Can granulomatosis with polyangiitis be diagnosed earlier in primary care? A case-control study

BACKGROUND

People with granulomatosis with polyangiitis (GPA) commonly described long delays before diagnosis.

AIM

To study the natural history of GPA prior to diagnosis using primary care data, and determine whether clinical features could be identified to help earlier diagnosis.

DESIGN

Case-control study using the Clinical Practice Research Datalink.

METHODS

We compared primary care activity and clinical features between cases and 10 matched controls.

RESULTS

We identified 757 cases and matched 7546 controls. Compared to controls, cases had more GP consultations and overall healthcare activity in the 5 years prior to their diagnosis, with a marked increase in the year before diagnosis, and particularly in the last 3 months. However, consultations were mostly for symptoms that were not specifically related to GPA. In the year prior to diagnosis, the most frequent and strongly predictive clinical features of GPA were Ear Nose and Throat (ENT) symptoms [34.5% of cases, odds ratio (OR) 10.5, 95% confidence intervals (CI) 8.6-12.7], and general (constitutional) symptoms (21.5% of cases, OR 9.0, 95% CI 7.1-11.3). In the year before diagnosis a larger number of cases attended secondary care (382, 50.5%) than had records of clinical features of GPA.

CONCLUSIONS

After discussing our findings, we conclude that it would be difficult to identify cases of GPA earlier in primary care. Our results support a need for heightened awareness of this condition among secondary care clinicians, especially those assessing emergency admissions, and in the clinics which were most frequently attended by cases 3-12 months prior to diagnosis.

EULAR/ERA-EDTA recommendations for the management of ANCA-associated vasculitis

In this article, the 2009 European League Against Rheumatism (EULAR) recommendations for the management of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) have been updated. The 2009 recommendations were on the management of primary small and medium vessel vasculitis. The 2015 update has been developed by an international task force representing EULAR, the European Renal Association and the European Vasculitis Society (EUVAS). The recommendations are based upon evidence from systematic literature reviews, as well as expert opinion where appropriate. The evidence presented was discussed and summarised by the experts in the course of a consensus-finding and voting process. Levels of evidence and grades of recommendations were derived and levels of agreement (strengths of recommendations) determined. In addition to the voting by the task force members, the relevance of the recommendations was assessed by an online voting survey among members of EUVAS. Fifteen recommendations were developed, covering general aspects, such as attaining remission and the need for shared decision making between clinicians and patients. More specific items relate to starting immunosuppressive therapy in combination with glucocorticoids to induce remission, followed by a period of remission maintenance; for remission induction in life-threatening or organ-threatening AAV, cyclophosphamide and rituximab are considered to have similar efficacy; plasma exchange which is recommended, where licensed, in the setting of rapidly progressive renal failure or severe diffuse pulmonary haemorrhage. These recommendations are intended for use by healthcare professionals, doctors in specialist training, medical students, pharmaceutical industries and drug regulatory organisations.

A comparative study of the diagnostic accuracy of ELISA systems for the detection of anti-neutrophil cytoplasm antibodies available in Japan and Europe

OBJECTIVES

Primary systemic vasculitis associated with anti-neutrophil cytoplasm antibodies (ANCA) differs in its frequency and clinical expression between Japan and Europe. We sought to ascertain whether such differences arise from the performance of enzyme-linked immunosorbent assays (ELISAs) for ANCA.

METHODS

Plasma samples from 64 consecutive Japanese patients with a clinical and histological diagnosis of primary systemic vasculitis including microscopic polyangiitis (MPA; n=52), Churg-Strauss syndrome (CSS; n=1), and Wegener's granulomatosis (WG; n=11), or those from disease controls with non-vasculitic glomerulonephritis (n=54) and healthy controls (n=55) were tested for the presence of myeloperoxidase (MPO) by ELISAs available in Japan (Nipro and MBL) and compared with those in Europe (Wieslab). The sensitivity and specificity were calculated for each ELISA, and its diagnostic performance was assessed by receiver operating characteristic curve analysis.

