AB0511 INTERNATIONAL CONSENSUS ON ANCA TESTING AND INTERPRETATION BEYOND SYSTEMIC VASCULITIS

Background:

ANCA can be detected in sera from patients with autoimmune, inflammatory, infectious or neoplastic diseases.

Objectives:

To issue a Consensus Statement on ANCA testing and interpretation beyond systemic vasculitis.

Methods:

This Statement was prepared by a group of experts, based on the results of a comprehensive search in PubMed.

Results:

In certain settings beyond systemic vasculitis, ANCA may have diagnostic, clinical, and/or prognostic relevance. Testing for PR3- and MPO-ANCA by specific immunoassays should be performed in any patient with clinical features suggesting ANCA-associated vasculitis and in patients with anti-GBM disease and idiopathic interstitial pneumonia. Routine ANCA testing is not recommended in patients with connective tissue diseases (CTD), autoimmune liver diseases, inflammatory bowel diseases, infections, and/or malignancy unless there is evidence for small vessel vasculitis. ANCA testing by specific immunoassays may be useful in patients with rheumatoid arthritis, systemic sclerosis or primary Sjögren’s syndrome who have kidney disease with a nephritic sediment or in patients with systemic lupus erythematosus if a kidney biopsy shows prominent necrotizing and crescentic lesions or proliferative lupus nephritis. ANCA testing may be justified in patients with suspected autoimmune hepatitis type 1, who do not have conventional disease-related autoantibodies, or in patients with inflammatory bowel diseases in case of diagnostic uncertainty to discriminate ulcerative colitis from Crohn’s disease. In these cases, ANCA should be tested by indirect immunofluorescence since target antigens are not well characterized. ANCA against bactericidal/permeability-increasing protein may be a biomarker for deteriorating lung function and a poor prognosis in patients with cystic fibrosis.

Conclusion:

ANCA testing is clinically relevant not only in patients with manifestations suggesting systemic vasculitis, but also in patients with certain other disorders, particularly in patients with anti-GBM disease or idiopathic interstitial pneumonia.

Disclosure of Interests:

Sergey Moiseev Grant/research support from: This work was supported by the 5-100 Project, Sechenov University, Moscow, Jan Willem Cohen Tervaert: None declared, Yoshihiro Arimura: None declared, Dimitrios Bogdanos: None declared, Csernok Elena: None declared, Jan Damoiseaux: None declared, Marc Ferrante: None declared, Luis Felipe Flores-Suárez: None declared, Marvin Fritzler: None declared, Pietro Invernizzi: None declared, David Jayne Grant/research support from: ChemoCentryx, GSK, Roche/Genentech, Sanofi-Genzyme, Consultant of: Astra-Zeneca, ChemoCentryx, GSK, InflaRx, Takeda, Insmed, Chugai, Boehringer-Ingelheim, J. Charles Jennette: None declared, Mark Little: None declared, Stephen P. McAdoo: None declared, Pavel Novikov Grant/research support from: This work was supported by the 5-100 Project, Sechenov University, Moscow, Charles D. Pusey: None declared, Antonella Radice: None declared, Alan D. Salama: None declared, Judith Savige: None declared, Mårten Segelmark: None declared, Yehuda Shoenfeld: None declared, Renato Alberto Sinico: None declared, Maria Jose Rego de Sousa: None declared, Ulrich Specks: None declared, Benjamin Terrier: None declared, Athanasios Tzioufas: None declared, Severine Vermeire: None declared, Ming-hui Zhao: None declared, Xavier Bossuyt: None declared

Retinal disease in the C3 glomerulopathies and the risk of impaired vision

BACKGROUND

Dense deposit disease and atypical hemolytic uremic syndrome are often caused by Complement Factor H (CFH) mutations. This study describes the retinal abnormalities in dense deposit disease and, for the first time, atypical haemolytic uremic syndrome. It also reviews our understanding of drusen pathogenesis and their relevance for glomerular disease.

METHODS

Six individuals with dense deposit disease and one with atypical haemolytic uremic syndrome were studied from 2 to 40 years after presentation. Five had renal transplants. All four who had genetic testing had CFH mutations. Individuals underwent ophthalmological review and retinal photography, and in some cases, optical coherence tomography, and further tests of retinal function.

RESULTS

All subjects with dense deposit disease had impaired night vision and retinal drusen or whitish-yellow deposits. Retinal atrophy, pigmentation, and hemorrhage were common. In late disease, peripheral vision was restricted, central vision was distorted, and there were scotoma from sub-retinal choroidal neovascular membranes and atypical serous retinopathy. Drusen were present but less prominent in the young person with atypical uremic syndrome due to a heterozygous CFH mutation.

CONCLUSIONS

Drusen are common in forms of C3 glomerulopathy caused by compound heterozygous or heterozygous CFH mutations. They are useful diagnostically but also impair vision. Drusen have an identical composition to glomerular deposits. They are also identical to the drusen of age-related macular degeneration, and may respond to the same treatments. Individuals with a C3 glomerulopathy should be assessed ophthalmologically at diagnosis, and monitored regularly for vision-threatening complications.

The retinal "lozenge" or "dull macular reflex" in Alport syndrome may be associated with a severe retinopathy and early-onset renal failure

BACKGROUND AND AIMS

Alport syndrome is an inherited disease with renal failure, and often a hearing loss, lenticonus and dot-and-fleck retinopathy. A retinal "lozenge" or "dull macular reflex" has been described in some patients. This study determined the prevalence and significance of this sign.

METHODS

Twenty-three patients from 14 families with X linked Alport syndrome and seven from four families with autosomal recessive disease underwent slit-lamp biomicroscopy for lenticonus, direct and indirect ophthalmoscopy, and photography for the retinopathy.

RESULTS

The lozenge was present in five males (38%) but no females with X linked Alport syndrome, as well as one individual with recessive disease (1/7, 14%). It resulted from the sharp demarcation between the normal fovea and a perifoveal annnulus of confluent dots and flecks that were obvious with magnification of retinal photographs. The lozenge was first noted in adolescence and was always associated with early-onset renal failure, hearing loss and lenticonus.

CONCLUSION

Clinicians must be aware that the "lozenge" or "dull macular reflex" described in Alport syndrome is not a normal variant but reflects a severe, almost confluent perimacular dot and fleck retinopathy. This sign is useful diagnostically and also prognostically, since it is associated with early-onset renal failure.

