NDT Advance Access originally published online on May 3, 2007
Nephrology Dialysis Transplantation 2007 22(7):2068-2071; doi:10.1093/ndt/gfm169
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Elastase-ANCA-associated idiopathic necrotizing crescentic glomerulonephritis—a report of three cases
1Department of Nephrology, Boulogne sur Mer, Docteur Duchenne Hospital, 2Department of Nephrology, La Louvière Polyclinic, 3Department of Nephrology, Valenciennes Hospital, 4Immuno-Hématology Laboratory, Valenciennes Hospital and 5AP-HP, Necker Hospital, France
Correspondence and offprint requests to: Pierre Bataille, Department of Nephrology, Boulogne sur Mer, Docteur Duchenne Hospital, France. Email: ppierrebataille{at}aol.com
Keywords: acute renal failure; antineutrophil cytoplasmic antibodies; elastase; vasculitis
 |
Introduction |
|---|
 Top Introduction CasesDiscussionReferences |
|---|
As it is well known, the two major antigens against anti-neutrophil cytoplasmic antibodies (ANCAs), proteinase 3 (PR3) and myeloperoxidase (MPO), are commonly observed in small-vessel systemic vasculitis. The diagnosis value of anti-PR3 antibody (PR3-ANCA) for Wegener's granulomatosis and anti-MPO antibody (MPO-ANCA) for idiopathic necrotizing crescentic glomerulonephritis (NCGN) and microscopic polyangiitis are well established. Human neutrophil elastase antibody (HNE-ANCA), a minor ANCA [1] is sometimes detected along with PR3-ANCA or MPO-ANCA in systemic vasculitis [2,3]. Although patients with drug-induced vasculitis or with cocaine-induced midline destructive lesions (CIMDL) without autoimmune vasculitis may be positive for only HNE-ANCA, the diagnostic value of only positive HNE-ANCA remains doubtful in microscopic polyangiitis and NCGN [4–6]. We report here three cases of NCGN associated with systemic vasculitis, which were positive for HNE-ANCA but not for MPO or PR3.
|
Cases |
|---|
|
TopIntroductionCasesDiscussionReferences |
|---|
Case 1
A 66-year-old male, smoker, was referred for asthenia, anorexia and abdominal pain. On admission, he was apyretic, with a blood pressure (BP) of 140/90 mmHg. Arthralgia, macroscopic haematuria and multiplex mononeuritis were noted. Serum creatinine was 750 µmol/l, proteinuria 3 g/day, C-reactive protein (CRP) 14 mg/dl. No serum or urinary monoclonal protein chains were detected. Anti-nuclear antibody (ANA) and anti-glomerular basement membrane (anti-GBM) antibodies were negative. Serum complement fractions (C3, C4) were normal. A renal biopsy showed typical NCGN, with extracapillary proliferation on nearly 50% of glomeruli. Immunofluorescence study showed anti-fibrinogen staining in extracapillary space and non-significant C1q deposits. IgG, IgA and C3 were negative. By indirect immunofluroescent (IIF) examination of normal peripheral blood neutrophils, an atypical ANCA pattern was observed, with a mix of both atypical cytoplasmic ANCAs (flat neutrophil cytoplasmic fluorescence without central accentuation) (C-ANCA atypical) and atypical perinuclear ANCAs (sharp perinuclear fluorescence) with a high antibody level (> 1/160) (Figure 1). By enzyme-linked immuno-assay (ELISA) (Wieslab kit), no specificity was found against MPO and PR3. HNE antibodies were detected by two ELISA tests, using extrative human antigen (Wieslab kit PAN 106© and Bioadvance ANCA profile©). With the two latter ELISA tests, bactericidal/permeability protein (BPI) antibodies was found as well, but azurocidin, cathepsin G, lactoferrin and lysozyme specificities were negative.
|
After 10 monthly pulses of cyclophophamide (CYC) (750 mg/pulse) combined with oral prednisone (at 1 mg/kg/day and progressively tapered), clinical remission with a decrease of serum creatinine to 150 µmol/l was obtained at month 10. Azathioprine was then introduced and stopped 2 years later. At 4 years of follow-up, the patient is in excellent condition with a serum creatinine level of 205 µmol/l and a proteinuria <1 g/day on angiotensin-converting enzyme inhibitor (ACEI) and diuretic.
Case 2
A 84-year-old male, with a known exposure to silica, was admitted for progressive respiratory failure with alveolar haemorrhage. The acute respiratory distress syndrome required rapid admission to intensive care for endotracheal intubation and mechanical ventilation. Serum creatinine was 400 µmol/l and proteinuria 3 g/day. Macroscopic haematuria and inflammatory syndrome (CRP 21 mg/dl) were noted. No serum or urinary monoclonal protein chains were found. The ANA and anti-GBM antibody tests were negative. Serum complement fractions(C3, C4) were normal. A renal biopsy revealed NCGN with extracapillary proliferation on nearly 80% of glomeruli. Immunofluorescence staining was not significative for IgA, IgM, IgG, C3 and C1q. Anti-fibrinogen staining was positive.