RESULTS

The sensitivity and specificity of either MPO-ANCA assays for a diagnosis of MPA were 90.4% and 98.2% (Nipro), 88.2% and 96.3% (MBL), and 86.5% and 99.1% (Wieslab). The overall diagnostic performance, assessed as the area under curve of the MPO-ANCA ELISAs for MPA were 0.946+/-0.022 (Nipro), 0.970+/-0.017 (MBL), and 0.971+/-0.017 (Wieslab), while that of PR3-ANCA ELISAs for WG were 0.986+/-0.025 (Nipro), 0.993+/-0.017 (MBL), and 0.916+/-0.059 (Wieslab).

CONCLUSIONS

The MPO-ANCA ELISAs commercially available in Japan exhibited high sensitivity and specificity for the diagnosis of ANCA-associated vasculitides and provided similar diagnostic value to those in Europe. These results facilitate further international comparison of ANCA-associated vasculitides between Japanese and European populations.

Primary systemic vasculitis: clinical features and mortality

BACKGROUND

Wegener's granulomatosis (WG), Churg Strauss syndrome (CSS) and microscopic polyangiitis (MPA) are primary systemic vasculitides (PSV), the clinical features of which have been described from tertiary centres.

AIM

To provide the first clinical description of MPA from a general hospital and compare clinical features with WG and CSS.

DESIGN

Retrospective analysis of patient records.

METHODS

Records of 99 PSV patients attending a single hospital, from 1988 to 2000, were reviewed for: clinical features, date/age at diagnosis, sex, duration of illness, anti-neutrophil cytoplasmic antibodies (ANCA), treatment, comorbidity and deaths. Cases were classified using ACR, CHCC and Lanham criteria/definitions. Birmingham vasculitis activity scores (BVAS) and damage index (VDI) were calculated. Survival was assessed using Cox proportional hazards model and standardized mortality ratios (SMRs).

RESULTS

Compared to previous reports there was more ENT (29%) and respiratory (29%) but less renal (92%) involvement in MPA, and less ENT involvement in WG (81%). CSS showed high neurological (72%), cardiovascular (28%) and gastrointestinal (17%) involvement and the highest median (range) VDI (p = 0.01 vs. WG; p = 0.001 vs. MPA). BVAS1 was significantly lower in MPA than in WG [median (range) 15 (4-29) vs. 21 (6-39), (p = 0.001)] but not in CSS [20 (7-28), p = 0.08]. SMR (95%CI) for PSV was 4.8 (3.0-6.6); 5-year survival was 45.1% for MPA, 75.9% for WG and 68.1% for CSS. Age was a significant risk, but only to the same extent as in the reference population. When age was adjusted for, no other significant factor was found.

DISCUSSION

The clinical characteristics seen here are similar to those in previous series. There are difficulties in using the MPA CHCC definitions in classification. There is a high proportion of neurological involvement in CSS, causing permanent damage. MPA may have a poorer prognosis than WG or CSS.

Rheumatoid vasculitis: becoming extinct?

BACKGROUND

Systemic rheumatoid vasculitis (SRV) is a relatively rare complication of RA. The incidence of SRV appeared to increase during the 1970s and 1980s from 6.0 to 12.5/million. During the 1990s there have been major changes in the treatment of RA, with more aggressive control of inflammation. Our aim was to study the epidemiology of SRV in a stable, well-defined population over a 15-yr period.

METHODS

Since 1988 we have maintained a prospective register of all patients with systemic vasculitis attending the Norfolk and Norwich University Hospital. Patients presenting with new-onset SRV, as defined by the criteria of Scott and Bacon, and registered with general practitioners in the former Norwich Health Authority area between 1988 and 2002 were identified. The population in 2002 was estimated to be 445 000 (215 000 males).

RESULTS

Fifty-one patients (24 male) with SRV were identified, with median age 61 yr and disease duration 16.8 yr. The overall annual incidence was 7.9/million (95% CI 5.9-10.4) (males, 7.7/million; females, 8.1/million). During the first quinquennium (1988-92) the incidence was 11.6/million (95% CI 7.4-17.0) and during the third (1998-2002) it was 3.6/million (95% CI 1.6-7.1). A rolling 3-yr average showed that the peak incidence was in 1992-94, at 15.2/million (95% CI 9.1-23.8), and the nadir was in 1998-2000, at 3.0/million (95% CI 0.8-7.8). A similar pattern was seen for males and females. There was no difference in age or disease duration at onset of SRV between the three quinquennia.