The binding of proteinase 3 antineutrophil cytoplasmic antibodies (PR3-ANCA) varies in different ELISAs

BACKGROUND

The demonstration of proteinase 3 specific antineutrophil cytoplasmic antibodies (PR3-ANCA), and the estimation of antibody values are useful in the diagnosis and management of patients with Wegener's granulomatosis (WG). However, external quality assessment programmes suggest that PR3-ANCA binding varies in different assays.

AIM

To demonstrate variations in PR3-ANCA binding in different commercial and in house enzyme linked immunosorbent assays (ELISAs).

METHOD

Binding of a PR3-ANCA standard and 19 sera from patients with WG was compared in eight commercial and in house assays. Binding was expressed in different units depending on the kit.

RESULTS

One commercial assay performed unsatisfactorily. Three commercial kits produced PR3-ANCA binding (70, 102, and 84 U/ml) close to the expected value for the standard (100 U/ml). Serial dilutions of this standard were linear in only one commercial assay and the in house assay. Sera from patients with WG with borderline binding in the in house assay bound in the eight commercial kits at 0-148 kit units; low binding sera ranged from 0 to 273 units; moderately strong sera bound at 7-260 units; and strongly binding sera bound at 13-336 units. In four assays, at least one strongly positive serum bound at levels greater than the provided range.

CONCLUSIONS

Levels of antibody binding and units of binding have not been standardised in commercially available PR3-ANCA ELISAs. This may affect the diagnosis and management of patients with WG, in addition to the implementation of international guidelines for treatment.

Antineutrophil cytoplasmic antibody (ANCA)-associated systemic vasculitis after immunisation with bacterial proteins

OBJECTIVE

There is circumstantial evidence for a role for infections in the development of the small vessel vasculitides associated with antineutrophil cytoplasmic antibodies (ANCA). The aim of this study was to determine whether the immunisation of rats with bacterial proteins could result in circulating ANCA, T cells with specificity for ANCA antigens, and a systemic vasculitis.

METHODS

Adult male Wistar rats were immunised with pasteurised sonicated S. aureus (n = 7), E. coli (n = 8), purified protein derivative (PPD, n = 5), myeloperoxidase (MPO, n = 5) or phosphate-buffered saline (PBS, n = 5), in complete and in incomplete Freund's adjuvant. ANCA were assayed by indirect immunofluorescent (IIF) examination of normal rat neutrophils, and in ELISAs using human proteinase 3 (PR3), MPO and bactericidal/permeability-inreasing protein (BPI). The T cell response to PR3, MPO and BPI was assessed by a whole blood T cell proliferative assay in vitro, and by a delayed type hypersensitivity (DTH) response in vivo. Kidney and bowel were examined histologically for evidence of vasculitis and colitis.

RESULTS

One rat from each group immunised with S. aureus or E. coli developed pauciimmune segmental glomerular sclerosis. The rat immunised with E. coli had additionally an arteritis affecting renal interlobular and gut vessels. This rat had circulating C-ANCA, that produced granular cytoplasmic neutrophil fluorescence with central accentuation, but the target antigen could not be determined in ELISAs using human PR3, MPO or BPI. In animals immunised with S. aureus or E. coli, there was no significant T cell proliferative or DTH response specific for human PR3, MPO or BPI.

CONCLUSION

The development of ANCA and vasculitis in a rat immunised with bacterial proteins indicates that the relationship between infections and ANCA should be investigated further.

Immunofluorescent patterns produced by antineutrophil cytoplasmic antibodies (ANCA) vary depending on neutrophil substrate and conjugate

BACKGROUND

The "International consensus statement on testing and reporting antineutrophil cytoplasmic antibodies (ANCA)" advocates screening by indirect immunofluorescence (IIF), but external quality assessment programmes often demonstrate different IIF patterns for a single serum.

AIM

To determine whether the variation in IIF patterns can be attributed solely to errors in interpretation.

METHODS

This study compared the IIF patterns produced by four sera (two with cytoplasmic or C-ANCA; one with perinuclear or P-ANCA with myeloperoxidase (MPO) specificity; and one P-ANCA without MPO specificity) that were tested in 11 different laboratories. The sera were examined according to individual laboratory protocols at dilutions of 1/10 to 1/40 using P1 (n = 4), P2 (n = 2), P3 (n = 2), or in house (n=3) neutrophil preparations and conjugates from manufacturers C1 (n = 3), C2 (n = 1), C3 (n = 2), C4 (n = 1), C5 (n = 2), and C6 (n = 2). The IIF patterns were noted in each laboratory, the testing repeated, and the fluorescent patterns photographed and subsequently discussed at a meeting of the Australian ANCA study group.

RESULTS

All IIF patterns described in individual laboratories were confirmed on retesting and by the ANCA study group. Neutrophil substrates produced commercially or in house varied in their ability to demonstrate cytoplasmic granularity and interlobular accentuation, which distinguish between "C-ANCA" and "C-ANCA (atypical)". All commercial and in house neutrophil substrates demonstrated neutrophil nuclear extension of P-ANCA fluorescence, which correlates with MPO specificity. However, eight assays (eight of 43) from eight laboratories resulted in IIF patterns different from those usually seen. One of these produced a C-ANCA (atypical) rather than a C-ANCA pattern. The other seven resulted in at least some cytoplasmic fluorescence when the consensus pattern was P-ANCA with (n = 4) or without (n = 3) MPO specificity. These assays used three different commercial and one in house neutrophil substrate, and six different conjugates, with anti-IgG, anti-(Fab)'(2), anti-Ig (heavy and light chain), and anti-G, A, and M activity. Four of the seven assays tested on commercial substrates had used the manufacturer's conjugates.

CONCLUSIONS

This study indicates that the variation in IIF patterns seen with ANCA positive sera tested in different laboratories does not necessarily result from errors in the interpretation of patterns and cannot be attributed solely to the use of a particular neutrophil substrate or conjugate, or to the use of substrate from one manufacturer and conjugate from another.

