Kenneth Merle Brinkhous, M.D. 1908-2000.
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History, 20th Century↗
Biomedical subjects
J C Jennette
Publications and source records attributed to J C Jennette.
Internalization of proteinase 3 is concomitant with endothelial cell apoptosis and internalization of myeloperoxidase with generation of intracellular oxidants.
The important issue addressed by the studies presented here is the mechanism of neutrophil-mediated damage to endothelial and epithelial cells during inflammation. Binding of neutrophil-released granule proteins to endothelial cells may be involved in vascular damage in patients with inflammatory vascular diseases. We have determined whether granule proteins proteinase 3(PR3) and/or myeloperoxidase (MPO) are internalized into endothelial cells, as examined by UV light, confocal, and electron microscopy. Coincident induction of apoptosis and/or the generation of intracellular oxidants were monitored. The results indicate that human endothelial cells (human umbilical vein endothelial cells, human umbilical arterial endothelial cells, human lung microvascular endothelial cells) internalize both PR3 and MPO, which are detected on the cell surface, in the cytoplasm, and possibly nuclear. Epithelial cells (small airway epithelial cells) internalized MPO but not PR3, implying that the mechanism of PR3 internalization may be cell-type specific and different from that of MPO. Internalization of PR3, but not MPO, correlated with activation of apoptosis. Internalization of MPO correlated with an increase in intracellular oxidant radicals. The requirement for the proteolytic activity of PR3 for the induction of apoptosis was examined by generating PR3-truncated fragments that did not contain the components of the catalytic triad. An apoptotic function was localized to the C-terminal portion of PR3. These studies reveal novel mechanisms by which the neutrophil granule proteins PR3 and MPO contribute to tissue injury at sites of inflammation.
Apoptosis↗
Interferon-gamma is required for lupus nephritis in mice treated with the hydrocarbon oil pristane.
BACKGROUND: Although the precise mechanisms leading to lupus nephritis remain obscure, both TH1 and TH2 cytokines have been implicated. The present study examined the roles of interleukin (IL)-4 and interferon-gamma (IFN-gamma) in a novel inducible form of lupus that develops in non-autoimmune mice treated with the hydrocarbon oil pristane. METHODS: BALB/c IL-4 or IFN-gamma deficient mice (IL-4 -/-, IFNgamma -/-) and wild type controls (+/+) received either pristane or phosphate-buffered saline (PBS) IP. Serial sera were analyzed for anti-DNA/chromatin, anti-RNP/Sm, and total immunoglobulin levels. Proteinuria was measured and kidneys were examined by direct immunofluorescence and light microscopy. RESULTS: Renal disease did not develop in pristane-treated IFN-gamma -/- mice, as assessed by the absence of capillary immune deposits, glomerular pathology and proteinuria whereas IL-4 -/- mice developed renal disease similar to +/+ mice. Production of IgG anti-single stranded DNA and anti-chromatin antibodies was abrogated in IFN-gamma -/- mice. In contrast, these autoantibodies were produced at similar or higher frequencies and levels by IL-4 -/- versus wild-type mice. The frequency of anti-nRNP/Sm was markedly reduced in IFN-gamma -/- mice. IL-4 deficiency had little effect on the production of anti-DNA/chromatin and anti-nRNP/Sm. CONCLUSIONS: IFN-gamma is essential for the induction of nephritis and anti-DNA/chromatin following pristane exposure in BALB/c mice, suggesting that genetic or environmental factors influencing TH1-TH2 balance could be an important determinant of renal disease in lupus.
Animals↗
Crescentic glomerulonephritis.
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Anti-Glomerular Basement Membrane Disease↗
Coexistence of Fabry's disease and necrotizing and crescentic glomerulonephritis.
The coexistence of Fabry's disease, an X-linked hereditary disease, and other renal diseases, has rarely been described in the same patient. Combined Fabry's disease and pauci-immune necrotizing and crescentic glomerulonephritis (NCGN) is hitherto unreported. We present the clinical and pathologic data of two patients with combined Fabry's disease and NCGN. Both patients presented with fevers of unknown origin and progressive renal insufficiency, however, lacked any other pathognomic signs of Fabry's disease such as acroparesthesias, dyshidrosis, and cutaneous angiokeratomas. The possible pathogenic mechanisms and causal relationship between the two disease processes are discussed.
Adult↗
Microscopic polyangiitis (microscopic polyarteritis).