CONCLUSIONS

The incidence of SRV has declined dramatically since the 1980s. This could be due to better control of inflammatory disease or changes in smoking habits.

Increased level of hemoglobin 1 enhances survival of hypoxic stress and promotes early growth in Arabidopsis thaliana

Overexpression of a class 1 Hb (GLB1) protects Arabidopsis thaliana plants from the effects of severe hypoxia. Overexpression of the bifunctional symbiotic Hb (GLB1S) from Parasponia andersonii in A. thaliana also increases survival after hypoxia. Plants overexpressing the Hb 1 protein, mutated to have a low oxygen affinity, are as susceptible to hypoxia as WT plants, suggesting that the protection against hypoxia depends on the ability of the Hb to bind ligands, such as oxygen, with high affinity. A mild hypoxia pretreatment (5%) induces the Hb gene and increases the survival of plants after severe hypoxic treatment (0.1%). These results with Hb 1 show that plant Hbs have a role other than in nitrogen-fixing root nodules. Plants overexpressing the GLB1 protein show early vigorous growth in nonhypoxic conditions and are 50% larger in weight than the controls at 14 days. The constitutive expression of GLB1 also resulted in a reduced number of root hairs and increased number of laterals in the root system.

Evaluation of the Sørensen diagnostic criteria in the classification of systemic vasculitis

OBJECTIVES

To evaluate the use of the diagnostic criteria for Wegener's granulomatosis (WG) and microscopic polyangiitis (mPA) proposed by Sørensen et al. in the classification of primary systemic vasculitis (PSV).

METHODS

We applied to our cohort of PSV patients the American College of Rheumatology (ACR) criteria for WG, Churg-Strauss syndrome (CSS) and polyarteritis nodosa (PAN), the Chapel Hill Consensus Conference (CHCC) definitions for WG, mPA and CSS, the Hammersmith criteria for CSS and the Sørensen criteria for WG and mPA.

RESULTS

Ninety-nine PSV cases were identified. Fifty-six fulfilled criteria for WG (ACR), 60 for PAN (ACR) and 15 for CSS (ACR). Four fulfilled the Hammersmith criteria for CSS. Thirty-nine were defined as mPA (CHCC). Fifty-three patients fulfilled the Sørensen criteria for WG and three for mPA. Five of six patients classified as WG (ACR) who did not meet the Sørensen criteria were excluded by eosinophilia. Six patients who did not fulfil WG (ACR) met the Sørensen criteria for WG.

CONCLUSION

The classification of systemic vasculitis is complicated and many cases fulfil more than one set of criteria. The Sørensen criteria for WG is limited by its exclusion of eosinophilia despite reports of an association. We recommend that tissue eosinophilia or peripheral eosinophilia of <1.5x10(9)/l should not exclude a diagnosis of WG. With this modification, the Sørensen criteria for WG may be a useful method of classification, especially in confirming the classification of WG in patients who fulfil both WG (ACR) and mPA (CHCC). Few patients fulfilled the Sørensen criteria for mPA which suggests that they are not of value in classification.

Expression and evolution of functionally distinct haemoglobin genes in plants

Haemoglobin genes have been found in a number of plant species, but the number of genes known has been too small to allow effective evolutionary inferences. We present nine new non-symbiotic haemoglobin sequences from a range of plants, including class 1 haemoglobins from cotton, Citrus and tomato, class 2 haemoglobins from cotton, tomato, sugar beet and canola and two haemoglobins from the non-vascular plants, Marchantia polymorpha (a liverwort) and Physcomitrella patens (a moss). Our molecular phylogenetic analysis of all currently known non-symbiotic haemoglobin genes and a selection of symbiotic haemoglobins have confirmed the existence of two distinct classes of haemoglobin genes in the dicots. It is likely that all dicots have both class 1 and class 2 non-symbiotic haemoglobin genes whereas in monocots we have detected only class 1 genes. The symbiotic haemoglobins from legumes and Casuarina are related to the class 2 non-symbiotic haemoglobins, whilst the symbiotic haemoglobin from Parasponia groups with the class 1 non-symbiotic genes. Probably, there have been two independent recruitments of symbiotic haemoglobins. Although the functions of the two non-symbiotic haemoglobins remain unknown, their patterns of expression within plants suggest different functions. We examined the expression in transgenic plants of the two non-symbiotic haemoglobins from Arabidopsis using promoter fusions to a GUS reporter gene. The Arabidopsis GLB1 and GLB2 genes are likely to be functionally distinct. The class 2 haemoglobin gene (GLB2) is expressed in the roots, leaves and inflorescence and can be induced in young plants by cytokinin treatment in contrast to the class 1 gene (GLB1) which is active in germinating seedlings and can be induced by hypoxia and increased sucrose supply, but not by cytokinin treatment.