A comparison of the clinical, histopathologic, and ultrastructural phenotypes in carriers of X-linked and autosomal recessive Alport's syndrome

Previous series that described phenotypes in carriers of Alport's syndrome did not distinguish genetically between carriers of X-linked and autosomal recessive disease. In this study, modes of inheritance in unselected families with Alport's syndrome associated with two city and two provincial hospitals were determined using microsatellite markers, and carriers of disease haplotypes were identified within these families. All 47 carriers (100%) from 18 families with X-linked Alport's syndrome had dysmorphic hematuria on phase-contrast microscopy, but few developed renal failure (3 of 40 carriers; 8%), clinical hearing loss (2 of 45 carriers; 4%), retinopathy (1 of 30 carriers; 3%), or lenticonus (0 of 30 carriers; 0%). Eleven of the 14 carriers (79%) from 2 families with autosomal recessive disease had dysmorphic hematuria, but none had renal failure, clinical hearing loss, retinopathy, or lenticonus. Urinary red blood cell counts in carriers of X-linked Alport's syndrome were greater than those in carriers of autosomal recessive disease (P < 0.0001), but the frequency of proteinuria and hypertension and levels of proteinuria were not different. There was more tubulointerstitial damage in carriers of X-linked disease (P = 0.012); however, carriers of autosomal recessive disease had more widespread and more uniform thinning of the glomerular basement membrane (P < 0.0001) and less lamellation (P < 0.04).

Testing for antineutrophil cytoplasmic antibodies

The most common reason to request a test for antineutrophil cytoplasmic antibodies (ANCA) is to diagnose Wegener's granulomatosis and microscopic polyangiitis and to monitor inflammatory activity in these diseases. Several retrospective and prospective studies have suggested that the demonstration of ANCA lacks sensitivity and specificity, but these series have detected ANCA with neutrophil-indirect immunofluorescence alone, have used a disease classification that did not describe microscopic polyangiitis and have included patients with inactive disease. The 'International Consensus Statement on Testing and Reporting ANCA' has been developed to optimize the clinical relevance of ANCA testing by the adoption of standardized testing and reporting procedures. International collaborative efforts continue to focus on improving the tests for ANCA.

COL4A4 mutation in thin basement membrane disease previously described in Alport syndrome

BACKGROUND

Carriers of autosomal-recessive and X-linked Alport syndrome often have a thinned glomerular basement membrane (GBM) and have mutations in the COL4A3/COL4A4 and COL4A5 genes respectively. Recently, we have shown that many individuals with thin basement membrane disease (TBMD) are also from families where hematuria segregates with the COL4A3/COL4A4 locus. This study describes the first COL4A4 mutation in an individual with biopsy-proven TBMD who did not have a family member with autosomal-recessive or X-linked Alport syndrome, inherited renal failure, or deafness.

METHODS

The index case and all available family members were examined for dysmorphic hematuria> 50,000/mL using phase contrast microscopy and for segregation of hematuria with the COL4A3/COL4A4 and COL4A5 loci using DNA satellite markers. COL4A4 exons from the index case were then studied using the enzyme mismatch cleavage method, and exons that demonstrated abnormal cleavage products were sequenced.

RESULTS

Hematuria in this family segregated with a haplotype at the COL4A3/COL4A4 locus (P = 0.031) but not with haplotypes at the COL4A5 locus. A mutation in COL4A4 that changed C to T resulting in an arginine residue being replaced by a stop codon (R1377X) was demonstrated in exon 44, which encodes part of the alpha 4(IV) collagen sequence close to the junction with the noncollagenous domain. This mutation was present in all five family members with hematuria, but not in the four unaffected family members, 33 unrelated individuals with TBMD, or 22 nonhematuric normals.

CONCLUSIONS

R1377X has been described previously in a compound heterozygous form of autosomal-recessive Alport syndrome. Our observation is evidence that TBMD can represent a carrier state for autosomal-recessive Alport syndrome in at least some individuals.

Segregation of hematuria in thin basement membrane disease with haplotypes at the loci for Alport syndrome

BACKGROUND

Inherited hematuria is common and is usually attributed to thin basement membrane disease (TBMD). The aim of this study was to determine how often hematuria in families with TBMD segregated with haplotypes at the chromosomal loci for autosomal recessive and X-linked Alport syndrome (COL4A3/COL4A4 and COL4A5, respectively).

METHODS

The families of 22 individuals with TBMD on renal biopsy and with urinary glomerular red blood cell (RBC) counts of more than 50,000/mL were studied using phase-contrast microscopy of the urine and DNA microsatellite markers. Eighteen families had at least two members with hematuria.

RESULTS

Hematuria segregated with or was consistent with segregation at the COL4A3/COL4A4 locus in eight (36%) families (P < 0.05 in 5 of these) and at the COL4A5 locus in four (18%) families (P < 0.05 in 2). The lack of segregation in the other 10 (45%) families may have occurred because of incomplete penetrance of the hematuria, de novo mutations, coincidental hematuria in other family members, or the presence of a novel gene locus. In four different families, three of which had hematuria that segregated with the COL4A3/COL4A4 locus, four family members with the hematuria haplotype had spouses with coincidental hematuria (4 of 29, 14%). However, none of their four offspring who had also inherited the hematuria haplotype had the clinical features of autosomal recessive Alport syndrome.

CONCLUSIONS

Hematuria in families with TBMD commonly segregates with the COL4A3/COL4A4 locus and thus results from mutations in the same genes as autosomal recessive Alport syndrome. Sometimes TBMD may be confused with the carrier state for X-linked Alport syndrome. However, nearly half of the families in this study had hematuria that did not segregate with the loci for either autosomal recessive or X-linked Alport syndrome.

Absence of ocular manifestations in autosomal dominant Alport syndrome associated with haematological abnormalties

Most patients with Alport syndrome have X-linked or autosomal recessive disease that is characterised by renal failure, hearing loss, and, in nearly 75% of the cases, a dot-and-fleck retinopathy and anterior lenticonus. There are only case reports of individuals with the rare autosomal dominant form, who can have haematuria or renal failure, deafness, and, in addition, low platelet counts and neutrophil inclusions. The ocular features of autosomal dominant inheritance have not been described. We have examined the eyes in the members of two families where Alport syndrome was diagnosed on the basis of the clinical features and family history, and where autosomal dominant inheritance was confirmed by father-to-son disease transmission, the associated haematological abnormalities, and haplotypes that segregated with the recently described locus at chromosome 22q. In Family A, the eyes of two individuals with haematuria, hearing loss, and haematological abnormalities and of nine unaffected family members were examined. In Family B, the eyes of two individuals with renal failure, normal hearing, and haematological abnormalities were examined. None of the affected or unaffected members in either family had a dot-and-fleck retinopathy, anterior lenticonus, a history suggesting recurrent corneal erosions, or corneal dystrophy. These results indicate that the protein abnormality in autosomal dominant Alport syndrome does not produce the retinopathy and lenticonus typical of X-linked and autosomal recessive disease. This may be because the abnormal protein is not present or is less important in the ocular basement membranes than elsewhere, or because the presence of a normal allele in autosomal dominant disease compensates for the defective allele.

