Choice of replacement solution and anticoagulant in continuous venovenous hemofiltration.

BACKGROUND: Several types of replacement fluid and methods of anticoagulation have been employed for continuous renal replacement therapy, but there is no consensus on a preferred approach. We evaluated the indications for the selection of replacement fluid and anticoagulant among critically ill patients receiving continuous venovenous hemofiltration (CVVH) and assessed the effect of the selection on the efficacy of anticoagulation and complications. METHODS: We retrospectively studied 29 consecutive patients who received CVVH in the Medical Intensive Care Unit at Massachusetts General Hospital. There were 3 types of replacement solution available, an isotonic citrate solution which was also used for regional anticoagulation of the extracorporeal circuit, and bicarbonate and lactate solutions which were used with low-dose heparin or no anticoagulant. Blood flow rate was set at 120 ml/min when citrate replacement fluid was used and at 200 ml/min with bicarbonate or lactate. The replacement fluid was administered proximal to the hemofilter at a constant rate of 1,600 ml/h. RESULTS: There were 22 patients who received citrate replacement fluid which was mainly chosen for the purpose of anticoagulation in the setting of contraindications to heparin. 12 patients received bicarbonate, predominantly when citrate was considered contraindicated due to liver failure or high-anion gap metabolic acidosis, and 2 received lactate; 8 of these 14 patients were anticoagulated with heparin and 6 were managed without anticoagulation. There were 44 filters used in the patients receiving citrate with a median filter life of 42.0 (interquartile range 22.2 - 70.7) hours. Only 8 of the 44 filters were lost due to clotting. Heparin was used for anticoagulation of 17 filters and no anticoagulation was used in the case of 15 filters, resulting in a median filter life of 43.0 (13.5 - 75.0) and 12.0 (4.0 - 33.0) hours, respectively. Clinically significant bleeding occurred in 2 patients, 1 receiving citrate and another receiving heparin. No patient had evidence for citrate toxicity, metabolic alkalosis or hypernatremia. 14 (48.3%) patients survived. CONCLUSIONS: The use of regional citrate anticoagulation of the CVVH circuit appears advantageous in patients with increased risk of bleeding and bicarbonate-based replacement fluid seems desirable in patients with lactic acidosis due to shock and/or severe liver failure. Tailoring the type of replacement fluid and method of anticoagulation to the individual patient leads to long filter lives, excellent metabolic control and minimal complications.

Diagnostic performance of antineutrophil cytoplasmic antibody tests for idiopathic vasculitides: metaanalysis with a focus on antimyeloperoxidase antibodies.

OBJECTIVE: The diagnostic value of tests for antimyeloperoxidase antibodies (anti-MPO) for systemic vasculitis is less established than that for cytoplasmic antineutrophil cytoplasmic antibody (cANCA)/antiproteinase 3 antibodies (anti-PR3). Controversy exists regarding the optimal utilization of indirect immunofluorescence (IIF) ANCA testing versus antigen-specific ANCA testing. To summarize the pertinent data, we conducted a metaanalysis examining the diagnostic value of ANCA testing systems that include assays for anti-MPO. METHODS: We performed a structured Medline search and reference list review. Target articles in the search strategy were those reporting the diagnostic value of immunoassays for anti-MPO for the spectrum of systemic necrotizing vasculitides that includes Wegener's granulomatosis, microscopic polyangiitis, the Churg-Strauss syndrome, and isolated pauci-immune necrotizing or crescentic glomerulonephritis, regardless of other types of ANCA tests. Inclusion criteria required specification of a consecutive or random patient selection method and the use of acceptable criteria for the diagnosis of vasculitis exclusive of ANCA test results. Weighted pooled summary estimates of sensitivity and specificity were calculated for anti-MPO alone, anti-MPO + perinuclear ANCA (pANCA), and anti-MPO/pANCA + anti-PR3/cANCA. RESULTS: Of 457 articles reviewed, only 7 met the selection criteria. Summary estimates of sensitivity and specificity (against disease controls only) of assays for anti-MPO for the diagnosis of systemic necrotizing vasculitides were 37.1% (confidence interval 26.6% to 47.6%) and 96.3% (CI 94.1% to 98.5%), respectively. When the pANCA pattern by IIF was combined with anti-MPO testing, the specificity improved to 99.4%, with a lower sensitivity, 31.5%. The combined ANCA testing system (anti-PR3/cANCA + anti-MPO/pANCA) increased the sensitivity to 85.5% with a specificity of 98.6%. CONCLUSION: These results suggest that while anti-MPO is relatively specific for the diagnosis of systemic vasculitis, the combination system of immunoassays for anti-MPO and IIF for pANCA is highly specific and both tests should be used together given the high diagnostic precision required for these conditions. Because patients with ANCA associated vasculitis have either anti-MPO with pANCA or anti-PR3 with cANCA, and rarely both, a combined ANCA testing system including anti-PR3/cANCA and anti-MPO/pANCA is recommended to optimize the diagnostic performance of ANCA testing.