A hemoglobin from plants homologous to truncated hemoglobins of microorganisms

We have identified a nuclear-encoded Hb from plants (GLB3) that has a central domain similar to the "truncated" Hbs of bacteria, protozoa, and algae. The three-dimensional structure of these Hbs is a 2-on-2 arrangement of alpha-helices, distinct from the 3-on-3 arrangement of the standard globin fold [Pesce, A., Couture, M., Dewilde, S., Guertin, M., Yamauchi, K., Ascenzi, P., Moens, L. & Bolognesi, M. (2000) EMBO J. 19, 2424-2434]. GLB3-like genes are not found in animals or yeast, but our analysis reveals that they are present in a wide range of Angiosperms and a Bryophyte. Although cyanobacteria and Chlamydomonas have 2-on-2 Hbs (GLBN), GLB3 is more likely related to GLBO-type 2-on-2 Hbs from bacteria. Consequently, GLB3 is unlikely to have arisen from a horizontal transfer between the chloroplast and nuclear genomes. Arabidopsis thaliana GLB3 protein exhibits unusual concentration-independent binding of O(2) and CO. The absorbance spectrum of deoxy-GLB3 is unique; the protein forms a transient six-coordinate structure after reduction and deoxygenation, which slowly converts to a five-coordinate structure. In A. thaliana, GLB3 is expressed throughout the plant but responds to none of the treatments that induce plant 3-on-3 Hbs. Our analysis of the sequence, ligand interactions, and expression profile of GLB3 indicates that this protein has unique biochemical properties, evolutionary history, and, most likely, a function distinct from those of other plant Hbs.

Human neuroglobin, a hexacoordinate hemoglobin that reversibly binds oxygen

Neuroglobin is a newly discovered mammalian hemoglobin that is expressed predominately in the brain (Burmester, T., Welch, B., Reinhardt, S., and Hankeln, T. (2000) Nature 407, 520-523). Neuroglobin has less than 25% identity with other vertebrate globins and shares less than 30% identity with the annelid nerve myoglobin it most closely resembles among known hemoglobins. Spectroscopic and kinetic experiments with the recombinant protein indicate that human neuroglobin is the first example of a hexacoordinate hemoglobin in vertebrates and is similar to plant and bacterial hexacoordinate hemoglobins in several respects. The ramifications of hexacoordination and potential physiological roles are explored in light of the determination of an O(2) affinity that precludes neuroglobin from functioning in traditional O(2) storage and transport.

Geoepidemiology of systemic vasculitis: comparison of the incidence in two regions of Europe

OBJECTIVE

The aetiopathogenesis of the primary systemic vasculitides (PSV) is unknown but includes both environmental and genetic factors. The development of classification criteria/definitions for PSV allows comparison of the epidemiology between different regions.

METHODS

The same methods and the American College of Rheumatology (1990) criteria or Chapel Hill definitions were used to compare the epidemiology of Wegener's granulomatosis, Churg-Strauss syndrome, microscopic polyangiitis, and polyarteritis nodosa in Norwich (east England population 413 500) and Lugo (northwest Spain population 204 100). Patients with PSV were identified between 1 January 1988 and 31 December 1998.

RESULTS

Overall, the incidence of PSV in adults was almost equal in Norwich (18.9/million) and Spain (18.3/million). The incidence of Wegener's granulomatosis in Norwich (10.6/million) was greater than in Spain (4.9/million). There was a marked age-specific increase in incidence in Norwich with a peak age 65-74 years (52.9/million), but a virtually equal age distribution between ages 45 and 74 in Lugo (34.1/million). There was no significant increase with time in either population, or evidence of cyclical changes in incidence.