Indirect immunofluorescence (IIF) of normal washed peripheral blood cells to demonstrate antineutrophil cytoplasmic antibodies (ANCA)

BACKGROUND

The "International consensus document on testing and reporting of antineutrophil cytoplasmic antibodies (ANCA)" requires all sera to be examined by indirect immunofluorescence (IIF). However, commercial neutrophil slides are expensive, fluorescence patterns can be difficult to interpret, and coincidental antinuclear antibodies (ANA) cannot be demonstrated; in addition, in house cytospin neutrophil preparations are time consuming to prepare and deteriorate with time.

AIMS

To compare the IIF demonstration of ANCA, using washed peripheral blood cell smears, with commercial neutrophil preparations and with ANCA positivity as demonstrated by enzyme linked immunosorbent assay (ELISA).

METHODS

Serum fluorescence positivity, pattern, and intensity using washed peripheral blood cell smears were compared with the results obtained using commercial neutrophil slides (INOVA). Fluorescence positivity, pattern, and intensity of 500 sera from consecutive patients with suspected vasculitis tested with washed peripheral blood cells were compared with binding in ELISAs for proteinase 3 (PR3) and myeloperoxidase (MPO).

RESULTS

IIF of washed peripheral blood cell smears detected seven of eight sera with cytoplasmic fluorescence (C-ANCA), and 11 of 12 sera with perinuclear fluorescence (P-ANCA) demonstrated using commercial slides. The two sera that were negative by IIF were also negative in the ELISAs for both PR3-ANCA and MPO-ANCA. Of the 500 sera examined, there were 35 (7%) with C-ANCA, 65 (13%) with P-ANCA, and eight (2%) IIF negative sera that were positive by either ELISA. There was a strong correlation between C-ANCA fluorescence and PR3-ANCA values (p < 0.0001), and a moderate to strong correlation between P-ANCA fluorescence and MPO-ANCA values (p < 0.001) when ANCA fluorescence was demonstrated with washed peripheral blood cell smears.

CONCLUSIONS

Washed peripheral blood cells are a convenient and useful low cost alternative to commercial or cytospin neutrophil preparations for the IIF demonstration of ANCA.

Clinical associations and characterisation of antineutrophil cytoplasmic antibodies directed against bactericidal/permeability-increasing protein and azurocidin

Bactericidal/permeability-increasing protein (BPI) and azurocidin (AZ) are recently described target antigens of antineutrophil cytoplasmic antibodies (ANCA). In this study, BPI-ANCA were demonstrated most often in patients with ulcerative colitis (36/92, 39%), Crohn's disease (17/66, 26%) and cystic fibrosis (11/14, 79%), but also in patients with rheumatoid arthritis (8/40, 20%), systemic lupus erythematosus (SLE) (111/65, 17%) and mixed connective tissue disease (4/18, 22%). BPI-ANCA were also common in sera containing antinuclear (ANA) (9/43, 21%) or antidouble-stranded (ds) DNA (7/28, 25%) antibodies. There was no increased frequency of abnormal alpha1-antitrypsin (alphal1AT) phenotypes in patients with BPI-ANCA, and BPI-ANCA were not more common in individuals with an abnormal phenotype. The predominant IgG subclasses were IgG1 and IgG3; IgA but not IgM was present. Both IgG and IgA BPI-ANCA were high affinity antibodies, and the affinity of IgG antibodies did not change with time in the sera tested. Four of the five sera (80%) containing BPI-ANCA did not bind to denatured, reduced BPI, suggesting that most BPI-ANCA recognised conformational epitopes. AZ-ANCA were demonstrated in 2/11 patients (18%) with Wegener's granulomatosis, 3/12 (25%) with cystic fibrosis and 3/14 (21%) with chronic active hepatitis. AZ-ANCA were present in 5/25 sera (25%) with ANA, but the levels were only marginally elevated. AZ-ANCA were uncommon in patients with inflammatory bowel and rheumatological diseases, and in sera containing other autoantibodies. Again, there was no association with abnormal alpha1-AT phenotypes. BPI represents a major ANCA target antigen in patients with rheumatological as well as inflammatory bowel disease and cystic fibrosis, but AZ-ANCA are uncommon.

Ultrastructural appearance of renal and other basement membranes in the Bull terrier model of autosomal dominant hereditary nephritis

Bull terrier hereditary nephritis may represent a model for autosomal dominant Alport's syndrome because affected dogs have the typically lamellated glomerular basement membrane (GBM) and father-to-son disease transmission occurs. This study examined the ultrastructural appearance of the renal and extrarenal basement membranes and their composition in affected Bull terriers. Affected stillborn animals and puppies had subepithelial frilling and vacuolation of the GBM. In adult dogs, lamellation was common, and subepithelial frilling and vacuolation were less prominent. Foot-process effacement and mesangial matrix expansion occurred frequently. Basement membranes in the glomeruli, tubules, and Bowman's capsule were significantly thickened and often mineralized. Immunohistochemical examination showed alpha 1(IV) and alpha 2(IV) collagen chains in all renal basement membranes; alpha 3(IV), alpha 4(IV), and alpha 5(IV) chains in the GBM, distal tubular basement membrane, and Bowman's capsule; and the alpha 6(IV) chain in Bowman's capsule. Conversely, the basement membranes from the affected Bull terrier cornea, lens capsule, retina, skin, lung, and muscle had a normal ultrastructural appearance and were not thickened compared with membranes in normal age-matched dogs. The distribution of basement membrane abnormalities in Bull terrier hereditary nephritis may occur because the defective protein is present exclusively or more abundantly in the kidney and is structurally more important in the kidney or because of local intrarenal stresses.

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."

Pyoderma gangrenosum with secondary pyarthrosis following propylthiouracil

The association of pyoderma gangrenosum and arthritic symptoms is well documented. We present a rarely reported variant of this in a 44-year-old woman with pyoderma gangrenosum and bilateral large purulent effusions of her knees. She had no evidence of underlying rheumatoid arthritis or a specific seronegative spondyloarthropathy. Of note she had a history of Graves' disease for which she had been treated with propylthiouracil for 3 years and on investigation at this presentation had a markedly elevated perinuclear antineutrophil cytoplasm antibody (P-ANCA) level with specificities for IgM myeloperoxidase, IgG elastase and IgG lactoferrin. We believe this patient had pyoderma gangrenosum with secondary sterile pyarthrosis and a P-ANCA precipitated by propylthiouracil.