Microscopic polyangiitis ("microscopic polyarteritis") is a form of necrotizing small vessel vasculitis that most often affects venules, capillaries, arterioles, and small arteries, although it occasionally involves medium-sized arteries. Microscopic polyangiitis is a more appropriate name than microscopic polyarteritis because some patients have no evidence for arterial involvement. The absence or paucity of immunoglobulin localization in vessel walls distinguishes microscopic polyangiitis from immune complex mediated small vessel vasculitis, such as Henoch-Schonlein purpura and cryoglobulinemic vasculitis. Clinical, epidemiological, and pathologic differences warrant the separation of microscopic polyangiitis from polyarteritis nodosa on the basis of involvement of capillaries and venules by the former but not the latter. Pauci-immune necrotizing and crescentic glomerulonephritis, and hemorrhagic pulmonary capillaritis are common in patients with microscopic polyangiitis. Microscopic polyangiitis is the most common cause for pulmonary-renal vasculitic syndrome. The vasculitis in patients with microscopic polyangiitis is pathologically indistinguishable from the vasculitis of Wegener's granulomatosis and Churg-Strauss syndrome. Granulomatous inflammation distinguishes Wegener's granulomatosis from microscopic polyangiitis. Asthma and eosinophilia distinguish Churg-Strauss syndrome from microscopic polyangiitis. Microscopic polyangiitis, Wegener's granulomatosis, and Churg-Strauss syndrome are all associated with circulating antineutrophil cytoplasmic autoantibodies.
Antibodies, Antineutrophil Cytoplasmic↗
Restriction in V kappa gene use and antigen selection in anti-myeloperoxidase response in mice.
Anti-neutrophil cytoplasmic Abs, directed primarily toward myeloperoxidase (MPO) and proteinase 3, are detected in the majority of patients with distinct forms of small vessel vasculitides and pauci-immune necrotizing glomerulonephritis. However, the origin of these autoantibodies remains unknown. We studied the V region gene use in murine anti-MPO Abs derived from Spontaneous Crescentic Glomerulonephritis/Kinjoh mice. A total of 13 anti-MPO-producing hybridomas were generated from four unimmunized mice. Ten of the 13 hybridomas (corresponding to 3 of 4 clones) expressed Vkappa1C but differed in their use of VH genes. The remaining three hybridomas expressed a Vkappa5 gene. Anti-MPO hybridomas from individual mice were derived from single clones as deduced by sequence similarity and splice-site identity. We found a statistically significant bias of amino acid replacement mutations to the complementarity-determining regions (CDR) in the Vkappa1C-expressing hybridomas. Intriguingly, all 10 Vkappa1C hybridomas share a lysine to glutamate mutation in the CDR1. To determine the effects of somatic V gene mutations on binding to MPO, we generated an anti-MPO Ab with an unmutated Vkappa1C L chain and compared its ability to bind MPO with its mutated counterpart. The mutated hybridoma-derived Ab has a 4.75-fold higher avidity for MPO than the unmutated Ab. These results suggest that: 1) the L chain plays a dominant role in determining Ab specificity to MPO, 2) the anti-MPO Ab response is oligoclonal, consistent with Ag selection, and 3) MPO is a driving Ag in the murine anti-MPO Ab response.
Amino Acid Sequence↗
Overview of the nomenclature and diagnostic categorization of vasculitis.
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Arteritis↗
Idiopathic collapsing glomerulopathy in children.
Idiopathic collapsing glomerulopathy (ICG) is a clinically and pathologically distinct variant of focal segmental glomerulosclerosis, characterized clinically by rapid progression of renal insufficiency, a male and African-American racial predominance, and pathologically by segmental glomerular collapse, visceral epithelial cell hypertrophy and hyperplasia, and the absence of endothelial tubuloreticular inclusions. Pathologically similar lesions have been reported in adult and pediatric patients with human immunodeficiency virus (HIV) infection and/or intravenous (IV) drug abuse. Most patients with ICG who have been reported in the literature are adults. Six children with ICG were retrospectively identified (two from East Carolina University, four from University of North Carolina-Chapel Hill). Clinical data and renal biopsy findings were reviewed for all patients. All six patients were male; five African-American and one Hispanic. Ages ranged from 2 to 17 years (mean 12 years). Steroid-resistant nephrotic syndrome was the presenting clinical finding. Average 24-h urine protein excretion was 6.3 g (range 3.2-15 g). Five patients were serologically negative for HIV infection (one patient not tested) and none had a history of IV drug abuse or known HIV risk factors. Progression to end-stage renal insufficiency in two patients within 1 year of biopsy required renal transplantation, and within 1 month of biopsy one patient required dialysis. We report a series of pediatric patients with ICG, an aggressive variant of focal segmental glomerulosclerosis. ICG in children is similar clinically and pathologically to this disease in adult patients.