CONCLUSION

These data support the suggestion that environmental factors may be important in the pathogenesis of PSV.

Wegener's granulomatosis: unusual presentations

Wegener's granulomatosis is a necrotizing vasculitis characterized by respiratory tract involvement and focal glomerulonephritis. Rare presentations include abdominal pain as a result of gut involvement, pericarditis, cardiac arteritis and blindness. Detection of antineutrophil cytoplasmic antibodies should not be used as a substitute for a histological diagnosis.

Epidemiology of systemic vasculitis: a ten-year study in the United Kingdom

OBJECTIVE

To describe the epidemiology of the primary systemic vasculitides (PSV; Wegener's granulomatosis, Churg-Strauss syndrome, microscopic polyangiitis, polyarteritis nodosa) in a well-defined population over a 10-year period.

METHODS

An inception cohort of patients from the Norwich Health Authority (NHA) who were >15 years of age and had PSV first diagnosed between January 1, 1988 and December 31, 1997 was collected. Incidence rates were adjusted for age and sex to the 1992 population. The prevalence of PSV in this cohort was estimated on December 31, 1997. Patients were classified according to the American College of Rheumatology 1990 vasculitis criteria and the Chapel Hill Consensus definitions.

RESULTS

Eighty-two NHA residents fulfilled the inclusion criteria. There were 47 men and 35 women, with a mean age of 62.9 years (median 65.0 years). The overall annual incidence of PSV among NHA residents was 19.8/million (95% confidence interval [95% CI] 15.8-24.6). The point prevalence on December 31, 1997 was 144.5/million (95% CI 110.4-185.3). PSV was more common in males (23.5/million; 95% CI 17.3-31.3) than females (16.4/million; 95% CI 11.4-22.8). The age- and sex-specific incidence showed a clear increase with age, with an overall peak in the 65-74 year age group (60.1/million).

CONCLUSION

In our study population, the annual incidence of PSV is slowly increasing with time and the incidence is greatest in the elderly.

Epidemiology of systemic vasculitis: a ten-year study in the United Kingdom

OBJECTIVE

To describe the epidemiology of the primary systemic vasculitides (PSV; Wegener's granulomatosis, Churg-Strauss syndrome, microscopic polyangiitis, polyarteritis nodosa) in a well-defined population over a 10-year period.

METHODS

An inception cohort of patients from the Norwich Health Authority (NHA) who were >15 years of age and had PSV first diagnosed between January 1, 1988 and December 31, 1997 was collected. Incidence rates were adjusted for age and sex to the 1992 population. The prevalence of PSV in this cohort was estimated on December 31, 1997. Patients were classified according to the American College of Rheumatology 1990 vasculitis criteria and the Chapel Hill Consensus definitions.

RESULTS

Eighty-two NHA residents fulfilled the inclusion criteria. There were 47 men and 35 women, with a mean age of 62.9 years (median 65.0 years). The overall annual incidence of PSV among NHA residents was 19.8/million (95% confidence interval [95% CI] 15.8-24.6). The point prevalence on December 31, 1997 was 144.5/million (95% CI 110.4-185.3). PSV was more common in males (23.5/million; 95% CI 17.3-31.3) than females (16.4/million; 95% CI 11.4-22.8). The age- and sex-specific incidence showed a clear increase with age, with an overall peak in the 65-74 year age group (60.1/million).

CONCLUSION

In our study population, the annual incidence of PSV is slowly increasing with time and the incidence is greatest in the elderly.

Epidemiology of systemic vasculitis: a ten-year study in the United Kingdom

OBJECTIVE

To describe the epidemiology of the primary systemic vasculitides (PSV; Wegener's granulomatosis, Churg-Strauss syndrome, microscopic polyangiitis, polyarteritis nodosa) in a well-defined population over a 10-year period.

METHODS

An inception cohort of patients from the Norwich Health Authority (NHA) who were >15 years of age and had PSV first diagnosed between January 1, 1988 and December 31, 1997 was collected. Incidence rates were adjusted for age and sex to the 1992 population. The prevalence of PSV in this cohort was estimated on December 31, 1997. Patients were classified according to the American College of Rheumatology 1990 vasculitis criteria and the Chapel Hill Consensus definitions.