A comparison of the clinical and laboratory features of thin basement membrane disease (TBMD) and IgA glomerulonephritis (IgA GN)

AIM

The aim of this study was to determine the clinical and laboratory characteristics that distinguished thin basement membrane disease (TBMD) from IgA glomerulonephritis (IgA GN) at presentation and at follow-up.

PATIENTS AND METHODS

Seventy-one patients with TBMD and 31 with IgA GN were studied. Males accounted for 11/71 (15%) patients with TBMD, and 20/31 (65%) of those with IgA GN (p < 0.001).

RESULTS

At presentation, patients with TBMD had hematuria (42%) or proteinuria (42%), and sometimes both (24%), while those with IgA GN usually had both hematuria and proteinuria (71%, p < 0.0001). Furthermore, patients with IgA GN were more likely to have higher urinary RBC counts (p < 0.001), and more proteinuria (p < 0.001) than those with TBMD. An elevated serum creatinine or blood pressure did not distinguish between TBMD and IgA GN at presentation. At review, fewer individuals with IgA GN had elevated levels of urinary RBC and protein, and the proportions were not different from those in patients with TBMD. This was presumably because the acute episode had resolved.

CONCLUSION

The outcome was worse in patients with IgA GN, with 8/31 (26%) having an elevated serum creatinine and 3/31 (10%) with end-stage renal failure, compared with an elevated serum creatinine in 3/61 (5%) patients with TBMD (p < 0.02) and no patients with renal failure (p < 0.05).

International Consensus Statement on Testing and Reporting of Antineutrophil Cytoplasmic Antibodies (ANCA)

Antineutrophil cytoplasmic antibody (ANCA) tests are used to diagnose and monitor inflammatory activity in the primary systemic small vessel vasculitides. ANCA is best demonstrated in these diseases by using a combination of indirect immunofluorescence (IIF) of normal peripheral blood neutrophils and enzyme-linked immunosorbent assays (ELISAs) that detect ANCA specific for proteinase 3 (PR3) or myeloperoxidase (MPO). For ANCA testing in "new" patients, IIF must be performed on all serum samples. Serum samples containing ANCA, any other cytoplasmic fluorescence, or an antinuclear antibody (ANA) that results in homogeneous or peripheral nuclear fluorescence then should be tested in ELISAs for PR3-ANCA and MPO-ANCA. Optimally, ELISAs for PR3-ANCA and MPO-ANCA should be performed on all serum samples. Inclusion of the most recent positive sample in the IIF or ELISA may help demonstrate a change in antibody level. Reports should use recommended terms. Any report of positive neutrophil fluorescence issued before the ELISA results are available should indicate that positive fluorescence alone is not specific for the diagnosis of Wegener granulomatosis or microscopic polyangiitis and that decisions about treatment should not be based solely on the ANCA results.

A comparison of commercial and in-house ELISAs for antineutrophil cytoplasmic antibodies directed against proteinase 3 and myeloperoxidase

This study compares the concordance of results in different ELISAs for antineutrophil cytoplasmic antibodies (ANCA) directed against proteinase 3 (PR3) or myeloperoxidase (MPO). Sera were considered "true positives" if they were positive according to the manufacturer's criteria in a least three of the five PR3-ANCA ELISAs, or in at least four of the six MPO-ANCA ELISAs. Of the 26 sera that demonstrated cytoplasmic fluorescence (C-ANCA), 23 (89%) contained PR3-ANCA and three (11%) had MPO-ANCA. Two sera that were negative by indirect immunofluorescence (IIF) contained PR3-ANCA. Of the 26 sera with perinuclear fluorescence (P-ANCA), 19 (73%) contained MPO-ANCA, and one (4%) had PR3-ANCA. Six sera with P-ANCA did not have PR3- or MPO-ANCA. No serum that was negative by IIF contained MPO-ANCA. For the different PR3-ANCA ELISAs, sensitivities ranged from 88 to 100%, and specificities from 91 to 100%. For the MPO-ANCA ELISAs, sensitivities varied from 59 to 100% and specificities from 83 to 100%. The highest sensitivity and specificity for both the PR3- and MPO-ANCA ELISAs were obtained with the IBL and Eurodiagnostica assays. The in-house PR3-ANCA ELISA performed slightly less well than the commercial assays, but the performance of the in-house MPO-ANCA assay was comparable or better.

Antineutrophil cytoplasmic antibody (ANCA)-positive cutaneous leucocytoclastic vasculitis associated with antithyroid therapy in Graves' disease

Presented is a case of a 27-year-old male with Graves' disease on long-term propylthiouracil treatment who, when changed to carbimazole, rapidly developed a petechial and purpuric eruption on the legs, which subsequently flared on treatment with radioiodine. The clinical diagnosis of leucocytoclastic vasculitis was confirmed on skin biopsy. High-titre antineutrophil cytoplasmic antibodies in a perinuclear pattern (P-ANCA) were identified. No anti-myeloperoxidase activity was noted; therefore, the P-ANCA were classified in the atypical group. The target antigens, as determined by enzyme-linked immunosorbent assay, were lysozyme, lactoferrin and bactericidal/permeability increasing protein. Propylthiouracil and carbimazole are chemically related antithyroid drugs. There are reports of typical and atypical P-ANCA-positive cutaneous vasculitis due to propylthiouracil. Cutaneous vasculitis associated with atypical P-ANCA has not been noted previously to be temporally related to carbimazole use. The consideration of thionamides as possible aetiological agents in cases of P-ANCA-positive drug-induced vasculitis is suggested.

Anti-glomerular basement membrane (GBM)-antibody-mediated disease with normal renal function

BACKGROUND

This study compared the clinical and laboratory characteristics of patients with anti-glomerular basement membrane (GBM) disease and normal renal function, with those of patients with anti-GBM disease where there was renal impairment.

METHODS

The medical records of the 14 patients who had presented with anti-GBM disease to our hospital in the past 20 years were reviewed.