A disease-specific activity index for Wegener's granulomatosis: modification of the Birmingham Vasculitis Activity Score. International Network for the Study of the Systemic Vasculitides (INSSYS).

OBJECTIVE: To refine and validate the Birmingham Vasculitis Activity Score (BVAS) as a disease-specific activity index for Wegener's granulomatosis (WG). METHODS: Sixteen members of the International Network for the Study of the Systemic Vasculitides (INSSYS) revised the BVAS, with 3 goals: to reduce the redundancy of some component items, to enhance its ability to capture important disease manifestations specific to WG, and to streamline the instrument for use in clinical research. We defined the items and weighted them empirically as either minor (e.g., nasal crusting = 1 point) or major (e.g., alveolar hemorrhage = 3 points). We then validated the new, disease-specific BVAS/WG in 2 simulation exercises and a clinical case series that involved 117 patients with WG. RESULTS: We removed 38 items from the original BVAS, revised 9 items, and added 7 new items. Correlations between the scores on the BVAS/WG and the physician's global assessment (PGA) of disease activity were high, even when patients in remission were excluded. In the clinical case series, Spearman's rank correlation coefficient between the BVAS/WG and the PGA was r = 0.81 (95% confidence interval 0.73-0.87). The interobserver reliability using intraclass (within-case) correlation coefficients in the 2 simulation exercises was r = 0.93 for the BVAS/WG and r = 0.88 for the PGA in the first and r = 0.91 for the BVAS/WG and r = 0.88 for the PGA in the second. There was no significant observer effect in the scoring of the BVAS/WG or the PGA. The discriminant validity of the BVAS/WG was good: r = 0.73 (95% confidence interval 0.43-0.83). CONCLUSION: The BVAS/WG is a valid, disease-specific activity index for WG. Tested in simulation exercises and in actual patients, the BVAS/WG correlates well with the PGA, is sensitive to change, and has good inter- and intraobserver reliability. The INSSYS will use the BVAS/WG to assess the primary outcome in a phase II/III trial of etanercept in WG.

Clinical, biological, and histologic parameters as predictors of relapse in ulcerative colitis.

BACKGROUND & AIMS: Ulcerative colitis (UC) is a chronic relapsing inflammatory bowel disease. We aimed to assess whether clinical, biological, and histologic parameters in quiescent UC predict time to clinical relapse. METHODS: Seventy-four patients with clinically and endoscopically determined inactive UC were followed up for 1 year or for a shorter period if they had a relapse. Serum erythrocyte sedimentation rate; C-reactive protein, interleukin (IL)-1beta, IL-6, and IL-15 values; anti-neutrophil cytoplasmic antibody titers; and rectal biopsy specimens were obtained at baseline, at 6 and 12 months, and/or at relapse. Multivariate survival analysis was performed to determine independent predictors of clinical relapse. RESULTS: Twenty-seven patients relapsed (19/42 women; 8/32 men). Multivariate Cox regression analysis retained younger age (P = 0.003; hazard ratio, 0.4 per decade), greater number of prior relapses in women (P < 0.001; hazard ratio, 1.6 per prior relapse), and basal plasmacytosis (P = 0.003; hazard ratio, 4.5) on rectal biopsy specimens as predictors of shorter time to clinical relapse. Kaplan-Meier survival curves showed the 20-30-year-old age group and women with more than 5 prior relapses to be groups with shorter times to relapse. CONCLUSIONS: Younger age, multiple previous relapses (for women), and basal plasmacytosis on rectal biopsy specimens were independent predictors of earlier relapse. These findings may help identify patients with inactive UC who will require optimal maintenance medical therapy.