RESULTS

Eighty-two NHA residents fulfilled the inclusion criteria. There were 47 men and 35 women, with a mean age of 62.9 years (median 65.0 years). The overall annual incidence of PSV among NHA residents was 19.8/million (95% confidence interval [95% CI] 15.8-24.6). The point prevalence on December 31, 1997 was 144.5/million (95% CI 110.4-185.3). PSV was more common in males (23.5/million; 95% CI 17.3-31.3) than females (16.4/million; 95% CI 11.4-22.8). The age- and sex-specific incidence showed a clear increase with age, with an overall peak in the 65-74 year age group (60.1/million).

CONCLUSION

In our study population, the annual incidence of PSV is slowly increasing with time and the incidence is greatest in the elderly.

Musculoskeletal and systemic reactions to biological therapeutic agents

Autoimmune disease, in particular systemic lupus erythematosus (SLE), can be induced by drugs. Over the past couple of years biologic agents have become available for the treatment of inflammatory disease; simultaneously, researchers have realized that these drugs can not only suppress autoimmune disease but may also potentiate it. Interferon-alpha and interferon-beta both may induce autoimmune disease, but this is more frequent with interferon-alpha. Therapy to block tumor necrosis factor-alpha, either with monoclonal antibodies or fusion proteins, has been associated with the development of antinuclear antibodies, but only rarely with clinical development of SLE. None of the three reported cases of SLE occuring after anti-tumor necrosis factor-alpha therapy has developed major organ involvement. The continued use of biologic agents will provide interesting insights into the pathogenesis of autoimmune disease.

Primary renal vasculitis in Norfolk--increasing incidence or increasing recognition?

BACKGROUND

The incidence of renal vasculitis has previously been estimated using histological definitions or only a single clinical diagnosis, e.g. Wegener's Granulomatosis (WG). Our hospital is the single referral centre for the former Norwich Health Authority (NHA) which encompasses a stable, homogeneous, well-defined and studied population. We estimated the overall incidence of primary renal vasculitis and the incidence within individual clinical disease classifications.

METHODS

All cases of primary renal vasculitis diagnosed within the NHA over 66 months (1992-1997) were identified by review of renal biopsies, the Norfolk Vasculitis Register, hospital discharge summaries and plasmapheresis records. Patients were classified using the 1990 American College of Rheumatology criteria for Polyarteritis Nodosa (PAN), Churg Strauss Syndrome (CSS) and Henoch-Schonlein Purpura; the Chapel Hill Consensus Conference Definitions for Microscopic Polyangiitis (mPA) and the Lanham criteria for CSS. Incidence figures were calculated using the NHA adult population of 413747 (1994). Ninety-five per cent confidence intervals (C.I.) were calculated using the poisson distribution.

RESULTS

The overall annual incidence for primary renal vasculitis was 18/million (C.I. 12.9-24.4). The annual incidence of renal involvement of individual diseases was as follows: WG 7.9/million (95% C.I. 4.7-12.5); mPA 7.5/million (95% C. I. 4.4-12.0); PAN 7.0/million (95% C.I. 4.0-11.4); HSP 3.1/million (95% C.I. 1.2-6.3); CSS 1.3/million (95% C.I. 0.3-3.9).

CONCLUSIONS

The annual incidence for primary renal vasculitis overall and the individual subtypes in Norfolk is much higher than previous European estimates. This may reflect an increasing incidence in primary renal vasculitis with time or underestimation in previous studies. However the incidence of renal vasculitis in our population is markedly lower than reported in Kuwait. There may therefore be true variation in incidence between populations which could have implications for the aetiology of primary vasculitis.

Cutaneous vasculitis in a defined population--clinical and epidemiological associations

OBJECTIVE

To examine the value of the American College of Rheumatology (ACR) 1990 criteria for Henoch-Schönlein purpura (HSP) and hypersensitivity vasculitis (HSV) and the Chapel Hill Consensus Conference (CHCC) definition of cutaneous leukocytoclastic angiitis (CLA) in the classification of cutaneous vasculitis and to estimate the annual incidence of biopsy proven cutaneous vasculitis in a well defined population.