Adolescent↗
Do vasculitis categorization systems really matter?
The diagnosis of systemic vasculitides is challenging for many reasons. The etiology and pathogenesis of most vasculitides are unknown or incompletely known. Vasculitides have protean and overlapping clinical and pathologic features. There are conflicting if not contradictory approaches to diagnostic categorization. In spite of these challenges, precise diagnostic categorization is essential for appropriate treatment. This overview reviews the history behind the modern approach to diagnosis of selected vasculitides, including giant cell arteritis, Takayasu arteritis, polyarteritis nodosa, Kawasaki disease, Henoch-Schönlein purpura, cryoglobulinemic vasculitis, Wegener's granulomatosis, microscopic polyangiitis, and Churg-Strauss syndrome. Evidence is provided that the categorization for systemic vasculitis really does matter.
Diagnosis, Differential↗
Lack of endothelial nitric oxide synthase aggravates murine accelerated anti-glomerular basement membrane glomerulonephritis.
Nitric oxide (NO) radicals generated by endothelial nitric oxide synthase (eNOS) are involved in the regulation of vascular tone. In addition, NO radicals derived from eNOS inhibit platelet aggregation and leukocyte adhesion to the endothelium and, thus, may have anti-inflammatory effects. To study the role of eNOS in renal inflammation, the development of accelerated anti-glomerular basement membrane (GBM) glomerulonephritis was examined in mice lacking a functional gene for eNOS and compared with wild-type (WT) C57BL/B6j mice. WT C57BL/6j mice (n = 12) and eNOS knockout (-/-) mice (n = 12) were immunized intraperitoneally with sheep IgG (0.2 mg in complete Freund's adjuvant). At day 6.5 after immunization, mice received a single i.v. injection of sheep anti-mouse GBM (1 mg in 200 microl PBS). Mice were sacrificed at day 1 and 10 after induction of the disease. All WT mice survived until day 10, whereas 1 eNOS-/- mouse died and 2 more became moribund, requiring sacrifice. At day 10, eNOS-/- mice had higher levels of blood urea nitrogen than WT mice (P < 0.02), although proteinuria was comparable. Immunofluorescence microscopy documented similar IgG deposition in both WT and eNOS-/- mice, but eNOS-/- mice had more extensive glomerular staining for fibrin at day 10 (P < 0.007). At day 10, light microscopy demonstrated that eNOS-/- mice had more severe glomerular thrombosis (P < 0.003) and influx of neutrophils (P < 0. 006), but similar degrees of overall glomerular endocapillary hypercellularity and crescent formation. In conclusion, accelerated anti-GBM glomerulonephritis is severely aggravated in eNOS-/- mice, especially with respect to glomerular capillary thrombosis and neutrophil infiltration. These results indicate that NO radicals generated by eNOS play a protective role during renal inflammation.
Animals↗
Parvovirus B19 DNA in kidney tissue of patients with focal segmental glomerulosclerosis.
Focal segmental glomerulosclerosis (FSGS) represents a clinicopathological syndrome with diverse causes. We examined the possibility that some cases of FSGS are associated with parvovirus B19 infection. We studied renal biopsy tissue from 40 patients, including those with idiopathic FSGS, collapsing FSGS, membranous nephropathy, and minimal change disease, as well as normal renal tissue removed at the time of nephrectomy from 4 patients. DNA was extracted from frozen blocks of kidney tissue and amplified using nested polymerase chain reaction. Parvovirus B19 DNA was amplified from 8 of 10 patients with idiopathic FSGS, 9 of 10 patients with collapsing FSGS, 6 of 10 patients with membranous nephropathy, 5 of 10 patients with minimal change disease, and 2 of 4 cancer nephrectomy samples. The prevalence of parvovirus B19 DNA was greater among patients with idiopathic FSGS and collapsing FSGS compared with patients with other diagnoses (P = 0.05). In situ hybridization studies using digoxigenin-labeled DNA probes failed to detect parvovirus B19 nucleic acid in any of the kidney tissue samples. These results suggest that parvovirus B19 DNA is commonly found in the kidneys of patients with a range of renal diagnoses, possibly representing latent DNA from past infection. The failure to localize parvovirus B19 nucleic acid within kidney argues against ongoing, high-level viral replication. Nevertheless, the increased prevalence of B19 DNA in patients with idiopathic FSGS and collapsing FSGS could indicate a pathogenic role for the virus in the cause of FSGS in certain patients.