Evaluation of antineutrophil cytoplasmic antibody seroconversion induced by minocycline, sulfasalazine, or penicillamine.

OBJECTIVE: Case reports have suggested that minocycline, sulfasalazine, and penicillamine are associated with antineutrophil cytoplasmic antibody (ANCA)-positive vasculitis. This study evaluated ANCA seroconversion due to these agents in serum samples prospectively collected in randomized, double-blind, controlled trials. METHODS: The sources of study sera were 3 clinical trials: 1) a 48-week trial of minocycline for early rheumatoid arthritis, with 64 patients receiving minocycline compared with 68 receiving placebo; 2) a 37-week trial of sulfasalazine for rheumatoid arthritis, with 51 receiving sulfasalazine compared with 38 receiving placebo; and 3) a 104-week trial of penicillamine for early systemic sclerosis, with 15 undergoing high-dose penicillamine treatment versus 12 receiving low-dose penicillamine. ANCA were measured in the baseline and study-end serum samples by indirect immunofluorescence (IIF) for perinuclear ANCA (pANCA) and cytoplasmic ANCA (cANCA) patterns, and by antigen-specific enzyme-linked immunosorbent assay (ELISA) for antibodies to myeloperoxidase (anti-MPO) and proteinase 3 (anti-PR3). Laboratory personnel were blinded to the group identity of the samples. ANCA results were interpreted using an ANCA scoring system that combines the results of IIF and ELISA testing. RESULTS: No patient in any of the active study drug groups demonstrated ANCA seroconversion according to the final interpretation of the combined IIF and ELISA results. Twelve of the 248 patients (5%) were positive for anti-MPO with pANCA at baseline. No subject was positive for anti-PR3 with cANCA. There were no findings suggestive of vasculitis in any of these patients. CONCLUSION: From our study results, there was no suggestion of ANCA seroconversion induced by minocycline, sulfasalazine, or penicillamine. However, these findings do not rule out the possibility of rare, sporadic cases of either ANCA seroconversion or true drug-induced vasculitis with these drugs.

Drug-associated antineutrophil cytoplasmic antibody-positive vasculitis: prevalence among patients with high titers of antimyeloperoxidase antibodies.

OBJECTIVE: The triggers that induce antineutrophil cytoplasmic antibody (ANCA)-positive vasculitis (APV) are largely unknown. However, there have been reports suggesting that hydralazine, propylthiouracil, and several other drugs may cause some cases of APV, and the majority of these cases have been associated with antimyeloperoxidase (anti-MPO) ANCA. Our experience led us to hypothesize that cases of high titers of anti-MPO antibodies are often drug-associated. METHODS: In this study, we determined the prevalence of exposure to hydralazine, propylthiouracil, and other drugs previously implicated in APV among 30 patients with vasculitis and the highest titers of anti-MPO antibodies newly detected in our laboratory between 1994 and 1998. The clinical, histologic, and other serologic features of these 30 patients were also examined. RESULTS: The 30 study patients accounted for 12% of the 250 new patients with APV and anti-MPO who were tested during the study period. All 30 study subjects had anti-MPO titers that were more than 12 times the median titer of the 250 patients. Ten (33%) of the 30 patients had been exposed to hydralazine and 3 (10%) had been exposed to propylthiouracil. An additional 5 patients (17%) had been exposed to 1 of the other previously reported candidate drugs: 2 to penicillamine, 2 to allopurinol, and 1 to sulfasalazine. One of the patients exposed to hydralazine had also been exposed to allopurinol. In all cases, the clinical and histologic findings were typical of APV. There was a strong association between the presence of antielastase and/ or antilactoferrin antibodies and exposure to candidate drugs. CONCLUSION: These data suggest that a sizable proportion of cases of APV with high titers of anti-MPO antibodies are drug-associated, especially following exposure to hydralazine or propylthiouracil. We recommend that the use of these drugs should be sought in cases of anti-MPO-positive vasculitis, particularly among patients with high titers of these antibodies.

Subacute bacterial endocarditis with positive cytoplasmic antineutrophil cytoplasmic antibodies and anti-proteinase 3 antibodies.