METHODS

ACR criteria for HSP and HSV and the CHCC definition for CLA and HSP were applied to an unselected cohort of 84 patients with biopsy proven cutaneous vasculitis attending a single district hospital in the United Kingdom between January 1990 and December 1994.

RESULTS

Thirty-seven patients fulfilled ACR criteria for HSV, of whom 27 also fulfilled the ACR criteria for HSP. Thirty-two patients met the CHCC definition for CLA and 7 the CHCC definition for HSP. The overall annual incidence of cutaneous vasculitis was 38.6/million (95% CI 30.6-48.1), and for CLA 15.4/million (95% CI 10.6-21.8).

CONCLUSION

The ACR 1990 criteria for HSP and HSV overlap; the CHCC definitions for CLA and HSP provide clearer distinction. Cutaneous vasculitis is as common as systemic vasculitis.

Churg-Strauss syndrome in a district hospital

Published series on Churg-Strauss syndrome (CSS) come from tertiary referral centres. We retrospectively studied 23 patients with CSS (18 male) seen over 14 years (1982-1995) in a District General Hospital serving a population of 500,000. Mean age of onset of vasculitis was 57, 10-19 years older than in previous series. The commonest clinical features were asthma (22) and eosinophilia > 1.5 x 10(9)/l (21). Systemic vasculitis involving two or more extrapulmonary organs occurred in 22 patients, with specific organ involvement of nervous system (18), joints (13), muscles (13), lungs (11), skin (11), kidneys (11), heart (10), and bowel (7). Various classification systems were applied including the Lanham criteria, which were met in 19 patients; the American College of Rheumatology criteria, met in 14; Churg and Strauss criteria, met in four; and the Chapel Hill Consensus definition, met only in two. ANCA was detected in 10/17 patients where measured. Treatment included corticosteroids (21), cyclophosphamide (8), azathioprine (9), immunoglobulin (2), and methotrexate (1). During follow-up six patients died, two due to myocardial vasculitis (mean age 52 years), three due to infection (mean age 80 years), and one cause unknown. Significant long-term disability was due to asthma in five and neuropathy in six.

Humanized anti-CD4 monoclonal antibody therapy of autoimmune and inflammatory disease

We have investigated the biological and therapeutic properties of a humanized anti-CD4 MoAb, hIgG1-CD4, in patients with refractory psoriasis and rheumatoid arthritis (RA). hIgG1-CD4 is a modulating, non-depleting MoAb, which induced a first-dose reaction in most patients treated. It provided brief symptomatic relief in both conditions, and psoriasis appeared easier to control with conventional agents after MoAb therapy. At the doses used, hIgG1-CD4 did not synergize therapeutically with the panlymphocyte MoAb CAMPATH-1H (C1H) in patients with RA treated sequentially with both agents. There were no serious adverse effects definitely attributable to therapy. Our results are compared with those of other CD4 MoAb studies, and factors influencing the outcome of therapy are discussed.

Two hemoglobin genes in Arabidopsis thaliana: the evolutionary origins of leghemoglobins

We cloned two hemoglobin genes from Arabidopsis thaliana. One gene, AHB1, is related in sequence to the family of nonsymbiotic hemoglobin genes previously identified in a number of plant species (class 1). The second hemoglobin gene, AHB2, represents a class of nonsymbiotic hemoglobin (class 2) related in sequence to the symbiotic hemoglobin genes of legumes and Casuarina. The properties of these two hemoglobins suggest that the two families of nonsymbiotic hemoglobins may differ in function from each other and from the symbiotic hemoglobins. AHB1 is induced, in both roots and rosette leaves, by low oxygen levels. Recombinant AHB1 has an oxygen affinity so high as to make it unlikely to function as an oxygen transporter. AHB2 is expressed at a low level in rosette leaves and is low temperature-inducible. AHB2 protein has a lower affinity for oxygen than AHB1 but is similar to AHB1 in having an unusually low, pH-sensitive oxygen off-rate.