RESULTS

Five (36%) had a normal serum creatinine or creatinine clearance at presentation. Other features were haemoptysis (2/5, 40%), macroscopic haematuria (2/5, 40%) or systemic symptoms (1/5, 20%). All five (100%) had some degree of haematuria, four (80%) had proteinuria of at least 1 g/day, and none was hypertensive. Anaemia, a raised WCC, or elevated ESR (> 35 mm/h) occurred less often than in patients with impaired renal function (P<0.05). Two of the five (40%) with normal renal function had circulating anti-GBM antibodies, which were present at low or moderate levels; but seven of the nine with renal impairment (77%) had circulating antibodies, with high levels in five. Renal biopsies from patients with normal renal function were normal (1/5, 20%), showed mesangial proliferation (4/5, 80%) or had more than 20% glomeruli sclerosed (1/5, 20%). Complement deposition was present in 2/4 biopsies (50%). The kidneys from patients with renal impairment had crescents in more than 50% glomeruli (9/9, 100%), and four had more than 20% glomeruli sclerosed (44%). All four kidneys from patients with renal impairment that were examined had complement deposits (100%). Treatment was identical in both groups; patients with normal renal function were followed for a median of 48 months, and those with renal impairment for 180 months. There were no further episodes of haemoptysis, haematuria, or other symptoms of relapse in either group. All five patients with normal renal function are alive, and the serum creatinine is less than 0.2 mmol/l in all (100%), but haematuria persists in one (20%), and proteinuria >1 g/day in two (40%). Eight of the nine (89%) patients with impaired renal function survive, but all are currently being dialysed or have had a renal transplant.

CONCLUSION

Patients with anti-GBM disease with normal renal function are not uncommon, and often have a good prognosis. There is less renal damage, possibly because of lower levels of circulating anti-GBM antibodies and less glomerular complement deposition.

Alport syndrome. A review of the ocular manifestations

Alport syndrome has a prevalence of 1/5000, and 85% of patients have the X-linked form, where affected males develop renal failure and usually have a high-tone sensorineural deafness by the age of 20. The typical ocular associations are a dot-and-fleck retinopathy which occurs in about 85% of affected adult males, anterior lenticonus which occurs in about 25%, and the rare posterior polymorphous corneal dystrophy. The retinopathy and anterior lenticonus are not usually demonstrated in childhood but worsen with time so that the retinal lesion is often present at the onset of renal failure, and the anterior lenticonus, later. The demonstration of a dot-and-fleck retinopathy in any individual with a family history of Alport syndrome or with end-stage renal disease is diagnostic of Alport syndrome. The presence of anterior lenticonus or posterior polymorphous corneal dystrophy in any individual is highly suggestive of the diagnosis of Alport syndrome. Additional ocular features described in X-linked Alport syndrome include other corneal dystrophies, microcornea, arcus, iris atrophy, cataracts, spontaneous lens rupture, spherophakia, posterior lenticonus, a poor macular reflex, fluorescein angiogram hyperfluorescence, electrooculogram and electroretinogram abnormalities, and retinal pigmentation. All mutations demonstrated to date in X-linked Alport syndrome have affected the COL4A5 gene which encodes the alpha 5 chain of type IV collagen. This protein is probably common to the basement membranes of the glomerulus, cochlea, retina, lens capsule, and cornea. However, the alpha 3(IV) and 4(IV) as well as the alpha 5(IV) collagen chains are usually absent from the affected basement membranes, because the abnormal alpha 5(IV) molecule interferes with the stability of all three. The loss of these collagen molecules from the affected basement membranes results in an abnormal ultrastructural appearance. The ocular and other clinical features of autosomal recessive Alport syndrome are identical to those seen in X-linked disease, while retinopathy and cataracts are the only ocular abnormalities described in the rare autosomal dominant form of Alport syndrome. There are no ocular associations of thin basement membrane disease which is a common disease that probably represents the heterozygous expression of X-linked or autosomal recessive Alport syndrome.

Ocular manifestations of autosomal recessive Alport syndrome

Ocular abnormalities are common in X-linked Alport syndrome, but they have not been studied in patients with the rarer autosomal recessive disease. We have examined the eyes of a family with autosomal recessive Alport syndrome. Four of the eight offspring of a consanguineous marriage had renal failure and deafness by the age of 20 years. The diagnosis of Alport syndrome was confirmed on the ultrastructural demonstration of a lamellated glomerular basement membrane (GBM) in one affected family member. Autosomal recessive inheritance was suggested by the lack of linkage to the COL4A5/COL4A6 locus, and by linkage to the COL4A3/COL4A4 locus. All four affected family members had anterior lenticonus (or had had a lens replacement for this) and the three who were examined had a dot-and-fleck retinopathy. Neither of the two unaffected offspring who were examined nor the father had these abnormalities. The ocular manifestations of autosomal recessive Alport syndrome are probably identical to those for the X-linked form. Although the mutations in these diseases affect genes for different type IV collagen chains, these chains occur together in the basement membranes of the kidney, eye and ear, and abnormalities in any one may result in the same clinical phenotype.

Ocular abnormalities in thin basement membrane disease

AIM/BACKGROUND

Alport syndrome is an X linked disease that results in renal failure, deafness, and ocular abnormalities including a dot and fleck retinopathy and anterior lenticonus. The ultrastructural appearance of the glomerular basement membrane in thin basement membrane disease (TBMD) resembles that seen in some patients with Alport syndrome, and in some cases this disease is inherited too. The aim of this study was to determine whether patients with TBMD have any ocular abnormalities.

METHODS

The eyes of 17 unrelated individuals with TBMD were studied by slit-lamp, including biomicroscopic fundus examination with a 78 D lens, by direct ophthalmoscopy, and by fundal photographs. The findings were compared with those in patients with IgA glomerulonephritis or Alport syndrome, and in normals.

RESULTS

No patient with TBMD had a dot and fleck retinopathy or anterior lenticonus. A corneal dystrophy (n = 2) or pigmentation (n = 1), and retinal pigment epithelial clumping and maculopathy (n = 1) were noted. Corneal, lens, and retinal dots were found in five (29%), three (18%), and 16 (94%) patients, respectively, but these were also demonstrated in individuals with other renal diseases and in normal individuals.

CONCLUSIONS

The dot and fleck retinopathy and anterior lenticonus typical of Alport syndrome do not occur in TBMD. The protein abnormality and genetic defect in TBMD are not known, but the lack of ocular lesions suggests that the abnormal protein in this disease is more sparsely distributed or less important in the basement membranes of the eye than of the kidney. Alternatively, the protein may be less affected by the mutations responsible for TBMD.