Biopsy↗
Target antigens for anti-neutrophil cytoplasmic autoantibodies (ANCA) are on the surface of primed and apoptotic but not unstimulated neutrophils.
The reaction of ANCA with ANCA antigens on the surface of neutrophils may play a critical role in the pathogenesis of ANCA vasculitis. Therefore, an understanding of the circumstances that result in surface expression of these antigens is important for an understanding of pathogenic mechanisms. In this study we investigated the surface expression of ANCA antigens on quiescent, primed, and apoptotic neutrophils. ANCA antigens and other granule constituents were not detected on the surface of neutrophils in freshly heparinized blood. ANCA antigens were on the surface of neutrophils primed by in vitro incubation for 4 h and 8 h. These cells did not show evidence of apoptosis. After 24 h incubation, about 30% of the neutrophils were apoptotic, and ANCA antigens and other granule constituents were present on the surface of both apoptotic and non-apoptotic cells. Our data indicate that there are no ANCA antigens on the surface of quiescent neutrophils, but that they are on the surface of primed neutrophils before the cells become apoptotic, and remain on the surface of cells after they become apoptotic. Based on these observations, we hypothesize that ANCA can react in vivo with primed but not quiescent neutrophils. Previously published observations indicate that the interaction of ANCA with primed neutrophils results in neutrophil activation, which may be involved in the pathogenesis of ANCA vasculitis.
Animals↗
False-positive myeloperoxidase binding activity due to DNA/anti-DNA antibody complexes: a source for analytical error in serologic evaluation of anti-neutrophil cytoplasmic autoantibodies.
Anti-myeloperoxidase antibodies (anti-MPO) are a major type of anti-neutrophil cytoplasmic antibody (ANCA). While evaluating anti-MPO monoclonal antibodies from SCG/Kj mice, we observed several hybridomas that appeared to react with both MPO and DNA. Sera from some patients with systemic lupus erythematosus (SLE) also react with MPO and DNA. We hypothesized that the MPO binding activity is a false-positive result due to the binding of DNA, contained within the antigen binding site of anti-DNA antibodies, to the cationic MPO. Antibodies from tissue culture supernatants from 'dual reactive' hybridomas were purified under high-salt conditions (3 M NaCl) to remove any antigen bound to antibody. The MPO and DNA binding activity were measured by ELISA. The MPO binding activity was completely abrogated while the DNA binding activity remained. The MPO binding activity was restored, in a dose-dependent manner, by the addition of increasing amount of calf-thymus DNA (CT-DNA) to the purified antibody. Sera from six patients with SLE that reacted with both MPO and DNA were treated with DNase and showed a decrease in MPO binding activity compared with untreated samples. MPO binding activity was observed when CT-DNA was added to sera from SLE patients that initially reacted with DNA but not with MPO. These results suggest that the DNA contained within the antigen binding site of anti-DNA antibodies could bind to the highly cationic MPO used as substrate antigen in immunoassays, resulting in a false-positive test.
Animals↗
ANCA antigens, proteinase 3 and myeloperoxidase, are not expressed in endothelial cells.
BACKGROUND: One hypothesis for the pathogenesis of vasculitis associated with antineutrophil cytoplasmic autoantibodies (ANCAs) proposes that ANCAs bind to ANCA antigens, such as proteinase 3 (PR3) or myeloperoxidase (MPO), which are produced by endothelial cells and expressed on their surfaces. There are conflicting reports, however, on whether endothelial cells express the ANCA antigen PR3, and there are no reports on endothelial expression of MPO. The aim of this study was to determine the presence or absence of PR3 and MPO mRNA in both venous and arterial endothelial cells, employing standard reverse transcription-polymerase chain reaction (RT-PCR) techniques and also the quantitative and highly specific method, TaqMan PCR. METHODS: RT-PCR (with 3 primer sets) and TaqMan PCR, a method for detecting low copy transcripts, were used to probe for PR3 and MPO transcripts in human endothelial cells from umbilical vein (HUVEC) and artery (HUAEC) and from lung microvascular (HLMVEC). Cells were treated with interferon-gamma (200 units/mL) or tumor necrosis factor-alpha (3 or 10 ng/mL) or both. RESULTS: Transcripts for PR3 and/or MPO were not detected in HUVEC, HUAEC, and HLMVEC by standard RT-PCR. Analyses for PR3 protein confirmed that PR3 is not expressed in HUVEC. HUVEC and HUAEC were negative for PR3 and MPO by TaqMan PCR. CONCLUSIONS: PR3 and MPO are not expressed in HUVEC, HUAEC, or HLMVEC. Endothelial cell presentation of endogenous PR3 and MPO antigens is not involved in the pathogenesis of ANCA-associated vasculitis. Alternative explanations need to be explored to determine the pathogenic effect of ANCAs.