Classification and epidemiology of the vasculitides

The systemic vasculitides are rare inflammatory conditions of blood vessel walls. A number of different classification schemes have been published since the first in 1952. The important developments have been the recognition of dominant blood vessel size, the distinction between primary and secondary vasculitis and the incorporation of pathogenic markers such as anti-neutrophil cytoplasmic antibodies. In 1990 the American College of Rheumatology (ACR) published criteria for the diagnosis of polyarteritis nodosa, Churg-Strauss syndrome, Wegener's granulomatosis, hypersensitivity vasculitis, Schönlein-Henoch purpura, giant cell arteritis and Takayasu arteritis. Sensitivity and specificity rates varied considerably: 71.0-95.3% for sensitivity and 78.7-99.7% for specificity. The criteria were not tested against the general population or against patients with other connective tissue diseases or rheumatic conditions. Four years later the Chapel Hill Consensus Conference (CHCC) produced definitions for the major types of vasculitis, however, these have proved controversial. Comparison in unselected patients with systemic vasculitis (in particular polyarteritis nodosa and microscopic polyangiitis) has shown that the ACR criteria and CHCC definitions identify different patients. The systemic vasculitides are somewhat more common than previously believed. The overall annual incidence approaches 40/million adults. The most common form of primary systemic vasculitis is giant cell arteritis; Wegener's granulomatosis, microscopic polyangiitis and Churg-Strauss syndrome have similar incidences. Classical polyarteritis nodosa and Takayasu arteritis are very rare in the UK.

Effect of classification on the incidence of polyarteritis nodosa and microscopic polyangiitis

OBJECTIVE

Polyarteritis nodosa (PAN) has been used as a generic term for systemic vasculitis. The distinction between classic PAN and microscopic polyangiitis (MPA) has not always been made. The aims of this study were to compare the American College of Rheumatology (ACR) criteria for PAN with the Chapel Hill Consensus Conference (CHCC) definitions of classic PAN and MPA, and to estimate the annual incidence of PAN and MPA.

METHODS

The 1990 ACR criteria and CHCC definitions for systemic vasculitis were applied to an unselected cohort of 130 patients with systemic vasculitis attending a single district hospital in the UK between February 1, 1988 and January 31, 1994.

RESULTS

Eight patients who met the ACR criteria for PAN and who also met the CHCC definition of MPA but not classic PAN were identified. A further 5 patients met the CHCC definition of MPA but not the ACR criteria for any other type of systemic vasculitis. No patient who met the CHCC definition of classic PAN was identified. The annual incidence of MPA was calculated to be 3.6/million (95% confidence interval 1.7-6.9), and the annual incidence of PAN (ACR criteria) was 2.4/million (95% confidence interval 0.9-5.3).

CONCLUSION

Classic PAN as defined by the CHCC is rare, because small vessel involvement is excluded from this definition.

Correlation between expression of antibodies to histone H2B and clinical activity in HIV-infected individuals

Levels of autoantibodies specific for the histone, H2B, were measured in individuals with HIV infection. In comparison with normal (uninfected) controls, infected patients, particularly those with symptomatic disease, had significantly elevated titres of anti-H2B antibodies. Longitudinal studies confirmed that levels of these antibodies were highest in patients with lymphadenopathy and declined with the development of AIDS. In preliminary experiments designed to determine the biological significance of the anti-histone antibodies, H2B was shown to be immunologically cross-reactive with an 18-kD antigen on the surface of HIV-infected or mitogen-activated CD4+ cells. Protein sequencing of the 18-kD antigen has since shown complete homology with histone H2B. Because the titres of H2B autoantibodies were found to parallel the numbers of circulating CD4 cells, it is possible that these antibodies are involved in the destruction of the helper/inducer T lymphocyte population.

Wegener's granulomatosis--increased incidence or increased recognition?

We aimed to calculate the annual incidence of Wegener's granulomatosis (WG) in Norfolk (UK) and to compare the clinical spectrum of disease to that seen in tertiary centres in both the UK and USA. We also aimed to examine the seasonal onset of symptoms. This was a prospective study of all patients presenting with WG to a district hospital with a well-defined stable population (515,000) during the period 1988-1993. The annual incidence for WG in the adult population is 8.5/million (95% CI 5.2-12.9). These are the first incidence figures for a well-defined population and are higher than previously published. The clinical spectrum of disease in Norfolk was similar to that seen in tertiary centres and there is supportive evidence for a seasonal variation in the onset of symptoms (highest in winter).