By IIF examination of normal peripheral blood neutrophils, an atypical ANCA pattern was observed, with a mix of both C-ANCA atypical and atypical perinuclear ANCAs with a high antibody level (> 1/160) (Figure 2). By ELISA (Wieslab kit), no specificity was found for MPO and PR3. HNE antibodies were detected by two ELISA tests using extrative human antigen (Wieslab kit PAN 106© and Bioadvance ANCA profile©). With the two latter ELISA tests, BPI antibodies were also found, but azurocidin, cathepsin G, lactoferrin and lysozyme specificities were negative. Rapidly, after discarding bacterial endocarditis, one pulse of CYC (750 mg) and one pulse of steroids (500 mg of methylprednisolone) were given. Unfortunately, the patient died on day 9, presumably due to cardiac failure. No autopsy was performed.
|
Case 3
A 46-year-old male was hospitalized for dyspnoea and arthralgia. On admission, physical examination disclosed pulmonary haemorrhage and leg oedema. BP was normal (140/90 mmHg). Serum creatinine level was elevated to 230 µmol/l in association with proteinuria (2 g/24 h) and microscopic haematuria (granular and hyaline casts). CRP was elevated to 2 mg/dl and serum C3 and C4 levels were normal. The ANA and anti-GBM antibody tests were negative. No serum or urinary monoclonal protein chains were found. A renal biopsy revealed crescentic glomerulonephritis with segmentary extracapillary proliferation on nearly 50% of glomeruli. Immunofluorescence staining was negative for IgM, IgG and C3. Anti-fibrinogen staining was positive.
By IIF examination of normal peripheral blood neutrophils, an atypical C-ANCA pattern was observed, with a high antibody level (> 1/160). By ELISA (Wieslab kit), no specificity was found for MPO and PR3. HNE antibodies were detected by two ELISA tests using extrative human antigen (Wieslab kit PAN 106© and Bioadvance ANCA profile©). With the two latter ELISA tests, BPI, azurocidin, cathepsin G, lactoferrin and lysozyme antibodies were negative.
After 6 monthly pulses of CYC (750 mg/pulse) combined with oral prednisone (starting at 1 mg/kg/day and progressively tapered), the course of illness was rapidly favourable. Serum creatinine level decreased to 160 µmol/l. Mycophenolate mofetil (Cellcept®) was introduced at 6 months. After 1 year of follow-up, the patient was in perfect condition with a serum creatinine of 120 µmol/l. Proteinuria was reduced to 1.5 g/day on ACEI and diuretic.
|
Discussion |
|---|
|
TopIntroductionCasesDiscussionReferences |
|---|
It is well known that ANCAs, especially MPO-ANCA or PR3-ANCA, are serological markers of pauciimmune NCGN, with and without systemic small vessel vasculitis. Our three patients had rapidly progressive glomerulonephritis with systemic vasculitis (alveolar haemorrhage in two cases and neuropathy in one case). By IIF, patterns of ANCA were atypical and reacted against HNE. In two of the three cases, sera reacted to BPI. However, with both ANCA panel kits, cathepsin G, azurocidin, lactoferrin and lysozyme specificities were not detected in any of our patients.
In patients with systemic vasculitis, the clinical significance of HNE-ANCAs are mainly controversial, and HNE-ANCAs are found with a frequency between nearly 0% and 20% [2,3]. In the large majority of these patients, HNE-ANCAs are associated with MPO or PR3-ANCAs. Their presence seems to be correlated with a more frequent and severe renal involvement [3]. There are very few reports of patients suspected of systemic vasculitis without detection in their sera of MPO or PR3-ANCAs, but only of HNE-ANCAs. During a study period of more than 6 years, only four serum samples were found positive only for HNE in a series of 1102 patients with a suspected diagnosis of vasculitis. Three out of four were suspected of limited Wegener's granulomatosis without definite histological finding of vasculitis, and one was classified as having polyangiitis overlap syndrome with subcutaneous nodules showing granulomatous arteritis [2].
Recently, in the clinical setting of necrotizing inflammation of the upper respiratory tract, the finding of HNE-ANCA has been suggested to be a specific marker of CIMDL but not of autoimmune vasculitis [6]. Indeed in a series of 25 patients with CIMDL, HNE-ANCAs were detected in 84% of patients by two specific assays (IIF using an expression system for recombinant HNE and capture ELISA using purified native HNE target antigen). By IIF, different patterns of ANCA were observed. A few sera generated a granular cytoplasmic staining, some exhibited only perinuclear staining and others displayed both patterns. No simultaneous reactivity with MPO antigen was observed, whereas 57% of these patients reacted positively with PR3 antigen. These patients with simultaneous reactivities against HNE and PR3 antigens had a C-ANCA pattern staining by IIF. Therefore, it was suggested that the few patients previously described with limited Wegener granulomatosis but without definite histological proof of vasculitis could have CIMDL and were ‘mimickers’ of limited Wegener vasculitis. In none of our three patients, was cocaine use suspected nor midline destructive lesions observed. Vasculitis was limited to the kidney, lung or peripheral nerves without ENT involvement in any case.