OBJECTIVE: To report a potentially important limitation of antineutrophil cytoplasmic antibody (ANCA) testing: positive results in patients with subacute bacterial endocarditis (SBE). METHODS: We describe 3 patients with SBE who presented with features mimicking ANCA-associated vasculitis (AAV) and positive findings on tests for cytoplasmic ANCA (cANCA) by indirect immunofluorescence and for anti-proteinase 3 (anti-PR3)antibodies by antigen-specific enzyme-linked immunosorbent assay (ELISA). We also reviewed the published literature describing infectious diseases with (misinterpreted) positive ANCA results through a Medline search of English-language articles published between 1966 and January 1999. These previously reported cases were reinterpreted using an ANCA scoring system that combines the findings of immunofluorescence and antigen-specific ELISA testing. RESULTS: We are now aware of a total of 7 cases of SBE with positive cANCA and anti-PR3 antibodies. We are not aware of any cases of SBE associated with antimyeloperoxidase/perinuclear ANCA. Clinical manifestations mimicking AAV included glomerulonephritis, purpura, epistaxis, or sinus symptoms in 6 of the patients. Streptococcal species were identified in 5 patients, and cardiac valvular abnormalities were demonstrated in 6. All patients except 1, who died of a complication of SBE, recovered with antibiotic therapy. CONCLUSION: Findings of tests for anti-PR3/ cANCA antibodies may be positive in patients with SBE. When encountering ANCA positivity in patients suspected of having systemic vasculitis, physicians should take appropriate steps to rule out infectious diseases, including SBE, before committing the patient to long-term, aggressive immunosuppressive therapy.

Regional citrate anticoagulation in continuous venovenous hemofiltration in critically ill patients with a high risk of bleeding.

BACKGROUND: Systemic heparinization is associated with a high rate of bleeding when used to maintain patency of the extracorporeal circuit during continuous renal replacement therapy (CRRT) in critically ill patients. Regional anticoagulation can be achieved with citrate, but previously described techniques are cumbersome and associated with metabolic complications. METHODS: We designed a simplified system for delivering regional citrate anticoagulation during continuous venovenous hemofiltration (CVVH). We evaluated filter life and hemorrhagic complications in the first 17 consecutive patients who received this therapy at our institution. Blood flow rate was set at 180 ml/min. Ultrafiltration rate was maintained at 2.0 liters/hr and citrate-based replacement fluid (trisodium citrate 13.3 mM, sodium chloride 100 mM, magnesium chloride 0.75 mM, dextrose 0.2%) was infused proximal to the filter to maintain the desired fluid balance. Calcium gluconate was infused through a separate line to maintain a serum-ionized calcium level of 1.0 to 1.1 mM. RESULTS: All patients were critically ill and required mechanical ventilation and vasopressor therapy. Systemic heparin anticoagulation was judged to be contraindicated in all of the patients. A total of 85 filters were used, of which 64 were lost because of clotting, with a mean life span of 29.5 +/- 17.9 hours. The remaining 21 filters were discontinued for other reasons. Control of fluid and electrolyte balance and azotemia was excellent (mean serum creatinine after 48 to 72 hr of treatment was 2.4 +/- 1.2 mg/dl). No bleeding episodes occurred. Two patients, one with septic shock and the other with fulminant hepatic failure, developed evidence for citrate toxicity without a significant alteration in clinical status. Nine patients survived (52.9%). CONCLUSION: Our simplified technique of regional anticoagulation with citrate is an effective and safe form of anticoagulation for CVVH in critically ill patients with a high risk of bleeding.

Interaction of purified human proteinase 3 (PR3) with reconstituted lipid bilayers.

