonstrating a role for VLA-4/fibronectin interactions especially at intraglomerular sites in acute rejection where VCAM-1 is notably absent. We therefore propose a prominent functional role for ICAM-1, VCAM-1, and CS-1 domain fibronectin in T cell recruitment to the inflamed kidney.
Histological studies have demonstrated vascular damage in all types of allograft rejection. It is likely that donor endothelium suffers the major and the first insult by the recipient's immune system since, in vivo, capillary endothelium expresses human lymphocyte antigen (HLA) class I and class II antigens. The present study was designed to examine whether injury to donor endothelial cells (ECs) by recipient peripheral blood mononuclear cells (PBMCs) can be demonstrated in vitro, and whether there is a relationship between the in vitro findings and the clinical outcome of renal allografts. Twenty renal transplant recipients were included in this study, and all patients were followed up for 6 months. PBMCs were isolated from the renal transplant recipients on three occasions; in the first 24-h post-transplantation, at the beginning of the second week, and in the third week post-transplantation. Additional samples were taken at the time of any acute rejection episode. These patients received renal allografts from 15 local cadaveric donors whose ECs were isolated. Donor-specific ECs and the corresponding renal transplant recipients' PBMCs and sera were employed in proliferation and cytotoxicity assays. Our results show that donor-specific ECs consistently induced a highly significant degree of recipient lymphocyte proliferative response (p < 0.05). However, no significant correlation between acute graft rejection and the degree of donor-specific EC-induced recipient lymphocyte proliferation was found. In contrast, there was a significant correlation between lymphocyte-induced EC cytolytic effects and acute renal graft rejection (p < 0.05). When conducted in larger studies, such information can have important implications in clinical transplantation.
ANCA, implicated as having a pathogenic role in systemic vasculitis, can activate tumour necrosis factor-alpha (TNF-alpha)-primed neutrophils by cross-linking surface-expressed ANCA antigens with neutrophil FcgammaRIIa receptors to release reactive oxygen species. The FcgammaRIIa receptor exists as polymorphic variants, R131 and H131, which differ in their ability to ligate human IgG2 and IgG3. Neutrophils homozygous for the FcgammaRIIa-H131 allotype bind more efficiently to IgG3 than the FcgammaRIIa-R131 allotype and are the only human FcgammaR which bind IgG2. Our aim was to determine whether the homozygous FcgammaRIIa-H131 individuals are more susceptible to developing ANCA-associated systemic vasculitis and nephritis due to differential IgG binding and activation. FcgammaRIIa allotype was determined by both allele-specific polymerase chain reaction (PCR) and Southern blotting with allele-specific oligonucleotide probes end-labelled with 32P-gammaATP, after PCR amplification of genomic FcgammaRIIa DNA in 107 Caucasian patients with ANCA+ vasculitis (of whom 89 had renal disease) and 100 ethnically matched controls. Phenotyping of neutrophil FcgammaRIIa alleles was confirmed in some patients by quantitative flow cytometry using murine MoAbs 41H16 and IV.3. Of the patients with ANCA+ systemic vasculitis, 75 had ANCA with specificity for proteinase 3 and 32 with specificity for myeloperoxidase. Overall, no skewing in FcgammaRIIa allotypes was seen in patients compared with controls. No significant increase of the FcgammaRIIa-H131 allotype was found amongst patients irrespective of ANCA specificity, and no association between the FcgammaRIIa allotype and nephritis was found. Our data suggest that the FcgammaRIIa receptor allotype is not a major factor predisposing to the development of ANCA+ systemic vasculitis, or to nephritis.
BACKGROUND: In neutrophil trafficking, the role of interleukin-8 (IL-8) is location dependent. Tissue IL-8 directs transmigration, whereas intravascular IL-8 frustrates this process. The bystander damage of glomerular endothelium by antineutrophil cytoplasmic autoantibody (ANCA)-activated neutrophils is believed to be an early event in the pathogenesis of ANCA-associated glomerulonephritis. We have studied the role of IL-8 in this process. METHODS: Intraglomerular expression of IL-8 in patients with ANCA-associated glomerulonephritis was studied by in situ hybridization and immunohistochemistry and location of neutrophils by serial section immunohistochemistry. In vitro, we analyzed ANCA-stimulated neutrophil IL-8 production by enzyme-linked immunosorbent assay, and the IL-8 attributable effect of ANCA-stimulated neutrophil supernatant by chemotactic and transendothelial assays. RESULTS: There was intraglomerular expression of IL-8 at segmental, crescentic, and parietal epithelial sites. IL-8 protein expression colocalized to intraglomerular neutrophils; many localized within glomerular capillary loops, suggesting failed trafficking to tissue IL-8. ANCAs differentially stimulated time- and dose-dependent neutrophil IL-8 production, and ANCA-stimulated neutrophil supernatant demonstrated potent IL-8-dependent chemotactic activity and inhibited transendothelial migration of normal human neutrophils toward an IL-8 gradient. CONCLUSION: Despite heavy tissue expression of IL-8 in ANCA-associated GN, the production of IL-8 by ANCA-stimulated neutrophils within the intravascular compartment may frustrate neutrophil transmigration, encourage intravascular stasis, and contribute to bystander damage of glomerular endothelial cells.