Some investigators have reported HNE-ANCAs in patients with systemic lupus erythematous (SLE) [3,7,8] or drug-induced vasculitis [4,5]. In the latter condition, multiple simultaneous reactivities with MPO or PR3 antigens are observed. Clearly in our three patients, the diagnosis of SLE was discarded on the grounds of clinical presentation, histological findings and negative ANA or anti-DNA tests. None of our patients had taken propylthiouracyl or other drugs known for inducing vasculitis.
Elastase, a major serine proteinase of neutrophils, is thought to participate in host defense and in tissue remodelling. On activation, degranulation of neutrophils occurs, resulting in release of these proteins in the extracellular space. The enzymes usually form complexes with serum-derived protease inhibitors. Deficiency of these inhibitors has been suggested as a potential risk factor for vasculitis [9]. In two of our patients (cases 1 and 3), no specific deficiency in 
1-anti-trypsin (1-AT), an elastase inhibitor, was detected. The concentration for 1-AT was not determined in the second patient who died rapidly. Recently, experimental studies have demonstrated that neutrophil surface-associated elastase was enzymatically active in patients with Wegener's granulomatosis and that antibodies to elastase are not inhibitory for elastase activity but rather upregulate this activity, thereby possibly contributing to tissue damage [10]. However, the pathogenic role of HNE-ANCA for inducing pauci-immune vasculitis has never been demonstrated in humans or in animal models.
In patients suspected of vasculitis with atypical ANCAs detected by IIIF, the diagnosis of ANCA-associated systemic vasculitis should not be discarded when specific reactivities for MPO or PR3 antigens are negative. Screening for HNE-ANCA should be performed, since HNE-ANCA might be a marker of systemic vasculitis, mainly in patients with renal involvement and no midline destructive lesions.
Conflict of interest statement. None declared.
|
References |
|---|
|
TopIntroductionCasesDiscussionReferences |
|---|
- Savige J, Davies D, Falk RJ, Jennette JC, Wiik A. Antineutrophil cytoplasmic antibodies and associated diseases. A review of the clinical and laboratory features. Kidney Int (2000) 57:846–862.[CrossRef][Web of Science][Medline]
- Cohen Tervaert JW, Mulder J, Stegman C, et al. Occurence of autoantibodies to human leucocyte elastase in Wegener's granulomatosis and other inflammatory disorders. Ann Rheum Dis (1993) 52:115–120.
[Abstract/Free Full Text] - Apenberg S, Andrassy K, Wörmer I, et al. Antibodies to neutrophil elastase: a study in patients with vasculitis. Am J Kidney Dis (1996) 28:178–185.[Web of Science][Medline]
- Choi HK, Merkel PA, Walker AM, et al. Drug-associated antineutrophil cytoplasmic antibody-positive vasculitis: prevalence among patients with high titers of antimyeloperoxidase antibodies. Arthritis Rheum (2000) 43:405–413.[CrossRef][Web of Science][Medline]
- Zhao MH, Chen M, Gao Y, et al. Propylthiouracyl-induced anti-neutrophil cytoplasmic antibody-associated vasculitis. Kidney Int (2006) 69:1477–1481.[Web of Science][Medline]
- Wiesner O, Russel KA, Lee AS, et al. Antineutrophil cytoplasmic antibodies reacting with human neutrophil elastase as a diagnostic marker for cocaine-induced midline destructive lesions but not autoimmune vasculitis. Arthritis Rheum (2004) 50:2954–2965.[CrossRef][Web of Science][Medline]
- Nässberg L, Jonsson H, Sjöholm AG, et al. Circulating anti-elastase in systemic lupus erythematous. Lancet (1989) 1:509.[Medline]
- Gallicchio MC, Savige JA. Detection of anti-myeloperoxidase and anti-elastase antibodies in vasculitides and infection. Clin Exp Immunol (1991) 84:232–237.[Web of Science][Medline]
- Audrain MAP, Sesboüé R, Baranger TAR, et al. Analysis of anti-neutrophil cytoplasmic antibodies (ANCA): frequency and specificity in a sample of 191 homozygous (PIZZ) alpha1-antitrypsin-deficient subjects. Nephro Dial Transplant (2001) 16:39–44.[CrossRef]
- Morcos M, Zimmerman F, Radsak M, et al. Autoantibodies to polymorphonuclear neutrophil elastase do not inhibit but enhance elastase activity. Am J Kidney Dis (1998) 31:978–985.[Web of Science][Medline]
Accepted in revised form: 5. 3.07
CiteULike 
Connotea 
Del.icio.us What's this?
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||