Proteinase 3 (PR3), the major target autoantigen in Wegener's granulomatosis is a serine proteinase that is normally stored intracellularly in the primary granules of quiescent neutrophils and monocytes. Upon cell activation, a significant portion of this antigen is detected on the cell surface membrane. The nature of the association of PR3 with the membrane and its functional significance are unknown. We investigated the interaction of purified human PR3 with mixtures of zwitterionic (dimyristoyl-L-alpha-phosphatidylcholine, DMPC) and anionic (dimyristoyl-L-alpha-phosphatidylglycerol, DMPG) phospholipids in reconstituted lipid bilayers using differential scanning calorimetry and lipid photolabeling, and measured the affinity of this interaction using spectrophotometry. Two other primary granule constituents, human neutrophil elastase (HNE) and myeloperoxidase (MPO) were investigated for comparison. In calorimetric assays, using lipid vesicles of mixed DMPC/DMPG, increasing PR3 concentrations (protein/lipid molar ratio from 0 to 1 : 110) induced a significant decrease of the main chain transition enthalpy and a shift in chain melting temperatures which is indicative of partial insertion of PR3 into the hydrophobic region of the lipid membranes. This was confirmed by hydrophobic photolabeling using liposomes containing trace amounts of the photoactivable [125I]-labeled phosphatidylcholine analog TID-PC/16. The molar affinity of PR3, HNE, and MPO to lipid vesicles of different DMPC/DMPG ratios was then determined by spectrophotometry. At a DMPC/DMPG ratio of 1 : 1, molar affinities of PR3, Kd = 4.5 +/- 0.3 microm; HNE, 14.5 +/- 1.2 microm; and MPO, 50 +/- 5 microm (n = 3) were estimated. The lipid-associated PR3 exhibited two-fold lower Vmax and Km values, and its enzyme activity was slightly more inhibited (Ki) by the natural alpha1-proteinase inhibitor (alpha1-PI) or an autoantibody to PR3.

Alternating antineutrophil cytoplasmic antibody specificity: drug-induced vasculitis in a patient with Wegener's granulomatosis.

We describe a patient who presented with Wegener's granulomatosis associated with antineutrophil cytoplasmic antibodies (ANCA) directed against proteinase 3 (PR3) with a cytoplasmic immunofluorescence pattern (cANCA), whose ANCA type changed to antimyeloperoxidase antibodies with a perinuclear immunofluorescence pattern (pANCA) when treated with propylthiouracil, and changed back to anti-PR3 antibodies with cANCA after the medication was discontinued. The patient developed flares of vasculitis symptoms associated with rises in either type of ANCA. Tests for antimyeloperoxidase ANCA were repeatedly negative before the drug was started, strongly implicating the drug as the cause of the episode. This case demonstrates that patients with idiopathic ANCA-positive vasculitis may quickly develop a superimposed drug-associated ANCA-positive vasculitis. Iatrogenic vasculitis should be suspected when a patient with idiopathic vasculitis with one type of ANCA develops the other type of ANCA.

Anticoagulation in continuous renal replacement therapy.

Continuous renal replacement therapies (CRRTs) allow for gradual solute and fluid removal. In very sick patients with acute renal failure, they may be better tolerated than hemodialysis. The major drawback to CRRTs is the need for anticoagulation to maintain filter patency. The patients who are likely to benefit from CRRTs are also at higher risk for bleeding from systemic anticoagulation. The most commonly used form of anticoagulation for CRRTs, low-dose heparin, causes bleeding in 10-50% of patients. Regional anticoagulation using protamine may reduce the risk of bleeding, but it is difficult to use. Low molecular weight heparin and prostacyclin both may partially reduce bleeding, but are difficult to dose. Regional anticoagulation with citrate is easy to use and has been shown to prolong filter life without systemic anticoagulation. It is the anticoagulant of choice for most patients on CRRT.

ANCA-positive vasculitis associated with allopurinol therapy.

The triggers that induce ANCA-positive vasculitis are largely unknown. In a minority of cases, however, the disease appears to be medication-induced. This report provides the first description of a case of ANCA-positive vasculitis associated with allopurinol treatment.

Antineutrophil cytoplasmic antibodies in T-cell receptor alpha-deficient mice with chronic colitis.

BACKGROUND & AIMS: Antineutrophil cytoplasmic antibodies (ANCAs) have been detected in approximately 60% of sera from patients with ulcerative colitis. The aim of this study was to examine the presence of ANCAs and distribution of ANCA-producing B cells in the lymphoid tissue of T-cell receptor alpha-deficient (TCR-alpha-/-) mice that develop chronic colitis resembling human ulcerative colitis. METHODS: Sera from 87 TCR-alpha-/- mice were tested for the presence of ANCAs by enzyme-linked immunosorbent assay against a human neutrophil extract and selected antigens and by immunofluorescence study using human neutrophils. Enzyme-linked immunospot assay was used for detecting ANCA-producing cells from spleen, mesenteric lymph node (MLN), or colon. RESULTS: Approximately 70% of sera from TCR-alpha-/- mice showed reactivity against human neutrophil extracts by enzyme-linked immunosorbent assay. Sixty percent of ANCA-positive sera showed a perinuclear reaction pattern. By enzyme-linked immunospot, ANCA-producing cells were detected in MLN and colon and less often in the spleen of TCR-alpha-/- mice with chronic colitis. The predominant immunoglobulin isotype of these autoantibodies was immunoglobulin A in the colon but not in the MLN and spleen. CONCLUSIONS: TCR-alpha-/- mice produce ANCAs. The ANCA (immunoglobulin A isotype)-producing B cells exist primarily in the diseased colonic mucosa of TCR-alpha-/- mice.