Classical polyarteritis nodosa and microscopic polyarteritis with medium vessel involvement--a comparison of the clinical and laboratory features

Microscopic polyarteritis may involve medium-sized and small blood vessels as well as arterioles, venules and capillaries. We have compared the clinical and laboratory features in patients with microscopic polyarteritis and medium vessel involvement, with the features found in patients with polyarteritis nodosa affecting medium vessels alone. In a 9-year period, 21 patients presented to our hospital with a form of polyarteritis. Seven had microscopic polyarteritis demonstrated histologically (6/7, 86%) and associated with dysmorphic urinary red cells (7/7, 100%), as well as medium vessel vasculitis demonstrated histologically (7/7) or by angiography (1/7, 14%). Five patients had polyarteritis nodosa with medium vessel vasculitis demonstrated histologically (3/5, 60%) or by angiography (2/5, 40%); and no evidence of a glomerular vasculitis on biopsy (2/7, 29%) or in the urinary sediment (0/7, 0%). The remaining 9 patients had microscopic polyarteritis but medium vessel involvement was not excluded by angiography. All patients with microscopic polyarteritis and medium vessel involvement had glomerular hematuria (> 100,000 glomerular RBC/ml), proteinuria > 0.5 g/24 hours), and an elevated serum creatinine (0.166 to 0.811 mmol/l). Other symptoms included fever (6/7, 86%), night sweats (5/7, 71%), gastrointestinal bleeding (4/7, 57%), proximal myopathy (3/7, 43%) and peripheral neuropathy (3/7, 43%). One patient (1/7, 14%) had hypertension. Anemia (6/7, 86%), a raised ESR (6/7, 86%), thrombocytosis (6/7, 86%), hypoalbuminemia (6/7, 86%) and abnormal liver function tests (6/7, 86%) were common. Two patients (29%) had an eosinophilia. All 5 individuals who were tested for ANCA were positive (2cANCA, 2pANCA and one pattern not described). In contrast, in patients with polyarteritis nodosa and medium vessel involvement alone, an elevated ESR was common (4/5, 80%) but fever (1/5, 20%), night sweats (0/5, 0%), proximal myopathy (1/5, 20%) and peripheral neuropathy (1/5, 20%) were seen infrequently; hypertension (1/5, 20%) and eosinophilia (1/5, 20%) were also uncommon; and ANCA were not demonstrated (0/3, 0%). Medium-sized vessel involvement is common in patients with microscopic polyarteristis, and these patients are more likely to have renal involvement and systemic symptoms, and be ANCA-positive, than patients with polyarteritis nodosa alone. Gastrointestinal symptoms are often seen in both groups.

Clinical features in two patients with IgA glomerulonephritis and thin-basement-membrane disease

BACKGROUND

Both IgA glomerulonephritis (IgA gn) and thin basement membrane disease (TBMD) are common forms of glomerulonephritis. Patients with these conditions may present with identical clinical features, but higher urinary RBC counts, heavier proteinuria, and impaired renal function are more common in patients with IgA gn. Because IgA gn and TBMD are common, some patients will have both diseases.

SUBJECTS

We describe the clinical features of two individuals with both Iga gn and TBMD, and compare them with the clinical and laboratory characteristics in patients with TBMD (n=15) or IgA gn (n=32) alone.

RESULTS

IgA gn was found in two individuals of the 110 with TBMD who were studied. They both had haematuria with >/100 000 RBC/ml and proteinuria >0.2/day (one had more than 1 g/day). These features were more consistent with Iga gn than TBMD alone. However, both individuals had normal serum creatinine and creatinine clearance at presentation. Additional clinical features were macroscopic haematuria in one and hypertension in both.

CONCLUSIONS

IgA deposits are not uncommon in patients with TBMD, and these patients have clinical features that resemble those seen in IgA gn rather than TBMD. Patients with both IgA gn and TBMD do not necessarily have the worse prognosis noted in some patients with Iga gn.

Polyarteritis nodosa and antiglomerular basement membrane disease without antineutrophil cytoplasm antibodies

Antiglomerular basement membrane (GBM) antibodies have been described previously in patients with microscopic polyarteritis but not in patients with polyarteritis nodosa alone. Where anti-GBM antibodies occur in microscopic polyarteritis, antineutrophil cytoplasm antibodies (ANCA) are usually present. We describe here a patient with polyarteritis nodosa and anti-GBM antibodies in whom ANCA could not be demonstrated. A 72-year-old woman presented with abdominal pain, diarrhoea and acute renal failure. A renal biopsy showed crescentic glomerulonephritis and linear immunofluorescence of the GBM consistent with anti-GBM disease. In addition, there was evidence of large-and medium-sized vessel vasculitis on abdominal angiography, performed because of persisting abdominal pain. There was no small vessel vasculitis on histological examination of the renal biopsy and ANCA could not be demonstrated by indirect immunofluorescence or ELISA.

Epitope mapping of anti-proteinase 3 and anti-myeloperoxidase antibodies

Anti-proteinase 3 (PR3) and anti-myeloperoxidase (MPO) autoantibodies are present in many patients with Wegener's granulomatosis (WG) and microscopic polyarteritis. The aim of this study was to determine whether these antibodies bound to linear peptide sequences on their target antigens. If common linear epitopes were demonstrated, then these could be manufactured and used in diagnostic ELISAs for anti-PR3 and anti-MPO antibodies. In addition, any homology between these epitopes and bacterial or viral sequences might implicate those microorganisms in the development of these antibodies and the pathogenesis of the associated diseases. The presence of linear epitopes on PR3 and MPO was suggested by the binding of the corresponding autoantibodies to these proteins after they had been reduced with beta-mercaptoethanol (beta-ME) and denatured with SDS or boiling, and digested with proteases. Four of the 22 sera with anti-PR3 antibodies bound to PR3 in Western blots after treatment with SDS, beta-ME and boiling for 5 min. Thermal denaturation reduced the amount of binding more than other forms of denaturation. One serum with anti-PR3 antibodies bound to Lys-C and Glu-C-digested PR3 in dot blots. Linear epitopes could not be further defined by their binding in an ELISA using overlapping peptides corresponding to the PR3 molecule because of non-specific binding. Three of the five sera with anti-MPO antibodies bound to MPO in Western blots after treatment with SDS, beta-ME and boiling for 5 min. One serum with anti-MPO antibodies bound to Lys-C and Glu-C-digested MPO in dot blots. Again, linear epitopes could not be further defined using an ELISA with overlapping peptides because of non-specific binding. Some anti-PR3 and anti-MPO antibodies are likely to recognize linear epitopes, but these cannot be defined by use of a PIN ELISA system.