Antibodies, Antineutrophil Cytoplasmic↗
Antineutrophil cytoplasmic antibodies and associated diseases: a review of the clinical and laboratory features.
There have been a number of recent advances in this field. First, the "International Consensus Statement on Testing and Reporting of Antineutrophil Cytoplasmic Antibodies (ANCA)" has been developed to optimize ANCA testing. It requires that all sera are tested by indirect immunofluorescent (IIF) examination of normal peripheral blood neutrophils and, where there is positive fluorescence, in enzyme-linked immunosorbent assays (ELISAs) for antibodies against both proteinase 3 (PR3) and myeloperoxidase (MPO). Testing will be further improved when international standards and common ELISA units are available. Second, new diagnostic criteria for the small vessel vasculitides that take into account ANCA-positivity and target antigen specificity as well as histologic features are currently being produced. Third, we understand that the complications associated with treatment of the ANCA-associated vasculitides are often more hazardous than the underlying disease, and regimens that use effective but less toxic agents are being evaluated. The factors associated with increased risk of relapse, however, remain incompletely understood. Finally, ANCA with specificities other than PR3 and MPO are present in many nonvasculitic autoimmune diseases. Their clinical significance is still largely unclear, and some of the target antigens are present in other cells as well as neutrophils and thus are not strictly "ANCA."
Antibodies, Antineutrophil Cytoplasmic↗
Enhanced atherosclerosis and kidney dysfunction in eNOS(-/-)Apoe(-/-) mice are ameliorated by enalapril treatment.
Hypertension and atherosclerosis are each important causes of morbidity and mortality in the developed world. We have investigated the interaction between these conditions by breeding mice that are atherosclerotic due to lack of apolipoprotein (apo) E with mice that are hypertensive due to lack of endothelial nitric oxide synthase (eNOS). The doubly deficient mice (nnee) have higher blood pressure (BP) and increased atherosclerotic lesion size but no change in plasma lipoprotein profiles compared with normotensive but atherosclerotic (NNee) mice. The nnee mice also develop kidney damage, evidenced by increased plasma creatinine, decreased kidney weight/body weight ratio, and glomerular lipid deposition and calcification. Enalapril treatment abolishes the deleterious effects of eNOS deficiency on BP, atherosclerosis, and kidney dysfunction in nnee mice. In striking contrast, a genetic lack of inducible NOS, which does not affect BP, has no effect on the development of atherosclerotic lesions in Apoe(-/-) mice. We also observed a positive relationship between BP and size of atherosclerotic lesions These results suggest that the atherogenic effects of eNOS deficiency can be partially explained by an increase in BP and reemphasize the importance of controlling hypertension in preventing atherosclerosis.
Angiotensin-Converting Enzyme Inhibitors↗
Future molecular approaches to the diagnosis and treatment of glomerular disease.
Current diagnoses and treatment decisions for renal disease are made based upon a combination of clinical and pathological determinations. With the advances in both biochemical and molecular biological techniques, identifying the underlying biochemical and genetic changes that may have initiated and/or contributed to the disease is possible. We describe here technologies that may lead to significant changes in renal disease diagnosis, characterization, treatment, and potentially prevention. For example, differential display techniques and DNA gene chip arrays show the changes in mRNA expression patterns and can potentially identify previously unknown genes and reveal new roles for previously known genes in renal disease. The generation of the single nucleotide polymorphisms (SNP) genomic map will facilitate genetic screening that may identify a gene or combination of genes that produce enhanced disease susceptibility. Combining genomic analysis with epidemiological studies may identify environmental factors that contribute to renal disease onset in genetically susceptible individuals. A number of novel therapies are already on the horizon. These include reagents that abrogate the function of specific cytokines, chemokines, and effector cells. With the list of renal disease genes in hand, their role in renal physiology and pathophysiology can be determined, which should lead to the discovery of pharmacological intervention directed at those genes and their products that play a role in the pathogenesis of renal disease.
Biotechnology↗