Prevalence of antineutrophil cytoplasmic antibodies in a large inception cohort of patients with connective tissue disease.

BACKGROUND: Two types of antineutrophil cytoplasmic antibodies (ANCA), antiproteinase 3 antibodies (anti-PR3) and antimyeloperoxidase antibodies (anti-MPO), are useful in the diagnosis of such types of vasculitis as Wegener granulomatosis and microscopic polyangiitis. Connective tissue diseases frequently appear in the differential diagnosis of this spectrum of vasculitis. OBJECTIVE: To determine the prevalence of ANCA in patients with connective tissue disease. DESIGN: Blinded, controlled study of a 5-year inception cohort. SETTING: Tertiary-care university teaching hospitals. PATIENTS: 70 patients with rheumatoid arthritis, 70 patients with systemic lupus erythematosus, 45 patients with scleroderma, 36 patients with inflammatory myositis, 44 patients with the sjögren syndrome, 33 patients with the antiphospholipid syndrome, and 165 patients with early undifferentiated connective tissue disease (EUCTD). Serum was taken from 200 blood donors and 52 patients who had known vasculitis and positive results on tests for anti-PR3 or anti-MPO; these patients served as controls. MEASUREMENTS: The presence of anti-PR3 and anti-MPO was determined by combining the results of indirect immunofluorescence tests for cytoplasmic (C-ANCA) and perinuclear (P-ANCA) patterns with the results of enzymelinked immunosorbent assays (ELISAs) directed to measure antigen. RESULTS: Cytoplasmic ANCA was not detected in any study or control patient. Perinuclear ANCA was commonly detected among patients with lupus (31%) but was uncommon among patients in other groups (0% to 5%). In all cases, P-ANCA was associated with the presence of antinuclear antibodies. Atypical ANCA immunofluorescence patterns were fairly common in all groups (11% to 39%). Antiproteinase 3 was detected by ELISA in study patients (1 patient with rheumatoid arthritis, 1 with lupus, 1 with polymyositis, and 6 with EUCTD). Antimyeloperoxidase was detected by ELISA in 2 study patients (1 with rheumatoid arthritis and 1 with lupus). None of the patients with positive ELISA results had evidence of renal vasculitis during follow-up. When an ANCA scoring system that combines immunofluorescence and ELISA was used, the test specificity for vasculitis was 99.5% among patients with connective tissue disease. CONCLUSIONS: Patients with connective tissue disease are known to develop multiple autoantibodies; positivity for anti-PR3 and anti-MPO ANCA in such patients is highly specific for anti-PR3. However, P-ANCA immunofluorescence, which may have positive results because of the presence of antinuclear antibodies, is not a specific marker of anti-MPO. A rigorous ANCA testing system that combines the results of immunofluorescence with those of ELISA is highly specific for Wegener granulomatosis and related vasculitides even in patients with connective tissue disease.

Comparison of anti-GBM antibodies in sera with or without ANCA.