ANCA with specificity for myeloperoxidase (MPO) and proteinase 3 (PR3) are present in patients with systemic vasculitis. The aim of this work was to determine whether such patients have T cell responses to these antigens and whether these responses are related to disease activity. Peripheral blood lymphocytes from 45 patients and 19 controls were cultured with ANCA antigens and proliferation measured. The antigens used were heat-inactivated (HI) MPO, HI PR3, native (non-HI) PR3, HI whole alpha-granules, and 25 overlapping peptides covering the entire PR3 sequence. Significant responses to both whole PR3 preparations were seen from patient and control groups, and to the alpha-granules from the patient group. Patients responded at all stages of disease: active, remitting, treated or untreated. Only two patients responded significantly to MPO. Responses were significantly higher with the patient group than the control group to all four whole ANCA antigens. Responses to those PR3 peptides containing epitopes known to be recognized by ANCA were detected from one patient. Thus, these studies demonstrate that T cells from vasculitis patients can proliferate to PR3 and occasionally to associated ANCA antigens. Further, responses may persist even after disease remission has been achieved.
BACKGROUND: Glomerular and tubulointerstitial accumulations of macrophages and T cells are a prominent feature of immune inflammatory glomerulonephritis. The C-C family of chemokines are major mononuclear-cell chemoattractants and may be central to the recruitment of these cells. METHODS: Using in situ hybridization (ISH) we analyzed the expression of mRNA for the C-C chemokines monocyte chemoattractant protein-1 (MCP-1), macrophage inflammatory protein-1alpha and beta (MIP-1alpha, MIP-1beta) and RANTES in renal biopsy material from twenty patients with glomerulonephritis. RESULTS: In overt inflammatory glomerulonephritides, chemokine transcripts were differentially expressed by glomerular and tubulointerstitial leukocyte infiltrates, glomerular parietal and proximal tubular epithelial cells and endothelial cells. There was little expression in minimal change nephropathy and normal tissue. Expression of individual chemokines correlated with intrarenal T cell and macrophage infiltrates. Combined immunohistochemistry and ISH demonstrated that 56.9% of cells expressing MCP-1 mRNA were CD68+ve (monocytes/macrophages) and 53% of infiltrating CD68 +ve cells were MCP-1 mRNA positive. CONCLUSIONS: These studies indicate that the in situ production of C-C chemokines by resident and infiltrating cells may play a crucial role in regulating macrophage and T-cell recruitment in glomerulonephritis.
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A glomerular and kidney organ culture method was developed to study cytokine inducibility of adhesion molecules and MHC antigen expression. Glomerular cells showed constitutive expression of intercellular cell adhesion molecule-1 (ICAM-1) and MHC class I and II antigens, but not vascular cell adhesion molecule-1 (VCAM-1), E-selectin, or P-selectin. Expression of E-selectin on glomerular endothelial cells (ECs) was induced by interleukin-1 (IL-1), tumour necrosis factor (TNF), interferon-gamma (IFN-gamma) and granulocyte/ macrophage-colony stimulating factor (GM-CSF); this induction was inhibited by transforming growth factor beta (TGF beta) and by IL-4. P-selectin expression was never seen within glomeruli. VCAM-1 was constitutively expressed by Bowman's capsule and proximal tubules and was weakly induced on glomerular ECs by TNF and IL-4 in combination. Glomerular endothelial ICAM-1 expression was increased by IL-1, TNF, IFN-gamma, and GM-CSF, while TGF beta inhibited induction by TNF and IL-1. Expression of MHC class I and II antigens by glomerular ECs was constitutive; further upregulation of MHC class II by IFN-gamma was observed. These studies suggest that leukocyte-endothelial cell interactions that occur within the kidney follow broadly similar principles as are proposed to occur elsewhere in the body but, in addition, there are subtle differences that reflect local conditions.
OBJECTIVE: To develop and validate the Vasculitis Damage Index (VDI) for the standardized clinical assessment of damage in the systemic vasculitides. METHODS: Using a nominal group consensus approach, the Birmingham Vasculitis Group generated guiding principles for assessment of damage in all systemic vasculitides. Damage was defined as irreversible change resulting from scars. Consensus principles were developed into the VDI, including guidelines for use, a list of items of damage, and a glossary. RESULTS: For 100 surviving patients with systemic vasculitis, the median VDI score at last observation was 3 (range 0-8). Within the Wegener's granulomatosis subgroup, the median VDI score for 12 non-survivors was higher than for 47 survivors (non-survivors median score 7, interquartile range 5-8 versus survivors median score 4, interquartile range 2-5; P = 0.003). VDI scores for 100 patients with systemic vasculitis increased from initial presentation to last observation by a median score of 3 (range 1-4; P < 0.001). The VDI assesses more items and is more sensitive to change than other indices of damage (P < 0.001). Using the VDI, trained observers can produce moderately consistent damage scores. CONCLUSION: The VDI is a sensitive, reproducible, comprehensive, and credible clinical tool for quantifying damage. The data presented herein should enable further validation and testing of the VDI in specific vasculitic syndromes, and should facilitate the comparison of different therapies.