Bull terrier hereditary nephritis: a model for autosomal dominant Alport syndrome

Bull terrier hereditary nephritis is inherited as an autosomal dominant disease and causes renal failure at variable ages in affected dogs. The aims of this study were to compare the clinical, ultrastructural and immunohistochemical features of bull terrier hereditary nephritis with the characteristics of the human forms of Alport syndrome. Many animals with bull terrier hereditary nephritis have hematuria, and some have anterior lenticonus. However, deafness is not associated with the renal disease, and affected dogs do not have the large platelets that are occasionally seen in patients with autosomal Alport syndrome. The glomerular capillary basement membrane (GCBM) in affected bull terriers has an identical ultrastructural appearance to that seen in X-linked Alport syndrome, with lamellations and intramembranous electron-dense deposits. However, both the Goodpasture and the Alport antigens, which represent parts of the alpha 3(IV) and alpha 5(IV) collagen chains, respectively, are present in the GCBM of affected dogs. Bull terrier hereditary nephritis represents an animal model for autosomal dominant Alport syndrome, and can be used to further examine how genetic mutations affect a basement membrane protein and the corresponding membrane structure.

Lupus anticoagulant in anti-neutrophil cytoplasmic antibody-associated polyarteritis

Lupus anticoagulant has been described in association with many autoimmune disorders. Here we describe its occurrence in a patient with ANCA-associated microscopic polyarteritis with medium vessel involvement. A 62-year-old man presented with mononeuritis multiplex and abdominal pain and was demonstrated to have multiple aneurysms on visceral angiography, consistent with the diagnosis of medium vessel vasculitis or classical polyarteritis nodosa. In addition he had active tuberculosis. He developed a deep venous thrombosis at this admission and, on one occasion, had a prolonged APTT but this was not confirmed to be due to a lupus anticoagulant. Two years later when the patient was readmitted with fevers, headaches and nasal discharge, both ANCA and a lupus anticoagulant were demonstrated in his serum, although there was no evidence of a venous thrombosis. Six months later the patient was demonstrated for the first time to have dysmorphic urinary RBC consistent with glomerular bleeding; at the same time he developed a deep venous thrombosis. ANCA was still present, but the lupus anticoagulant could not be detected. The patient was treated with cyclophosphamide and prednisolone and a Greenfield filter inserted into his inferior vena cava.

Albipunctatus retinopathy in inherited interstitial nephritis

We describe here a patient with familial interstitial nephritis and albipunctatus retinopathy. Albipunctatus is often seen in patients with Alport syndrome, which is an X-linked disorder characterised in affected males by renal failure by the age of 25, high-tone sensorineural deafness, anterior lenticonus and albipunctatus. The diagnosis of Alport syndrome depends on the electron microscopic appearance of a trabeculated glomerular basement membrane (GBM); and mutations have been demonstrated in the gene for the alpha 5 chain of type IV collagen. In the familial interstitial nephritis described here, the inheritance was autosomal dominant, renal failure developed in middle age, and there was no associated hearing loss or anterior lenticonus. The finding of albipunctatus retinopathy in this patient suggests that the genetic mutation responsible involves a protein common to both retinal and interstitial basement membranes. In addition, we conclude that the demonstration of albipunctatus in an individual with familial nephritis does not necessarily indicate that the underlying disease is Alport syndrome.

Studies to demonstrate inhibition of functional activity of neutrophil lysosomal enzymes with ANCA

Many autoantibodies that have enzymes as their targets bind to the catalytic sites and inhibit enzymatic activity. We have established functional assays for the targets of anti-neutrophil cytoplasm antibodies (ANCA) in order to determine whether these antibodies are directed against the corresponding catalytic sites. Anti-proteinase 3 activity was measured by the cleavage of alpha-naphthyl acetate; myeloperoxidase activity by peroxidation of monochlorodimedon or guaiacol using hydrogen peroxide; and elastase activity by a fluorimetric assay of the hydrolytic product of N-succ (ala)3 amido-methyl coumarin. The addition of immunoglobulin from patients with ANCA to these assays did not result in inhibition of functional activity of the corresponding enzyme when compared with normal immunoglobulin. Furthermore the removal of specific immunoglobulin by solid phase adsorption to the corresponding antigen did not result in an increase in enzymatic activity compared with the starting material. However preliminary results suggest that anti-neutrophil proteinase 3 binding may be inhibited in a solid-phase ELISA by preincubation with a peptide corresponding to the catalytic site.

Hereditary abnormalities of renal basement membranes

The glomerular and tubular basement membranes are the principal barriers to filtration and re-absorption of water and molecules in the nephron. They are composed primarily of type IV collagen, laminin, fibronectin, sulphated proteoglycans and collagen type I. Three common inherited diseases are associated with abnormalities of basement membrane proteins: Alport's syndrome, thin basement membrane disease (TBMD) and adult polycystic kidney disease. In this review we describe the application of molecular biological techniques to the study of these conditions. Classic Alport's syndrome is an X-linked disorder with a lamellated glomerular basement membrane (GBM) which typically results in renal failure in males. Studies with sera from patients with Goodpasture's syndrome, or monoclonal antibodies specific for the Goodpasture antigen, show that the Goodpasture antigen is absent or masked in the kidneys of individuals with Alport's syndrome. There is some evidence to suggest that the Goodpasture antigen is best represented by the non-collagenous domain of the alpha 3 chain of type IV collagen, but that other non-collagenous regions may also contribute to the antigen. It is through these non-collagenous regions that the type IV collagen chains form the typical network, and the abnormality in Alport's syndrome interferes with this network formation. However, we have recently demonstrated that the gene for the non-collagenous domain of the alpha 3 collagen chain is present in individuals with Alport's syndrome. Furthermore, other groups have shown a defect in a novel type IV collagen chain, the alpha 5 chain, in 3 unrelated cases of Alport's syndrome.(ABSTRACT TRUNCATED AT 250 WORDS)

Mortality and morbidity of diabetes in Papua New Guinea

A 95% follow-up of all known diabetic patients in one racial group in Papua New Guinea was performed. Mortality was high with an average life-span of 4-5 years from the time of diagnosis. Microvascular diabetic complications were detected in over half of the surviving diabetic patients whose average duration of known disease was 3.8 years. At present, diabetes mellitus is both a rapidly fatal and morbid disease in Papua New Guinea.

Diabetes mellitus in the Tolais of the Gazelle Peninsula, New Britain

Diabetes is relatively common in the Tolais of the Gazelle Peninsula. The syndrome has the clinical and biochemical features of maturity-onset diabetes, with a familial tendency, a tendency to obesity and insulin release in response to a carbohydrate load. There is a high incidence of microvascular complications in these patients, and the median survival time is between 4 and 5 years. Health workers should assess those at risk for this condition and try to provide regular supervision of diagnosed diabetics.