An appreciable percentage of patients with serum anti-glomerular basement membrane (anti-GBM) antibodies also have antineutrophil cytoplasmic antibodies (ANCA), against either myeloperoxidase (MPO-ANCA), or proteinase 3 (PR3-ANCA). In sera without ANCA, the anti-GBM antibodies have been shown to react mainly with the noncollagenous domain (NC1) of Type IV collagen, and especially with its alpha 3 chain, alpha 3(IV)NC1. In most sera, the antibodies can be partially blocked by a monoclonal antibody (Mab17) against alpha 3(IV)NC1, suggesting that a limited region is recognized. Although there is evidence that some anti-GBM antibodies that coexist with ANCA react with alpha 3(IV)NC1, extensive analysis of the specificity of such anti-GBM antibodies has not been reported. In the study presented here, sera were analyzed from 332 patients tested both for anti-GBM antibodies and ANCA (MPO or PR3-ANCA) and found to have one or more positive tests. Of the 100 sera with anti-GBM antibodies, 38 also had ANCA-25 with MPO-ANCA (66%), 12 with PR3-ANCA (32%), and one with both (2%). Of the 232 sera with ANCA only, 153 had MPO-ANCA (66%), 75 had PR3-ANCA (32%), and four had both (2%). Sera was also analyzed from 259 other patients who had positive ANCA tests and were not tested for anti-GBM antibodies: 138 had MPO-ANCA (54%), and 121 had PR3-ANCA (46%). The relative frequencies of MPO or PR3-ANCA in patients with coexisting anti-GBM antibodies did not differ significantly from those in all patients with ANCA (P = 0.35). Seventeen sera with anti-GBM antibodies only and 16 sera with anti-GBM antibodies plus ANCA were selected for further studies to compare the specificity of anti-GBM antibodies in sera with or without ANCA. Using enzyme-linked immunosorbent assays (ELISA), all sera in both groups were found to react with the NC1 domain (as a hexamer) of bovine Type IV collagen and with alpha 3 (IV)NC1 monomers. Furthermore, all but six sera also reacted with one or more of the alpha 1, 2, and 4 (IV)NC1 monomers, generally with considerably lower titers. Reactivity to alpha 3(IV)NC1 was partially blocked by Mab17, with comparable degrees of inhibition in both groups. Western blot analysis with the human NC1 domains revealed no differences in reactivity between the two groups. Thus, differences in antigen specificities of anti-GBM antibodies in sera with or without ANCA were not detected. The anti-GBM response in both situations is hypothesized to be driven by the same immunogen, which is probably derived from NC1 domains of endogenous Type IV collagen.

The syndrome of lung hemorrhage and nephritis is usually an ANCA-associated condition.

BACKGROUND: In the absence of evidence of arteritis or Wegener's granulomatosis, the syndrome of lung hemorrhage and nephritis has been commonly associated with anti-glomerular basement membrane (GBM) antibodies. However, it has been increasingly recognized that many cases are associated with antineutrophil cytoplasmic antibodies (ANCAs). OBJECTIVE: To review available clinical and pathologic findings to determine the diseases accounting for lung hemorrhage and nephritis. METHODS: We studied the records of 750 patients from whom serum samples were sent to our laboratory for anti-GBM antibody assays between 1981 and 1993 and found 88 patients with evidence of lung hemorrhage and nephritis. Serum samples were retested, using current methods, for anti-GBM antibodies (against noncollagenous 1 domain of the alpha 3 chain of type IV collagen) and for antibodies to proteinase 3 and myeloperoxidase--the two types of ANCA of diagnostic value. RESULTS: Of 88 patients with evidence of lung hemorrhage and nephritis, 48 had ANCAs, six had anti-GBM antibodies, and seven had both. In 48 patients with ANCAs, the pathologic findings that accounted for the pulmonary renal syndrome were pauci-immune necrotizing and crescentic glomerulonephritis and pulmonary capillaritis. Only eight had convincing evidence (during life) of Wegener's granulomatosis and only one other had documented arteritis. In 27 patients without ANCAs or anti-GBM antibodies, a variety of unrelated renal and pulmonary diseases were found. CONCLUSIONS: The largest group of patients who present with the syndrome of lung hemorrhage and nephritis have ANCAs and not anti-GMB antibodies. Appropriate tests for antibodies to proteinase 3, antibodies to myeloperoxidase, and anti-GBM antibodies provide reliable guides for making a diagnosis in patients with this pulmonary renal syndrome.

Antineutrophil cytoplasmic antibodies in the classification of vasculitis.

Two important types of antineutrophil cytoplasmic antibodies (ANCA) have been identified: anti-proteinase 3 and anti-myeloperoxidase antibodies. In the appropriate clinical setting, the presence of either is virtually diagnostic of the subset of vasculitis that includes Wegener's granulomatosis, microscopic polyangiitis (microscopic polyarteritis), the Churg-Strauss syndrome, idiopathic pauci-immune necrotizing and crescentic glomerulonephritis, and related and overlapping forms of these vasculitidies. The finding of ANCA throughout this group identifies these syndromes as belonging to a single category or spectrum of disease.