BACKGROUND: The concomitant occurrence of a vasculitic glomerulonephritis and membranous nephropathy in the same patient is unusual. We report data on 10 patients with this unusual combination. METHODS: Ten patients (nine males/one female; median age 63.5 years, range 30-70 years) presented between 1981 and 1995 with: acute renal failure (n = 3), nephrotic syndrome (n = 4), non-nephrotic range proteinuria and renal insufficiency (n = 3). The median serum creatinine at presentation was 296 mumol/l (range 65-1749 mumol/l). One patient had a vasculitic transformation from membranous nephropathy 5 years after the original presentation, coincident with an acute deterioration of renal function requiring dialysis; in all other patients the two glomerular disorders were seen together at presentation. Treatment was with oral prednisolone and cyclophosphamide (eight patients), of whom one also had plasma exchange; and oral prednisolone and azathioprine (one patient). Specific immunosuppressive treatment was withheld in one patient with histological evidence of chronic renal damage. Sera from four patients out of nine tested were positive for ANCA. RESULTS: After a median follow-up of 3.5 years (range 2 months-10 years), renal function had improved in three patients and remained stable in two. Two patients required renal replacement therapy. Three patients had died: one was ANCA-negative and died of a systemic vasculitis, and the other two died of sepsis. CONCLUSION: Membranous nephropathy complicated by a vasculitic glomerulonephritis: (1) has a more aggressive clinical course than membranous nephropathy alone, (2) appears to have an association with ANCA, (3) should be considered in those patients with an accelerated decline in renal function, and (4) may respond to treatment with immunosuppressive drugs.
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We report ten patients with rheumatoid arthritis (RA) who developed a focal segmental necrotizing glomerulonephritis (FSNGN) and extracapillary proliferation typical of vasculitic glomerulonephritis. Five patients also had extrarenal vasculitis. Renal presentation was with renal impairment (n = 9) (median creatinine 726 mumol/l, range 230-1592 mumol/l), microscopic haematuria (n = 8) and proteinuria (n = 10). Nine patients were seropositive for rheumatoid factor and nine had bone erosions. Serum from four of five patients tested by indirect immunofluorescence was positive for antineutrophil cytoplasmic antibody (ANCA) with perinuclear staining. Only three patients had penicillamine or gold therapy. Treatment was with prednisolone and cyclophosphamide (six patients, two of whom were also plasma-exchanged), prednisolone and azathioprine (two patients) and prednisolone alone (two patients). There was a marked improvement in renal function in eight patients. Two patients with dialysis-dependent renal failure recovered renal function, although in one patient this was transient and she required further dialysis 4 months later. Two other patients progressed to dialysis at 3 months and 1 year respectively. Four patients died, one remains dialysis-dependent, and four continue to have good renal function at 5 year follow-up (median creatinine 148.5 mumol/l, range 120-193 mumol/l). One patient was lost to follow-up at 5 years. FSNGN should be considered in all patients with RA and renal impairment, proteinuria and/or microscopic haematuria. This diagnosis appears to be more likely in patients with clinical extrarenal vasculitis, bone erosions or who are seropositive. In these cases, an urgent renal biopsy is indicated.
Although cyclophosphamide and prednisolone are effective in treating systemic vasculitis, the optimum treatment regimes and duration of treatment are unknown. We randomized 54 patients aged 15-70 years (median 57.5 years) with systemic vasculitis (classical polyarteritis n = 8, microscopic polyarteritis n = 17, Wegener's granulomatosis n = 29) to treatment with either pulse cyclophosphamide and prednisolone (PCYP) (n = 24) or continuous oral and prednisolone and cyclophosphamide, with the latter followed after a median of 3 months (range 1.5-10 months) by azathioprine (CCAZP) (n = 30). Patients on CCAZP were more likely to develop leucopenia (13/30) than patients on PCYP, (7/24) although the difference was not significant. The numbers of infective episodes during follow up were comparable in the two groups at 1.7/patient for PCYP and 1.66/patient for CCAZP. Overall, 26/30 patients (87%) treated with CCAZP developed treatment-related toxicity, as did 17/24 patients (71%) treated with PCYP. After a median follow-up of 40.4 months (range 0.7-64.8), there was no difference in the frequency of deaths (PCYP 5, CCAZP 4), relapses (PCCYP 7, CCAZP 8), treatment failures (PCYP 4, CCAZP 4), improvement in disease activity scores or renal function. Survival at three years was 77% in patients treated with PCYP, and 90% in patients on CCAZP (p = 0.38). There was a tendency towards increased toxicity in patients treated with the continuous regimen.